Comparison of oxygen saturation levels in patients receiving Technegas by the conventional unassisted method vs. the positive ventilation delivery system (PVDS)

International Nuclear Information System (INIS)

Dobson, M.P.; Leiper, C.A.; Lee, K.; Dixson, H.

2000-01-01

Full text: The purpose of this study is to compare oxygen saturation levels (SaO 2 ) in 289 patients undergoing conventional lung ventilation scintigraphy (control group) and 27 patients undergoing Positive Ventilation Delivery System (PVDS). The 27 patients where selected as their conventional method of inhalation proved to be inadequate or non-diagnostic. The patients underwent a second ventilation using PVDS, which improved the diagnostic quality of the ventilation image and assisted in clinical management decisions. Some patients in both the PVDS and the control group experienced a transient lowering in their SaO 2 . The mean initial SaO 2 in the control group did not fall below 94.9% and in the PVDS group measured 90.6%. 93% (25/27) of patients in the PVDS group were assessed as non CO 2 retaining, and received oxygen at 10L/min during Technegas inhalation. The mean trough saturation in the PVDS group was 91.7% which was significantly higher than that of the control group (86.9%). No patient in either group experienced any significant complication attributed to the transient tall in SaO 2 during technegas administration. We conclude that oxygen supplied as part of the PVDS system ameliorates the transient reduction in SaO 2 seen during standard Technegas administration. Copyright (2000) The Australian and New Zealand Society of Nuclear Medicine Inc

Oxygen delivery and consumption during on-bypass cabg in htea and central analgesia

Directory of Open Access Journals (Sweden)

Віталій Олексійович Собокарь

2015-04-01

Full Text Available Objective. Despite some advantages, the use of high thoracic epidural anesthesia (HTEA during on-bypass cardiac surgery may be discouraged by fear of adverse hemodynamic effects and associated disturbances of oxygen delivery.Aim. To compare oxygen delivery and consumption during on-bypass coronary artery bypass grafting in settings of HTEA and central analgesia (CA.Methods. 132 patients were assigned into two groups – study group (n=85, where the surgery was performed under HTEA and control group (n=47 - where the surgery was carried out under CA. Using data of transesophageal cardiac ultrasound and blood oximetry blood oxygen delivery (DO2, oxygen consumption (VO2, oxygen extraction coefficient (CEO2 were calculated at four stages of the surgery: after induction, sternotomy, cardiopulmonary bypass and at the end of the surgery.Results. In the initial stages of the surgery DO2 and VO2 were reduced relative to reference values with a tendency to increase in the course of the operation and achievement of the normal or supernormal level (VO2, study group in the final stage. The decrease was due to moderate hypodynamic circulation and hemodilution. After sternotomy DO2 in the study group was higher than that of the control: 356 (279; 458 vs 317±89 ml·min-1·m-2, (р=0,021. After cardiopulmonary bypass oxygen saturation of venous blood (SatvO2, in the study group was 71 ± 9 % compared with 68 ± 10 % in the control group. At the end of the surgery SatvO2 in the study group was 71 (66; 75 vs 59 (53; 70 % in the control (р = 0,005 and oxygen tension of venous blood (РvО2 was correspondingly 39 ± 6 and 33 (30; 38 mm Hg (р = 0,027. Despite the decrease in DO2 and VO2, oxygen extraction indices - CEO2, pvO2, SatvO2, and remained within the reference range, except that of the control group at the end of the surgery. Furthermore, at no stage lactate rise or acid-base deviations was observed in the both groups.Conclusions. In patients operated

Implementing oxygen control in chip-based cell and tissue culture systems.

Science.gov (United States)

Oomen, Pieter E; Skolimowski, Maciej D; Verpoorte, Elisabeth

2016-09-21

Oxygen is essential in the energy metabolism of cells, as well as being an important regulatory parameter influencing cell differentiation and function. Interest in precise oxygen control for in vitro cultures of tissues and cells continues to grow, especially with the emergence of the organ-on-a-chip and the desire to emulate in vivo conditions. This was recently discussed in this journal in a Critical Review by Brennan et al. (Lab Chip (2014). DOI: ). Microfluidics can be used to introduce flow to facilitate nutrient supply to and waste removal from in vitro culture systems. Well-defined oxygen gradients can also be established. However, cells can quickly alter the oxygen balance in their vicinity. In this Tutorial Review, we expand on the Brennan paper to focus on the implementation of oxygen analysis in these systems to achieve continuous monitoring. Both electrochemical and optical approaches for the integration of oxygen monitoring in microfluidic tissue and cell culture systems will be discussed. Differences in oxygen requirements from one organ to the next are a challenging problem, as oxygen delivery is limited by its uptake into medium. Hence, we discuss the factors determining oxygen concentrations in solutions and consider the possible use of artificial oxygen carriers to increase dissolved oxygen concentrations. The selection of device material for applications requiring precise oxygen control is discussed in detail, focusing on oxygen permeability. Lastly, a variety of devices is presented, showing the diversity of approaches that can be employed to control and monitor oxygen concentrations in in vitro experiments.

Leg oxygen uptake in the initial phase of intense exercise is slowed by a marked reduction in oxygen delivery

DEFF Research Database (Denmark)

Christensen, Peter Møller; Nyberg, Michael Permin; Mortensen, Stefan Peter

2013-01-01

-extensor exercise (60±3 W) for 4 min in a control setting (CON) and with arterial infusion of L-NMMA and indomethacin in the working leg to reduce blood flow by inhibiting formation of nitric oxide and prostanoids (double blockade; DB). In DB leg blood flow (LBF) and oxygen delivery during the first minute...

Ionized gas (plasma) delivery of reactive oxygen species (ROS) into artificial cells

International Nuclear Information System (INIS)

Hong, Sung-Ha; Jenkins, A Toby A; Szili, Endre J; Short, Robert D

2014-01-01

This study was designed to enhance our understanding of how reactive oxygen species (ROS), generated ex situ by ionized gas (plasma), can affect the regulation of signalling processes within cells. A model system, comprising of a suspension of phospholipid vesicles (cell mimics) encapsulating a ROS reporter, was developed to study the plasma delivery of ROS into cells. For the first time it was shown that plasma unequivocally delivers ROS into cells over a sustained period and without compromising cell membrane integrity. An important consideration in cell and biological assays is the presence of serum, which significantly reduced the transfer efficiency of ROS into the vesicles. These results are key to understanding how plasma treatments can be tailored for specific medical or biotechnology applications. Further, the phospholipid vesicle ROS reporter system may find use in other studies involving the application of free radicals in biology and medicine. (fast track communication)

Ionized gas (plasma) delivery of reactive oxygen species (ROS) into artificial cells

Science.gov (United States)

Hong, Sung-Ha; Szili, Endre J.; Jenkins, A. Toby A.; Short, Robert D.

2014-09-01

This study was designed to enhance our understanding of how reactive oxygen species (ROS), generated ex situ by ionized gas (plasma), can affect the regulation of signalling processes within cells. A model system, comprising of a suspension of phospholipid vesicles (cell mimics) encapsulating a ROS reporter, was developed to study the plasma delivery of ROS into cells. For the first time it was shown that plasma unequivocally delivers ROS into cells over a sustained period and without compromising cell membrane integrity. An important consideration in cell and biological assays is the presence of serum, which significantly reduced the transfer efficiency of ROS into the vesicles. These results are key to understanding how plasma treatments can be tailored for specific medical or biotechnology applications. Further, the phospholipid vesicle ROS reporter system may find use in other studies involving the application of free radicals in biology and medicine.

Determining the Source of Water Vapor in a Cerium Oxide Electrochemical Oxygen Separator to Achieve Aviator Grade Oxygen

Science.gov (United States)

Graf, John; Taylor, Dale; Martinez, James

2014-01-01

]. Combined with a mechanical compressor, a Solid Electrolyte Oxygen Separator (SEOS) should be capable of producing ABO grade oxygen at pressures >2400 psia, on the space station. Feasibility tests using a SEOS integrated with a mechanical compressor identified an unexpected contaminant in the oxygen: water vapour was found in the oxygen product, sometimes at concentrations higher than 40 ppm (the ABO limit for water vapour is 7 ppm). If solid electrolyte membranes are really "infinitely selective" to oxygen as they are reported to be, where did the water come from? If water is getting into the oxygen, what other contaminants might get into the oxygen? Microscopic analyses of wafers, welds, and oxygen delivery tubes were performed in an attempt to find the source of the water vapour contamination. Hot and cold pressure decay tests were performed. Measurements of water vapour as a function of O2 delivery rate, O2 delivery pressure, and process air humidity levels were the most instructive in finding the source of water contamination (Fig 3). Water contamination was directly affected by oxygen delivery rate (doubling the oxygen production rate cut the water level in half). Water was affected by process air humidity levels and delivery pressure in a way that indicates the water was diffusing into the oxygen delivery system.

Life-threatening Vesicular Bronchial Injury Requiring Veno-venous Extracorporeal Membrane Oxygenation Rescue in an Electronic Nicotine Delivery System User

Directory of Open Access Journals (Sweden)

Thomas Carter

2017-07-01

Full Text Available The use of electronic nicotine delivery systems (ENDS is increasing across the United States as tobacco bans increase and more people use these devices in an attempt to quit smoking. They are unregulated by the Food and Drug Administration, and there is significant concern that ENDS could produce several toxic byproducts. In this case a 35-year-old female presented to the emergency department with sudden-onset dyspnea. She denied current tobacco smoking, but she was a user of ENDS. When bronchoscopy was performed, an extensive pattern of suspected chemical injury was noted in her airways. She required transfer to a tertiary center where she required extracorporeal membranous oxygenation. Despite public opinion that ENDS are generally safe, or at least safer than tobacco smoking, contrary evidence is mounting. We postulate that her injuries were likely suffered secondary to use of an ENDS.

TRANSDERMAL DRUG DELIVERY SYSTEM: REVIEW

OpenAIRE

Vishvakarama Prabhakar; Agarwal Shivendra; Sharma Ritika; Saurabh Sharma

2012-01-01

Various new technologies have been developed for the transdermal delivery of some important drugs. Today about 74% of drugs are taken orally and are found not to be as effective as desired. To improve such characters transdermal drug delivery system was emerged. Drug delivery through the skin to achieve a systemic effect of a drug is commonly known as transdermal drug delivery and differs from traditional topical drug delivery. Transdermal drug delivery systems (TDDS) are dosage forms involve...

UAV Delivery Monitoring System

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San Khin Thida

2018-01-01

Full Text Available UAV-based delivery systems are increasingly being used in the logistics field, particularly to achieve faster last-mile delivery. This study develops a UAV delivery system that manages delivery order assignments, autonomous flight operation, real time control for UAV flights, and delivery status tracking. To manage the delivery item assignments, we apply the concurrent scheduler approach with a genetic algorithm. The present paper describes real time flight data based on a micro air vehicle communication protocol (MAVLink. It also presents the detailed hardware components used for the field tests. Finally, we provide UAV component analysis to choose the suitable components for delivery in terms of battery capacity, flight time, payload weight and motor thrust ratio.

Noninvasive diffuse optical monitoring of head and neck tumor blood flow and oxygenation during radiation delivery

Science.gov (United States)

Dong, Lixin; Kudrimoti, Mahesh; Cheng, Ran; Shang, Yu; Johnson, Ellis L.; Stevens, Scott D.; Shelton, Brent J.; Yu, Guoqiang

2012-01-01

This study explored using a novel diffuse correlation spectroscopy (DCS) flow-oximeter to noninvasively monitor blood flow and oxygenation changes in head and neck tumors during radiation delivery. A fiber-optic probe connected to the DCS flow-oximeter was placed on the surface of the radiologically/clinically involved cervical lymph node. The DCS flow-oximeter in the treatment room was remotely operated by a computer in the control room. From the early measurements, abnormal signals were observed when the optical device was placed in close proximity to the radiation beams. Through phantom tests, the artifacts were shown to be caused by scattered x rays and consequentially avoided by moving the optical device away from the x-ray beams. Eleven patients with head and neck tumors were continually measured once a week over a treatment period of seven weeks, although there were some missing data due to the patient related events. Large inter-patient variations in tumor hemodynamic responses were observed during radiation delivery. A significant increase in tumor blood flow was observed at the first week of treatment, which may be a physiologic response to hypoxia created by radiation oxygen consumption. Only small and insignificant changes were found in tumor blood oxygenation, suggesting that oxygen utilizations in tumors during the short period of fractional radiation deliveries were either minimal or balanced by other effects such as blood flow regulation. Further investigations in a large patient population are needed to correlate the individual hemodynamic responses with the clinical outcomes for determining the prognostic value of optical measurements. PMID:22312579

Closed Loop Control of Oxygen Delivery and Oxygen Generation

Science.gov (United States)

2017-08-01

were used for this study and were connected via a USB cable to allow communication. The ventilator was modified to allow closed loop control of oxygen...connected via a USB cable to allow communication. The ventilator was modified to allow closed loop control of oxygen based on the oxygen saturation...2017-4119, 28 Aug 2017. oximetry (SpO2) and intermittent arterial blood sampling for arterial oxygen tension (partial pressure of oxygen [PaO2]) and

Acute oxygen therapy: a review of prescribing and delivery practices

Directory of Open Access Journals (Sweden)

Cousins JL

2016-05-01

Full Text Available Joyce L Cousins,1–3 Peter AB Wark,3–5 Vanessa M McDonald2–5 1Faculty of Arts, Nursing and Theology, Avondale College of Higher Education, Sydney, 2School of Nursing and Midwifery, 3Priority Research Centre for Healthy Lungs, 4School of Medicine and Public Health, The University of Newcastle, 5Department of Respiratory and Sleep Medicine, Hunter Medical Research Institute, John Hunter Hospital, Newcastle, NSW, Australia Abstract: Oxygen is a commonly used drug in the clinical setting and like other drugs its use must be considered carefully. This is particularly true for those patients who are at risk of type II respiratory failure in whom the risk of hypercapnia is well established. In recent times, several international bodies have advocated for the prescription of oxygen therapy in an attempt to reduce this risk in vulnerable patient groups. Despite this guidance, published data have demonstrated that there has been poor uptake of these recommendations. Multiple interventions have been tested to improve concordance, and while some of these interventions show promise, the sustainability of these interventions are less convincing. In this review, we summarize data that have been published on the prevalence of oxygen prescription and the accurate and appropriate administration of this drug therapy. We also identify strategies that have shown promise in facilitating changes to oxygen prescription and delivery practice. There is a clear need to investigate the barriers, facilitators, and attitudes of clinicians in relation to the prescription of oxygen therapy in acute care. Interventions based on these findings then need to be designed and tested to facilitate the application of evidence-based guidelines to support sustained changes in practice, and ultimately improve patient care. Keywords: chronic obstructive pulmonary disease, COPD, type II respiratory failure, oxygen therapy, prescribing, hypoxia, hypercapnia

Ventilation onset prior to umbilical cord clamping (physiological-based cord clamping improves systemic and cerebral oxygenation in preterm lambs.

Directory of Open Access Journals (Sweden)

Graeme R Polglase

Full Text Available As measurement of arterial oxygen saturation (SpO2 is common in the delivery room, target SpO2 ranges allow clinicians to titrate oxygen therapy for preterm infants in order to achieve saturation levels similar to those seen in normal term infants in the first minutes of life. However, the influence of the onset of ventilation and the timing of cord clamping on systemic and cerebral oxygenation is not known.We investigated whether the initiation of ventilation, prior to, or after umbilical cord clamping, altered systemic and cerebral oxygenation in preterm lambs.Systemic and cerebral blood-flows, pressures and peripheral SpO2 and regional cerebral tissue oxygenation (SctO2 were measured continuously in apnoeic preterm lambs (126±1 day gestation. Positive pressure ventilation was initiated either 1 prior to umbilical cord clamping, or 2 after umbilical cord clamping. Lambs were monitored intensively prior to intervention, and for 10 minutes following umbilical cord clamping.Clamping the umbilical cord prior to ventilation resulted in a rapid decrease in SpO2 and SctO2, and an increase in arterial pressure, cerebral blood flow and cerebral oxygen extraction. Ventilation restored oxygenation and haemodynamics by 5-6 minutes. No such disturbances in peripheral or cerebral oxygenation and haemodynamics were observed when ventilation was initiated prior to cord clamping.The establishment of ventilation prior to umbilical cord clamping facilitated a smooth transition to systemic and cerebral oxygenation following birth. SpO2 nomograms may need to be re-evaluated to reflect physiological management of preterm infants in the delivery room.

Peptide and protein delivery using new drug delivery systems.

Science.gov (United States)

Jain, Ashish; Jain, Aviral; Gulbake, Arvind; Shilpi, Satish; Hurkat, Pooja; Jain, Sanjay K

2013-01-01

Pharmaceutical and biotechnological research sorts protein drug delivery systems by importance based on their various therapeutic applications. The effective and potent action of the proteins/peptides makes them the drugs of choice for the treatment of numerous diseases. Major research issues in protein delivery include the stabilization of proteins in delivery devices and the design of appropriate target-specific protein carriers. Many efforts have been made for effective delivery of proteins/peptidal drugs through various routes of administrations for successful therapeutic effects. Nanoparticles made of biodegradable polymers such as poly lactic acid, polycaprolactone, poly(lactic-co-glycolic acid), the poly(fumaric-co-sebacic) anhydride chitosan, and modified chitosan, as well as solid lipids, have shown great potential in the delivery of proteins/peptidal drugs. Moreover, scientists also have used liposomes, PEGylated liposomes, niosomes, and aquasomes, among others, for peptidal drug delivery. They also have developed hydrogels and transdermal drug delivery systems for peptidal drug delivery. A receptor-mediated delivery system is another attractive strategy to overcome the limitation in drug absorption that enables the transcytosis of the protein across the epithelial barrier. Modification such as PEGnology is applied to various proteins and peptides of the desired protein and peptides also increases the circulating life, solubility and stability, pharmacokinetic properties, and antigenicity of protein. This review focuses on various approaches for effective protein/peptidal drug delivery, with special emphasis on insulin delivery.

Tubing length for long-term oxygen therapy.

Science.gov (United States)

Aguiar, Carolina; Davidson, Josy; Carvalho, Andréa K; Iamonti, Vinícius C; Cortopassi, Felipe; Nascimento, Oliver A; Jardim, José R

2015-02-01

Most patients on long-term oxygen therapy use stationary oxygen delivery systems. It is not uncommon for guidelines to instruct patients to use tubing lengths no longer than 19.68 ft (6 m) when using an oxygen concentrator and 49.21 ft (15 m) when using cylinders. However, these concepts are not based on sufficient evidence. Thus, our objective was to evaluate whether a 98.42-ft (30-m) tubing length affects oxygen flow and FIO2 delivery from 1 cylinder and 2 oxygen concentrators. The 3 oxygen delivery systems were randomly selected, and 1, 3, and 5 L/min flows and FIO2 were measured 5 times at each flow at the proximal and distal outlets of the tubing by a gas-flow analyzer. Paired Student t test was used to analyze the difference between flows and FIO2 at proximal and distal outlets of tubing length. A total of 45 flows were measured between proximal and distal outlets of the 98.42-ft (30-m) tubing. Flows were similar for 1 and 3 L/min, but distal flow was higher than proximal flow at 5 L/min (5.57×5.14 L/min, Ptubing at flows 1, 3, and 5 L/min, but the mean difference between measurements was less than 1%. Tubing length of 98.42 ft (30 m) may be used by patients for home delivery oxygen with flows up to 5 L/min, as there were no important changes in flows or FIO2. Copyright © 2015 by Daedalus Enterprises.

The effects of altitude/hypoxic training on oxygen delivery capacity of the blood and aerobic exercise capacity in elite athletes - a meta-analysis.

Science.gov (United States)

Park, Hun-Young; Hwang, Hyejung; Park, Jonghoon; Lee, Seongno; Lim, Kiwon

2016-03-31

This study was designed as a meta-analysis of randomized controlled trials comparing effectiveness of altitude/hypoxic training (experimental) versus sea-level training (control) on oxygen delivery capacity of the blood and aerobic exercise capacity of elite athletes in Korea. Databases (Research Information Service System, Korean studies Information Service System, National Assembly Library) were for randomized controlled trials comparing altitude/hypoxic training versus sea-level training in elite athletes. Studies published in Korea up to December 2015 were eligible for inclusion. Oxygen delivery capacity of the blood was quantified by red blood cell (RBC), hemoglobin (Hb), hematocrit (Hct), erythropoietin (EPO); and aerobic exercise capacity was quantified by maximal oxygen consumption (VO2max). RBC, Hb, Hct, VO2max represented heterogeneity and compared post-intervention between altitude/hypoxic training and sea-level training in elite athletes by a random effect model meta-analysis. EPO represented homogeneity and meta-analysis performed by a fixed effect model. Eight independent studies with 156 elite athletes (experimental: n = 82, control: n = 74) were included in the metaanalysis. RBC (4.499×10(5) cell/ul, 95 % CI: 2.469 to 6.529), Hb (5.447 g/dl, 95 % CI: 3.028 to 7.866), Hct (3.639 %, 95 % CI: 1.687 to 5.591), EPO (0.711 mU/mL, 95% CI: 0.282 to 1.140), VO2max (1.637 ml/kg/min, 95% CI: 0.599 to 1.400) showed significantly greater increase following altitude/hypoxic training, as compared with sea-level training. For elite athletes in Korea, altitude/ hypoxic training appears more effective than sea-level training for improvement of oxygen delivery capacity of the blood and aerobic exercise capacity.

Effect of hypoxia on cerebral blood flow regulation during rest and exercise : role of cerebral oxygen delivery on performance

OpenAIRE

Fan, J.-L.

2014-01-01

Adequate supply of oxygen to the brain is critical for maintaining normal brain function. Severe hypoxia, such as that experienced during high altitude ascent, presents a unique challenge to brain oxygen (O2) supply. During high-intensity exercise, hyperventilation-induced hypocapnia leads to cerebral vasoconstriction, followed by reductions in cerebral blood flow (CBF), oxygen delivery (DO2), and tissue oxygenation. This reduced O2 supply to the brain could potentially account for the reduce...

Does recombinant human Epo increase exercise capacity by means other than augmenting oxygen transport?

DEFF Research Database (Denmark)

Lundby, C; Robach, P; Boushel, R

2008-01-01

This study was performed to test the hypothesis that administration of recombinant human erythropoietin (rHuEpo) in humans increases maximal oxygen consumption by augmenting the maximal oxygen carrying capacity of blood. Systemic and leg oxygen delivery and oxygen uptake were studied during...... before rHuEpo treatment). Blood buffer capacity remained unaffected by rHuEpo treatment and hemodilution. The augmented hematocrit did not compromise peak cardiac output. In summary, in healthy humans, rHuEpo increases maximal oxygen consumption due to augmented systemic and muscular peak oxygen delivery....

Project delivery system (PDS)

CERN Document Server

2001-01-01

As business environments become increasingly competitive, companies seek more comprehensive solutions to the delivery of their projects. "Project Delivery System: Fourth Edition" describes the process-driven project delivery systems which incorporates the best practices from Total Quality and is aligned with the Project Management Institute and ISO Quality Standards is the means by which projects are consistently and efficiently planned, executed and completed to the satisfaction of clients and customers.

An overview of Ball Aerospace cryogen storage and delivery systems

International Nuclear Information System (INIS)

Marquardt, J; Keller, J; Mills, G; Schmidt, J

2015-01-01

Starting on the Gemini program in the 1960s, Beech Aircraft (now Ball Aerospace) has been designing and manufacturing dewars for a variety of cryogens including liquid hydrogen and oxygen. These dewars flew on the Apollo, Skylab and Space Shuttle spacecraft providing fuel cell reactants resulting in over 150 manned spaceflights. Since Space Shuttle, Ball has also built the liquid hydrogen fuel tanks for the Boeing Phantom Eye unmanned aerial vehicle. Returning back to its fuel cell days, Ball has designed, built and tested a volume-constrained liquid hydrogen and oxygen tank system for reactant delivery to fuel cells on unmanned undersea vehicles (UUVs). Herein past history of Ball technology is described. Testing has been completed on the UUV specific design, which will be described. (paper)

Synthetic sustained gene delivery systems.

Science.gov (United States)

Agarwal, Ankit; Mallapragada, Surya K

2008-01-01

Gene therapy today is hampered by the need of a safe and efficient gene delivery system that can provide a sustained therapeutic effect without cytotoxicity or unwanted immune responses. Bolus gene delivery in solution results in the loss of delivered factors via lymphatic system and may cause undesired effects by the escape of bioactive molecules to distant sites. Controlled gene delivery systems, acting as localized depot of genes, provide an extended sustained release of genes, giving prolonged maintenance of the therapeutic level of encoded proteins. They also limit the DNA degradation in the nuclease rich extra-cellular environment. While attempts have been made to adapt existing controlled drug delivery technologies, more novel approaches are being investigated for controlled gene delivery. DNA encapsulated in nano/micro spheres of polymers have been administered systemically/orally to be taken up by the targeted tissues and provide sustained release once internalized. Alternatively, DNA entrapped in hydrogels or scaffolds have been injected/implanted in tissues/cavities as platforms for gene delivery. The present review examines these different modalities for sustained delivery of viral and non-viral gene-delivery vectors. Design parameters and release mechanisms of different systems made with synthetic or natural polymers are presented along with their prospective applications and opportunities for continuous development.

The effects of altitude/hypoxic training on oxygen delivery capacity of the blood and aerobic exercise capacity in elite athletes – a meta-analysis

Science.gov (United States)

Park, Hun-young; Hwang, Hyejung; Park, Jonghoon; Lee, Seongno; Lim, Kiwon

2016-01-01

[Purpose] This study was designed as a meta-analysis of randomized controlled trials comparing effectiveness of altitude/hypoxic training (experimental) versus sea-level training (control) on oxygen delivery capacity of the blood and aerobic exercise capacity of elite athletes in Korea. [Methods] Databases (Research Information Service System, Korean studies Information Service System, National Assembly Library) were for randomized controlled trials comparing altitude/hypoxic training versus sea-level training in elite athletes. Studies published in Korea up to December 2015 were eligible for inclusion. Oxygen delivery capacity of the blood was quantified by red blood cell (RBC), hemoglobin (Hb), hematocrit (Hct), erythropoietin (EPO); and aerobic exercise capacity was quantified by maximal oxygen consumption (VO2max). RBC, Hb, Hct, VO2max represented heterogeneity and compared post-intervention between altitude/hypoxic training and sea-level training in elite athletes by a random effect model meta-analysis. EPO represented homogeneity and meta-analysis performed by a fixed effect model. Eight independent studies with 156 elite athletes (experimental: n = 82, control: n = 74) were included in the metaanalysis. [Results] RBC (4.499×105 cell/ul, 95 % CI: 2.469 to 6.529), Hb (5.447 g/dl, 95 % CI: 3.028 to 7.866), Hct (3.639 %, 95 % CI: 1.687 to 5.591), EPO (0.711 mU/mL, 95% CI: 0.282 to 1.140), VO2max (1.637 ml/kg/min, 95% CI: 0.599 to 1.400) showed significantly greater increase following altitude/hypoxic training, as compared with sea-level training. [Conclusion] For elite athletes in Korea, altitude/ hypoxic training appears more effective than sea-level training for improvement of oxygen delivery capacity of the blood and aerobic exercise capacity. PMID:27298808

Model analysis of local oxygen delivery with liposome-encapsulated hemoglobin.

Science.gov (United States)

Matsumoto, Takeshi; Mano, Katsuhiko; Ueha, Ryohei; Naito, Hisashi; Tanaka, Masao

2009-03-01

Liposome-encapsulated hemoglobins (LHs) are comparable to red blood cells (RBCs) in terms of oxygen (O(2))-carrying capacity. The smaller particle size of LHs than of platelets allows their homogeneous dispersion in circulating plasma. In this study, we evaluated the effect of LH transfusion on arterial O(2) delivery through vascular trees by simulation. A mathematical model was established on the basis of the coronary arterial anatomy, the conservation of flow and RBC flux, and Poiseuille's law. The Fåhraeus-Lindqvist, Fåhraeus, and phase separation effects were considered in the model. By assuming steady perfusion, the arterial flow and O(2) delivery were calculated for five model trees undergoing the isovolumic replacement of RBCs (0.3 mg hemoglobin (Hb)/mL) with LHs (0.2 mg Hb/mL) or a plasma volume expander (PVE). The RBC-LH exchange increased both the total flow and the total O(2) flux but had almost no effect on the relative distribution of O(2) flux. In contrast, the RBC-PVE exchange decreased the total O(2) flux and increased the proportion of regions receiving a relatively low O(2) supply. Thus, LH transfusion may compensate for an enhanced bias in RBC-associated O(2) flux under hemodilution and is expected to be beneficial for both total and local O(2) delivery.

Colloidal drug delivery system: amplify the ocular delivery.

Science.gov (United States)

Ali, Javed; Fazil, Mohd; Qumbar, Mohd; Khan, Nazia; Ali, Asgar

2016-01-01

The ocular perceivers are the most voluntarily accessible organs in terms of location in the body, yet drug distribution to these tissues is one of the most intriguing and challenging endeavors and problematic to the pharmaceutical scientist. The most of ocular diseases are treated with topical application of conventional formulation, i.e. solutions, suspensions and ointment. Typically on installation of these conventional formulations, only <5% of the applied dose penetrates the cornea and reaches intraocular tissues, while a major fraction of the instilled dose is wastage due to the presence of many ocular barriers like external barriers, rapid loss of the instilled solution from the precorneal area and nasolacrimal drainage system. Systemic absorption caused systemic side effects varying from mild to life-threatening events. The main objective of this review is to explore the role of colloidal delivery of drug to minimize the drawbacks associated with them. This review provides an insight into the various constraints associated with ocular drug delivery, summarizes recent findings and applications of colloidal delivery systems, i.e. nanoparticles, nanosuspensions, liposomes, niosomes, dendrimers and contact lenses containing nanoparticles have the capacity to distribute ocular drugs to categorical target sites and hold promise to revolutionize the therapy of many ocular perceiver diseases and minimized the circumscription of conventional delivery. Form the basis of literature review, it has been found that the novel delivery system have greater impact to maximize ocular drug absorption, and minimize systemic absorption and side effects.

Comparison of actual oxygen delivery kinetics to those predicted by mathematical modeling following stage 1 palliation just prior to superior cavopulmonary anastomosis.

Science.gov (United States)

Yuki, Koichi; DiNardo, James A

2015-02-01

Optimizing systemic oxygen delivery (DO2) and hemodynamics in children with hypoplastic left heart syndrome (HLHS) is a clinical challenge. Mathematical modeling of the HLHS circulation has been used to determine the relationship between oxygen kinetic parameters and DO2 and to determine how DO2 might be optimized. The model demonstrates that neither arterial oxygen saturation (SaO2) nor mixed venous oxygen saturation (SvO2) alone accurately predicts DO2. Oxygen delivery kinetics predicted by previously described mathematical modeling were compared with actual patients' hemodynamic data. We sought to determine which patient derived parameters correlated best with DO2. Patients with HLHS who underwent cardiac catheterization prior to surgery to create a superior cavopulmonary anastomosis from 2007 to 2011 were identified. Hemodynamic data obtained were compared with the data derived from the mathematical model. Correlations between SaO2, SvO2, SaO2-SvO2, SaO2/(SaO2-SvO2), pulmonary-to-systemic blood flow ratio (Qp/Qs), and DO2 were evaluated using both linear and nonlinear analyses, and R(2) was calculated. Patients' data fit most aspects of the mathematical model. DO2 had the best correlation with SaO2/(SaO2-SvO2; R(2) = 0.8755) followed by SaO2 -SvO2 (R(2) = 0.8063), while SaO2 or SvO2 alone did not demonstrate a significant correlation as predicated by the mathematical model (R(2) = 0.09564 and 0.4831, respectively). SaO2/(SaO2 -SvO2) would be useful clinically to track changes in DO2 that occur with changes in patient condition or with interventions. © 2014 John Wiley & Sons Ltd.

An On-Line Oxygen Forecasting System for Waterless Live Transportation of Flatfish Based on Feature Clustering

Directory of Open Access Journals (Sweden)

Yongjun Zhang

2017-09-01

Full Text Available Accurate prediction of forthcoming oxygen concentration during waterless live fish transportation plays a key role in reducing the abnormal occurrence, increasing the survival rate in delivery operations, and optimizing manufacturing costs. The most effective ambient monitoring techniques that are based on the analysis of historical process data when performing forecasting operations do not fully consider current ambient influence. This is likely lead to a greater deviation in on-line oxygen level forecasting in real situations. Therefore, it is not advisable for the system to perform early warning and on-line air adjustment in delivery. In this paper, we propose a hybrid method and its implementation system that combines a gray model (GM (1, 1 with least squares support vector machines (LSSVM that can be used effectively as a forecasting model to perform early warning effectively according to the dynamic changes of oxygen in a closed system. For accurately forecasting of the oxygen level, the fuzzy C-means clustering (FCM algorithm was utilized for classification according to the flatfish’s physical features—i.e., length and weight—for more pertinent training. The performance of the gray model-particle swarm optimization-least squares support vector machines (GM-PSO-LSSVM model was compared with the traditional modeling approaches of GM (1, 1 and LSSVM by applying it to predict on-line oxygen level, and the results showed that its predictions were more accurate than those of the LSSVM and grey model. Therefore, it is a suitable and effective method for abnormal condition forecasting and timely control in the waterless live transportation of flatfish.

The nursing perspective on monitoring hemodynamics and oxygen transport.

Science.gov (United States)

Tucker, Dawn; Hazinski, Mary Fran

2011-07-01

Maintenance of adequate systemic oxygen delivery requires careful clinical assessment integrated with hemodynamic measurements and calculations to detect and treat conditions that may compromise oxygen delivery and lead to life-threatening shock, respiratory failure, or cardiac arrest. The bedside nurse constantly performs such assessments and measurements to detect subtle changes and trends in patient condition. The purpose of this editorial is to highlight nursing perspectives about the hemodynamic and oxygen transport monitoring systems summarized in the Pediatric Cardiac Intensive Care Society Evidence- Based Review and Consensus Statement on Monitoring of Hemodynamics and Oxygen Transport Balance. There is no substitute for the observations of a knowledgeable and experienced clinician who understands the patient's condition and potential causes of deterioration and is able to evaluate response to therapy.

Self-nanoemulsifying drug delivery systems for oral insulin delivery

DEFF Research Database (Denmark)

Li, Ping; Tan, Angel; Prestidge, Clive A

2014-01-01

This study aims at evaluating the combination of self-nanoemulsifying drug delivery systems (SNEDDS) and enteric-coated capsules as a potential delivery strategy for oral delivery of insulin. The SNEDDS preconcentrates, loaded with insulin-phospholipid complex at different levels (0, 2.5 and 10% w...

Advanced Oxygen Systems for Aircraft (Systemes d’Oxygene Avances)

Science.gov (United States)

1996-04-01

Oxygen Generating System (NAOGS), SAM-TR-80-12, Brooks AFB TX 78235, 1980. 11. Horch TC, Miller RL, Bomar JB, Tedor JB, Holden RD, Ikels KG, and...sieve oxygen generation sys- tem. Data from Horch et al (15). cabin altitude. The minimum and maximum oxygen concen- tration lines depict the...an AV-8A Aircraft; Naval Air Test Center Report No. SY-136R-81, 1981. 15. Horch TC, Miller RL, Bomar JB Jr, Tedor JB, Holden RD, Ikels KG, and

Inner Retinal Oxygen Delivery, Metabolism, and Extraction Fraction in Ins2Akita Diabetic Mice.

Science.gov (United States)

Blair, Norman P; Wanek, Justin; Felder, Anthony E; Brewer, Katherine C; Joslin, Charlotte E; Shahidi, Mahnaz

2016-11-01

Retinal nonperfusion and hypoxia are important factors in human diabetic retinopathy, and these presumably inhibit energy production and lead to cell death. The purpose of this study was to elucidate the effect of diabetes on inner retinal oxygen delivery and metabolism in a mouse model of diabetes. Phosphorescence lifetime and blood flow imaging were performed in spontaneously diabetic Ins2Akita (n = 22) and nondiabetic (n = 22) mice at 12 and 24 weeks of age to measure retinal arterial (O2A) and venous (O2V) oxygen contents and total retinal blood flow (F). Inner retinal oxygen delivery (DO2) and metabolism (MO2) were calculated as F ∗ O2A and F ∗ (O2A - O2V), respectively. Oxygen extraction fraction (OEF), which equals MO2/DO2, was calculated. DO2 at 12 weeks were 112 ± 40 and 97 ± 29 nL O2/min in nondiabetic and diabetic mice, respectively (NS), and 148 ± 31 and 85 ± 37 nL O2/min at 24 weeks, respectively (P < 0.001). MO2 were 65 ± 31 and 66 ± 27 nL O2/min in nondiabetic and diabetic mice at 12 weeks, respectively, and 79 ± 14 and 54 ± 28 nL O2/min at 24 weeks, respectively (main effects = NS). At 12 weeks OEF were 0.57 ± 0.17 and 0.67 ± 0.09 in nondiabetic and diabetic mice, respectively, and 0.54 ± 0.07 and 0.63 ± 0.08 at 24 weeks, respectively (main effect of diabetes: P < 0.01). Inner retinal MO2 was maintained in diabetic Akita mice indicating that elevation of the OEF adequately compensated for reduced DO2 and prevented oxidative metabolism from being limited by hypoxia.

Simultaneous sampling of tissue oxygenation and oxygen consumption in skeletal muscle.

Science.gov (United States)

Nugent, William H; Song, Bjorn K; Pittman, Roland N; Golub, Aleksander S

2016-05-01

Under physiologic conditions, microvascular oxygen delivery appears to be well matched to oxygen consumption in respiring tissues. We present a technique to measure interstitial oxygen tension (PISFO2) and oxygen consumption (VO2) under steady-state conditions, as well as during the transitions from rest to activity and back. Phosphorescence Quenching Microscopy (PQM) was employed with pneumatic compression cycling to achieve 1 to 10 Hz sampling rates of interstitial PO2 and simultaneous recurrent sampling of VO2 (3/min) in the exteriorized rat spinotrapezius muscle. The compression pressure was optimized to 120-130 mmHg without adverse effect on the tissue preparation. A cycle of 5s compression followed by 15s recovery yielded a resting VO2 of 0.98 ± 0.03 ml O2/100 cm(3)min while preserving microvascular oxygen delivery. The measurement system was then used to assess VO2 dependence on PISFO2 at rest and further tested under conditions of isometric muscle contraction to demonstrate a robust ability to monitor the on-kinetics of tissue respiration and the compensatory changes in PISFO2 during contraction and recovery. The temporal and spatial resolution of this approach is well suited to studies seeking to characterize microvascular oxygen supply and demand in thin tissues. Copyright © 2015 Elsevier Inc. All rights reserved.

Cardiopulmonary function and oxygen delivery during total liquid ventilation.

Science.gov (United States)

Tsagogiorgas, Charalambos; Alb, Markus; Herrmann, Peter; Quintel, Michael; Meinhardt, Juergen P

2011-10-01

Total liquid ventilation (TLV) with perfluorocarbons has shown to improve cardiopulmonary function in the injured and immature lung; however there remains controversy over the normal lung. Hemodynamic effects of TLV in the normal lung currently remain undetermined. This study compared changes in cardiopulmonary and circulatory function caused by either liquid or gas tidal volume ventilation. In a prospective, controlled study, 12 non-injured anesthetized, adult New Zealand rabbits were primarily conventionally gas-ventilated (CGV). After instrumentation for continuous recording of arterial (AP), central venous (CVP), left artrial (LAP), pulmonary arterial pressures (PAP), and cardiac output (CO) animals were randomized into (1) CGV group and (2) TLV group. In the TLV group partial liquid ventilation was initiated with instillation of perfluoroctylbromide (12 ml/kg). After 15 min, TLV was established for 3 hr applying a volume-controlled, pressure-limited, time-cycled ventilation mode using a double-piston configured TLV. Controls (CGV) remained gas-ventilated throughout the experiment. During TLV, heart rate, CO, PAP, MAP, CVP, and LAP as well as derived hemodynamic variables, arterial and mixed venous blood gases, oxygen delivery, PVR, and SVR did not differ significantly compared to CGV. Liquid tidal volumes suitable for long-term TLV in non-injured rabbits do not significantly impair CO, blood pressure, and oxygen dynamics when compared to CGV. Copyright © 2011 Wiley-Liss, Inc.

Preparing and evaluating delivery systems for proteins

DEFF Research Database (Denmark)

Jorgensen, L; Moeller, E H; van de Weert, M

2006-01-01

From a formulation perspective proteins are complex and therefore challenging molecules to develop drug delivery systems for. The success of a formulation depends on the ability of the protein to maintain the native structure and activity during preparation and delivery as well as during shipping...... and long-term storage of the formulation. Therefore, the development and evaluation of successful and promising drug delivery systems is essential. In the present review, some of the particulate drug delivery systems for parenteral delivery of protein are presented and discussed. The challenge...... for incorporation of protein in particulate delivery systems is exemplified by water-in-oil emulsions....

Bulk manufacture of concentrated oxygen gas-filled microparticles for intravenous oxygen delivery.

Science.gov (United States)

Kheir, John N; Polizzotti, Brian D; Thomson, Lindsay M; O'Connell, Daniel W; Black, Katherine J; Lee, Robert W; Wilking, James N; Graham, Adam C; Bell, David C; McGowan, Francis X

2013-08-01

Self-assembling, concentrated, lipid-based oxygen microparticles (LOMs) have been developed to administer oxygen gas when injected intravenously, preventing organ injury and death from systemic hypoxemia in animal models. Distinct from blood substitutes, LOMs are a one-way oxygen carrier designed to rescue patients who experience life-threatening hypoxemia, as caused by airway obstruction or severe lung injury. Here, we describe methods to manufacture large quantities of LOMs using an in-line, recycling, high-shear homogenizer, which can create up to 4 liters of microparticle emulsion in 10 minutes, with particles containing a median diameter of 0.93 microns and 60 volume% of gas phase. Using this process, we screen 30 combinations of commonly used excipients for their ability to form stable LOMs. LOMs composed of DSPC and cholesterol in a 1:1 molar ratio are stable for a 100 day observation period, and the number of particles exceeding 10 microns in diameter does not increase over time. When mixed with blood in vitro, LOMs fully oxygenate blood within 3.95 seconds of contact, and do not cause hemolysis or complement activation. LOMs can be manufactured in bulk by high shear homogenization, and appear to have a stability and size profile which merit further testing. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Retinal Oxygen Delivery and Metabolism in Healthy and Sickle Cell Retinopathy Subjects.

Science.gov (United States)

Shahidi, Mahnaz; Felder, Anthony E; Tan, Ou; Blair, Norman P; Huang, David

2018-04-01

Reduction in inner retinal oxygen delivery (DO2) can cause retinal hypoxia and impair inner retinal oxygen metabolism (MO2), leading to vision loss. The purpose of the current study was to establish measurements of DO2 and MO2 in healthy subjects and test the hypothesis that DO2 and MO2 are reduced in sickle cell retinopathy (SCR) subjects. Dual wavelength retinal oximetry and Doppler optical coherence tomography were performed in 12 healthy control and 12 SCR subjects. Images were analyzed to measure retinal arterial and venous oxygen content (O2A and O2V), venous diameter (DV), and total retinal blood flow (TRBF). Retinal arteriovenous oxygen content difference (O2AV), DO2, MO2, and oxygen extraction fraction (OEF) were calculated according to the following equations: O2AV = O2A - O2V; DO2 = TRBF * O2A; MO2 = TRBF * O2AV; OEF = MO2/DO2. Retinal DV and TRBF were higher in the SCR group as compared to the control group, whereas, O2A, O2V, and O2AV were lower in SCR group as compared to the control group. DO2, MO2, and OEF were not significantly different between control and SCR groups. MO2 and DO2 were linearly related, such that higher MO2 was associated with higher DO2. There was an inverse relationship between TRBF and OEF, such that lower TRBF was associated with higher OEF. Increased blood flow compensated for decreased oxygen content, thereby maintaining DO2, MO2, and OEF at predominately lower stages of SCR. Quantitative assessment of these parameters has the potential to advance knowledge and improve diagnostic evaluation of retinal ischemic conditions.

A Systems Approach to Nitrogen Delivery

Energy Technology Data Exchange (ETDEWEB)

Goins, Bobby [Y-12 National Security Complex, Oak Ridge, TN (United States)

2017-10-23

A systems based approach will be used to evaluate the nitrogen delivery process. This approach involves principles found in Lean, Reliability, Systems Thinking, and Requirements. This unique combination of principles and thought process yields a very in depth look into the system to which it is applied. By applying a systems based approach to the nitrogen delivery process there should be improvements in cycle time, efficiency, and a reduction in the required number of personnel needed to sustain the delivery process. This will in turn reduce the amount of demurrage charges that the site incurs. In addition there should be less frustration associated with the delivery process.

A Systems Approach to Nitrogen Delivery

Energy Technology Data Exchange (ETDEWEB)

Goins, Bobby [Y-12 National Security Complex, Oak Ridge, TN (United States); Univ. of Tennessee, Knoxville, TN (United States)

2017-10-17

A systems based approach will be used to evaluate the nitrogen delivery process. This approach involves principles found in Lean, Reliability, Systems Thinking, and Requirements. This unique combination of principles and thought process yields a very in depth look into the system to which it is applied. By applying a systems based approach to the nitrogen delivery process there should be improvements in cycle time, efficiency, and a reduction in the required number of personnel needed to sustain the delivery process. This will in turn reduce the amount of demurrage charges that the site incurs. In addition there should be less frustration associated with the delivery process.

Relationship between oxygen delivery and its compensatory factors and acute mountain sickness

Directory of Open Access Journals (Sweden)

Ming LI

2013-03-01

Full Text Available Objective 　To investigate the changes in oxygen delivery (DO2 to the body and brain and its compensatory factors to acute hypoxia and their relation to acute mountain sickness (AMS. Methods 　One hundred and forty-seven participants were recruited from Chinese young men who had lived in plain all along arrived in Tibet by flight. All of them were asked to complete an AMS questionnaire within 48h after arrival. The resting heart rate (HR, blood pressure (BP, cardiac output (CO, oxygen saturation (SaO2, stroke volume (SV and blood flow velocity in the middle cerebral artery (MCAv were measured one week before departure from the plain and within 48h after arrival in Tibet. AMS was diagnosed according to Louis Lake Score System (LLS, and the results were then statistically analyzed. Results 　AMS was diagnosed in eighty-six subjects (58.5%. After exposure to hypoxia, SaO2 was decreased by 10% and was negatively correlated with AMS score. Systemic DO2, CO and HR were increased by 19%, 32.5% and 31.7%, respectively, and were positively correlated with AMS, while the SV remained unchanged. MCAv accelerated by 10%, and that of AMS subjects was higher than of non-AMS ones. The cerebral DO2 (DO2C was maintained because the MCAv matched with SaO2 changes. The middle cerebral artery resistance units (RMCA decreased obviously with an increase in MBP, and RMCA in AMS subjects was lower than that in non-AMS ones. HR and MCAv, the key compensation factors of DO2, were used as the objective evaluation indices, in collaboration of HR≥85 beat/min and MCAv≥66cm/s, could be a better means to evaluate AMS, with a positive predictive value of 82.4% and specificity of 90.2%. Conclusions 　DO2 and its compensatory factors may play a key role in the regulation response to acclimatize to acute hypoxia. Among them, HR and MCAv may relate to the mechanism of AMS development, and indirectly reflect the compensation level to oxygen debt, implying that HR and MCAv are

STRATEGIES AND PROSPECTS OF NASAL DRUG DELIVERY SYSTEMS

OpenAIRE

Gannu Praveen Kumar

2012-01-01

The recent advancement of nasal drug delivery systems has increased enormously and is gaining significant importance. Intranasal therapy has been an accepted form of treatment in the Ayurvedic system of Indian Medicine. The non-invasive delivery of nasal drug delivery systems made to exploit for the development of successful treatment. The advantages, disadvantages, mechanism of action and application of nasal drug delivery system in local delivery, systematic delivery, nasal vaccines and CNS...

Fiber coupled optical spark delivery system

Science.gov (United States)

Yalin, Azer; Willson, Bryan; Defoort, Morgan

2008-08-12

A spark delivery system for generating a spark using a laser beam is provided, the spark delivery system including a laser light source and a laser delivery assembly. The laser delivery assembly includes a hollow fiber and a launch assembly comprising launch focusing optics to input the laser beam in the hollow fiber. In addition, the laser delivery assembly includes exit focusing optics that demagnify an exit beam of laser light from the hollow fiber, thereby increasing the intensity of the laser beam and creating a spark. In accordance with embodiments of the present invention, the assembly may be used to create a spark in a combustion engine. In accordance with other embodiments of the present invention, a method of using the spark delivery system is provided. In addition, a method of choosing an appropriate fiber for creating a spark using a laser beam is also presented.

Sterile Product Packaging and Delivery Systems.

Science.gov (United States)

Akers, Michael J

2015-01-01

Both conventional and more advanced product container and delivery systems are the focus of this brief article. Six different product container systems will be discussed, plus advances in primary packaging for special delivery systems and needle technology.

Reduction of treatment delivery variances with a computer-controlled treatment delivery system

International Nuclear Information System (INIS)

Fraass, B.A.; Lash, K.L.; Matrone, G.M.; Lichter, A.S.

1997-01-01

Purpose: To analyze treatment delivery variances for 3-D conformal therapy performed at various levels of treatment delivery automation, ranging from manual field setup to virtually complete computer-controlled treatment delivery using a computer-controlled conformal radiotherapy system. Materials and Methods: All external beam treatments performed in our department during six months of 1996 were analyzed to study treatment delivery variances versus treatment complexity. Treatments for 505 patients (40,641 individual treatment ports) on four treatment machines were studied. All treatment variances noted by treatment therapists or quality assurance reviews (39 in all) were analyzed. Machines 'M1' (CLinac (6(100))) and 'M2' (CLinac 1800) were operated in a standard manual setup mode, with no record and verify system (R/V). Machines 'M3' (CLinac 2100CD/MLC) and ''M4'' (MM50 racetrack microtron system with MLC) treated patients under the control of a computer-controlled conformal radiotherapy system (CCRS) which 1) downloads the treatment delivery plan from the planning system, 2) performs some (or all) of the machine set-up and treatment delivery for each field, 3) monitors treatment delivery, 4) records all treatment parameters, and 5) notes exceptions to the electronically-prescribed plan. Complete external computer control is not available on M3, so it uses as many CCRS features as possible, while M4 operates completely under CCRS control and performs semi-automated and automated multi-segment intensity modulated treatments. Analysis of treatment complexity was based on numbers of fields, individual segments (ports), non-axial and non-coplanar plans, multi-segment intensity modulation, and pseudo-isocentric treatments (and other plans with computer-controlled table motions). Treatment delivery time was obtained from the computerized scheduling system (for manual treatments) or from CCRS system logs. Treatment therapists rotate among the machines, so this analysis

MINI-SLAR delivery system

International Nuclear Information System (INIS)

Alstein, D.

1996-01-01

In the Spring of 1993, a need to complete Spacer Location and Repositioning (SLAR) on the Bruce 'A', Unit 1 Reactor was identified. An alternate SLAR delivery system was required due to conversion constraints that prevented the existing Bruce SLAR System from being used in Unit 1. A Portable SLAR Delivery System called MINI-SLAR Delivery System was developed, designed and fabricated in a 14 month period, then used to successfully SLAR 109 channels. The system is a portable remotely operated Nuclear Class 1 registered fitting that is independent of the Fuelling Machine, allowing the station to continue normal Fuelling and Maintenance activities. It is designed to a Level 'D' faulted condition of HPECI Pressure thus minimizing PHT Heat Sink configuration requirements and minimizing outage set-up times. The system is based on a modular design allowing for easy fabrication, assembly and repair. It consists of a Snout Assembly, a Closure Plug Assembly, Shield Plug Assembly, SLAR Ram assembly, Work Table Assembly and Control Panel. Controls are through a Programmable Logic Controller with software tested and certified to a Software Quality Assurance of Level Ill. (author). 2 refs., 2 figs

MINI-SLAR delivery system

Energy Technology Data Exchange (ETDEWEB)

Alstein, D [Ontario Hydro, Tiverton, ON (Canada). Bruce Nuclear Generating Station-A; Dalton, K [Spectrum Engineering, Peterborough, ON (Canada)

1997-12-31

In the Spring of 1993, a need to complete Spacer Location and Repositioning (SLAR) on the Bruce `A`, Unit 1 Reactor was identified. An alternate SLAR delivery system was required due to conversion constraints that prevented the existing Bruce SLAR System from being used in Unit 1. A Portable SLAR Delivery System called MINI-SLAR Delivery System was developed, designed and fabricated in a 14 month period, then used to successfully SLAR 109 channels. The system is a portable remotely operated Nuclear Class 1 registered fitting that is independent of the Fuelling Machine, allowing the station to continue normal Fuelling and Maintenance activities. It is designed to a Level `D` faulted condition of HPECI Pressure thus minimizing PHT Heat Sink configuration requirements and minimizing outage set-up times. The system is based on a modular design allowing for easy fabrication, assembly and repair. It consists of a Snout Assembly, a Closure Plug Assembly, Shield Plug Assembly, SLAR Ram assembly, Work Table Assembly and Control Panel. Controls are through a Programmable Logic Controller with software tested and certified to a Software Quality Assurance of Level Ill. (author). 2 refs., 2 figs.

Health care delivery systems.

NARCIS (Netherlands)

Stevens, F.; Zee, J. van der

2007-01-01

A health care delivery system is the organized response of a society to the health problems of its inhabitants. Societies choose from alternative health care delivery models and, in doing so, they organize and set goals and priorities in such a way that the actions of different actors are effective,

Designing and assessing a sustainable networked delivery (SND) system: hybrid business-to-consumer book delivery case study.

Science.gov (United States)

Kim, Junbeum; Xu, Ming; Kahhat, Ramzy; Allenby, Braden; Williams, Eric

2009-01-01

We attempted to design and assess an example of a sustainable networked delivery (SND) system: a hybrid business-to-consumer book delivery system. This system is intended to reduce costs, achieve significant reductions in energy consumption, and reduce environmental emissions of critical local pollutants and greenhouse gases. The energy consumption and concomitant emissions of this delivery system compared with existing alternative delivery systems were estimated. We found that regarding energy consumption, an emerging hybrid delivery system which is a sustainable networked delivery system (SND) would consume 47 and 7 times less than the traditional networked delivery system (TND) and e-commerce networked delivery system (END). Regarding concomitant emissions, in the case of CO2, the SND system produced 32 and 7 times fewer emissions than the TND and END systems. Also the SND system offer meaningful economic benefit such as the costs of delivery and packaging, to the online retailer, grocery, and consumer. Our research results show that the SND system has a lot of possibilities to save local transportation energy consumption and delivery costs, and reduce environmental emissions in delivery system.

Some Recent Advances in Transdermal Drug Delivery Systems ...

African Journals Online (AJOL)

Some Recent Advances in Transdermal Drug Delivery Systems. ... Advances in Transdermal Drug Delivery Systems. EC Ibezim, B Kabele-Toge, CO Anie, C Njoku. Abstract. Transdermal delivery systems are forms of drug delivery involving the dermis, as distinct from topical, oral or other forms of parenteral dosage forms.

Drug delivery systems with modified release for systemic and biophase bioavailability.

Science.gov (United States)

Leucuta, Sorin E

2012-11-01

This review describes the most important new generations of pharmaceutical systems: medicines with extended release, controlled release pharmaceutical systems, pharmaceutical systems for the targeted delivery of drug substances. The latest advances and approaches for delivering small molecular weight drugs and other biologically active agents such as proteins and nucleic acids require novel delivery technologies, the success of a drug being many times dependent on the delivery method. All these dosage forms are qualitatively superior to medicines with immediate release, in that they ensure optimal drug concentrations depending on specific demands of different disease particularities of the body. Drug delivery of these pharmaceutical formulations has the benefit of improving product efficacy and safety, as well as patient convenience and compliance. This paper describes the biopharmaceutical, pharmacokinetic, pharmacologic and technological principles in the design of drug delivery systems with modified release as well as the formulation criteria of prolonged and controlled release drug delivery systems. The paper presents pharmaceutical prolonged and controlled release dosage forms intended for different routes of administration: oral, ocular, transdermal, parenteral, pulmonary, mucoadhesive, but also orally fast dissolving tablets, gastroretentive drug delivery systems, colon-specific drug delivery systems, pulsatile drug delivery systems and carrier or ligand mediated transport for site specific or receptor drug targeting. Specific technologies are given on the dosage forms with modified release as well as examples of marketed products, and current research in these areas.

Future of Automated Insulin Delivery Systems.

Science.gov (United States)

Castle, Jessica R; DeVries, J Hans; Kovatchev, Boris

2017-06-01

Advances in continuous glucose monitoring (CGM) have brought on a paradigm shift in the management of type 1 diabetes. These advances have enabled the automation of insulin delivery, where an algorithm determines the insulin delivery rate in response to the CGM values. There are multiple automated insulin delivery (AID) systems in development. A system that automates basal insulin delivery has already received Food and Drug Administration approval, and more systems are likely to follow. As the field of AID matures, future systems may incorporate additional hormones and/or multiple inputs, such as activity level. All AID systems are impacted by CGM accuracy and future CGM devices must be shown to be sufficiently accurate to be safely incorporated into AID. In this article, we summarize recent achievements in AID development, with a special emphasis on CGM sensor performance, and discuss the future of AID systems from the point of view of their input-output characteristics, form factor, and adaptability.

A Low-Pressure Oxygen Storage System for Oxygen Supply in Low-Resource Settings.

Science.gov (United States)

Rassool, Roger P; Sobott, Bryn A; Peake, David J; Mutetire, Bagayana S; Moschovis, Peter P; Black, Jim Fp

2017-12-01

Widespread access to medical oxygen would reduce global pneumonia mortality. Oxygen concentrators are one proposed solution, but they have limitations, in particular vulnerability to electricity fluctuations and failure during blackouts. The low-pressure oxygen storage system addresses these limitations in low-resource settings. This study reports testing of the system in Melbourne, Australia, and nonclinical field testing in Mbarara, Uganda. The system included a power-conditioning unit, a standard oxygen concentrator, and an oxygen store. In Melbourne, pressure and flows were monitored during cycles of filling/emptying, with forced voltage fluctuations. The bladders were tested by increasing pressure until they ruptured. In Mbarara, the system was tested by accelerated cycles of filling/emptying and then run on grid power for 30 d. The low-pressure oxygen storage system performed well, including sustaining a pressure approximately twice the standard working pressure before rupture of the outer bag. Flow of 1.2 L/min was continuously maintained to a simulated patient during 30 d on grid power, despite power failures totaling 2.9% of the total time, with durations of 1-176 min (mean 36.2, median 18.5). The low-pressure oxygen storage system was robust and durable, with accelerated testing equivalent to at least 2 y of operation revealing no visible signs of imminent failure. Despite power cuts, the system continuously provided oxygen, equivalent to the treatment of one child, for 30 d under typical power conditions for sub-Saharan Africa. The low-pressure oxygen storage system is ready for clinical field trials. Copyright © 2017 by Daedalus Enterprises.

High temperature microcalorimetry. Study of metal-oxygen systems

International Nuclear Information System (INIS)

Tetot, R.; Picard, C.; Boureau, G.; Gerdanian, P.

1981-01-01

Determination of partial molar enthalpy in metal-oxygen systems at 1050 0 C. Three representative systems are studied: the solution of oxygen in titanium, the titanium-oxygen system and the uranium-oxygen system from UOsub(2.00) to UOsub(2.60) [fr

Communications data delivery system analysis task 2 report : high-level options for secure communications data delivery systems.

Science.gov (United States)

2012-05-16

This Communications Data Delivery System Analysis Task 2 report describes and analyzes options for Vehicle to Vehicle (V2V) and Vehicle to Infrastructure (V2I) communications data delivery systems using various communication media (Dedicated Short Ra...

Levodopa delivery systems: advancements in delivery of the gold standard.

Science.gov (United States)

Ngwuluka, Ndidi; Pillay, Viness; Du Toit, Lisa C; Ndesendo, Valence; Choonara, Yahya; Modi, Girish; Naidoo, Dinesh

2010-02-01

Despite the fact that Parkinson's disease (PD) was discovered almost 200 years ago, its treatment and management remain immense challenges because progressive loss of dopaminergic nigral neurons, motor complications experienced by the patients as the disease progresses and drawbacks of pharmacotherapeutic management still persist. Various therapeutic agents have been used in the management of PD, including levodopa (l-DOPA), selegiline, amantadine, bromocriptine, entacapone, pramipexole dihydrochloride and more recently istradefylline and rasagiline. Of all agents, l-DOPA although the oldest, remains the most effective. l-DOPA is easier to administer, better tolerated, less expensive and is required by almost all PD patients. However, l-DOPA's efficacy in advanced PD is significantly reduced due to metabolism, subsequent low bioavailability and irregular fluctuations in its plasma levels. Significant strides have been made to improve the delivery of l-DOPA in order to enhance its bioavailability and reduce plasma fluctuations as well as motor complications experienced by patients purportedly resulting from pulsatile stimulation of the striatal dopamine receptors. Drug delivery systems that have been instituted for the delivery of l-DOPA include immediate release formulations, liquid formulations, dispersible tablets, controlled release formulations, dual-release formulations, microspheres, infusion and transdermal delivery, among others. In this review, the l-DOPA-loaded drug delivery systems developed over the past three decades are elaborated. The ultimate aim was to assess critically the attempts made thus far directed at improving l-DOPA absorption, bioavailability and maintenance of constant plasma concentrations, including the drug delivery technologies implicated. This review highlights the fact that neuropharmaceutics is at a precipice, which is expected to spur investigators to take that leap to enable the generation of innovative delivery systems for the

Total hydrocarbon content (THC) testing in liquid oxygen (LOX) systems

Science.gov (United States)

Meneghelli, B. J.; Obregon, R. E.; Ross, H. R.; Hebert, B. J.; Sass, J. P.; Dirschka, G. E.

2015-12-01

The measured Total Hydrocarbon Content (THC) levels in liquid oxygen (LOX) systems at Stennis Space Center (SSC) have shown wide variations. Examples of these variations include the following: 1) differences between vendor-supplied THC values and those obtained using standard SSC analysis procedures; and 2) increasing THC values over time at an active SSC test stand in both storage and run vessels. A detailed analysis of LOX sampling techniques, analytical instrumentation, and sampling procedures will be presented. Additional data obtained on LOX system operations and LOX delivery trailer THC values during the past 12-24 months will also be discussed. Field test results showing THC levels and the distribution of the THC's in the test stand run tank, modified for THC analysis via dip tubes, will be presented.

Oxygen Tension in the Aqueous Humor of Human Eyes under Different Oxygenation Conditions

Directory of Open Access Journals (Sweden)

Farideh Sharifipour

2013-01-01

Full Text Available Purpose: To measure oxygen tension in the aqueous humor of human eyes under different oxygenation conditions. Methods: This prospective comparative interventional case series consisted of two parts. In the first part, 120 consecutive patients scheduled for cataract surgery were randomized into group I (control group in which surgery was performed under local anesthesia inhaling 21% oxygen; group II in whom general anesthesia using 50% oxygen was employed; and group III receiving general anesthesia with 100% oxygen. After aspirating 0.2 ml aqueous humor under sterile conditions, the aqueous sample and a simultaneously drawn arterial blood sample were immediately analyzed using a blood gas analyzer. In part II the same procedures were performed in 10 patients after fitting a contact lens and patching the eye for 20 minutes (group IV and in 10 patients after transcorneal delivery of oxygen at a flow rate of 5 L/min (group V. Results: Mean aqueous PO2 in groups I, II and III was 112.3±6.2, 141.1±20.4, and 170.1±27 mmHg, respectively (P values <0.001 and mean arterial PO2 was 85.7±7.9, 184.6±46, and 379.1±75.9 mmHg, respectively (P values <0.001. Aqueous PO2 was 77.2±9.2 mmHg in group IV and 152.3±10.9 mmHg in group V (P values <0.001. There was a significant correlation between aqueous and blood PO2 (r=0.537, P<0.001. The contribution of atmospheric oxygen to aqueous PO2 was 23.7%. Conclusion: Aqueous oxygen tension is mostly dependent on the systemic circulation and in part on the atmosphere. Increasing inspiratory oxygen and transcorneal oxygen delivery both increase aqueous PO2 levels.

Solar Energy Systems for Lunar Oxygen Generation

Science.gov (United States)

Colozza, Anthony J.; Heller, Richard S.; Wong, Wayne A.; Hepp, Aloysius F.

2010-01-01

An evaluation of several solar concentrator-based systems for producing oxygen from lunar regolith was performed. The systems utilize a solar concentrator mirror to provide thermal energy for the oxygen production process. Thermal energy to power a Stirling heat engine and photovoltaics are compared for the production of electricity. The electricity produced is utilized to operate the equipment needed in the oxygen production process. The initial oxygen production method utilized in the analysis is hydrogen reduction of ilmenite. Utilizing this method of oxygen production a baseline system design was produced. This baseline system had an oxygen production rate of 0.6 kg/hr with a concentrator mirror size of 5 m. Variations were performed on the baseline design to show how changes in the system size and process (rate) affected the oxygen production rate. An evaluation of the power requirements for a carbothermal lunar regolith reduction reactor has also been conducted. The reactor had a total power requirement between 8,320 to 9,961 W when producing 1000 kg/year of oxygen. The solar concentrator used to provide the thermal power (over 82 percent of the total energy requirement) would have a diameter of less than 4 m.

Ion-Responsive Drug Delivery Systems.

Science.gov (United States)

Yoshida, Takayuki; Shakushiro, Kohsuke; Sako, Kazuhiro

2018-02-08

Some kinds of cations and anions are contained in body fluids such as blood, interstitial fluid, gastrointestinal juice, and tears at relatively high concentration. Ionresponsive drug delivery is available to design the unique dosage formulations which provide optimized drug therapy with effective, safe and convenient dosing of drugs. The objective of the present review was to collect, summarize, and categorize recent research findings on ion-responsive drug delivery systems. Ions in body fluid/formulations caused structural changes of polymers/molecules contained in the formulations, allow formulations exhibit functions. The polymers/molecules responding to ions were ion-exchange resins/fibers, anionic or cationic polymers, polymers exhibiting transition at lower critical solution temperature, self-assemble supramolecular systems, peptides, and metalorganic frameworks. The functions of ion-responsive drug delivery systems were categorized to controlled drug release, site-specific drug release, in situ gelation, prolonged retention at the target sites, and enhancement of drug permeation. Administration of the formulations via oral, ophthalmic, transdermal, and nasal routes has showed significant advantages in the recent literatures. Many kinds of drug delivery systems responding to ions have been reported recently for several administration routes. Improvement and advancement of these systems can maximize drugs potential and contribute to patients in the world. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

A Comprehensive Review on: Transdermal drug delivery systems.

OpenAIRE

Kharat, Rekha; Bathe, Ritesh Suresh

2016-01-01

Transdermal drug delivery system was introduced to overcome the difficulties of drug delivery through oral route. Despite their relatively higher costs, transdermal delivery systems have proved advantageous for delivery of selected drugs, such as estrogens, testosterone, clonidine and nitro-glycerine. Transdermal delivery provides a leading edge over injectable and oral routes by increasing patient compliance and avoiding first pass metabolism respectively. Topical  administration  of  therap...

Electronic Nicotine Delivery Systems Key Facts Infographic

Data.gov (United States)

U.S. Department of Health & Human Services — Explore the Electronic Nicotine Delivery Systems Key Facts Infographic which outlines key facts related to electronic nicotine delivery systems (ENDS), including...

Effect of thoracic epidural anesthesia on oxygen delivery and utilization in cardiac surgical patients scheduled to undergo off-pump coronary artery bypass surgery: a prospective study.

Science.gov (United States)

Suryaprakash, Sharadaprasad; Chakravarthy, Murali; Gautam, Mamatha; Gandhi, Anurag; Jawali, Vivek; Patil, Thimmannagowda; Jayaprakash, Krishnamoorthy; Pandey, Saurabh; Muniraju, Geetha

2011-01-01

To evaluate the effect of thoracic epidural anesthesia (TEA) on tissue oxygen delivery and utilization in patients undergoing cardiac surgery. This prospective observational study was conducted in a tertiary referral heart hospital. A total of 25 patients undergoing elective off-pump coronary artery bypass surgery were enrolled in this study. All patients received thoracic epidural catheter in the most prominent inter-vertebral space between C7 and T3 on the day before operation. On the day of surgery, an arterial catheter and Swan Ganz catheter (capable of measuring cardiac index) was inserted. After administering full dose of local anesthetic in the epidural space, serial hemodynamic and oxygen transport parameters were measured for 30 minute prior to administration of general anesthesia, with which the study was culminated. A significant decrease in oxygen delivery index with insignificant changes in oxygen extraction and consumption indices was observed. We conclude that TEA does not affect tissue oxygenation despite a decrease in arterial pressures and cardiac output.

Effect of thoracic epidural anesthesia on oxygen delivery and utilization in cardiac surgical patients scheduled to undergo off-pump coronary artery bypass surgery: A prospective study

Directory of Open Access Journals (Sweden)

Suryaprakash Sharadaprasad

2011-01-01

Full Text Available To evaluate the effect of thoracic epidural anesthesia (TEA on tissue oxygen delivery and utilization in patients undergoing cardiac surgery. This prospective observational study was conducted in a tertiary referral heart hospital. A total of 25 patients undergoing elective off-pump coronary artery bypass surgery were enrolled in this study. All patients received thoracic epidural catheter in the most prominent inter-vertebral space between C7 and T3 on the day before operation. On the day of surgery, an arterial catheter and Swan Ganz catheter (capable of measuring cardiac index was inserted. After administering full dose of local anesthetic in the epidural space, serial hemodynamic and oxygen transport parameters were measured for 30 minute prior to administration of general anesthesia, with which the study was culminated. A significant decrease in oxygen delivery index with insignificant changes in oxygen extraction and consumption indices was observed. We conclude that TEA does not affect tissue oxygenation despite a decrease in arterial pressures and cardiac output.

Replacing the Transfusion of 1–2 Units of Blood with Plasma Expanders that Increase Oxygen Delivery Capacity: Evidence from Experimental Studies

Directory of Open Access Journals (Sweden)

Amy G. Tsai

2014-10-01

Full Text Available At least a third of the blood supply in the world is used to transfuse 1–2 units of packed red blood cells for each intervention and most clinical trials of blood substitutes have been carried out at this level of oxygen carrying capacity (OCC restoration. However, the increase of oxygenation achieved is marginal or none at all for molecular hemoglobin (Hb products, due to their lingering vasoactivity. This has provided the impetus for the development of “oxygen therapeutics” using Hb-based molecules that have high oxygen affinity and target delivery of oxygen to anoxic areas. However it is still unclear how these oxygen carriers counteract or mitigate the functional effects of anemia due to obstruction, vasoconstriction and under-perfusion. Indeed, they are administered as a low dosage/low volume therapeutic Hb (subsequently further diluted in the circulatory pool and hence induce extremely small OCC changes. Hyperviscous plasma expanders provide an alternative to oxygen therapeutics by increasing the oxygen delivery capacity (ODC; in anemia they induce supra-perfusion and increase tissue perfusion (flow by as much as 50%. Polyethylene glycol conjugate albumin (PEG-Alb accomplishes this by enhancing the shear thinning behavior of diluted blood, which increases microvascular endothelial shear stress, causes vasodilation and lowering peripheral vascular resistance thus facilitating cardiac function. Induction of supra-perfusion takes advantage of the fact that ODC is the product of OCC and blood flow and hence can be maintained by increasing either or both. Animal studies suggest that this approach may save a considerable fraction of the blood supply. It has an additional benefit of enhancing tissue clearance of toxic metabolites.

Micro- and nano bio-based delivery systems for food applications: In vitro behavior.

Science.gov (United States)

de Souza Simões, Lívia; Madalena, Daniel A; Pinheiro, Ana C; Teixeira, José A; Vicente, António A; Ramos, Óscar L

2017-05-01

Micro- and nanoencapsulation is an emerging technology in the food field that potentially allows the improvement of food quality and human health. Bio-based delivery systems of bioactive compounds have a wide variety of morphologies that influence their stability and functional performance. The incorporation of bioactive compounds in food products using micro- and nano-delivery systems may offer extra health benefits, beyond basic nutrition, once their encapsulation may provide protection against undesired environmental conditions (e.g., heat, light and oxygen) along the food chain (including processing and storage), thus improving their bioavailability, while enabling their controlled release and target delivery. This review provides an overview of the bio-based materials currently used for encapsulation of bioactive compounds intended for food applications, as well as the main production techniques employed in the development of micro- and nanosystems. The behavior of such systems and of bioactive compounds entrapped into, throughout in vitro gastrointestinal systems, is also tracked in a critical manner. Comparisons between various in vitro digestion systems (including the main advantages and disadvantages) currently in use, as well as correlations between the behavior of micro- and nanosystems studied through in vitro and in vivo systems were highlighted and discussed here for the first time. Finally, examples of bioactive micro- and nanosystems added to food simulants or to real food matrices are provided, together with a revision of the main challenges for their safe commercialization, the regulatory issues involved and the main legislation aspects. Copyright © 2017 Elsevier B.V. All rights reserved.

Supersaturating drug delivery systems

DEFF Research Database (Denmark)

Laitinen, Riikka; Löbmann, Korbinian; Grohganz, Holger

2017-01-01

of the bioavailability of poorly water-soluble drugs by increasing the driving force for drug absorption. However, ASDs often require a high weight percentage of carrier (usually a hydrophilic polymer) to ensure molecular mixing of the drug in the carrier and stabilization of the supersaturated state, often leading......Amorphous solid dispersions (ASDs) are probably the most common and important supersaturating drug delivery systems for the formulation of poorly water-soluble compounds. These delivery systems are able to achieve and maintain a sustained drug supersaturation which enables improvement...... strategy for poorly-soluble drugs. While the current research on co-amorphous formulations is focused on preparation and characterization of these systems, more detailed research on their supersaturation and precipitation behavior and the effect of co-formers on nucleation and crystal growth inhibition...

Spatially monitoring oxygen level in 3D microfabricated cell culture systems using optical oxygen sensing beads.

Science.gov (United States)

Wang, Lin; Acosta, Miguel A; Leach, Jennie B; Carrier, Rebecca L

2013-04-21

Capability of measuring and monitoring local oxygen concentration at the single cell level (tens of microns scale) is often desirable but difficult to achieve in cell culture. In this study, biocompatible oxygen sensing beads were prepared and tested for their potential for real-time monitoring and mapping of local oxygen concentration in 3D micro-patterned cell culture systems. Each oxygen sensing bead is composed of a silica core loaded with both an oxygen sensitive Ru(Ph2phen3)Cl2 dye and oxygen insensitive Nile blue reference dye, and a poly-dimethylsiloxane (PDMS) shell rendering biocompatibility. Human intestinal epithelial Caco-2 cells were cultivated on a series of PDMS and type I collagen based substrates patterned with micro-well arrays for 3 or 7 days, and then brought into contact with oxygen sensing beads. Using an image analysis algorithm to convert florescence intensity of beads to partial oxygen pressure in the culture system, tens of microns-size oxygen sensing beads enabled the spatial measurement of local oxygen concentration in the microfabricated system. Results generally indicated lower oxygen level inside wells than on top of wells, and local oxygen level dependence on structural features of cell culture surfaces. Interestingly, chemical composition of cell culture substrates also appeared to affect oxygen level, with type-I collagen based cell culture systems having lower oxygen concentration compared to PDMS based cell culture systems. In general, results suggest that oxygen sensing beads can be utilized to achieve real-time and local monitoring of micro-environment oxygen level in 3D microfabricated cell culture systems.

Methods and metrics challenges of delivery-system research

Directory of Open Access Journals (Sweden)

Alexander Jeffrey A

2012-03-01

Full Text Available Abstract Background Many delivery-system interventions are fundamentally about change in social systems (both planned and unplanned. This systems perspective raises a number of methodological challenges for studying the effects of delivery-system change--particularly for answering questions related to whether the change will work under different conditions and how the change is integrated (or not into the operating context of the delivery system. Methods The purpose of this paper is to describe the methodological and measurement challenges posed by five key issues in delivery-system research: (1 modeling intervention context; (2 measuring readiness for change; (3 assessing intervention fidelity and sustainability; (4 assessing complex, multicomponent interventions; and (5 incorporating time in delivery-system models to discuss recommendations for addressing these issues. For each issue, we provide recommendations for how research may be designed and implemented to overcome these challenges. Results and conclusions We suggest that a more refined understanding of the mechanisms underlying delivery-system interventions (treatment theory and the ways in which outcomes for different classes of individuals change over time are fundamental starting points for capturing the heterogeneity in samples of individuals exposed to delivery-system interventions. To support the research recommendations outlined in this paper and to advance understanding of the "why" and "how" questions of delivery-system change and their effects, funding agencies should consider supporting studies with larger organizational sample sizes; longer duration; and nontraditional, mixed-methods designs. A version of this paper was prepared under contract with the Agency for Healthcare Research and Quality (AHRQ, US Department of Health and Human Services for presentation and discussion at a meeting on "The Challenge and Promise of Delivery System Research," held in Sterling, VA, on

Recent Trends of Polymer Mediated Liposomal Gene Delivery System

Directory of Open Access Journals (Sweden)

Shyamal Kumar Kundu

2014-01-01

Full Text Available Advancement in the gene delivery system have resulted in clinical successes in gene therapy for patients with several genetic diseases, such as immunodeficiency diseases, X-linked adrenoleukodystrophy (X-ALD blindness, thalassemia, and many more. Among various delivery systems, liposomal mediated gene delivery route is offering great promises for gene therapy. This review is an attempt to depict a portrait about the polymer based liposomal gene delivery systems and their future applications. Herein, we have discussed in detail the characteristics of liposome, importance of polymer for liposome formulation, gene delivery, and future direction of liposome based gene delivery as a whole.

Stimuli-Responsive Polymeric Systems for Controlled Protein and Peptide Delivery: Future Implications for Ocular Delivery.

Science.gov (United States)

Mahlumba, Pakama; Choonara, Yahya E; Kumar, Pradeep; du Toit, Lisa C; Pillay, Viness

2016-07-30

Therapeutic proteins and peptides have become notable in the drug delivery arena for their compatibility with the human body as well as their high potency. However, their biocompatibility and high potency does not negate the existence of challenges resulting from physicochemical properties of proteins and peptides, including large size, short half-life, capability to provoke immune responses and susceptibility to degradation. Various delivery routes and delivery systems have been utilized to improve bioavailability, patient acceptability and reduce biodegradation. The ocular route remains of great interest, particularly for responsive delivery of macromolecules due to the anatomy and physiology of the eye that makes it a sensitive and complex environment. Research in this field is slowly gaining attention as this could be the breakthrough in ocular drug delivery of macromolecules. This work reviews stimuli-responsive polymeric delivery systems, their use in the delivery of therapeutic proteins and peptides as well as examples of proteins and peptides used in the treatment of ocular disorders. Stimuli reviewed include pH, temperature, enzymes, light, ultrasound and magnetic field. In addition, it discusses the current progress in responsive ocular drug delivery. Furthermore, it explores future prospects in the use of stimuli-responsive polymers for ocular delivery of proteins and peptides. Stimuli-responsive polymers offer great potential in improving the delivery of ocular therapeutics, therefore there is a need to consider them in order to guarantee a local, sustained and ideal delivery of ocular proteins and peptides, evading tissue invasion and systemic side-effects.

The Research Progress of Targeted Drug Delivery Systems

Science.gov (United States)

Zhan, Jiayin; Ting, Xizi Liang; Zhu, Junjie

2017-06-01

Targeted drug delivery system (DDS) means to selectively transport drugs to targeted tissues, organs, and cells through a variety of drugs carrier. It is usually designed to improve the pharmacological and therapeutic properties of conventional drugs and to overcome problems such as limited solubility, drug aggregation, poor bio distribution and lack of selectivity, controlling drug release carrier and to reduce normal tissue damage. With the characteristics of nontoxic and biodegradable, it can increase the retention of drug in lesion site and the permeability, improve the concentration of the drug in lesion site. at present, there are some kinds of DDS using at test phase, such as slow controlled release drug delivery system, targeted drug delivery systems, transdermal drug delivery system, adhesion dosing system and so on. This paper makes a review for DDS.

A study on nanodiamond-based drug delivery system

International Nuclear Information System (INIS)

Li Jing; Zhang Xiaoyong; Zhu Ying; Li Wenxin; Huang Qing

2010-01-01

A multifunctional drug delivery system based on nanodiamonds (NDs) has been developed. FITC, HCPT and TF were absorbed on NDs successively to form the multifunctional complex. The NDs and ND complex samples were characterized by TEM, FR-IR and UV-V. The results indicated that this drug delivery system is a high loading system. Efficacy of the drug delivery system on Hela cell was evaluated with MTT assays and fluorescence microscopy. The results show that multifunction of the NDs complex include fluorescence, targeting and high efficacy. (authors)

Elastin-Like Recombinamers As Smart Drug Delivery Systems.

Science.gov (United States)

Arias, F Javier; Santos, Mercedes; Ibanez-Fonseca, Arturo; Pina, Maria Jesus; Serrano, Sofía

2018-02-19

Drug delivery systems that are able to control the release of bioactive molecules and designed to carry drugs to target sites are of particular interest for tissue therapy. Moreover, systems comprising materials that can respond to environmental stimuli and promote self-assembly and higher order supramolecular organization are especially useful in the biomedical field. Objetive: This review focuses on biomaterials suitable for this purpose and that include elastin-like recombinamers (ELRs), a class of proteinaceous polymers bioinspired by natural elastin, designed using recombinant technologies. The self-assembly and thermoresponsive behaviour of these systems, along with their biodegradability, biocompatibility and well-defined composition as a result of their tailormade design, make them particularly attractive for controlled drug delivery. ELR-based delivery systems that allow targeted delivery are reviewed, especially ELR-drug recombinant fusion constructs, ELR-drug systems chemically bioconjugated in their monomeric and soluble forms, and drug encapsulation by nanoparticle-forming ELRs. Subsequently, the review focuses on those drug carriers in which smart release is triggered by pH or temperature with a particular focus on cancer treatments. Systems for controlled drug release based on depots and hydrogels that act as both a support and reservoir in which drugs can be stored will be described, and their applications in drug delivery discussed. Finally, smart drug-delivery systems not based on ELRs, including those comprising proteins, synthetic polymers and non-polymeric systems, will also be briefly discussed. Several different constructions based on ELRs are potential candidates for controlled drug delivery to be applied in advanced biomedical treatments. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Safety Standard for Oxygen and Oxygen Systems: Guidelines for Oxygen System Design, Materials Selection, Operations, Storage, and Transportation

Science.gov (United States)

1996-01-01

NASA's standard for oxygen system design, materials selection, operation, and transportation is presented. Minimum guidelines applicable to NASA Headquarters and all NASA Field Installations are contained.

The impact of an hematocrit of 20% during normothermic cardiopulmonary bypass for elective low risk coronary artery bypass graft surgery on oxygen delivery and clinical outcome – a randomized controlled study [ISRCTN35655335

Science.gov (United States)

von Heymann, Christian; Sander, Michael; Foer, Achim; Heinemann, Anja; Spiess, Bruce; Braun, Jan; Krämer, Michael; Grosse, Joachim; Dohmen, Pascal; Dushe, Simon; Halle, Jürgen; Konertz, Wolfgang F; Wernecke, Klaus-Dieter; Spies, Claudia

2006-01-01

Introduction Cardiopulmonary bypass (CPB) induces hemodilutional anemia, which frequently requires the transfusion of blood products. The objective of this study was to evaluate oxygen delivery and consumption and clinical outcome in low risk patients who were allocated to an hematocrit (Hct) of 20% versus 25% during normothermic CPB for elective coronary artery bypass graft (CABG) surgery. Methods This study was a prospective, randomized and controlled trial. Patients were subjected to normothermic CPB (35 to 36°C) and were observed until discharge from the intensive care unit (ICU). Outcome measures were calculated whole body oxygen delivery, oxygen consumption and clinical outcome. A nonparametric multivariate analysis of variance for repeated measurements and small sample sizes was performed. Results In a total of 54 patients (25% Hct, n = 28; 20% Hct, n = 26), calculated oxygen delivery (p = 0.11), oxygen consumption (p = 0.06) and blood lactate (p = 0.60) were not significantly different between groups. Clinical outcomes were not different between groups. Conclusion These data indicate that an Hct of 20% during normothermic CPB maintained calculated whole body oxygen delivery above a critical level after elective CABG surgery in low risk patients. The question of whether a transfusion trigger in excess of 20% Hct during normothermic CPB is still supported requires a larger prospective and randomized trial. PMID:16606474

Mars oxygen production system design

Science.gov (United States)

Cotton, Charles E.; Pillow, Linda K.; Perkinson, Robert C.; Brownlie, R. P.; Chwalowski, P.; Carmona, M. F.; Coopersmith, J. P.; Goff, J. C.; Harvey, L. L.; Kovacs, L. A.

1989-01-01

The design and construction phase is summarized of the Mars oxygen demonstration project. The basic hardware required to produce oxygen from simulated Mars atmosphere was assembled and tested. Some design problems still remain with the sample collection and storage system. In addition, design and development of computer compatible data acquisition and control instrumentation is ongoing.

Recent trends in challenges and opportunities of Transdermal drug delivery system

OpenAIRE

P.M.Patil; P.D.Chaudhari; Jalpa K.Patel; K.A.Kedar; P.P.Katolkar

2012-01-01

Drug delivery system relates to the production of a drug, its delivery medium, and the way of administration. Drug delivery systems are even used for administering nitroglycerin. Transdermal drug delivery system is the system in which the delivery of the active ingredients of the drug occurs by the means of skin. Various types of transdermal patches are used. There are various methods to enhance the transdermal drug delivery system. But using microfabricated microneedles drugs are delivered v...

A simplified concept for controlling oxygen mixtures in the anaesthetic machine--better, cheaper and more user-friendly?

Science.gov (United States)

Berge, J A; Gramstad, L; Grimnes, S

1995-05-01

Modern anaesthetic machines are equipped with several safety components to prevent delivery of hypoxic mixtures. However, such a technical development has increased the complexity of the equipment. We report a reconstructed anaesthetic machine in which a paramagnetic oxygen analyzer has provided the means to simplify the apparatus. The new machine is devoid of several components conventionally included to prevent hypoxic mixtures: oxygen failure protection device, reservoir O2 alarm, N2O/air selector, and proportioning system for oxygen/nitrous oxide delivery. These devices have been replaced by a simple safety system using a paramagnetic oxygen analyzer at the common gas outlet, which in a feed-back system cuts off the supply of nitrous oxide whenever the oxygen concentration falls below 25%. The simplified construction of the anaesthetic machine has important consequences for safety, cost and user-friendliness. Reducing the complexity of the construction also simplifies the pre-use checkout procedure, and an efficient 5-point check list is presented for the new machine.

Auditing Information System : Delivery Product Service

Directory of Open Access Journals (Sweden)

Purwoko Purwoko

2011-05-01

Full Text Available Purpose of the research is to ensure the securities of information system asset and to ensure if informa-tion system support the operational and data collected was valid. Research method that used in this research were library studies and field studies. Field studies such an observation, questioner, and inter-view. the expected result are founding the weakness of security management control, operational man-agement control, input control, and output control of risk happened in the company. Conclusion of this research are the system on the company work good and there’s no potential risk happened and make an impact to the delivery process of information system.Index Terms - Auditing Information system, Delivery product process.

Drug delivery from the oral cavity: a focus on mucoadhesive buccal drug delivery systems.

Science.gov (United States)

Shinkar, Dattatraya Manohar; Dhake, Avinash Sridhar; Setty, Chitral Mallikarjuna

2012-01-01

Since the early 1980s the concept of mucoadhesion has gained considerable interest in pharmaceutical technology. The various advantages associated with these systems made buccal drug delivery as a novel route of drug administration. It prolongs the residence time of the dosage form at the site of application. These systems remain in close contact with the absorption tissue, the mucous membrane, and thus contribute to improved and/or better therapeutic performance of the drug and of both local and systemic effects. This review highlights the anatomy and structure of oral mucosa, mechanism and theories of mucoadhesion, factors affecting mucoadhesion, characteristics and properties of desired mucoadhesive polymers, various types of dosage forms, and general considerations in design of mucoadhesive buccal dosage forms, permeation enhancers, and evaluation methods. Over the past few decades the mucoadhesive buccal drug delivery system has received a great deal of attention to develop mucoadhesive dosage forms to enable the prolonged retention at the site of action, providing a controlled release of drug for improved therapeutic outcome. Mucoadhesive drug delivery gives facility to include a permeation enhancer/enzyme inhibitor or pHmodifier in the formulation and versatility in designing as multidirectional or unidirectional release systems for local and systemic action. Local delivery to tissues of the oral cavity has a number of applications, including treatment of local conditions such as periodontal disease, bacterial and fungal infections, and aphthous stomatitis and vesiculo bullous diseases. For the treatment of chronic diseases, the mucoadhesive buccal drug delivery system allows easily accessibility and is generally well-accepted for administeringdrugs by systemic action.

A real-time virtual delivery system for photon radiotherapy delivery monitoring

Directory of Open Access Journals (Sweden)

Feng Shi

2014-03-01

Full Text Available Purpose: Treatment delivery monitoring is important for radiotherapy, which enables catching dosimetric error at the earliest possible opportunity. This project develops a virtual delivery system to monitor the dose delivery process of photon radiotherapy in real-time using GPU-based Monte Carlo (MC method.Methods: The simulation process consists of 3 parallel CPU threads. A thread T1 is responsible for communication with a linac, which acquires a set of linac status parameters, e.g. gantry angles, MLC configurations, and beam MUs every 20 ms. Since linac vendors currently do not offer interface to acquire data in real time, we mimic this process by fetching information from a linac dynalog file at the set frequency. Instantaneous beam fluence map (FM is calculated based. A FM buffer is also created in T1 and the instantaneous FM is accumulated to it. This process continues, until a ready signal is received from thread T2 on which an in-house developed MC dose engine executes on GPU. At that moment, the accumulated FM is transferred to T2 for dose calculations, and the FM buffer in T1 is cleared. Once the dose calculation finishes, the resulting 3D dose distribution is directed to thread T3, which displays it in three orthogonal planes in color wash overlaid on the CT image. This process continues to monitor the 3D dose distribution in real-time.Results: An IMRT and a VMAT cases used in our patient-specific QA are studied. Maximum dose differences between our system and treatment planning system are 0.98% and 1.58% for the IMRT and VMAT cases, respectively. The update frequency is >10Hz and the relative uncertainty level is 2%.Conclusion: By embedding a GPU-based MC code in a novel data/work flow, it is possible to achieve real-time MC dose calculations to monitor delivery process.------------------------------Cite this article as: Shi F, Gu X, Graves YJ, Jiang S, Jia X. A real-time virtual delivery system for photon radiotherapy delivery

Distance Synchronous Information Systems Course Delivery

Science.gov (United States)

Peslak, Alan R.; Lewis, Griffith R.; Aebli, Fred

2014-01-01

Teaching computer information systems via distance education is a challenge for both student and faculty. Much research work has been performed on methods of teaching via distance education. Today we are faced with a variety of options for course delivery. Asynchronous delivery via online or lesson instruction still remains most common. But…

Microemulsion Drug Delivery Systems for Radiopharmacy Studies

Directory of Open Access Journals (Sweden)

Emre Ozgenc

2016-11-01

Full Text Available Microemulsions have been used increasingly for last year’s because of ideal properties like favorable drug delivery, ease of preparation and physical stability. They have been improved the solubility and efficacy of the drug and reduce the side effects. Use of radiolabeled microemulsions plays an alternative role in drug delivery systems by investigating the formation, stability and application of microemulsions in radiopharmacy. Gama scintigraphic method is well recognized for developing and detecting the biodistribution of newly developed drugs or formulation. This review will focus on how radionuclides are able to play role with characterization studies of microemulsion drug delivery systems.

Central oxygen pipeline failure | Mostert | Southern African Journal ...

African Journals Online (AJOL)

Anaesthetic and critical care staff play a governing role in the comprehension of a hospital's oxygen delivery system and associated contingency plans for internal disaster management. Therefore, staff must be thoroughly prepared and properly trained to support an institution-wide emergency response in the event of ...

Comprehensive evaluation of carboxylated nanodiamond as a topical drug delivery system.

Science.gov (United States)

Lim, Dae Gon; Kim, Ki Hyun; Kang, Eunah; Lim, Sun Hee; Ricci, Jeremy; Sung, Si Kwon; Kwon, Myoung Taek; Jeong, Seong Hoon

2016-01-01

The best strategy in the development of topical drug delivery systems may be to facilitate the permeation of drugs without any harmful effects, while staying on the skin surface and maintaining stability of the system. Nanodiamonds (NDs) play a key role with their excellent physicochemical properties, including high biocompatibility, physical adsorption, reactive oxygen species (ROS) scavenging capability, and photostabilizing activity. Z-average sizes of carboxylated ND (ND-COOH) agglutinate decreased significantly as the pH increased. Fluorescein-conjugated ND was observed only on the stratum corneum, and no sample diffused into the dermal layer even after 48 hours. Moreover, ND-COOH and ND-COOH/eugenol complex did not show significant toxic effects on murine macrophage cells. ND improved in vitro skin permeation >50% acting as a "drug reservoir" to maintain a high drug concentration in the donor chamber, which was supported by quartz crystal microbalance results. Moreover, ND-COOH could adsorb a drug amount equivalent to 80% of its own weight. A photostability study showed that ND-COOH increased the photostability ~47% with regard to rate constant of the eugenol itself. A significant decrease in ROS was observed in the ND-COOH and ND-COOH/eugenol complex compared with the negative control during intracellular ROS assay. Moreover, ROS and cupric reducing antioxidant capacity evaluation showed that ND-COOH had synergistic effects of antioxidation with eugenol. Therefore, ND-COOH could be used as an excellent topical drug delivery system with improved permeability, higher stability, and minimized safety issue.

A wireless actuating drug delivery system

International Nuclear Information System (INIS)

Jo, Won-Jun; Baek, Seung-Ki; Park, Jung-Hwan

2015-01-01

A wireless actuating drug delivery system was devised. The system is based on induction heating for drug delivery. In this study, thermally generated nitrogen gas produced by induction heating of azobisisobutyronitrile (AIBN) was utilized for pressure-driven release of the drug. The delivery device consists of an actuator chamber, a drug reservoir, and a microchannel. A semicircular copper disc (5 and 6 mm in diameter and 100 µm thick), and thermal conductive tape were integrated as the heating element in the actuator chamber. The final device was 2.7 mm thick. 28 µl of drug solution were placed in the reservoir and the device released the drug quickly at the rate of 6 µl s −1 by induction heating at 160 µT of magnetic intensity. The entire drug solution was released and dispersed after subcutaneous implantation under identical experimental condition. This study demonstrates that the device was simply prepared and drug delivery could be achieved by wireless actuation of a thin, pressure-driven actuator. (paper)

Buccal Transmucosal Delivery System of Enalapril for Improved ...

African Journals Online (AJOL)

Purpose: To prepare and characterize buccal transmucosal delivery system of enalapril maleate for overcoming its low bioavailability, and hence provide improved therapeutic efficacy and patient compliance. Methods: Transmucosal drug delivery systems of enalapril maleate were formulated as buccal films by solvent ...

A high reliability oxygen deficiency monitoring system

International Nuclear Information System (INIS)

Parry, R.; Claborn, G.; Haas, A.; Landis, R.; Page, W.; Smith, J.

1993-05-01

The escalating use of cryogens at national laboratories in general and accelerators in particular, along with the increased emphasis placed on personnel safety, mandates the development and installation of oxygen monitoring systems to insure personnel safety in the event of a cryogenic leak. Numerous vendors offer oxygen deficiency monitoring systems but fail to provide important features and/or flexibility. This paper describes a unique oxygen monitoring system developed for the Magnet Test Laboratory (MTL) at the Superconducting Super Collider Laboratory (SSCL). Features include: high reliability, oxygen cell redundancy, sensor longevity, simple calibration, multiple trip points, offending sensor audio and visual indication, global alarms for building evacuation, local and remote analog readout, event and analog data logging, EMAIL event notification, phone line voice status system, and multi-drop communications network capability for reduced cable runs. Of particular importance is the distributed topology of the system which allows it to operate in a stand-alone configuration or to communicate with a host computer. This flexibility makes it ideal for small applications such as a small room containing a cryogenic dewar, as well as larger systems which monitor many offices and labs in several buildings

A high reliability oxygen deficiency monitoring system

International Nuclear Information System (INIS)

Parry, R.; Claborn, G.; Haas, A.; Landis, R.; Page, W.; Smith, J.

1993-01-01

The escalating use of cryogens at national laboratories in general and accelerators in particular, along with the increased emphasis placed on personnel safety, mandates the development and installation of oxygen monitoring systems to insure personnel safety in the event of a cryogenic leak. Numerous vendors offer oxygen deficiency monitoring systems but fail to provide important features and/or flexibility. This paper describes a unique oxygen monitoring system developed for the Magnet Test Laboratory (MTL) at the Superconducting Super Collider Laboratory (SSCL). Features include: high reliability, oxygen cell redundancy, sensor longevity, simple calibration, multiple trip points, offending sensor audio and visual indication, global alarms for building evacuation, local and remote analog readout, event and analog data logging, EMAIL event notification, phone line voice status system, and multi-drop communications network capability for reduced cable runs. Of particular importance is the distributed topology of the system which allows it to operate in a stand-alone configuration or to communicate with a host computer. This flexibility makes it ideal for small applications such as a small room containing a cryogenic dewar, as well as larger systems which monitor many offices and labs in several buildings

Oral Drug Delivery Systems Comprising Altered Geometric Configurations for Controlled Drug Delivery

Directory of Open Access Journals (Sweden)

Priya Bawa

2011-12-01

Full Text Available Recent pharmaceutical research has focused on controlled drug delivery having an advantage over conventional methods. Adequate controlled plasma drug levels, reduced side effects as well as improved patient compliance are some of the benefits that these systems may offer. Controlled delivery systems that can provide zero-order drug delivery have the potential for maximizing efficacy while minimizing dose frequency and toxicity. Thus, zero-order drug release is ideal in a large area of drug delivery which has therefore led to the development of various technologies with such drug release patterns. Systems such as multilayered tablets and other geometrically altered devices have been created to perform this function. One of the principles of multilayered tablets involves creating a constant surface area for release. Polymeric materials play an important role in the functioning of these systems. Technologies developed to date include among others: Geomatrix® multilayered tablets, which utilizes specific polymers that may act as barriers to control drug release; Procise®, which has a core with an aperture that can be modified to achieve various types of drug release; core-in-cup tablets, where the core matrix is coated on one surface while the circumference forms a cup around it; donut-shaped devices, which possess a centrally-placed aperture hole and Dome Matrix® as well as “release modules assemblage”, which can offer alternating drug release patterns. This review discusses the novel altered geometric system technologies that have been developed to provide controlled drug release, also focusing on polymers that have been employed in such developments.

A theoretical model for the effects of reduced hemoglobin-oxygen affinity on tumor oxygenation

International Nuclear Information System (INIS)

Kavanagh, Brian D.; Secomb, Timothy W.; Hsu, Richard; Lin, P.-S.; Venitz, Jurgen; Dewhirst, Mark W.

2002-01-01

Purpose: To develop a theoretical model for oxygen delivery to tumors, and to use the model to simulate the effects of changing the affinity of hemoglobin for oxygen on tumor oxygenation. Methods and Materials: Hemoglobin affinity is expressed in terms of P 50 , the partial pressure of oxygen (Po 2 ) at half saturation. Effects of changing P 50 on arterial Po 2 are predicted using an effective vessel approach to describe diffusive oxygen transport in the lungs, assuming fixed systemic oxygen demand and fixed blood flow rate. The decline in oxygen content of blood as it flows through normal tissue before entering the tumor region is assumed fixed. The hypoxic fraction of the tumor region is predicted using a three-dimensional simulation of diffusion from a network of vessels whose geometry is derived from observations of tumor microvasculature in the rat. Results: In air-breathing rats, predicted hypoxic fraction decreases with moderate increases in P 50 , but increases with further increases of P 50 , in agreement with previous experimental results. In rats breathing hyperoxic gases, and in humans breathing either normoxic or hyperoxic gases, increased P 50 is predicted to improve tumor oxygenation. Conclusions: The results support the administration of synthetic agents to increase P 50 during radiation treatment of tumors

Coolant Chemistry Control: Oxygen Mass Transport in Lead Bismuth Eutectic

International Nuclear Information System (INIS)

Weisenburger, A.; Mueller, G.; Bruzzese, C.; Glass, A.

2015-01-01

In lead-bismuth cooled transmutation systems, oxygen, dissolved in the coolant at defined quantities, is required for stable long-term operation by assuring the formation of protective oxide scales on structural steel surfaces. Extracted oxygen must be permanently delivered to the system and distributed in the entire core. Therefore, coolant chemistry control involves detailed knowledge on oxygen mass transport. Beside the different flow regimes a core might have stagnant areas at which oxygen delivery can only be realised by diffusion. The difference between oxygen transport in flow paths and in stagnant zones is one of the targets of such experiments. To investigate oxygen mass transport in flowing and stagnant conditions, a dedicated facility was designed based on computational fluid dynamics (CFD). CFD also was applied to define the position of oxygen sensors and ultrasonic Doppler velocimetry transducers for flow measurements. This contribution will present the test facility, design relevant CFD calculations and results of first tests performed. (authors)

Efficiency performance of China's health care delivery system.

Science.gov (United States)

Zhang, Luyu; Cheng, Gang; Song, Suhang; Yuan, Beibei; Zhu, Weiming; He, Li; Ma, Xiaochen; Meng, Qingyue

2017-07-01

Improving efficiency performance of the health care delivery system has been on the agenda for the health system reform that China initiated in 2009. This study examines the changes in efficiency performance and determinants of efficiency after the reform to provide evidence to assess the progress of the reform from the perspective of efficiency. Descriptive analysis, Data Envelopment Analysis, the Malmquist Index, and multilevel regressions are used with data from multiple sources, including the World Bank, the China Health Statistical Yearbook, and routine reports. The results indicate that over the last decade, health outcomes compared with health investment were relatively higher in China than in most other countries worldwide, and the trend was stable. The overall efficiency and total factor productivity increased after the reform, indicating that the reform was likely to have had a positive impact on the efficiency performance of the health care delivery system. However, the health care delivery structure showed low system efficiency, mainly attributed to the weakened primary health care system. Strengthening the primary health care system is central to enhancing the future performance of China's health care delivery system. Copyright © 2017 John Wiley & Sons, Ltd.

Current and emerging lipid-based systems for transdermal drug delivery.

Science.gov (United States)

Singla, Sumeet K; Sachdeva, Vishal

2015-01-01

Developing a transdermal drug delivery system is a challenging task considering the selective permeability of the skin and the physicochemical properties the drug must possess to permeate through the skin. Lipid-based drug delivery systems have contributed a great deal in this direction in the last few decades, and thereby have helped to expand the range of therapeutic molecules that can be delivered through the skin in a safe and effective manner. Additionally, vesicular delivery systems such as nanoparticles and emulsions have also played important roles in providing alternative novel approaches for drug delivery. In this article, we will discuss some of the current and future lipid-based systems for transdermal drug delivery along with the associated challenges.

Long-term oxygen therapy for COPD. Improving longevity and quality of life in hypoxemic patients.

Science.gov (United States)

Weg, J G; Haas, C F

1998-04-01

Long-term oxygen therapy can increase life expectancy in hypoxemic patients with COPD. Accurate identification of hypoxemia requires arterial blood gas measurements. Pulse oximetry can be used to measure trends in oxygenation, oxygen needs, and oxygen requirements during exercise and sleep. A detailed oxygen prescription indicates: (1) the oxygen dose (L/min), (2) the number of hours per day that oxygen therapy is required, (3) the dose required during exercise, (4) the oxygen supply system: concentrator, compressed gas cylinder, or liquid oxygen reservoir, and (5) the delivery device: nasal cannula, demand-flow device, reservoir cannula, or transtracheal oxygen catheter.

Advanced drug delivery systems: Nanotechnology of health design A review

Directory of Open Access Journals (Sweden)

Javad Safari

2014-04-01

Full Text Available Nanotechnology has finally and firmly entered the realm of drug delivery. Performances of intelligent drug delivery systems are continuously improved with the purpose to maximize therapeutic activity and to minimize undesirable side-effects. This review describes the advanced drug delivery systems based on micelles, polymeric nanoparticles, and dendrimers. Polymeric carbon nanotubes and many others demonstrate a broad variety of useful properties. This review emphasizes the main requirements for developing new nanotech-nology-based drug delivery systems.

Engineering the system of healthcare delivery

National Research Council Canada - National Science Library

Rouse, William B; Cortese, Denis A

2010-01-01

"As the United States continues to debate reform of its healthcare system, this book argues that providing health insurance for all without improving the delivery system will not improve the current...

Applications of polymeric nanocapsules in field of drug delivery systems.

Science.gov (United States)

Rong, Xinyu; Xie, Yinghua; Hao, Xiaomei; Chen, Tao; Wang, Yingming; Liu, Yuanyuan

2011-09-01

Drug-loaded polymeric nanocapsules have exhibited potential applications in the field of drug delivery systems in recent years. This article entails the biodegradable polymers generally used for preparing nanocapsules, which include both natural polymers and synthetic polymers. Furthermore, the article presents a general review of the different preparation methods: nanoprecipitation method, emulsion-diffusion method, double emulsification method, emulsion-coacervation method, layer-by-layer assembly method. In addition, the analysis methods of nanocapsule characteristics, such as mean size, morphology, surface characteristics, shell thickness, encapsulation efficiency, active substance release, dispersion stability, are mentioned. Also, the applications of nanocapsules as carriers for use in drug delivery systems are reviewed, which primarily involve targeting drug delivery, controlled/sustained release drug delivery systems, transdermal drug delivery systems and improving stability and bioavailability of drugs. Nanocapsules, prepared with different biodegradable polymers, have received more and more attention and have been regarded as one of the most promising drug delivery systems.

Food Delivery System with the Utilization of Vehicle Using Geographical Information System (GIS) and A Star Algorithm

Science.gov (United States)

Siregar, B.; Gunawan, D.; Andayani, U.; Sari Lubis, Elita; Fahmi, F.

2017-01-01

Food delivery system is one kind of geographical information systems (GIS) that can be applied through digitation process. The main case in food delivery system is the way to determine the shortest path and food delivery vehicle movement tracking. Therefore, to make sure that the digitation process of food delivery system can be applied efficiently, it is needed to add shortest path determination facility and food delivery vehicle tracking. This research uses A Star (A*) algorithm for determining shortest path and location-based system (LBS) programming for moving food delivery vehicle object tracking. According to this research, it is generated the integrated system that can be used by food delivery driver, customer, and administrator in terms of simplifying the food delivery system. Through the application of shortest path and the tracking of moving vehicle, thus the application of food delivery system in the scope of geographical information system (GIS) can be executed.

Nanotechnology-based drug delivery systems

Directory of Open Access Journals (Sweden)

Singh Baljit

2007-12-01

Full Text Available Abstract Nanoparticles hold tremendous potential as an effective drug delivery system. In this review we discussed recent developments in nanotechnology for drug delivery. To overcome the problems of gene and drug delivery, nanotechnology has gained interest in recent years. Nanosystems with different compositions and biological properties have been extensively investigated for drug and gene delivery applications. To achieve efficient drug delivery it is important to understand the interactions of nanomaterials with the biological environment, targeting cell-surface receptors, drug release, multiple drug administration, stability of therapeutic agents and molecular mechanisms of cell signalling involved in pathobiology of the disease under consideration. Several anti-cancer drugs including paclitaxel, doxorubicin, 5-fluorouracil and dexamethasone have been successfully formulated using nanomaterials. Quantom dots, chitosan, Polylactic/glycolic acid (PLGA and PLGA-based nanoparticles have also been used for in vitro RNAi delivery. Brain cancer is one of the most difficult malignancies to detect and treat mainly because of the difficulty in getting imaging and therapeutic agents past the blood-brain barrier and into the brain. Anti-cancer drugs such as loperamide and doxorubicin bound to nanomaterials have been shown to cross the intact blood-brain barrier and released at therapeutic concentrations in the brain. The use of nanomaterials including peptide-based nanotubes to target the vascular endothelial growth factor (VEGF receptor and cell adhesion molecules like integrins, cadherins and selectins, is a new approach to control disease progression.

Resistive-wall Wake Effect in the Beam Delivery System

International Nuclear Information System (INIS)

Delayen, J.R.; Jefferson Lab; Wu, Juhao; Raubenheimer, T.O.; SLAC; Wang, Jiunn-Ming; BNL, NSLS

2005-01-01

General formulae for resistive-wall induced beam dilution are presented and then applied to the final beam delivery system of linear colliders. Criteria for the design of final beam delivery systems are discussed

A prosurvival and proangiogenic stem cell delivery system to promote ischemic limb regeneration.

Science.gov (United States)

Xu, Yanyi; Fu, Minghuan; Li, Zhihong; Fan, Zhaobo; Li, Xiaofei; Liu, Ying; Anderson, Peter M; Xie, Xiaoyun; Liu, Zhenguo; Guan, Jianjun

2016-02-01

Stem cell therapy is one of the most promising strategies to restore blood perfusion and promote muscle regeneration in ischemic limbs. Yet its therapeutic efficacy remains low owing to the inferior cell survival under the low oxygen and nutrient environment of the injured limbs. To increase therapeutic efficacy, high rates of both short- and long-term cell survival are essential, which current approaches do not support. In this work, we hypothesized that a high rate of short-term cell survival can be achieved by introducing a prosurvival environment into the stem cell delivery system to enhance cell survival before vascularization is established; and that a high rate of long-term cell survival can be attained by building a proangiogenic environment in the system to quickly vascularize the limbs. The system was based on a biodegradable and thermosensitive poly(N-Isopropylacrylamide)-based hydrogel, a prosurvival and proangiogenic growth factor bFGF, and bone marrow-derived mesenchymal stem cells (MSCs). bFGF can be continuously released from the system for 4weeks. The released bFGF significantly improved MSC survival and paracrine effects under low nutrient and oxygen conditions (0% FBS and 1% O2) in vitro. The prosurvival effect of the bFGF on MSCs was resulted from activating cell Kruppel-like factor 4 (KLF4) pathway. When transplanted into the ischemic limbs, the system dramatically improved MSC survival. Some of the engrafted cells were differentiated into skeletal muscle and endothelial cells, respectively. The system also promoted the proliferation of host cells. After only 2weeks of implantation, tissue blood perfusion was completely recovered; and after 4weeks, the muscle fiber diameter was restored similarly to that of the normal limbs. These pronounced results demonstrate that the developed stem cell delivery system has a potential for ischemic limb regeneration. Stem cell therapy is a promising strategy to restore blood perfusion and promote muscle

Biomimetics in drug delivery systems: A critical review.

Science.gov (United States)

Sheikhpour, Mojgan; Barani, Leila; Kasaeian, Alibakhsh

2017-05-10

Today, the advanced drug delivery systems have been focused on targeted drug delivery fields. The novel drug delivery is involved with the improvement of the capacity of drug loading in drug carriers, cellular uptake of drug carriers, and the sustained release of drugs within target cells. In this review, six groups of therapeutic drug carriers including biomimetic hydrogels, biomimetic micelles, biomimetic liposomes, biomimetic dendrimers, biomimetic polymeric carriers and biomimetic nanostructures, are studied. The subject takes advantage of the biomimetic methods of productions or the biomimetic techniques for the surface modifications, similar to what accrues in natural cells. Moreover, the effects of these biomimetic approaches for promoting the drug efficiency in targeted drug delivery are visible. The study demonstrates that the fabrication of biomimetic nanocomposite drug carriers could noticeably promote the efficiency of drugs in targeted drug delivery systems. Copyright © 2017 Elsevier B.V. All rights reserved.

Oxygenation measurement by multi-wavelength oxygen-dependent phosphorescence and delayed fluorescence: catchment depth and application in intact heart

NARCIS (Netherlands)

Balestra, Gianmarco M.; Aalders, Maurice C. G.; Specht, Patricia A. C.; Ince, Can; Mik, Egbert G.

2015-01-01

Oxygen delivery and metabolism represent key factors for organ function in health and disease. We describe the optical key characteristics of a technique to comprehensively measure oxygen tension (PO(2)) in myocardium, using oxygen-dependent quenching of phosphorescence and delayed fluorescence of

Design, fabrication, and analysis of miniature reflective oxygen monitoring system for use in PDT of esophageal carcinoma

Science.gov (United States)

Premasiri, Amaranath; Happawana, Gemunu

2008-02-01

Photodynamic therapy (PDT) is an effective and minimally invasive treatment modality with relatively less side effects, which is approved by FDA for the treatment of esophageal cancer. Maximum therapeutic outcome of the PDT protocol for each individual patient requires optimization of the components of PDT operating at their highest efficacy. Tumor necrosis, the method of malignant tissue destruction by PDT, is carried out by the toxic singlet oxygen molecules that are being formed from the molecular oxygen in the tumor. The availability of molecular oxygen, hence being the rate limiting step for PDT plays a key role in the treatment protocol. Currently the PDT of esophageal carcinoma is rather a blind process since there is no method to monitor the tumor oxygen level during the treatment. In this paper we present an optical technique to monitor molecular oxygen level in the PDT milieu. The technique described herein is a reflection oximetry technique designed with small semiconductor lasers and a silicon photodiode. The light used for monitoring system comes from two semiconductor diode lasers of 650 nm and 940 nm wavelengths. The two lasers and the photodiode are mounted onto a small package which is to be imprinted onto a balloon catheter containing the PDT light delivery system. Lasers and the photodiode are powered and controlled by a control box that is connected via a cable. Light sources and the respective photodiode output are controlled by the LabVIEW virtual instrumentation. The sequential on and off light source and the respective reflective signal are processed with MATLAB. The latter code integrates with LabVIEW to make an automatic calculation of the corresponding light absorption by each chromophore and to calculate the change in oxygen level as well as the amount of blood and oxygen present in the treatment area. The designed system is capable of monitoring the change in oxygen level and the blood flow in any part of the human body where the

Iontophoresis: A Potential Emergence of a Transdermal Drug Delivery System

Science.gov (United States)

Dhote, Vinod; Bhatnagar, Punit; Mishra, Pradyumna K.; Mahajan, Suresh C.; Mishra, Dinesh K.

2012-01-01

The delivery of drugs into systemic circulation via skin has generated much attention during the last decade. Transdermal therapeutic systems propound controlled release of active ingredients through the skin and into the systemic circulation in a predictive manner. Drugs administered through these systems escape first-pass metabolism and maintain a steady state scenario similar to a continuous intravenous infusion for up to several days. However, the excellent impervious nature of the skin offers the greatest challenge for successful delivery of drug molecules by utilizing the concepts of iontophoresis. The present review deals with the principles and the recent innovations in the field of iontophoretic drug delivery system together with factors affecting the system. This delivery system utilizes electric current as a driving force for permeation of ionic and non-ionic medications. The rationale behind using this technique is to reversibly alter the barrier properties of skin, which could possibly improve the penetration of drugs such as proteins, peptides and other macromolecules to increase the systemic delivery of high molecular weight compounds with controlled input kinetics and minimum inter-subject variability. Although iontophoresis seems to be an ideal candidate to overcome the limitations associated with the delivery of ionic drugs, further extrapolation of this technique is imperative for translational utility and mass human application. PMID:22396901

Delivery systems for antimicrobial peptides

DEFF Research Database (Denmark)

Nordström, Randi; Malmsten, Martin

2017-01-01

Due to rapidly increasing resistance development against conventional antibiotics, finding novel approaches for the treatment of infections has emerged as a key health issue. Antimicrobial peptides (AMPs) have attracted interest in this context, and there is by now a considerable literature...... on the identification such peptides, as well as on their optimization to reach potent antimicrobial and anti-inflammatory effects at simultaneously low toxicity against human cells. In comparison, delivery systems for antimicrobial peptides have attracted considerably less interest. However, such delivery systems...... are likely to play a key role in the development of potent and safe AMP-based therapeutics, e.g., through reducing chemical or biological degradation of AMPs either in the formulation or after administration, by reducing adverse side-effects, by controlling AMP release rate, by promoting biofilm penetration...

[Formulation aspects and ex-vivo examination of buccal drug delivery systems].

Science.gov (United States)

Szabó, Barnabás; Hetényi, Gergely; Majoros, Klaudia; Miszori, Veronika; Kállai, Nikolett; Zelkó, Romána

2011-01-01

Application of buccal dosage forms has several advantages. Buccal route can be used for systemic delivery because the mucosa has a rich blood supply and it is relatively permeable. This route of drug delivery is of special advantages, including the bypass of first pass effect and the avoidance of presystemic elimination within the GIT. Buccal delivery systems enable the systemic delivery of peptides and proteins. In our previous study the physiological background of this application and the excipients of the possible formulations were reviewed. In the present work the formulation and ex vivo examination aspects of buccal drug delivery systems are summarized.

Oxygen Compatibility of Brass-Filled PTFE Compared to Commonly Used Fluorinated Polymers for Oxygen Systems

Science.gov (United States)

Herald, Stephen D.; Frisby, Paul M.; Davis, Samuel Eddie

2009-01-01

Safe and reliable seal materials for high-pressure oxygen systems sometimes appear to be extinct species when sought out by oxygen systems designers. Materials that seal well are easy to find, but these materials are typically incompatible with oxygen, especially in cryogenic liquid form. This incompatibility can result in seals that leak, or much worse, seals that easily ignite and burn during use. Materials that are compatible with oxygen are easy to find, such as the long list of compatible metals, but these metallic materials are limiting as seal materials. A material that seals well and is oxygen compatible has been the big game in the designer's safari. Scientists at the Materials Combustion Research Facility (MCRF), part of NASA/Marshall Space Flight Center (MSFC), are constantly searching for better materials and processes to improve the safety of oxygen systems. One focus of this effort is improving the characteristics of polymers used in the presence of an oxygen enriched environment. Very few systems can be built which contain no polymeric materials; therefore, materials which have good impact resistance, low heat of combustion, high auto-ignition temperature and that maintain good mechanical properties are essential. The scientists and engineers at the Materials Combustion Research Facility, in cooperation with seal suppliers, are currently testing a new formulation of polytetrafluoroethylene (PTFE) with Brass filler. This Brass-filled PTFE is showing great promise as a seal and seat material for high pressure oxygen systems. Early research has demonstrated very encouraging results, which could rank this material as one of the best fluorinated polymers ever tested. This paper will compare the data obtained for Brass-filled PTFE with other fluorinated polymers, such as TFE-Teflon (PTFE) , Kel-F 81, Viton A, Viton A-500, Fluorel , and Algoflon . A similar metal filled fluorinated polymer, Salox-M , was tested in comparison to Brass-filled PTFE to

A REVIEW ON OSMOTIC DRUG DELIVERY SYSTEM

OpenAIRE

Harnish Patel; Upendra Patel; Hiren Kadikar; Bhavin Bhimani; Dhiren Daslaniya; Ghanshyam Patel

2012-01-01

Conventional oral drug delivery systems supply an instantaneous release of drug, which cannot control the release of the drug and effective concentration at the target site. This kind of dosing pattern may result in constantly changing, unpredictable plasma concentrations. Drugs can be delivered in a controlled pattern over a long period of time by the process of osmosis. Osmotic devices are the most promising strategy based systems for controlled drug delivery. They are the most reliable con...

Oxygen therapy reduces postoperative tachycardia

DEFF Research Database (Denmark)

Stausholm, K; Kehlet, H; Rosenberg, J

1995-01-01

Concomitant hypoxaemia and tachycardia in the postoperative period is unfavourable for the myocardium. Since hypoxaemia per se may be involved in the pathogenesis of postoperative tachycardia, we have studied the effect of oxygen therapy on tachycardia in 12 patients randomly allocated to blinded...... air or oxygen by facemask on the second or third day after major surgery. Inclusion criteria were arterial hypoxaemia (oxygen saturation 90 beat.min-1). Each patient responded similarly to oxygen therapy: an increase in arterial oxygen saturation and a decrease...... in heart rate (p oxygen has a positive effect on the cardiac oxygen delivery and demand balance....

Drug delivery systems and materials for wound healing applications.

Science.gov (United States)

Saghazadeh, Saghi; Rinoldi, Chiara; Schot, Maik; Kashaf, Sara Saheb; Sharifi, Fatemeh; Jalilian, Elmira; Nuutila, Kristo; Giatsidis, Giorgio; Mostafalu, Pooria; Derakhshandeh, Hossein; Yue, Kan; Swieszkowski, Wojciech; Memic, Adnan; Tamayol, Ali; Khademhosseini, Ali

2018-04-05

Chronic, non-healing wounds place a significant burden on patients and healthcare systems, resulting in impaired mobility, limb amputation, or even death. Chronic wounds result from a disruption in the highly orchestrated cascade of events involved in wound closure. Significant advances in our understanding of the pathophysiology of chronic wounds have resulted in the development of drugs designed to target different aspects of the impaired processes. However, the hostility of the wound environment rich in degradative enzymes and its elevated pH, combined with differences in the time scales of different physiological processes involved in tissue regeneration require the use of effective drug delivery systems. In this review, we will first discuss the pathophysiology of chronic wounds and then the materials used for engineering drug delivery systems. Different passive and active drug delivery systems used in wound care will be reviewed. In addition, the architecture of the delivery platform and its ability to modulate drug delivery are discussed. Emerging technologies and the opportunities for engineering more effective wound care devices are also highlighted. Copyright © 2018 Elsevier B.V. All rights reserved.

Improvement of different vaccine delivery systems for cancer therapy

Directory of Open Access Journals (Sweden)

Safaiyan Shima

2011-01-01

Full Text Available Abstract Cancer vaccines are the promising tools in the hands of the clinical oncologist. Many tumor-associated antigens are excellent targets for immune therapy and vaccine design. Optimally designed cancer vaccines should combine the best tumor antigens with the most effective immunotherapy agents and/or delivery strategies to achieve positive clinical results. Various vaccine delivery systems such as different routes of immunization and physical/chemical delivery methods have been used in cancer therapy with the goal to induce immunity against tumor-associated antigens. Two basic delivery approaches including physical delivery to achieve higher levels of antigen production and formulation with microparticles to target antigen-presenting cells (APCs have demonstrated to be effective in animal models. New developments in vaccine delivery systems will improve the efficiency of clinical trials in the near future. Among them, nanoparticles (NPs such as dendrimers, polymeric NPs, metallic NPs, magnetic NPs and quantum dots have emerged as effective vaccine adjuvants for infectious diseases and cancer therapy. Furthermore, cell-penetrating peptides (CPP have been known as attractive carrier having applications in drug delivery, gene transfer and DNA vaccination. This review will focus on the utilization of different vaccine delivery systems for prevention or treatment of cancer. We will discuss their clinical applications and the future prospects for cancer vaccine development.

Estimating oxygen needs for childhood pneumonia in developing country health systems: a new model for expecting the unexpected.

Directory of Open Access Journals (Sweden)

Beverly D Bradley

Full Text Available Planning for the reliable and cost-effective supply of a health service commodity such as medical oxygen requires an understanding of the dynamic need or 'demand' for the commodity over time. In developing country health systems, however, collecting longitudinal clinical data for forecasting purposes is very difficult. Furthermore, approaches to estimating demand for supplies based on annual averages can underestimate demand some of the time by missing temporal variability.A discrete event simulation model was developed to estimate variable demand for a health service commodity using the important example of medical oxygen for childhood pneumonia. The model is based on five key factors affecting oxygen demand: annual pneumonia admission rate, hypoxaemia prevalence, degree of seasonality, treatment duration, and oxygen flow rate. These parameters were varied over a wide range of values to generate simulation results for different settings. Total oxygen volume, peak patient load, and hours spent above average-based demand estimates were computed for both low and high seasons.Oxygen demand estimates based on annual average values of demand factors can often severely underestimate actual demand. For scenarios with high hypoxaemia prevalence and degree of seasonality, demand can exceed average levels up to 68% of the time. Even for typical scenarios, demand may exceed three times the average level for several hours per day. Peak patient load is sensitive to hypoxaemia prevalence, whereas time spent at such peak loads is strongly influenced by degree of seasonality.A theoretical study is presented whereby a simulation approach to estimating oxygen demand is used to better capture temporal variability compared to standard average-based approaches. This approach provides better grounds for health service planning, including decision-making around technologies for oxygen delivery. Beyond oxygen, this approach is widely applicable to other areas of

Sorbent-based Oxygen Production for Energy Systems

Energy Technology Data Exchange (ETDEWEB)

Sethi, Vijay [Western Research Inst. (WRI), Laramie, WY (United States)

2017-01-31

Project DE-FE0024075 deals with the development of a moderate-temperature sorbent-based oxygen production technology. Sorbent-based oxygen production process utilizes oxygen-storage properties of Perovskites to (1) adsorb oxygen from air in a solid sorbent, and (2) release the adsorbed oxygen into a sweep gas such as CO₂ and/or steam for gasification systems or recycled flue gas for oxy-combustion systems. Pure oxygen can be produced by the use of vacuum instead of a sweep gas to affect the pressure swing. By developing more efficient and stable, higher sorption capacity, newer class of materials operating at moderate temperatures this process represents a major advancement in air separation technology. Newly developed perovskite ceramic sorbent materials with order-disorder transition have a higher O₂ adsorption capacity, potentially 200 °C lower operating temperatures, and up to two orders of magnitude faster desorption rates than those used in earlier development efforts. The performance advancements afforded by the new materials lead to substantial savings in capital investment and operational costs. Cost of producing oxygen using sorbents could be as much as 26% lower than VPSA and about 13% lower than a large cryogenic air separation unit. Cost advantage against large cryogenic separation is limited because sorbent-based separation numbers up sorbent modules for achieving the larger capacity.

Comprehensive evaluation of carboxylated nanodiamond as a topical drug delivery system

Directory of Open Access Journals (Sweden)

Lim DG

2016-05-01

Full Text Available Dae Gon Lim,1,* Ki Hyun Kim,1,* Eunah Kang,2 Sun Hee Lim,3 Jeremy Ricci,3 Si Kwon Sung,3 Myoung Taek Kwon,3 Seong Hoon Jeong1 1College of Pharmacy, Dongguk University-Seoul, Gyeonggi, 2School of Chemical Engineering and Material Science, Chung-Ang University, 3NanoResource Co. Ltd., Seoul, Republic of Korea *These authors contributed equally to this work Abstract: The best strategy in the development of topical drug delivery systems may be to facilitate the permeation of drugs without any harmful effects, while staying on the skin surface and maintaining stability of the system. Nanodiamonds (NDs play a key role with their excellent physicochemical properties, including high biocompatibility, physical adsorption, reactive oxygen species (ROS scavenging capability, and photostabilizing activity. Z-average sizes of carboxylated ND (ND–COOH agglutinate decreased significantly as the pH increased. Fluorescein-conjugated ND was observed only on the stratum corneum, and no sample diffused into the dermal layer even after 48 hours. Moreover, ND–COOH and ND–COOH/eugenol complex did not show significant toxic effects on murine macrophage cells. ND improved in vitro skin permeation >50% acting as a “drug reservoir” to maintain a high drug concentration in the donor chamber, which was supported by quartz crystal microbalance results. Moreover, ND–COOH could adsorb a drug amount equivalent to 80% of its own weight. A photostability study showed that ND–COOH increased the photostability ~47% with regard to rate constant of the eugenol itself. A significant decrease in ROS was observed in the ND–COOH and ND–COOH/eugenol complex compared with the negative control during intracellular ROS assay. Moreover, ROS and cupric reducing antioxidant capacity evaluation showed that ND–COOH had synergistic effects of antioxidation with eugenol. Therefore, ND–COOH could be used as an excellent topical drug delivery system with improved permeability

Oral controlled release drug delivery system and Characterization of oral tablets; A review

Directory of Open Access Journals (Sweden)

Muhammad Zaman

2016-01-01

Full Text Available Oral route of drug administration is considered as the safest and easiest route of drug administration. Control release drug delivery system is the emerging trend in the pharmaceuticals and the oral route is most suitable for such kind of drug delivery system. Oral route is more convenient for It all age group including both pediatric and geriatrics. There are various systems which are adopted to deliver drug in a controlled manner to different target sites through oral route. It includes diffusion controlled drug delivery systems; dissolution controlled drug delivery systems, osmotically controlled drug delivery systems, ion-exchange controlled drug delivery systems, hydrodynamically balanced systems, multi-Particulate drug delivery systems and microencapsulated drug delivery system. The systems are formulated using different natural, semi-synthetic and synthetic polymers. The purpose of the review is to provide information about the orally controlled drug delivery system, polymers which are used to formulate these systems and characterizations of one of the most convenient dosage form which is the tablets. 

Broadly Applicable Nanowafer Drug Delivery System for Treating Eye Injuries

Science.gov (United States)

2015-09-01

Systems in Systemic , Dermal, Transdermal , and Ocular Drug Delivery . Crit. Rev. Ther. Drug 2008, 25, 545–584. 14. Choy, Y. B.; Park, J.-H.; McCarey, B...AWARD NUMBER: W81XWH-13-1-0146 TITLE: Broadly Applicable Nanowafer Drug Delivery System for Treating Eye Injuries PRINCIPAL INVESTIGATOR: Dr...Broadly Applicable Nanowafer Drug Delivery System for Treating Eye Injuries” 5b. GRANT NUMBER W81XWH-13-1-0146 5c. PROGRAM ELEMENT NUMBER 6

Chitosan microspheres in novel drug delivery systems.

Science.gov (United States)

Mitra, Analava; Dey, Baishakhi

2011-07-01

The main aim in the drug therapy of any disease is to attain the desired therapeutic concentration of the drug in plasma or at the site of action and maintain it for the entire duration of treatment. A drug on being used in conventional dosage forms leads to unavoidable fluctuations in the drug concentration leading to under medication or overmedication and increased frequency of dose administration as well as poor patient compliance. To minimize drug degradation and loss, to prevent harmful side effects and to increase drug bioavailability various drug delivery and drug targeting systems are currently under development. Handling the treatment of severe disease conditions has necessitated the development of innovative ideas to modify drug delivery techniques. Drug targeting means delivery of the drug-loaded system to the site of interest. Drug carrier systems include polymers, micelles, microcapsules, liposomes and lipoproteins to name some. Different polymer carriers exert different effects on drug delivery. Synthetic polymers are usually non-biocompatible, non-biodegradable and expensive. Natural polymers such as chitin and chitosan are devoid of such problems. Chitosan comes from the deacetylation of chitin, a natural biopolymer originating from crustacean shells. Chitosan is a biocompatible, biodegradable, and nontoxic natural polymer with excellent film-forming ability. Being of cationic character, chitosan is able to react with polyanions giving rise to polyelectrolyte complexes. Hence chitosan has become a promising natural polymer for the preparation of microspheres/nanospheres and microcapsules. The techniques employed to microencapsulate with chitosan include ionotropic gelation, spray drying, emulsion phase separation, simple and complex coacervation. This review focuses on the preparation, characterization of chitosan microspheres and their role in novel drug delivery systems.

The vanadium/oxygen system in the analysis of sodium for oxygen

International Nuclear Information System (INIS)

Walker, J.A.J.; Price, W.B.

1981-05-01

An investigation of the V-O-Na system at 1023 K is described for oxygen in sodium contents of 5 to 25 ppm. Electron spectroscopy combined with depth profiling is used to determine the vanadium/oxygen ratios inwards from the surface of vanadium foil and these ratios are compared with theoretical predictions. The validity of the vanadium wire technique as an analytical method is examined and a model for the vanadium oxidation is suggested. (author)

Renewable energy delivery systems and methods

Science.gov (United States)

Walker, Howard Andrew

2013-12-10

A system, method and/or apparatus for the delivery of energy at a site, at least a portion of the energy being delivered by at least one or more of a plurality of renewable energy technologies, the system and method including calculating the load required by the site for the period; calculating the amount of renewable energy for the period, including obtaining a capacity and a percentage of the period for the renewable energy to be delivered; comparing the total load to the renewable energy available; and, implementing one or both of additional and alternative renewable energy sources for delivery of energy to the site.

Injectable In-Situ Gelling Controlled Release Drug Delivery System

OpenAIRE

Kulwant Singh; S. L. HariKumar

2012-01-01

The administration of poorly bioavailable drug through parenteral route is regarded the most efficient for drug delivery. Parenteral delivery provides rapid onset even for the drug with narrow therapeutic window, but to maintain the systemic drug level repeated installation are required which cause the patient discomfort. This can be overcome by designing the drug into a system, which control the drug release even through parenteral delivery, which improve patient compliance as well as pharma...

Kinetic of the Oxygen Control System (OCS) for stagnant lead-bismuth systems

International Nuclear Information System (INIS)

Lefhalm, C.H.; Knebel, J.U.; Mack, K.J.

2001-09-01

Within the framework of the HGF strategy fund project 99/16 ''Thermalhydraulic and Material Specific Investigations into the Realization of an accelerator driven system (ADS) to Transmute Minor Actinides'' at the institute for nuclear and energy technology (IKET) investigations on the cooling of thermally high-loaded surfaces with liquid lead bismuth (Pb-Bi) are carried out. To operate a Pb-Bi loop safety, for example in order to cool a spallation target or a blanket of an accelerator driven system (ADS), the control of the oxygen concentration within the liquid metal is an inalienable prerequisite to prevent or minimize corrosion at the structure material. In this report the kinetic behaviour of the oxygen control system (OCS), which was developed at Forschungszentrum Karlsruhe, is examined. The OCS controls the chemical potential of oxygen in the liquid metal by regulating the oxygen content in the gas phase which flows over the free surface of the liquid metal. In this work the experimental facility KOCOS (kinetics of oxygen control system) in the karlsruhe lead laboratory (KALLA) was built. A physical diffusion model was utilised and extended to describe the exchange of oxygen between the gas and the liquid metal. The theoretical calculations are in very good agreement to the experimental findings. The OCS allows to control reversibly the oxygen concentration in the liquid metal. According to the observed kinetics of the process one can extrapolate that the control of large volumes, as they are necessary to operate an ADS demonstrator, is possible. Therefore, further experiments in liquid metal loop systems are suggested. (orig.)

Handheld Delivery System for Modified Boron-Type Fire Extinguishment Agent

Science.gov (United States)

1993-11-01

was to develop and test a handheld portable delivery system for use with the modified boron-type fire extinguishing agent for metal fires . B...BACKGROUND A need exists for an extinguishing agent and accompanying delivery system that are effective against complex geometry metal fires . A modified...agent and its delivery system have proven effective against complex geometry metal fires containing up to 200 pounds of magnesium metal. Further

[Domiciliary oxygen therapy].

Science.gov (United States)

Abdel Kafi, S

2010-09-01

In Belgium, oxygen therapy is becoming more and more accessible. When oxygen is needed for short periods or for special indications as palliative care, an agreement between mutual insurance companies and pharmacists allows the practitioner the home installation of gazeous oxygen cylinder or of oxygen concentrator. When long term oxygen therapy (LTOT) is indicated for patients with respiratory insufficiency, the pneumologist must first ask the INAMI the authorization to install one of the following modalities: oxygen concentrator with or without demand oxygen delivery cylinder and liquid oxygen. The goal of LTOT is to increase survival and quality of life. The principal and well accepted indication for LTOT is severe hypoxemia. The beneficial effects of oxygen therapy limited at night or on exertion are controversial. In order to increase patient's autonomy, oxygen can be prescribed for ambulation, respecting prescription's rules. At each step of oxygen therapy implementing (indication, choice of the device and follow-up) the patient under oxygen may benefit from a joint approach between the general practitioner and the chest specialist.

Characterization of particulate drug delivery systems for oral delivery of Peptide and protein drugs

DEFF Research Database (Denmark)

Christophersen, Philip Carsten; Fano, Mathias; Saaby, Lasse

2015-01-01

Oral drug delivery is a preferred route because of good patient compliance. However, most peptide/ protein drugs are delivered via parenteral routes because of the absorption barriers in the gastrointestinal (GI) tract such as enzymatic degradation by proteases and low permeability acrossthe...... delivery of peptide/protein drugs and to provide an overview of formulationand characterization strategies. For a better understanding of the challenges in oral delivery of peptide/protein drugs, the composition of GI fluids and the digestion processes of different kinds of excipients in the GI tract...... biological membranes. To overcome these barriers, different formulation strategies for oral delivery of biomacromolecules have been proposed, including lipid based formulations and polymer-based particulate drug delivery systems (DDS). The aim of this review is to summarize the existing knowledge about oral...

Controlled drug delivery systems towards new frontiers in patient care

CERN Document Server

Rossi, Filippo; Masi, Maurizio

2016-01-01

This book offers a state-of-the-art overview of controlled drug delivery systems, covering the most important innovative applications. The principles of controlled drug release and the mechanisms involved in controlled release are clearly explained. The various existing polymeric drug delivery systems are reviewed, and new frontiers in material design are examined in detail, covering a wide range of polymer modification techniques. The concluding chapter is a case study focusing on use of a drug-eluting stent. The book is designed to provide the reader with a complete understanding of the mechanisms and design of controlled drug delivery systems, and to this end includes numerous step-by-step tutorials. It illustrates how chemical engineers can advance medical care by designing polymeric delivery systems that achieve either temporal or spatial control of drug delivery and thus ensure more effective therapy that eliminates the potential for both under-and overdosing.

Printing technologies in fabrication of drug delivery systems.

Science.gov (United States)

Kolakovic, Ruzica; Viitala, Tapani; Ihalainen, Petri; Genina, Natalja; Peltonen, Jouko; Sandler, Niklas

2013-12-01

There has been increased activity in the field recently regarding the development and research on various printing techniques in fabrication of dosage forms and drug delivery systems. These technologies may offer benefits and flexibility in manufacturing, potentially paving the way for personalized dosing and tailor-made dosage forms. In this review, the most recent observations and advancements in fabrication of drug delivery systems by utilizing printing technologies are summarized. A general overview of 2D printing techniques is presented including a review of the most recent literature where printing techniques are used in fabrication of drug delivery systems. The future perspectives and possible impacts on formulation strategies, flexible dosing and personalized medication of using printing techniques for fabrication of drug delivery systems are discussed. It is evident that there is an urgent need to meet the challenges of rapidly growing trend of personalization of medicines through development of flexible drug-manufacturing approaches. In this context, various printing technologies, such as inkjet and flexography, can play an important role. Challenges on different levels exist and include: i) technological development of printers and production lines; ii) printable formulations and carrier substrates; iii) quality control and characterization; and iv) regulatory perspectives.

Model for determining and optimizing delivery performance in industrial systems

Directory of Open Access Journals (Sweden)

Fechete Flavia

2017-01-01

Full Text Available Performance means achieving organizational objectives regardless of their nature and variety, and even overcoming them. Improving performance is one of the major goals of any company. Achieving the global performance means not only obtaining the economic performance, it is a must to take into account other functions like: function of quality, delivery, costs and even the employees satisfaction. This paper aims to improve the delivery performance of an industrial system due to their very low results. The delivery performance took into account all categories of performance indicators, such as on time delivery, backlog efficiency or transport efficiency. The research was focused on optimizing the delivery performance of the industrial system, using linear programming. Modeling the delivery function using linear programming led to obtaining precise quantities to be produced and delivered each month by the industrial system in order to minimize their transport cost, satisfying their customers orders and to control their stock. The optimization led to a substantial improvement in all four performance indicators that concern deliveries.

Servir: an automated document delivery system

International Nuclear Information System (INIS)

Lima, E.C.; Azevedo Coutinho, O.C. de

1986-01-01

SERVIR, an automated document delivery system developed by CIN/CNEN, is described. Parametric procedures for reading bibliographic data bases and requesting documents from libraries through computer are specified. Statistical procedures, accounting system and the on-line fulfillment of requests are presented. (Author) [pt

Recent trends in drug delivery system using protein nanoparticles.

Science.gov (United States)

Sripriyalakshmi, S; Jose, Pinkybel; Ravindran, Aswathy; Anjali, C H

2014-09-01

Engineered nanoparticles that can facilitate drug formulation and passively target tumours have been under extensive research in recent years. These successes have driven a new wave of significant innovation in the generation of advanced particles. The fate and transport of diagnostic nanoparticles would significantly depend on nonselective drug delivery, and hence the use of high drug dosage is implemented. In this perspective, nanocarrier-based drug targeting strategies can be used which improve the selective delivery of drugs to the site of action, i.e. drug targeting. Pharmaceutical industries majorly focus on reducing the toxicity and side effects of drugs but only recently it has been realised that carrier systems themselves may pose risks to the patient. Proteins are compatible with biological systems and they are biodegradable. They offer a multitude of moieties for modifications to tailor drug binding, imaging or targeting entities. Thus, protein nanoparticles provide outstanding contributions as a carrier for drug delivery systems. This review summarises recent progress in particle-based therapeutic delivery and discusses important concepts in particle design and biological barriers for developing the next generation of particles drug delivery systems.

Grizzli mobile systems and LPG delivery management; Grizzli mobile systems

Energy Technology Data Exchange (ETDEWEB)

Anon.

2000-07-01

Complete text of publication follows: Grizzli Mobile Systems (and its sister companies) specialists in data communications and system solutions, offer their complete management solution for LPG deliveries, right through from remote reading of the gas level in the tank, through route management, management of the delivery itself and finally on-site invoicing and payment. The system permits a supplier to really differentiate itself from its competitors in terms of customer service and control of its operations. Domestic gas tanks are often difficult to access; visual reading of the gauge is not always easy and often leads to the customer re-ordering in panic mode. The supplier has also to react in panic mode to the customer. Grizzli Mobile Systems has developed a radio module that is fitted to the gas tank that calls, at regular set intervals with the tank level to a Call Rider gateway plug. The Call Rider is a small box plugged into the regular telephone socket (also supplying multiple operator telephony and other home automation services). As soon as the gas level reaches a predetermined minimum level, this radio information is relayed via the Internet to the LPG supplier. The supplier can then arrange (in non-panic mode) to deliver gas to the customer, via conventional means or by use of an interactive radio display (attached to a refrigerator or similar by magnets) that communicates with the Call Rider by radio. Once a delivery date has been set, a Grizzli Mobile Systems' dispatch system, installed at the supplier's headquarters creates and transfers routes via GSM communications to its fleet of delivery vehicles. A main-frame mapping software provides real-time follow-up and status checks of the vehicles using the GPS functionality and imports data back from the vehicles and updates databases. The driver is also assisted in localizing delivery sites. Inside the cabin of the vehicle the driver has available a Fujitsu PenCentra pen computer, a Microsoft

A Novel Nonviral Gene Delivery System: Multifunctional Envelope-Type Nano Device

Science.gov (United States)

Hatakeyama, Hiroto; Akita, Hidetaka; Kogure, Kentaro; Harashima, Hideyoshi

In this review we introduce a new concept for developing a nonviral gene delivery system which we call "Programmed Packaging." Based on this concept, we succeeded in developing a multifunctional envelope-type nano device (MEND), which exerts high transfection activities equivalent to those of an adenovirus in a dividing cell. The use of MEND has been extended to in vivo applications. PEG/peptide/DOPE ternary conjugate (PPD)-MEND, a new in vivo gene delivery system for the targeting of tumor cells that dissociates surface-modified PEG in tumor tissue by matrix metalloproteinase (MMP) and exerts significant transfection activities, was developed. In parallel with the development of MEND, a quantitative gene delivery system, Confocal Image-assisted 3-dimensionally integrated quantification (CIDIQ), also was developed. This method identified the rate-limiting step of the nonviral gene delivery system by comparing it with adenoviral-mediated gene delivery. The results of this analysis provide a new direction for the development of rational nonviral gene delivery systems.

Guidelines for Psychological Practice in Health Care Delivery Systems

Science.gov (United States)

American Psychologist, 2013

2013-01-01

Psychologists practice in an increasingly diverse range of health care delivery systems. The following guidelines are intended to assist psychologists, other health care providers, administrators in health care delivery systems, and the public to conceptualize the roles and responsibilities of psychologists in these diverse contexts. These…

Performance of Regolith Feed Systems for Analog Field Tests of In-Situ Resource Utilization Oxygen Production Plants in Mauna Kea, Hawaii

Science.gov (United States)

Townsend, Ivan I.; Mueller, Robert P.; Mantovani, James G.; Zacny, Kris A.; Craft, Jack

2010-01-01

This paper focuses on practical aspects of mechanical auger and pneumatic regolith conveying system feeding In-Situ Resource Utilization Oxygen production plants. The subsystems of these feedstock delivery systems include an enclosed auger device, pneumatic venturi educator, jet-lift regolith transfer, innovative electro-cyclone gas-particle separation/filtration systems, and compressors capable of dealing with hot hydrogen and/or methane gas re-circulating in the system. Lessons learned from terrestrial laboratory, reduced gravity and field testing on Mauna Kea Volcano in Hawaii during NASA lunar analog field tests will be discussed and practical design tips will be presented.

A mucoadhesive in situ gel delivery system for paclitaxel

OpenAIRE

Jauhari, Saurabh; Dash, Alekha K.

2006-01-01

MUC1 gene encodes a transmembrane mucin glycoprotein that is overexpressed in human breast cancer and colon cancer. The objective of this study was to develop an in situ gel delivery system containing paclitaxel (PTX) and mucoadhesives for sustained and targeted delivery of anticancer drugs. The delivery system consisted of chitosan and glyceryl monooleate (GMO) in 0.33M citric acid containing PTX. The in vitro release of PTX from the gel was performed in presence and absence of Tween 80 at d...

Interpenetrating Polymer Networks as Innovative Drug Delivery Systems

Directory of Open Access Journals (Sweden)

Alka Lohani

2014-01-01

Full Text Available Polymers have always been valuable excipients in conventional dosage forms, also have shown excellent performance into the parenteral arena, and are now capable of offering advanced and sophisticated functions such as controlled drug release and drug targeting. Advances in polymer science have led to the development of several novel drug delivery systems. Interpenetrating polymer networks (IPNs have shown superior performances over the conventional individual polymers and, consequently, the ranges of applications have grown rapidly for such class of materials. The advanced properties of IPNs like swelling capacity, stability, biocompatibility, nontoxicity and biodegradability have attracted considerable attention in pharmaceutical field especially in delivering bioactive molecules to the target site. In the past few years various research reports on the IPN based delivery systems showed that these carriers have emerged as a novel carrier in controlled drug delivery. The present review encompasses IPNs, their types, method of synthesis, factors which affects the morphology of IPNs, extensively studied IPN based drug delivery systems, and some natural polymers widely used for IPNs.

Biomaterial-based drug delivery systems for the controlled release of neurotrophic factors

International Nuclear Information System (INIS)

Mohtaram, Nima Khadem; Montgomery, Amy; Willerth, Stephanie M

2013-01-01

This review highlights recent work on the use of biomaterial-based drug delivery systems to control the release of neurotrophic factors as a potential strategy for the treatment of neurological disorders. Examples of neurotrophic factors include the nerve growth factor, the glial cell line-derived neurotrophic factor, the brain-derived neurotrophic factor and neurotrophin-3. In particular, this review focuses on two methods of drug delivery: affinity-based and reservoir-based systems. We review the advantages and challenges associated with both types of drug delivery system and how these systems can be applied to neurological diseases and disorders. While a limited number of affinity-based delivery systems have been developed for the delivery of neurotrophic factors, we also examine the broad spectrum of reservoir-based delivery systems, including microspheres, electrospun nanofibers, hydrogels and combinations of these systems. Finally, conclusions are drawn about the current state of such drug delivery systems as applied to neural tissue engineering along with some thoughts on the future direction of the field. (topical review)

Hybrid membrane--PSA system for separating oxygen from air

Science.gov (United States)

Staiger, Chad L [Albuquerque, NM; Vaughn, Mark R [Albuquerque, NM; Miller, A Keith [Albuquerque, NM; Cornelius, Christopher J [Blackburg, VA

2011-01-25

A portable, non-cryogenic, oxygen generation system capable of delivering oxygen gas at purities greater than 98% and flow rates of 15 L/min or more is described. The system consists of two major components. The first component is a high efficiency membrane capable of separating argon and a portion of the nitrogen content from air, yielding an oxygen-enriched permeate flow. This is then fed to the second component, a pressure swing adsorption (PSA) unit utilizing a commercially available, but specifically formulated zeolite compound to remove the remainder of the nitrogen from the flow. The system is a unique gas separation system that can operate at ambient temperatures, for producing high purity oxygen for various applications (medical, refining, chemical production, enhanced combustion, fuel cells, etc . . . ) and represents a significant advance compared to current technologies.

[Monitorization of the effects of spinal anaesthesia on cerebral oxygen saturation in elder patients using near-infrared spectroscopy].

Science.gov (United States)

Kusku, Aysegul; Demir, Guray; Cukurova, Zafer; Eren, Gulay; Hergunsel, Oya

2014-01-01

Central blockage provided by spinal anaesthesia enables realization of many surgical procedures, whereas hemodynamic and respiratory changes influence systemic oxygen delivery leading to the potential development of series of problems such as cerebral ischemia, myocardial infarction and acute renal failure. This study was intended to detect potentially adverse effects of hemodynamic and respiratory changes on systemic oxygen delivery using cerebral oxymetric methods in patients who underwent spinal anaesthesia. Twenty-five ASA I-II Group patients aged 65-80 years scheduled for unilateral inguinal hernia repair under spinal anaesthesia were included in the study. Following standard monitorization baseline cerebral oxygen levels were measured using cerebral oximetric methods. Standardized Mini Mental Test (SMMT) was applied before and after the operation so as to determine the level of cognitive functioning of the cases. Using a standard technique and equal amounts of a local anaesthetic drug (15mg bupivacaine 5%) intratechal blockade was performed. Mean blood pressure (MBP), maximum heart rate (MHR), peripheral oxygen saturation (SpO2) and cerebral oxygen levels (rSO2) were preoperatively monitored for 60min. Pre- and postoperative haemoglobin levels were measured. The variations in data obtained and their correlations with the cerebral oxygen levels were investigated. Significant changes in pre- and postoperative measurements of haemoglobin levels and SMMT scores and intraoperative SpO2 levels were not observed. However, significant variations were observed in intraoperative MBP, MHR and rSO2 levels. Besides, a correlation between variations in rSO2, MBP and MHR was determined. Evaluation of the data obtained in the study demonstrated that post-spinal decline in blood pressure and also heart rate decreases systemic oxygen delivery and adversely effects cerebral oxygen levels. However, this downward change did not result in deterioration of cognitive functioning

Monitorization of the effects of spinal anaesthesia on cerebral oxygen saturation in elder patients using near-infrared spectroscopy.

Science.gov (United States)

Kusku, Aysegul; Demir, Guray; Cukurova, Zafer; Eren, Gulay; Hergunsel, Oya

2014-01-01

Central blockage provided by spinal anaesthesia enables realization of many surgical procedures, whereas hemodynamic and respiratory changes influence systemic oxygen delivery leading to the potential development of series of problems such as cerebral ischemia, myocardial infarction and acute renal failure. This study was intended to detect potentially adverse effects of hemodynamic and respiratory changes on systemic oxygen delivery using cerebral oxymetric methods in patients who underwent spinal anaesthesia. Twenty-five ASA I-II Group patients aged 65-80 years scheduled for unilateral inguinal hernia repair under spinal anaesthesia were included in the study. Following standard monitorization baseline cerebral oxygen levels were measured using cerebral oximetric methods. Standardized Mini Mental Test (SMMT) was applied before and after the operation so as to determine the level of cognitive functioning of the cases. Using a standard technique and equal amounts of a local anaesthetic drug (15mg bupivacaine 5%) intratechal blockade was performed. Mean blood pressure (MBP), maximum heart rate (MHR), peripheral oxygen saturation (SpO2) and cerebral oxygen levels (rSO2) were preoperatively monitored for 60min. Pre- and postoperative haemoglobin levels were measured. The variations in data obtained and their correlations with the cerebral oxygen levels were investigated. Significant changes in pre- and postoperative measurements of haemoglobin levels and SMMT scores and intraoperative SpO2 levels were not observed. However, significant variations were observed in intraoperative MBP, MHR and rSO2 levels. Besides, a correlation between variations in rSO2, MBP and MHR was determined. Evaluation of the data obtained in the study demonstrated that post-spinal decline in blood pressure and also heart rate decreases systemic oxygen delivery and adversely effects cerebral oxygen levels. However, this downward change did not result in deterioration of cognitive functioning

Oxygen-hydrogen recombination system

International Nuclear Information System (INIS)

Sato, Shuichiro; Takejima, Masaki.

1981-01-01

Purpose: To avoid reduction in the performance of catalyst used for an oxygen-hydrogen recombiner in the off gas processing system of a nuclear reactor. Constitution: A thermometer is provided for the detection of temperature in an oxygen-hydrogen recombiner. A cooling pipe is provided in the recombiner and cooling medium is introduced externally. The cooling medium may be water or air. In accordance with the detection value from the thermometer, ON-OFF control is carried out for a valve to control the flow rate of the cooling medium thereby rendering the temperature in the recombiner to a predetermined value. This can prevent the catalyst from being exposed to high temperature and avoid the reduction in the performance of the catalyst. (Ikeda, J.)

Skin Redox Balance Maintenance: The Need for an Nrf2-Activator Delivery System

Directory of Open Access Journals (Sweden)

Maya Ben-Yehuda Greenwald

2016-01-01

Full Text Available The skin, being the largest organ of the body, functions as a barrier between our body and the environment. It is consistently exposed to various exogenous and endogenous stressors (e.g., air pollutants, ionizing and non-ionizing irradiation, toxins, mitochondrial metabolism, enzyme activity, inflammatory process, etc. producing reactive oxygen species (ROS and physical damage (e.g., wounds, sunburns also resulting in reactive oxygen species production. Although skin is equipped with an array of defense mechanisms to counteract reactive oxygen species, augmented exposure and continued reactive oxygen species might result in excessive oxidative stress leading to many skin disorders including inflammatory diseases, pigmenting disorders and some types of cutaneous malignancy. The nuclear factor erythroid 2-related factor 2 (Nrf2 is an emerging regulator of cellular resistance and of defensive enzymes such as the phase II enzymes. Induction of the Keap1–Nrf2 pathway may have a beneficial effect in the treatment of a large number of skin disorders by stimulating an endogenous defense mechanism. However, prolonged and enhanced activation of this pathway is detrimental and, thus, limits the therapeutic potential of Keap1–Nrf2 modulators. Here, we review the consequences of oxidative stress to the skin, and the defense mechanisms that skin is equipped with. We describe the challenges of maintaining skin redox balance and its impact on skin status and function. Finally, we suggest a novel strategy for maintenance of skin redox homeostasis by modulating the Keap1–Nrf2 pathway using nanotechnology-based delivery systems.

Osmotic phenomena in application for hyperbaric oxygen treatment.

Science.gov (United States)

Babchin, A; Levich, E; Melamed M D, Y; Sivashinsky, G

2011-03-01

Hyperbaric oxygen (HBO) treatment defines the medical procedure when the patient inhales pure oxygen at elevated pressure conditions. Many diseases and all injuries are associated with a lack of oxygen in tissues, known as hypoxia. HBO provides an effective method for fast oxygen delivery in medical practice. The exact mechanism of the oxygen transport under HBO conditions is not fully identified. The objective of this article is to extend the colloid and surface science basis for the oxygen transport in HBO conditions beyond the molecular diffusion transport mechanism. At a pressure in the hyperbaric chamber of two atmospheres, the partial pressure of oxygen in the blood plasma increases 10 times. The sharp increase of oxygen concentration in the blood plasma creates a considerable concentration gradient between the oxygen dissolved in the plasma and in the tissue. The concentration gradient of oxygen as a non-electrolyte solute causes an osmotic flow of blood plasma with dissolved oxygen. In other words, the molecular diffusion transport of oxygen is supplemented by the convective diffusion raised due to the osmotic flow, accelerating the oxygen delivery from blood to tissue. A non steady state equation for non-electrolyte osmosis is solved asymptotically. The solution clearly demonstrates two modes of osmotic flow: normal osmosis, directed from lower to higher solute concentrations, and anomalous osmosis, directed from higher to lower solute concentrations. The fast delivery of oxygen from blood to tissue is explained on the basis of the strong molecular interaction between the oxygen and the tissue, causing an influx of oxygen into the tissue by convective diffusion in the anomalous osmosis process. The transport of the second gas, nitrogen, dissolved in the blood plasma, is also taken into the consideration. As the patient does not inhale nitrogen during HBO treatment, but exhales it along with oxygen and carbon dioxide, the concentration of nitrogen in blood

Experimental and thermodynamic study of the erbium-oxygen-zirconium and gadolinium-oxygen-zirconium systems

International Nuclear Information System (INIS)

Jourdan, J.

2009-11-01

This work is a contribution to the development of innovative concepts for fuel cladding in pressurized water nuclear reactors. This concept implies the insertion of rare earth (erbium and gadolinium) in the zirconium fuel cladding. The determination of phase equilibria in the systems is essential prior to the implementation of such a promising solution. This study consisted in an experimental determination of the erbium-zirconium phase diagram. For this, we used many different techniques in order to obtain diagram data such as solubility limits, solidus, liquidus or invariant temperatures. These data allowed us to present a new diagram, very different from the previous one available in the literature. We also assessed the diagram using the CALPHAD approach. In the gadolinium-zirconium system, we determined experimentally the solubility limits. Those limits had never been determined before, and the values we obtained showed a very good agreement with the experimental and assessed versions of the diagram. Because these alloys are subjected to oxygen diffusion throughout their life, we focused our attention on the erbium-oxygen-zirconium and gadolinium-oxygen-zirconium systems. The first system has been investigated experimentally. The alloys fabrication has been performed using powder metallurgy. In order to obtain pure raw materials, we fabricated powder from erbium and zirconium bulk metals using hydrogen absorption/desorption. The characterisation of the ternary pellets allowed the determination of two ternary isothermal sections at 800 and 1100 C. For the gadolinium-oxygen-zirconium system, we calculated the phase equilibria at temperatures ranging from 800 to 1100 C, using a homemade database compiled from literature assessments of the oxygen-zirconium, gadolinium-zirconium and gadolinia-zirconia systems. Finally, we determined the mechanical properties, in connexion with the microstructure, of industrial quality alloys in order to identify the influence of

Carrier-Based Drug Delivery System for Treatment of Acne

Science.gov (United States)

Vyas, Amber; Kumar Sonker, Avinesh

2014-01-01

Approximately 95% of the population suffers at some point in their lifetime from acne vulgaris. Acne is a multifactorial disease of the pilosebaceous unit. This inflammatory skin disorder is most common in adolescents but also affects neonates, prepubescent children, and adults. Topical conventional systems are associated with various side effects. Novel drug delivery systems have been used to reduce the side effect of drugs commonly used in the topical treatment of acne. Topical treatment of acne with active pharmaceutical ingredients (API) makes direct contact with the target site before entering the systemic circulation which reduces the systemic side effect of the parenteral or oral administration of drug. The objective of the present review is to discuss the conventional delivery systems available for acne, their drawbacks, and limitations. The advantages, disadvantages, and outcome of using various carrier-based delivery systems like liposomes, niosomes, solid lipid nanoparticles, and so forth, are explained. This paper emphasizes approaches to overcome the drawbacks and limitations associated with the conventional system and the advances and application that are poised to further enhance the efficacy of topical acne formulations, offering the possibility of simplified dosing regimen that may improve treatment outcomes using novel delivery system. PMID:24688376

Systemic gene delivery to the central nervous system using Adeno-associated virus

Directory of Open Access Journals (Sweden)

Mathieu eBOURDENX

2014-06-01

Full Text Available Adeno-associated virus (AAV-mediated gene delivery has emerged as an effective and safe tool for both preclinical and clinical studies of neurological disorders. The recent discovery that several serotypes are able to cross the blood-brain-barrier when administered systemically has been a real breakthrough in the field of neurodegenerative diseases. Widespread transgene expression after systemic injection could spark interest as a therapeutic approach. Such strategy will avoid invasive brain surgery and allow non-focal gene therapy promising for CNS diseases affecting large portion of the brain. Here, we will review the recent results achieved through different systemic routes of injection generated in the last decade using systemic AAV-mediated delivery and propose a brief assessment of their values. In particular, we emphasize how the methods used for virus engineering could improve brain transduction after peripheral delivery.

Lipid nanoparticles as drug/gene delivery systems to the retina.

Science.gov (United States)

del Pozo-Rodríguez, Ana; Delgado, Diego; Gascón, Alicia R; Solinís, Maria Ángeles

2013-03-01

This review highlights the application of lipid nanoparticles (Solid Lipid Nanoparticles, Nanostructured Lipid Carriers, or Lipid Drug Conjugates) as effective drug/gene delivery systems for retinal diseases. Most drug products for ocular disease treatment are marketed as eye drop formulations but, due to ocular barriers, the drug concentration in the retina hardly ever turns out to be effective. Up to this date, several delivery systems have been designed to deliver drugs to the retina. Drug delivery strategies may be classified into 3 groups: noninvasive techniques, implants, and colloidal carriers. The best known systems for drug delivery to the posterior eye are intravitreal implants; in fact, some of them are being clinically used. However, their long-term accumulation might impact the patient's vision. On the contrary, colloidal drug delivery systems (microparticles, liposomes, or nanoparticles) can be easily administered in a liquid form. Nanoparticular systems diffuse rapidly and are better internalized in ocular tissues than microparticles. In comparison with liposomes, nanoparticles have a higher loading capacity and are more stable in biological fluids and during storage. In addition, their capacity to adhere to the ocular surface and interact with the endothelium makes these drug delivery systems interesting as new therapeutic tools in ophthalmology. Within the group of nanoparticles, those composed of lipids (Solid Lipid Nanoparticles, Nanostructred Lipid Carriers, and Lipid Drug Conjugates) are more biocompatible, easy to produce at large scale, and they may be autoclaved or sterilized. The present review summarizes scientific results that evidence the potential application of lipid nanoparticles as drug delivery systems for the retina and also as nonviral vectors in gene therapy of retina disorders, although much more effort is still needed before these lipidic systems could be available in the market.

Progress and Challenges in Developing Aptamer-Functionalized Targeted Drug Delivery Systems

Directory of Open Access Journals (Sweden)

Feng Jiang

2015-10-01

Full Text Available Aptamers, which can be screened via systematic evolution of ligands by exponential enrichment (SELEX, are superior ligands for molecular recognition due to their high selectivity and affinity. The interest in the use of aptamers as ligands for targeted drug delivery has been increasing due to their unique advantages. Based on their different compositions and preparation methods, aptamer-functionalized targeted drug delivery systems can be divided into two main categories: aptamer-small molecule conjugated systems and aptamer-nanomaterial conjugated systems. In this review, we not only summarize recent progress in aptamer selection and the application of aptamers in these targeted drug delivery systems but also discuss the advantages, challenges and new perspectives associated with these delivery systems.

Microcontainers - an oral drug delivery system for poorly soluble drugs

DEFF Research Database (Denmark)

Nielsen, Line Hagner; Petersen, Ritika Singh; Marizza, Paolo

In oral delivery, it can sometimes be necessary to employ drug delivery systems to achieve targeted delivery to the intestine. Microcontainers are polymeric, cylindrical devices in the micrometer size range (Figure 1), and are suggested as a promising oral drug delivery system [1],[2]. The purpose...... of these studies was to fabricate microcontainers in either SU-8 or biodegradable poly-L-lactic acid (PLLA), and fill the microcontainers with poorly soluble drugs. Furthermore, the application of the microcontainers as an oral drug delivery system was investigated in terms of release, in situ intestinal perfusion...... medium at pH 6.5 was observed. In situ intestinal perfusions were performed in rats of the Eudragit-coated ASSF-filled microcontainers and compared to a furosemide solution. At the end of the study, the small intestine was harvested from the rat and imaged under a light microscope. The absorption rate...

Spatially monitoring oxygen level in 3D microfabricated cell culture systems using optical oxygen sensing beads

OpenAIRE

Wang, Lin; Acosta, Miguel A.; Leach, Jennie B.; Carrier, Rebecca L.

2013-01-01

Capability of measuring and monitoring local oxygen concentration at the single cell level (tens of microns scale) is often desirable but difficult to achieve in cell culture. In this study, biocompatible oxygen sensing beads were prepared and tested for their potential for real-time monitoring and mapping of local oxygen concentration in 3D micro-patterned cell culture systems. Each oxygen sensing bead is composed of a silica core loaded with both an oxygen sensitive Ru(Ph2phen3)Cl2 dye and ...

VASCULAR PLANTS AS ENGINEERS OF OXYGEN IN AQUATIC SYSTEMS

Science.gov (United States)

The impact of organisms on oxygen is one of the most dramatic examples of ecosystem engineering on Earth. In aquatic systems, which have much lower oxygen concentrations than the atmosphere, vascular aquatic plants can affect oxygen concentrations significantly not only on long t...

Advanced and controlled drug delivery systems in clinical disease management

NARCIS (Netherlands)

Brouwers, JRBJ

1996-01-01

Advanced and controlled drug delivery systems are important for clinical disease management. In this review the most important new systems which have reached clinical application are highlighted. Microbiologically controlled drug delivery is important for gastrointestinal diseases like ulcerative

Cascade Storage and Delivery System for a Multi Mission Space Exploration Vehicle (MMSEV)

Science.gov (United States)

Yagoda, Evan; Swickrath, Michael; Stambaugh, Imelda

2012-01-01

NASA is developing a Multi Mission Space Exploration Vehicle (MMSEV) for missions beyond Low Earth Orbit (LEO). The MMSEV is a pressurized vehicle used to extend the human exploration envelope for Lunar, Near Earth Object (NEO), and Deep Space missions. The Johnson Space Center is developing the Environmental Control and Life Support System (ECLSS) for the MMSEV. The MMSEV s intended use is to support longer sortie lengths with multiple Extra Vehicular Activities (EVAs) on a higher magnitude than any previous vehicle. This paper presents an analysis of a high pressure oxygen cascade storage and delivery system that will accommodate the crew during long duration Intra Vehicular Activity (IVA) and capable of multiple high pressure oxygen fills to the Portable Life Support System (PLSS) worn by the crew during EVAs. A cascade is a high pressure gas cylinder system used for the refilling of smaller compressed gas cylinders. Each of the large cylinders are filled by a compressor, but the cascade system allows small cylinders to be filled without the need of a compressor. In addition, the cascade system is useful as a "reservoir" to accommodate low pressure needs. A regression model was developed to provide the mechanism to size the cascade systems subject to constraints such as number of crew, extravehicular activity duration and frequency, and ullage gas requirements under contingency scenarios. The sizing routine employed a numerical integration scheme to determine gas compressibility changes during depressurization and compressibility effects were captured using the Soave-Redlich-Kwong (SRK) equation of state. A multi-dimensional nonlinear optimization routine was used to find the minimum cascade tank system mass that meets the mission requirements. The sizing algorithms developed in this analysis provide a powerful framework to assess cascade filling, compressor, and hybrid systems to design long duration vehicle ECLSS architecture. 1

Commissioning of cryogen delivery system for superconducting cyclotron magnet

International Nuclear Information System (INIS)

Pal, G.; Nandi, C.; Bhattacharyya, T.K.; Chaudhuri, J.; Bhandari, R.K.

2005-01-01

A K-500 superconducting cyclotron is being constructed at VECC Kolkata. The cryogen delivery system distributes liquid helium and liquid nitrogen to the superconducting cyclotron. Liquid helium is required to cool the cyclotron magnet and cryopanels. Liquid nitrogen is used to reduce the capacity of the helium liquefier. This paper describes the system, the current status and the commissioning experiences of cryogen delivery system for cyclotron magnet. (author)

Nanostructured lipid carriers system: recent advances in drug delivery.

Science.gov (United States)

Iqbal, Md Asif; Md, Shadab; Sahni, Jasjeet Kaur; Baboota, Sanjula; Dang, Shweta; Ali, Javed

2012-12-01

Nanostructured lipid carrier (NLC) is second generation smarter drug carrier system having solid matrix at room temperature. This carrier system is made up of physiological, biodegradable and biocompatible lipid materials and surfactants and is accepted by regulatory authorities for application in different drug delivery systems. The availability of many products in the market in short span of time reveals the success story of this delivery system. Since the introduction of the first product, around 30 NLC preparations are commercially available. NLC exhibit superior advantages over other colloidal carriers viz., nanoemulsions, polymeric nanoparticles, liposomes, SLN etc. and thus, have been explored to more extent in pharmaceutical technology. The whole set of unique advantages such as enhanced drug loading capacity, prevention of drug expulsion, leads to more flexibility for modulation of drug release and makes NLC versatile delivery system for various routes of administration. The present review gives insights on the definitions and characterization of NLC as colloidal carriers including the production techniques and suitable formulations. This review paper also highlights the importance of NLC in pharmaceutical applications for the various routes of drug delivery viz., topical, oral, pulmonary, ocular and parenteral administration and its future perspective as a pharmaceutical carrier.

Nebuliser systems for drug delivery in cystic fibrosis.

Science.gov (United States)

Daniels, Tracey; Mills, Nicola; Whitaker, Paul

2013-04-30

Nebuliser systems are used to deliver medications to control the symptoms and the progression of lung disease in people with cystic fibrosis. Many types of nebuliser systems are available for use with various medications; however, there has been no previous systematic review which has evaluated these systems. To evaluate effectiveness, safety, burden of treatment and adherence to nebulised therapy using different nebuliser systems for people with cystic fibrosis. We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Trials Register comprising references identified from comprehensive electronic database searches, handsearching of relevant journals and abstract books of conference proceedings. We searched the reference lists of each study for additional publications and approached the manufacturers of both nebuliser systems and nebulised medications for published and unpublished data. Date of the most recent search: 15 Oct 2012. Randomised controlled trials or quasi-randomised controlled trials comparing nebuliser systems including conventional nebulisers, vibrating mesh technology systems, adaptive aerosol delivery systems and ultrasonic nebuliser systems. Two authors independently assessed studies for inclusion. They also independently extracted data and assessed the risk of bias. A third author assessed studies where agreement could not be reached. The search identified 40 studies with 20 of these (1936 participants) included in the review. These studies compared the delivery of tobramycin, colistin, dornase alfa, hypertonic sodium chloride and other solutions through the different nebuliser systems. This review demonstrates variability in the delivery of medication depending on the nebuliser system used. Conventional nebuliser systems providing higher flows, higher respirable fractions and smaller particles decrease treatment time, increase deposition and may be preferred by people with CF, as compared to conventional nebuliser systems providing

Delivery systems and local administration routes for therapeutic siRNA.

Science.gov (United States)

Vicentini, Fabiana Testa Moura de Carvalho; Borgheti-Cardoso, Lívia Neves; Depieri, Lívia Vieira; de Macedo Mano, Danielle; Abelha, Thais Fedatto; Petrilli, Raquel; Bentley, Maria Vitória Lopes Badra

2013-04-01

With the increasing number of studies proposing new and optimal delivery strategies for the efficacious silencing of gene-related diseases by the local administration of siRNAs, the present review aims to provide a broad overview of the most important and latest developments of non-viral siRNA delivery systems for local administration. Moreover, the main disease targets for the local delivery of siRNA to specific tissues or organs, including the skin, the lung, the eye, the nervous system, the digestive system and the vagina, were explored.

Spray-on transdermal drug delivery systems.

Science.gov (United States)

Ibrahim, Sarah A

2015-02-01

Transdermal drug delivery possesses superior advantages over other routes of administration, particularly minimizing first-pass metabolism. Transdermal drug delivery is challenged by the barrier nature of skin. Numerous technologies have been developed to overcome the relatively low skin permeability, including spray-on transdermal systems. A transdermal spray-on system (TSS) usually consists of a solution containing the drug, a volatile solvent and in many cases a chemical penetration enhancer. TSS promotes drug delivery via the complex interplay between solvent evaporation and drug-solvent drag into skin. The volatile solvent carries the drug into the upper layers of the stratum corneum, and as the volatile solvent evaporates, an increase in the thermodynamic activity of the drug occurs resulting in an increased drug loading in skin. TSS is easily applied, delivering flexible drug dosage and associated with lower incidence of skin irritation. TSS provides a fast-drying product where the volatile solvent enables uniform drug distribution with minimal vehicle deposition on skin. TSS ensures precise dose administration that is aesthetically appealing and eliminates concerns of residual drug associated with transdermal patches. Furthermore, it provides a better alternative to traditional transdermal products due to ease of product development and manufacturing.

Otic drug delivery systems: formulation principles and recent developments.

Science.gov (United States)

Liu, Xu; Li, Mingshuang; Smyth, Hugh; Zhang, Feng

2018-04-25

Disorders of the ear severely impact the quality of life of millions of people, but the treatment of these disorders is an ongoing, but often overlooked challenge particularly in terms of formulation design and product development. The prevalence of ear disorders has spurred significant efforts to develop new therapeutic agents, but perhaps less innovation has been applied to new drug delivery systems to improve the efficacy of ear disease treatments. This review provides a brief overview of physiology, major diseases, and current therapies used via the otic route of administration. The primary focuses are on the various administration routes and their formulation principles. The article also presents recent advances in otic drug deliveries as well as potential limitations. Otic drug delivery technology will likely evolve in the next decade and more efficient or specific treatments for ear disease will arise from the development of less invasive drug delivery methods, safe and highly controlled drug delivery systems, and biotechnology targeting therapies.

Safety design integrated in the building delivery system

DEFF Research Database (Denmark)

Jørgensen, Kirsten

2013-01-01

. The purpose of this article is to demonstrate how safety and health can be integrated in the design phases integrated in the management delivery systems within construction, The method for the research was to go through the building delivery system step by step and create a normative description of what, when......In construction, it is important to view safety and health as an integrated part of the way that “designers” are working. The designers cowers architects, constructors, engineers and others who carry out their consulting services in the design phase of a construction project. The philosophy...... and how to fully integrate safety in each part of the process. The result is a concept and guideline including control forms for how to integrate safety design in the Building Delivery System plus what to do and when. The concept has been tested in an educational context. The practical value...

Pharmacokinetics of a 5-fluorouracil liposomal delivery system.

Science.gov (United States)

Simmons, S T; Sherwood, M B; Nichols, D A; Penne, R B; Sery, T; Spaeth, G L

1988-01-01

A liposomal delivery system was developed in an attempt to prolong ocular levels of 5-fluorouracil for glaucoma filtering surgery. The pharmacokinetics of the 5-fluorouracil liposomal delivery system were studied in normal pigmented rabbits with 5-fluorouracil labelled with carbon-14 (C-14). 14C 5-fluorouracil was incorporated into the liposomes at a concentration of 10 g/l and injected subconjunctivally in doses of 5 and 10 mg. Concentrations of 5-fluorouracil were assayed at 10 time intervals from 0.5 to 96 hours in cornea, sclera, and conjunctiva and at six time intervals from 0.5 to 12 hours in aqueous. Two peak concentrations were noted at approximately one and eight hours, with measurable levels present at 96 hours. This study demonstrates the ability of this liposomal delivery system to prolong levels of 5-fluorouracial in normal pigmented rabbits. PMID:3179257

Safety design integrated in the Building Delivery System

DEFF Research Database (Denmark)

Jørgensen, Kirsten

2012-01-01

phases of the building delivery system by using the principle of the lean construction modelling. The method for the research was to go through the lean construction building delivery system step by step and create a normative description of what to do, when to do and how to do to fully integration...... of safety in each process. The group of participants who created the description had a high experience in a combination of research, safety and health in general and especial in construction and knowledge of the lean construction processes both from the clients perspective as well as from the designers...... and the consultants. The result is a concept and guideline including control schemes for how to integrate safety design in the lean construction building delivery system including what to do and when. The concept has been tested in an educational context and found useful by the designers. The practical value...

An Overview of Clinical and Commercial Impact of Drug Delivery Systems

Science.gov (United States)

Anselmo, Aaron C.; Mitragotri, Samir

2014-01-01

Drug delivery systems are widely researched and developed to improve the delivery of pharmaceutical compounds and molecules. The last few decades have seen a marked growth of the field fueled by increased number of researchers, research funding, venture capital and the number of start-ups. Collectively, the growth has led to novel systems that make use of micro/nano-particles, transdermal patches, inhalers, drug reservoir implants and antibody-drug conjugates. While the increased research activity is clearly an indication of proliferation of the field, clinical and commercial translation of early-stage research ideas is critically important for future growth and interest in the field. Here, we will highlight some of the examples of novel drug delivery systems that have undergone such translation. Specifically, we will discuss the developments, advantages, limitations and lessons learned from: (i) microparticle-based depot formulations, (ii) nanoparticle-based cancer drugs, (iii) transdermal systems, (iv) oral drug delivery systems, (v) pulmonary drug delivery, (vi) implants and (vii) antibody-drug conjugates. These systems have impacted treatment of many prevalent diseases including diabetes, cancer and cardiovascular diseases, among others. At the same time, these systems are integral and enabling components of products that collectively generate annual revenues exceeding US $100 billion. These examples provide strong evidence of the clinical and commercial impact of drug delivery systems. PMID:24747160

Understanding the organization of public health delivery systems: an empirical typology.

Science.gov (United States)

Mays, Glen P; Scutchfield, F Douglas; Bhandari, Michelyn W; Smith, Sharla A

2010-03-01

Policy discussions about improving the U.S. health care system increasingly recognize the need to strengthen its capacities for delivering public health services. A better understanding of how public health delivery systems are organized across the United States is critical to improvement. To facilitate the development of such evidence, this article presents an empirical method of classifying and comparing public health delivery systems based on key elements of their organizational structure. This analysis uses data collected through a national longitudinal survey of local public health agencies serving communities with at least 100,000 residents. The survey measured the availability of twenty core public health activities in local communities and the types of organizations contributing to each activity. Cluster analysis differentiated local delivery systems based on the scope of activities delivered, the range of organizations contributing, and the distribution of effort within the system. Public health delivery systems varied widely in organizational structure, but the observed patterns of variation suggested that systems adhere to one of seven distinct configurations. Systems frequently migrated from one configuration to another over time, with an overall trend toward offering a broader scope of services and engaging a wider range of organizations. Public health delivery systems exhibit important structural differences that may influence their operations and outcomes. The typology developed through this analysis can facilitate comparative studies to identify which delivery system configurations perform best in which contexts.

Buccoadhesive drug delivery systems--extensive review on recent patents.

Science.gov (United States)

Pathan, Shadab A; Iqbal, Zeenat; Sahani, Jasjeet K; Talegaonkar, Sushma; Khar, Roop K; Ahmad, Farhan J

2008-01-01

Peroral administration of drugs, although most preferred by both clinicians and patients has several disadvantages such as hepatic first pass metabolism and enzymatic degradation within the GI tract, that prohibit oral administration of certain classes of drugs especially peptides and proteins. Consequently, other absorptive mucosae are considered as potential sites for administration of these drugs. Among the various transmucosal routes studied the buccal mucosa offers several advantages for controlled drug delivery for extended period of time. The mucosa is well supplied with both vascular and lymphatic drainage and first-pass metabolism in the liver and pre-systemic elimination in the gastrointestinal tract is avoided. The area is well suited for a retentive device and appears to be acceptable to the patient. With the right dosage form, design and formulation, the permeability and the local environment of the mucosa can be controlled and manipulated in order to accommodate drug permeation. Buccal drug delivery is thus a promising area for continued research with the aim of systemic and local delivery of orally inefficient drugs as well as feasible and attractive alternative for non-invasive delivery of potent protein and peptide drug molecules. Extensive review pertaining specifically to the patents relating to buccal drug delivery is currently available. However, many patents e.g. US patents 6, 585,997; US20030059376A1 etc. have been mentioned in few articles. It is the objective of this article to extensively review buccal drug delivery by discussing the recent patents available. Buccal dosage forms will also be reviewed with an emphasis on bioadhesive polymeric based delivery systems.

Hydrogen storage and delivery system development: Analysis

Energy Technology Data Exchange (ETDEWEB)

Handrock, J.L. [Sandia National Labs., Livermore, CA (United States)

1996-10-01

Hydrogen storage and delivery is an important element in effective hydrogen utilization for energy applications and is an important part of the FY1994-1998 Hydrogen Program Implementation Plan. This project is part of the Field Work Proposal entitled Hydrogen Utilization in Internal Combustion Engines (ICE). The goal of the Hydrogen Storage and Delivery System Development Project is to expand the state-of-the-art of hydrogen storage and delivery system design and development. At the foundation of this activity is the development of both analytical and experimental evaluation platforms. These tools provide the basis for an integrated approach for coupling hydrogen storage and delivery technology to the operating characteristics of potential hydrogen energy use applications. Results of the analytical model development portion of this project will be discussed. Analytical models have been developed for internal combustion engine (ICE) hybrid and fuel cell driven vehicles. The dependence of hydride storage system weight and energy use efficiency on engine brake efficiency and exhaust temperature for ICE hybrid vehicle applications is examined. Results show that while storage system weight decreases with increasing engine brake efficiency energy use efficiency remains relatively unchanged. The development, capability, and use of a recently developed fuel cell vehicle storage system model will also be discussed. As an example of model use, power distribution and control for a simulated driving cycle is presented. Model calibration results of fuel cell fluid inlet and exit temperatures at various fuel cell idle speeds, assumed fuel cell heat capacities, and ambient temperatures are presented. The model predicts general increases in temperature with fuel cell power and differences between inlet and exit temperatures, but under predicts absolute temperature values, especially at higher power levels.

Mechanical valve assembly for xenon 133 gas delivery systems

Energy Technology Data Exchange (ETDEWEB)

Round, W.H. (Royal Brisbane Hospital, Herston (Australia))

Some gas delivery systems used in pulmonary ventilation scanning are unable to satisfactorily supply /sup 133/Xe gas to bed-ridden patients. A mechanical gas valve assembly to control the flow of gas in such systems was constructed. A commercially produced /sup 133/Xe gas delivery system when fitted with the new assembly was able to ventilate almost all patients whereas previously this could be achieved with approximately only 50% of patients.

Stabilization challenges and formulation strategies associated with oral biologic drug delivery systems.

Science.gov (United States)

Truong-Le, Vu; Lovalenti, Phillip M; Abdul-Fattah, Ahmad M

2015-10-01

Delivery of proteins to mucosal tissues of GI tract typically utilize formulations which protect against proteolysis and target the mucosal tissues. Using case studies from literature and the authors' own work, the in-process stability and solid state storage stability of biopharmaceuticals formulated in delivery systems designed for oral delivery to the GI tract will be reviewed. Among the range of delivery systems, biodegradable polymer systems for protection and controlled release of proteins have been the most studied; hence these systems will be covered in greater depth. These delivery systems include polymeric biodegradable microspheres or nanospheres that contain proteins or vaccines, which are designed to reduce the number of administrations/inoculations and the total protein dose required to achieve the desired biological effect. Specifically, this review will include a landscape survey of the systems that have been studied, the manufacturing processes involved, stability through the manufacturing process, key pharmaceutical formulation parameters that impact stability of the encased proteins, and storage stability of the encapsulated proteins in these delivery systems. Copyright © 2015 Elsevier B.V. All rights reserved.

Application of three-dimensional printing for colon targeted drug delivery systems.

Science.gov (United States)

Charbe, Nitin B; McCarron, Paul A; Lane, Majella E; Tambuwala, Murtaza M

2017-01-01

Orally administered solid dosage forms currently dominate over all other dosage forms and routes of administrations. However, human gastrointestinal tract (GIT) poses a number of obstacles to delivery of the drugs to the site of interest and absorption in the GIT. Pharmaceutical scientists worldwide have been interested in colon drug delivery for several decades, not only for the delivery of the drugs for the treatment of colonic diseases such as ulcerative colitis and colon cancer but also for delivery of therapeutic proteins and peptides for systemic absorption. Despite extensive research in the area of colon targeted drug delivery, we have not been able to come up with an effective way of delivering drugs to the colon. The current tablets designed for colon drug release depend on either pH-dependent or time-delayed release formulations. During ulcerative colitis the gastric transit time and colon pH-levels is constantly changing depending on whether the patient is having a relapse or under remission. Hence, the current drug delivery system to the colon is based on one-size-fits-all. Fails to effectively deliver the drugs locally to the colon for colonic diseases and delivery of therapeutic proteins and peptides for systemic absorption from the colon. Hence, to overcome the current issues associated with colon drug delivery, we need to provide the patients with personalized tablets which are specifically designed to match the individual's gastric transit time depending on the disease state. Three-dimensional (3D) printing (3DP) technology is getting cheaper by the day and bespoke manufacturing of 3D-printed tablets could provide the solutions in the form of personalized colon drug delivery system. This review provides a bird's eye view of applications and current advances in pharmaceutical 3DP with emphasis on the development of colon targeted drug delivery systems.

Project Delivery System Mode Decision Based on Uncertain AHP and Fuzzy Sets

Science.gov (United States)

Kaishan, Liu; Huimin, Li

2017-12-01

The project delivery system mode determines the contract pricing type, project management mode and the risk allocation among all participants. Different project delivery system modes have different characteristics and applicable scope. For the owners, the selection of the delivery mode is the key point to decide whether the project can achieve the expected benefits, it relates to the success or failure of project construction. Under the precondition of comprehensively considering the influence factors of the delivery mode, the model of project delivery system mode decision was set up on the basis of uncertain AHP and fuzzy sets, which can well consider the uncertainty and fuzziness when conducting the index evaluation and weight confirmation, so as to rapidly and effectively identify the most suitable delivery mode according to project characteristics. The effectiveness of the model has been verified via the actual case analysis in order to provide reference for the construction project delivery system mode.

Life Support Systems: Oxygen Generation and Recovery

Data.gov (United States)

National Aeronautics and Space Administration — The Advanced Exploration Systems (AES) Life Support Systems project Oxygen Generation and Recovery technology development area encompasses several sub-tasks in an...

Lunar and Planetary Science XXXV: Special Session: Oxygen in the Solar System, I

Science.gov (United States)

2004-01-01

The Special Session: Oxygen in the Solar System, I, included the following reports:Oxygen in the Solar System: Origins of Isotopic and Redox Complexity; The Origin of Oxygen Isotope Variations in the Early Solar System; Solar and Solar-Wind Oxygen Isotopes and the Genesis Mission; Solar 18O/17O and the Setting for Solar Birth; Oxygen Isotopes in Early Solar System Materials: A Perspective Based on Microbeam Analyses of Chondrules from CV Carbonaceous Chondrites; Insight into Primordial Solar System Oxygen Reservoirs from Returned Cometary Samples; Tracing Meteorites to Their Sources Through Asteroid Spectroscopy; Redox Conditions Among the Terrestrial Planets; Redox Complexity in Martian Meteorites: Implications for Oxygen in the Terrestrial Planets; Implications of Sulfur Isotopes for the Evolution of Atmospheric Oxygen; Oxygen in the Outer Solar System; and On the Oxidation States of the Galilean Satellites: Implications for Internal Structures.

Drug delivery system and radiation therapy

International Nuclear Information System (INIS)

Shibata, Tokushi

2005-01-01

This paper describes the review of radiation therapy, neutron capture therapy (NCT) and drug delivery system for the latter. In cancer radiation therapy, there are problems of body movement like breathing, needless irradiation of normal tissues, difficulty to decide the correct irradiation position and tumor morphology. NCT has advantages to overcome these, and since boron has a big cross section for thermal neutron, NPT uses the reaction 10 B(n, α) 7 Li in the target cancer which previously incorporated the boron-containing drug. During the period 1966-1996, 246 patients were treated with this in Japan and the treatment has been continued thereafter. The tasks for NCT are developments of drug delivery system efficient to deliver the drug into the tumor and of convenient neutron source like the accelerator. (S.I.)

Description and Documentation of the Dental School Dental Delivery System.

Science.gov (United States)

Chase, Rosen and Wallace, Inc., Alexandria, VA.

A study was undertaken to describe and document the dental school dental delivery system using an integrated systems approach. In late 1976 and early 1977, a team of systems analysts and dental consultants visited three dental schools to observe the delivery of dental services and patient flow and to interview administrative staff and faculty.…

Exogenous and endogenous angiotensin‐II decrease renal cortical oxygen tension in conscious rats by limiting renal blood flow

Science.gov (United States)

Emans, Tonja W.; Janssen, Ben J.; Pinkham, Maximilian I.; Ow, Connie P. C.; Evans, Roger G.; Joles, Jaap A.; Malpas, Simon C.; Krediet, C. T. Paul

2016-01-01

Key points Our understanding of the mechanisms underlying the role of hypoxia in the initiation and progression of renal disease remains rudimentary.We have developed a method that allows wireless measurement of renal tissue oxygen tension in unrestrained rats.This method provides stable and continuous measurements of cortical tissue oxygen tension (PO2) for more than 2 weeks and can reproducibly detect acute changes in cortical oxygenation.Exogenous angiotensin‐II reduced renal cortical tissue PO2 more than equi‐pressor doses of phenylephrine, probably because it reduced renal oxygen delivery more than did phenylephrine.Activation of the endogenous renin–angiotensin system in transgenic Cyp1a1Ren2 rats reduced cortical tissue PO2; in this model renal hypoxia precedes the development of structural pathology and can be reversed acutely by an angiotensin‐II receptor type 1 antagonist.Angiotensin‐II promotes renal hypoxia, which may in turn contribute to its pathological effects during development of chronic kidney disease. Abstract We hypothesised that both exogenous and endogenous angiotensin‐II (AngII) can decrease the partial pressure of oxygen (PO2) in the renal cortex of unrestrained rats, which might in turn contribute to the progression of chronic kidney disease. Rats were instrumented with telemeters equipped with a carbon paste electrode for continuous measurement of renal cortical tissue PO2. The method reproducibly detected acute changes in cortical oxygenation induced by systemic hyperoxia and hypoxia. In conscious rats, renal cortical PO2 was dose‐dependently reduced by intravenous AngII. Reductions in PO2 were significantly greater than those induced by equi‐pressor doses of phenylephrine. In anaesthetised rats, renal oxygen consumption was not affected, and filtration fraction was increased only in the AngII infused animals. Oxygen delivery decreased by 50% after infusion of AngII and renal blood flow (RBF) fell by 3.3 ml min−1

Oral delivery of peptides and proteins using lipid-based drug delivery systems

DEFF Research Database (Denmark)

Li, Ping; Nielsen, Hanne Mørck; Müllertz, Anette

2012-01-01

INTRODUCTION: In order to successfully develop lipid-based drug delivery systems (DDS) for oral administration of peptides and proteins, it is important to gain an understanding of the colloid structures formed by these DDS, the mode of peptide and protein incorporation as well as the mechanism...... by which intestinal absorption of peptides and proteins is promoted. AREAS COVERED: The present paper reviews the literature on lipid-based DDS, employed for oral delivery of peptides and proteins and highlights the mechanisms by which the different lipid-based carriers are expected to overcome the two...... and proteins. EXPERT OPINION: Lipid-based DDS are safe and suitable for oral delivery of peptides and proteins. Significant progress has been made in this area with several technologies on clinical trials. However, a better understanding of the mechanism of action in vivo is needed in order to improve...

Pharmacokinetic characteristics of formulated alendronate transdermal delivery systems in rats and humans.

Science.gov (United States)

Choi, Ahyoung; Gang, Hyesil; Whang, Jiae; Gwak, Hyesun

2010-05-01

The objective of this study was to examine the absorption of alendronate from formulated transdermal delivery systems in rats and humans. When alendronate was applied to rats by transdermal delivery systems (7.2 mg) and oral administration (30 mg/kg), a statistically significant difference was found in the amount remaining to be excreted at time t (Ae(t)) and the amount remaining to be excreted at time 0 (Ae(infinity)) (p transdermal delivery systems. There was a linear relationship (r(2) = 0.9854) between the drug loading dose and Ae(infinity). The Ae(infinity) values from the transdermal delivery system containing 6% caprylic acid (53.8 mg as alendronate) and an oral product (Fosamax), 70 mg as alendronate) in humans were 127.0 +/- 34.2 microg and 237.2 +/- 56.3 microg, respectively. The dose-adjusted relative Ae(infinity) ratio of the transdermal delivery system to oral product was calculated to be 69.7%. The long half-life of alendronate in the transdermal delivery system (50.6 +/- 6.4 h), compared to that of the oral product (3.5 +/- 1.1 h) could allow less-frequent dosing. In conclusion, this study showed that a transdermal delivery system containing 6% caprylic acid in PG could be a favorable alternative for alendronate administration.

Pharmacokinetics of a 5-fluorouracil liposomal delivery system.

OpenAIRE

Simmons, S T; Sherwood, M B; Nichols, D A; Penne, R B; Sery, T; Spaeth, G L

1988-01-01

A liposomal delivery system was developed in an attempt to prolong ocular levels of 5-fluorouracil for glaucoma filtering surgery. The pharmacokinetics of the 5-fluorouracil liposomal delivery system were studied in normal pigmented rabbits with 5-fluorouracil labelled with carbon-14 (C-14). 14C 5-fluorouracil was incorporated into the liposomes at a concentration of 10 g/l and injected subconjunctivally in doses of 5 and 10 mg. Concentrations of 5-fluorouracil were assayed at 10 time interva...

Mucoadhesive drug delivery systems

Directory of Open Access Journals (Sweden)

Rahamatullah Shaikh

2011-01-01

Full Text Available Mucoadhesion is commonly defined as the adhesion between two materials, at least one of which is a mucosal surface. Over the past few decades, mucosal drug delivery has received a great deal of attention. Mucoadhesive dosage forms may be designed to enable prolonged retention at the site of application, providing a controlled rate of drug release for improved therapeutic outcome. Application of dosage forms to mucosal surfaces may be of benefit to drug molecules not amenable to the oral route, such as those that undergo acid degradation or extensive first-pass metabolism. The mucoadhesive ability of a dosage form is dependent upon a variety of factors, including the nature of the mucosal tissue and the physicochemical properties of the polymeric formulation. This review article aims to provide an overview of the various aspects of mucoadhesion, mucoadhesive materials, factors affecting mucoadhesion, evaluating methods, and finally various mucoadhesive drug delivery systems (buccal, nasal, ocular, gastro, vaginal, and rectal.

Nanocomposites chitosan/montmorillonite for drug delivery system

International Nuclear Information System (INIS)

Braga, Carla R. Costa; Barbosa, Rossemberg C.; Lima, Rosemary S. Cunha; Fook, Marcus V. Lia; Silva, Suedina M. Lima

2009-01-01

In drugs delivery system the incorporation of an inorganic nanophase in polymer matrix, i.e. production of an inorganic-organic nanocomposite is an attractive alternative to obtain a constant release rate for a prolonged time. This study was performed to obtain films of nanocomposites Chitosan/montmorillonite intercalation by the technique of solution in the proportions of 1:1, 5:1 and 10:1. The nanocomposites were characterized by infrared spectroscopy, X-ray diffraction and thermogravimetric analysis. The results indicated that the feasibility of obtaining films of nanocomposites exfoliate. Among the suggested applications for films developed in this study includes them use for drugs delivery system. (author)

Intraoperative transfusion threshold and tissue oxygenation

DEFF Research Database (Denmark)

Nielsen, K; Dahl, B; Johansson, P I

2012-01-01

Transfusion with allogeneic red blood cells (RBCs) may be needed to maintain oxygen delivery during major surgery, but the appropriate haemoglobin (Hb) concentration threshold has not been well established. We hypothesised that a higher level of Hb would be associated with improved subcutaneous...... oxygen tension during major spinal surgery....

The ideal oxygen/nitrous oxide fresh gas flow sequence with the Anesthesia Delivery Unit machine.

Science.gov (United States)

Hendrickx, Jan F A; Cardinael, Sara; Carette, Rik; Lemmens, Hendrikus J M; De Wolf, Andre M

2007-06-01

To determine whether early reduction of oxygen and nitrous oxide fresh gas flow from 6 L/min to 0.7 L/min could be accomplished while maintaining end-expired nitrous oxide concentration > or =50% with an Anesthesia Delivery Unit anesthesia machine. Prospective, randomized clinical study. Large teaching hospital in Belgium. 53 ASA physical status I and II patients requiring general endotracheal anesthesia and controlled mechanical ventilation. Patients were randomly assigned to one of 4 groups depending on the duration of high oxygen/nitrous oxide fresh gas flow (two and 4 L/min, respectively) before lowering total fresh gas flow to 0.7 L/min (0.3 and 0.4 L/min oxygen and nitrous oxide, respectively): one, two, three, or 5 minutes (1-minute group, 2-minute group, 3-minute group, and 5-minute group), with n = 10, 12, 13, and 8, respectively. The course of the end-expired nitrous oxide concentration and bellows volume deficit at end-expiration was compared among the 4 groups during the first 30 minutes. At the end of the high-flow period the end-expired nitrous oxide concentration was 35.6 +/- 6.2%, 48.4 +/- 4.8%, 53.7 +/- 8.7%, and 57.3 +/- 1.6% in the 4 groups, respectively. Thereafter, the end-expired nitrous oxide concentration decreased to a nadir of 36.1 +/- 4.5%, 45.4 +/- 3.8%, 50.9 +/- 6.1%, and 55.4 +/- 2.8% after three, 4, 6, and 8 minutes after flows were lowered in the 1- to 5-minute groups, respectively. A decrease in bellows volume was observed in most patients, but was most pronounced in the 2-minute group. The bellows volume deficit gradually faded within 15 to 20 minutes in all 4 groups. A 3-minute high-flow period (oxygen and nitrous oxide fresh gas flow of 2 and 4 L/min, respectively) suffices to attain and maintain end-expired nitrous oxide concentration > or =50% and ensures an adequate bellows volume during the ensuing low-flow period.

Nano-scale gene delivery systems; current technology, obstacles, and future directions.

Science.gov (United States)

Garcia-Guerra, Antonio; Dunwell, Thomas L; Trigueros, Sonia

2018-01-07

Within the different applications of nanomedicine currently being developed, nano-gene delivery is appearing as an exciting new technique with the possibility to overcome recognised hurdles and fulfill several biological and medical needs. The central component of all delivery systems is the requirement for the delivery of genetic material into cells, and for them to eventually reside in the nucleus where their desired function will be exposed. However, genetic material does not passively enter cells; thus, a delivery system is necessary. The emerging field of nano-gene delivery exploits the use of new materials and the properties that arise at the nanometre-scale to produce delivery vectors that can effectively deliver genetic material into a variety of different types of cells. The novel physicochemical properties of the new delivery vectors can be used to address the current challenges existing in nucleic acid delivery in vitro and in vivo. While there is a growing interest in nanostructure-based gene delivery, the field is still in its infancy, and there is yet much to discover about nanostructures and their physicochemical properties in a biological context. We carry out an organized and focused search of bibliographic databases. Our results suggest that despite new breakthroughs in nanostructure synthesis and advanced characterization techniques, we still face many barriers in producing highly efficient and non-toxic delivery systems. In this review, we overview the types of systems currently used for clinical and biomedical research applications along with their advantages and disadvantages, as well as discussing barriers that arise from nano-scale interactions with biological material. In conclusion, we hope that by bringing the far reaching multidisciplinary nature of nano-gene delivery to light, new targeted nanotechnology-bases strategies are developed to overcome the major challenges covered in this review. Copyright© Bentham Science Publishers; For

Encapsulation systems for the delivery of hydrophilic nutraceuticals: Food application.

Science.gov (United States)

Aditya, N P; Espinosa, Yadira Gonzalez; Norton, Ian T

2017-07-01

Increased health risk associated with the sedentary life style is forcing the food manufacturers to look for food products with specific or general health benefits e.g. beverages enriched with nutraceuticals like catechin, curcumin rutin. Compounds like polyphenols, flavonoids, vitamins are the good choice of bioactive compounds that can be used to fortify the food products to enhance their functionality. However due to low stability and bioavailability of these bioactives (both hydrophobic and hydrophilic) within the heterogeneous food microstructure and in the Gastro Intestinal Tract (GIT), it becomes extremely difficult to pass on the real health benefits to the consumers. Recent developments in the application of nano-delivery systems for food product development is proving to be a game changer which has raised the expectations of the researchers, food manufacturers and consumers regarding possibility of enhancing the functionality of bioactives within the fortified food products. In this direction, nano/micro delivery systems using lipids, surfactants and other materials (carbohydrates, polymers, complexes, protein) have been fabricated to stabilize and enhance the biological activity of the bioactive compounds. In the present review, current status of the various delivery systems that are used for the delivery of hydrophilic bioactives and future prospects for using other delivery systems that have been not completely explored for the delivery of hydrophilic bioactives e.g. niosomes; bilosomes, cubosomes are discussed. Copyright © 2017 Elsevier Inc. All rights reserved.

Chitosan-based delivery systems for diclofenac delivery: preparation and characterization

Energy Technology Data Exchange (ETDEWEB)

Dreve, Simina; Kacso, Irina; Bratu, Ioan; Indrea, Emil, E-mail: simina.dreve@itim-cj.r [National Institute for Research and Development of Isotopic and Molecular Technologies, 65-103 Donath, 400293 Cluj-Napoca (Romania)

2009-08-01

The preparation and characterization of novel materials for drug delivery has rapidly gained importance in development of innovative medicine. The paper concerns the uses of chitosan as an excipient in oral formulations and as a drug delivery vehicle for burnt painful injuries. The use of chitosan (CTS) as base in polyelectrolyte complex systems, to prepare liquid release systems as hydrogels and solid release systems as sponges is presented. In this paper the preparation of CTS hydrogels and sponges carrying diclofenac (DCF), as anti-inflammatory drug is reported. The immobilization of DCF in CTS is done by mixing the CTS hydrogel with the anti-inflammatory drug solutions. The concentration of anti-inflammatory drug in the CTS hydrogel generating the sponges was of 57 mg/l, 72 mg/l and 114 mg/l. The CTS sponges with anti-inflammatory drugs were prepared by freeze-drying at -610{sup 0}C and 0,09 atm. The characterization of the hydrogels and sponges was done by infrared spectra (FTIR) and ultraviolet-visible spectroscopy (UV-VIS). The results indicated the formation of CTS-DCF intermediates. The DCF molecules are forming temporary chelates in CTS hydrogels and sponges and they are compatible with skin or some of biological fluids with satisfactory results.

Chitosan-based delivery systems for diclofenac delivery: preparation and characterization

International Nuclear Information System (INIS)

Dreve, Simina; Kacso, Irina; Bratu, Ioan; Indrea, Emil

2009-01-01

The preparation and characterization of novel materials for drug delivery has rapidly gained importance in development of innovative medicine. The paper concerns the uses of chitosan as an excipient in oral formulations and as a drug delivery vehicle for burnt painful injuries. The use of chitosan (CTS) as base in polyelectrolyte complex systems, to prepare liquid release systems as hydrogels and solid release systems as sponges is presented. In this paper the preparation of CTS hydrogels and sponges carrying diclofenac (DCF), as anti-inflammatory drug is reported. The immobilization of DCF in CTS is done by mixing the CTS hydrogel with the anti-inflammatory drug solutions. The concentration of anti-inflammatory drug in the CTS hydrogel generating the sponges was of 57 mg/l, 72 mg/l and 114 mg/l. The CTS sponges with anti-inflammatory drugs were prepared by freeze-drying at -610 0 C and 0,09 atm. The characterization of the hydrogels and sponges was done by infrared spectra (FTIR) and ultraviolet-visible spectroscopy (UV-VIS). The results indicated the formation of CTS-DCF intermediates. The DCF molecules are forming temporary chelates in CTS hydrogels and sponges and they are compatible with skin or some of biological fluids with satisfactory results.

Microemulsions based transdermal drug delivery systems.

Science.gov (United States)

Vadlamudi, Harini C; Narendran, Hyndavi; Nagaswaram, Tejeswari; Yaga, Gowri; Thanniru, Jyotsna; Yalavarthi, Prasanna R

2014-01-01

Since the discovery of microemulsions by Jack H Schulman, there has been huge progress made in applying microemulsion systems in plethora of research and industrial process. Microemulsions are optically isotropic systems consisting of water, oil and amphiphile. These systems are beneficial due to their thermodynamic stability, optical clarity, ease of preparation, higher diffusion and absorption rates. Moreover, it has been reported that the ingredients of microemulsion can effectively overcome the diffusion barrier and penetrate through the stratum corneum of the skin. Hence it becomes promising for both transdermal and dermal drug delivery. However, low viscosity of microemulsion restrains its applicability in pharmaceutical industry. To overcome the above drawback, the low viscous microemulsions were added to viscous gel bases to potentiate its applications as topical drug delivery systems so that various drug related toxic effects and erratic drug absorption can be avoided. The present review deals with the microemulsions, various techniques involved in the development of organic nanoparticles. The review emphasized on microemulsion based systems such as hydrogels and organogels. The physicochemical characteristics, mechanical properties, rheological and stability principles involved in microemulsion based viscous gels were also explored.

Excimer laser beam delivery systems for medical applications

Science.gov (United States)

Kubo, Uichi; Hashishin, Yuichi; Okada, Kazuyuki; Tanaka, Hiroyuki

1993-05-01

We have been doing the basic experiments of UV laser beams and biotissue interaction with both KrF and XeCl lasers. However, the conventional optical fiber can not be available for power UV beams. So we have been investigating about UV power beam delivery systems. These experiments carry on with the same elements doped quartz fibers and the hollow tube. The doped elements are OH ion, chlorine and fluorine. In our latest work, we have tried ArF excimer laser and biotissue interactions, and the beam delivery experiments. From our experimental results, we found that the ArF laser beam has high incision ability for hard biotissue. For example, in the case of the cow's bone incision, the incision depth by ArF laser was ca.15 times of KrF laser. Therefore, ArF laser would be expected to harden biotissue therapy as non-thermal method. However, its beam delivery is difficult to work in this time. We will develop ArF laser beam delivery systems.

Evaluation of Roadmap to Achieve Energy Delivery Systems Cybersecurity

Energy Technology Data Exchange (ETDEWEB)

Chavez, Adrian R. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

2017-10-01

The Department of Energy/Office of Electricity Delivery and Energy Reliability (DOE/OE) Cybersecurity for Energy Delivery Systems (CEDS) program is currently evaluating the Roadmap to Achieve Energy Delivery Systems Cybersecurity document that sets a vision and outlines a set of milestones. The milestones are divided into five strategic focus areas that include: 1. Build a Culture of Security; 2. Assess and Monitor Risk; 3. Develop and Implement New Protective Measures to Reduce Risk; 4. Manage Incidents; and 5. Sustain Security Improvements. The most current version of the roadmap was last updated in September of 2016. Sandia National Laboratories (SNL) has been tasked with revisiting the roadmap to update the current state of energy delivery systems cybersecurity protections. SNL is currently working with previous and current partners to provide feedback on which of the roadmap milestones have been met and to identify any preexisting or new gaps that are not addressed by the roadmap. The specific focus areas SNL was asked to evaluate are: 1. Develop and Implement New Protective Measures to Reduce Risk and 2. Sustain Security Improvements. SNL has formed an Industry Advisory Board (IAB) to assist in answering these questions. The IAB consists of previous partners on past CEDS funded efforts as well as new collaborators that have unique insights into the current state of cybersecurity within energy delivery systems. The IAB includes asset owners, utilities and vendors of control systems. SNL will continue to maintain regular communications with the IAB to provide various perspectives on potential future updates to further improve the breadth of cybersecurity coverage of the roadmap.

Nanoparticle-based drug delivery systems: promising approaches against infections

International Nuclear Information System (INIS)

Ranghar, Shweta; Sirohi, Parul; Verma, Pritam; Agarwal, Vishnu

2014-01-01

Despite the fact that many new drugs and technologies have been developed to combat the infectious diseases, these have continued to be global health challenges. The use of conventional antimicrobial agents against these infections is always associated with problems such as the development of multiple drug resistance and adverse side effects. In addition, the inefficient traditional drug delivery system results in inadequate therapeutic index, low bioavailability of drugs and many other limitations. In this regard, antimicrobial nanoparticles and nanosized drug delivery carriers have emerged as potent effective agents against the infections. Nanoparticles have unique properties owing to their ultra small and controllable size such as high surface area, enhanced reactivity, and functionalizable structure. This review focused on different classes of antimicrobial nanoparticles, including metal, metal oxide and others along with their mechanism of action and their potential use against the infections. The review also focused on the development of nanoparticle systems for antimicrobial drug delivery and use of these systems for delivery of various antimicrobial agents, giving an overview about modern nanoparticle based therapeutic strategies against the infections. (author)

Nanoparticle-based drug delivery systems: promising approaches against infections

Energy Technology Data Exchange (ETDEWEB)

Ranghar, Shweta; Sirohi, Parul [Department of Applied Mechanics, Motilal Nehru National Institute of Technology, Allahabad (India); Verma, Pritam; Agarwal, Vishnu [Department of Biotechnology, Motilal Nehru National Institute of Technology, Allahabad (India)

2014-03-15

Despite the fact that many new drugs and technologies have been developed to combat the infectious diseases, these have continued to be global health challenges. The use of conventional antimicrobial agents against these infections is always associated with problems such as the development of multiple drug resistance and adverse side effects. In addition, the inefficient traditional drug delivery system results in inadequate therapeutic index, low bioavailability of drugs and many other limitations. In this regard, antimicrobial nanoparticles and nanosized drug delivery carriers have emerged as potent effective agents against the infections. Nanoparticles have unique properties owing to their ultra small and controllable size such as high surface area, enhanced reactivity, and functionalizable structure. This review focused on different classes of antimicrobial nanoparticles, including metal, metal oxide and others along with their mechanism of action and their potential use against the infections. The review also focused on the development of nanoparticle systems for antimicrobial drug delivery and use of these systems for delivery of various antimicrobial agents, giving an overview about modern nanoparticle based therapeutic strategies against the infections. (author)

Delivery Systems for Biopharmaceuticals. Part I: Nanoparticles and Microparticles.

Science.gov (United States)

Silva, Ana C; Lopes, Carla M; Lobo, José M S; Amaral, Maria H

2015-01-01

Pharmaceutical biotechnology has been showing therapeutic success never achieved with conventional drug molecules. Therefore, biopharmaceutical products are currently well-established in clinic and the development of new ones is expected. These products comprise mainly therapeutic proteins, although nucleic acids and cells are also included. However, according to their sensitive molecular structures, the efficient delivery of biopharmaceuticals is challenging. Several delivery systems (e.g. microparticles and nanoparticles) composed of different materials (e.g. polymers and lipids) have been explored and demonstrated excellent outcomes, such as: high cellular transfection efficiency for nucleic acids, cell targeting, increased proteins and peptides bioavailability, improved immune response in vaccination, and viability maintenance of microencapsulated cells. Nonetheless, important issues need to be addressed before they reach clinics. For example, more in vivo studies in animals, accessing the toxicity potential and predicting in vivo failure of these delivery systems are required. This is the Part I of two review articles, which presents the state of the art of delivery systems for biopharmaceuticals. Part I deals with microparticles and polymeric and lipid nanoparticles.

Oral delivery of peptides and proteins using lipid-based drug delivery systems.

Science.gov (United States)

Li, Ping; Nielsen, Hanne Mørck; Müllertz, Anette

2012-10-01

In order to successfully develop lipid-based drug delivery systems (DDS) for oral administration of peptides and proteins, it is important to gain an understanding of the colloid structures formed by these DDS, the mode of peptide and protein incorporation as well as the mechanism by which intestinal absorption of peptides and proteins is promoted. The present paper reviews the literature on lipid-based DDS, employed for oral delivery of peptides and proteins and highlights the mechanisms by which the different lipid-based carriers are expected to overcome the two most important barriers (extensive enzymatic degradation and poor transmucosal permeability). This paper also gives a clear-cut idea about advantages and drawbacks of using different lipidic colloidal carriers ((micro)emulsions, solid lipid core particles and liposomes) for oral delivery of peptides and proteins. Lipid-based DDS are safe and suitable for oral delivery of peptides and proteins. Significant progress has been made in this area with several technologies on clinical trials. However, a better understanding of the mechanism of action in vivo is needed in order to improve the design and development of lipid-based DDS with the desired bioavailability and therapeutic profile.

Characterization of particulate drug delivery systems for oral delivery of Peptide and protein drugs.

Science.gov (United States)

Christophersen, Philip Carsten; Fano, Mathias; Saaby, Lasse; Yang, Mingshi; Nielsen, Hanne Mørck; Mu, Huiling

2015-01-01

Oral drug delivery is a preferred route because of good patient compliance. However, most peptide/ protein drugs are delivered via parenteral routes because of the absorption barriers in the gastrointestinal (GI) tract such as enzymatic degradation by proteases and low permeability acrossthe biological membranes. To overcome these barriers, different formulation strategies for oral delivery of biomacromolecules have been proposed, including lipid based formulations and polymer-based particulate drug delivery systems (DDS). The aim of this review is to summarize the existing knowledge about oral delivery of peptide/protein drugs and to provide an overview of formulationand characterization strategies. For a better understanding of the challenges in oral delivery of peptide/protein drugs, the composition of GI fluids and the digestion processes of different kinds of excipients in the GI tract are summarized. Additionally, the paper provides an overview of recent studies on characterization of solid drug carriers for peptide/protein drugs, drug distribution in particles, drug release and stability in simulated GI fluids, as well as the absorption of peptide/protein drugs in cell-based models. The use of biorelevant media when applicable can increase the knowledge about the quality of DDS for oral protein delivery. Hopefully, the knowledge provided in this review will aid the establishment of improved biorelevant models capable of forecasting the performance of particulate DDS for oral peptide/protein delivery.

Nonviral Delivery Systems For Cancer Gene Therapy: Strategies And Challenges.

Science.gov (United States)

Shim, Gayong; Kim, Dongyoon; Le, Quoc-Viet; Park, Gyu Thae; Kwon, Taekhyun; Oh, Yu-Kyoung

2018-01-19

Gene therapy has been receiving widespread attention due to its unique advantage in regulating the expression of specific target genes. In the field of cancer gene therapy, modulation of gene expression has been shown to decrease oncogenic factors in cancer cells or increase immune responses against cancer. Due to the macromolecular size and highly negative physicochemical features of plasmid DNA, efficient delivery systems are an essential ingredient for successful gene therapy. To date, a variety of nanostructures and materials have been studied as nonviral gene delivery systems. In this review, we will cover nonviral delivery strategies for cancer gene therapy, with a focus on target cancer genes and delivery materials. Moreover, we will address current challenges and perspectives for nonviral delivery-based cancer gene therapeutics. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Gene delivery systems by the combination of lipid bubbles and ultrasound.

Science.gov (United States)

Negishi, Yoichi; Endo-Takahashi, Yoko; Maruyama, Kazuo

2016-11-28

Gene therapy is promising for the treatment of many diseases including cancers and genetic diseases. From the viewpoint of safety, ultrasound (US)-mediated gene delivery with nano/ microbubbles was recently developed as a novel non-viral vector system. US-mediated gene delivery using nano/microbubbles are able to produce transient changes in the permeability of the cell membrane after US-induced cavitation while reducing cellular damage and enables the tissue-specific or the site-specific intracellular delivery of gene both in vitro and in vivo. We have recently developed novel lipid nanobubbles (Lipid Bubbles). These nanobubbles can also be used to enhance the efficacy of the US-mediated genes (plasmid DNA, siRNA, and miRNA etc.) delivery. In this review, we describe US-mediated delivery systems combined with nano/microbubbles and discuss their feasibility as non-viral vector systems.

Relationship Between Cerebral Oxygenation and Hemodynamic and Oxygen Transport Parameters in Surgery for Acquired Heart Diseases

Directory of Open Access Journals (Sweden)

A. I. Lenkin

2012-01-01

Full Text Available Objective: to evaluate the relationship between cerebral oxygenation and hemodynamic and oxygen transport parameters in surgical correction of concomitant acquired heart diseases. Subjects and methods. Informed consent was received from 40 patients who required surgery because of concomitant (two or more acquired heart defects. During procedure, perioperative monitoring of oxygen transport and cerebral oxygenation was performed with the aid of PiCCO2 monitor (Pulsion Medical Systems, Germany and a Fore-Sight cerebral oximeter (CASMED, USA. Anesthesia was maintained with propofol and fen-tanyl, by monitoring the depth of anesthesia. Early postoperative intensive therapy was based on the protocol for early targeted correction of hemodynamic disorders. Oxygen transport and cerebral oxygenation parameters were estimated intraopera-tively and within 24 postoperative hours. A statistical analysis including evaluation of Spearman correlations was performed with the aid of SPSS 15.0. Results. During perfusion, there was a relationship between cerebral oximetry values and hemat-ocrit levels, and oxygen partial pressure in the venous blood. Furthermore, a negative correlation between cerebral oximetry values and blood lactate levels was found 30 minutes after initiation of extracorporeal circulation (EC. During the study, there was a positive correlation between cerebral oxygenation and values of cardiac index, central venous saturation, and oxygen delivery index. There was a negative relationship between cerebral oxygenation and extravascular lung water at the beginning of surgery and a correlation between cerebral oximetry values and oxygenation index by the end of the first 24 postoperative hours. Conclusion. The cerebral oxygenation values correlate -with the main determinants of oxygen transport during EC and after cardiac surgical procedures. Cerebral oximetry may be used in early targeted therapy for the surgical correction of acquired combined

77 FR 11385 - Security Considerations for Lavatory Oxygen Systems

Science.gov (United States)

2012-02-27

... considerations for lavatory oxygen systems (77 FR 12550). The interim final rule addresses a security... and taken to restore the oxygen system with a design that would consider the security risk. Boeing... [Docket No. FAA-2011-0186; Amdt. Nos. 21-94, 25-133, 121-354, 129-50; SFAR 111] RIN 2120-AJ92 Security...

Nanoparticulate systems for nucleic acid delivery

NARCIS (Netherlands)

Varkouhi, A.K.

2011-01-01

Development of carrier systems with controllable physicochemical and delivery properties has opened up the possibility of nanomedicines containing nucleic acids. In the last decades, much effort has been dedicated to two exciting approaches in biomedicine, namely gene and RNA interference

Adamantane in Drug Delivery Systems and Surface Recognition.

Science.gov (United States)

Štimac, Adela; Šekutor, Marina; Mlinarić-Majerski, Kata; Frkanec, Leo; Frkanec, Ruža

2017-02-16

The adamantane moiety is widely applied in design and synthesis of new drug delivery systems and in surface recognition studies. This review focuses on liposomes, cyclodextrins, and dendrimers based on or incorporating adamantane derivatives. Our recent concept of adamantane as an anchor in the lipid bilayer of liposomes has promising applications in the field of targeted drug delivery and surface recognition. The results reported here encourage the development of novel adamantane-based structures and self-assembled supramolecular systems for basic chemical investigations as well as for biomedical application.

Adamantane in Drug Delivery Systems and Surface Recognition

Directory of Open Access Journals (Sweden)

Adela Štimac

2017-02-01

Full Text Available The adamantane moiety is widely applied in design and synthesis of new drug delivery systems and in surface recognition studies. This review focuses on liposomes, cyclodextrins, and dendrimers based on or incorporating adamantane derivatives. Our recent concept of adamantane as an anchor in the lipid bilayer of liposomes has promising applications in the field of targeted drug delivery and surface recognition. The results reported here encourage the development of novel adamantane-based structures and self-assembled supramolecular systems for basic chemical investigations as well as for biomedical application.

Oxygen discharge and post-discharge kinetics experiments and modeling for the electric oxygen-iodine laser system.

Science.gov (United States)

Palla, A D; Zimmerman, J W; Woodard, B S; Carroll, D L; Verdeyen, J T; Lim, T C; Solomon, W C

2007-07-26

Laser oscillation at 1315 nm on the I(2P1/2)-->I(2P3/2) transition of atomic iodine has been obtained by a near resonant energy transfer from O2(a1Delta) produced using a low-pressure oxygen/helium/nitric oxide discharge. In the electric discharge oxygen-iodine laser (ElectricOIL) the discharge production of atomic oxygen, ozone, and other excited species adds levels of complexity to the singlet oxygen generator (SOG) kinetics which are not encountered in a classic purely chemical O2(a1Delta) generation system. The advanced model BLAZE-IV has been introduced to study the energy-transfer laser system dynamics and kinetics. Levels of singlet oxygen, oxygen atoms, and ozone are measured experimentally and compared with calculations. The new BLAZE-IV model is in reasonable agreement with O3, O atom, and gas temperature measurements but is under-predicting the increase in O2(a1Delta) concentration resulting from the presence of NO in the discharge and under-predicting the O2(b1Sigma) concentrations. A key conclusion is that the removal of oxygen atoms by NOX species leads to a significant increase in O2(a1Delta) concentrations downstream of the discharge in part via a recycling process; however, there are still some important processes related to the NOX discharge kinetics that are missing from the present modeling. Further, the removal of oxygen atoms dramatically inhibits the production of ozone in the downstream kinetics.

LOGISTIC SYSTEM OF LOAD DELIVERY AND QUALITY OF ITS OPERATION

Directory of Open Access Journals (Sweden)

O. G. Drozdovskaya

2006-01-01

Full Text Available The paper considers an opportunity for obtaining a competitive advantage by a transport and dispatch service company in the market of transport services while establishing a logistic system of load delivery. A model of delivery system, an universal scheme of system designing for every specific case are presented and also indices for evaluation of its operational quality are proposed in the paper.

Advances in the Applications of Polyhydroxyalkanoate Nanoparticles for Novel Drug Delivery System

Directory of Open Access Journals (Sweden)

Anupama Shrivastav

2013-01-01

Full Text Available Drug delivery technology is emerging as an interdisciplinary science aimed at improving human health. The controlled delivery of pharmacologically active agents to the specific site of action at the therapeutically optimal rate and dose regimen has been a major goal in designing drug delivery systems. Over the past few decades, there has been considerable interest in developing biodegradable drug carriers as effective drug delivery systems. Polymeric materials from natural sources play an important role in controlled release of drug at a particular site. Polyhydroxyalkanoates, due to their origin from natural sources, are given attention as candidates for drug delivery materials. Biodegradable and biocompatible polyhydroxyalkanoates are linear polyesters produced by microorganisms under unbalanced growth conditions, which have emerged as potential polymers for use as biomedical materials for drug delivery due to their unique physiochemical and mechanical properties. This review summarizes many of the key findings in the applications of polyhydroxyalkanoates and polyhydroxyalkanoate nanoparticles for drug delivery system.

High-Pressure Oxygen Generation for Outpost EVA Study

Science.gov (United States)

Jeng, Frank F.; Conger, Bruce; Ewert, Michael K.; Anderson, Molly S.

2009-01-01

The amount of oxygen consumption for crew extravehicular activity (EVA) in future lunar exploration missions will be significant. Eight technologies to provide high pressure EVA O2 were investigated. They are: high pressure O2 storage, liquid oxygen (LOX) storage followed by vaporization, scavenging LOX from Lander followed by vaporization, LOX delivery followed by sorption compression, water electrolysis followed by compression, stand-alone high pressure water electrolyzer, Environmental Control and Life Support System (ECLSS) and Power Elements sharing a high pressure water electrolyzer, and ECLSS and In-Situ Resource Utilization (ISRU) Elements sharing a high pressure electrolyzer. A trade analysis was conducted comparing launch mass and equivalent system mass (ESM) of the eight technologies in open and closed ECLSS architectures. Technologies considered appropriate for the two architectures were selected and suggested for development.

Milrinone, dobutamine or epinephrine use in asphyxiated newborn pigs resuscitated with 100% oxygen.

Science.gov (United States)

Joynt, Chloë; Bigam, David L; Charrois, Gregory; Jewell, Laurence D; Korbutt, Gregory; Cheung, Po-Yin

2010-06-01

After resuscitation, asphyxiated neonates often develop poor cardiac function with hypotension, pulmonary hypertension and multiorgan ischemia. In a swine model of neonatal hypoxia-reoxygenation, effects of epinephrine, dobutamine and milrinone on systemic, pulmonary and regional hemodynamics and oxygen transport were compared. Controlled, block-randomized study. University research laboratory. Mixed breed piglets (1-3 days, 1.5-2.3 kg). In acutely instrumented piglets, normocapnic alveolar hypoxia (10-15% oxygen) was induced for 2 h followed by reoxygenation with 100% oxygen (1 h) then 21% oxygen (3 h). At 2 h of reoxygenation, after volume loading (Ringer's lactate 10 ml/kg), either saline (placebo), epinephrine (0.5 microg/kg/min), dobutamine (20 microg/kg/min) or milrinone (0.75 microg/kg/min) were infused for 2 h in a blinded, block-randomized fashion (n = 6/group). All medications similarly improved cardiac output, stroke volume and systemic oxygen delivery (vs. placebo-controls, p milrinone maintained, mean arterial pressure over pretreatment values while placebo-treated piglets developed hypotension and shock. The mean arterial to pulmonary arterial pressures ratio was not different among groups. All medications significantly increased carotid and intestinal, but not renal, arterial blood flows and oxygen delivery, whereas milrinone caused lower renal vascular resistance than epinephrine and dobutamine-treated groups. Plasma troponin I, plasma and myocardial lactate levels, and histologic ischemic features were not different among groups. In newborn piglets with hypoxia-reoxygenation, epinephrine, dobutamine and milrinone are effective inotropes to improve cardiac output, carotid and intestinal perfusion, without aggravating pulmonary hypertension. Milrinone may also improve renal perfusion.

Distance Learning Delivery Systems: Instructional Options.

Science.gov (United States)

Steele, Ray L.

1993-01-01

Discusses the availability of satellite and cable programing to provide distance education opportunities in school districts. Various delivery systems are described, including telephones with speakers, personal computers, and satellite dishes; and a sidebar provides a directory of distance learning opportunities, including telecommunications…

Nanoparticulate delivery systems for antiviral drugs.

Science.gov (United States)

Lembo, David; Cavalli, Roberta

2010-01-01

Nanomedicine opens new therapeutic avenues for attacking viral diseases and for improving treatment success rates. Nanoparticulate-based systems might change the release kinetics of antivirals, increase their bioavailability, improve their efficacy, restrict adverse drug side effects and reduce treatment costs. Moreover, they could permit the delivery of antiviral drugs to specific target sites and viral reservoirs in the body. These features are particularly relevant in viral diseases where high drug doses are needed, drugs are expensive and the success of a therapy is associated with a patient's adherence to the administration protocol. This review presents the current status in the emerging area of nanoparticulate delivery systems in antiviral therapy, providing their definition and description, and highlighting some peculiar features. The paper closes with a discussion on the future challenges that must be addressed before the potential of nanotechnology can be translated into safe and effective antiviral formulations for clinical use.

Non-viral Nucleic Acid Delivery Strategies to the Central Nervous System

Directory of Open Access Journals (Sweden)

James-Kevin Tan

2016-11-01

Full Text Available With an increased prevalence and understanding of central nervous system injuries and neurological disorders, nucleic acid therapies are gaining promise as a way to regenerate lost neurons or halt disease progression. While more viral vectors have been used clinically as tools for gene delivery, non-viral vectors are gaining interest due to lower safety concerns and the ability to deliver all types of nucleic acids. Nevertheless, there are still a number of barriers to nucleic acid delivery. In this focused review, we explore the in vivo challenges hindering non-viral nucleic acid delivery to the central nervous system and the strategies and vehicles used to overcome them. Advantages and disadvantages of different routes of administration including: systemic injection, cerebrospinal fluid injection, intraparenchymal injection, and peripheral administration are discussed. Non-viral vehicles and treatment strategies that have overcome delivery barriers and demonstrated in vivo gene transfer to the central nervous system are presented. These approaches can be used as guidelines in developing synthetic gene delivery vectors for central nervous system applications and will ultimately bring non-viral vectors closer to clinical application.

Software Build and Delivery Systems

Energy Technology Data Exchange (ETDEWEB)

Robey, Robert W. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2016-07-10

This presentation deals with the hierarchy of software build and delivery systems. One of the goals is to maximize the success rate of new users and developers when first trying your software. First impressions are important. Early successes are important. This also reduces critical documentation costs. This is a presentation focused on computer science and goes into detail about code documentation.

Efficient systemic DNA delivery to the tumor by self-assembled nanoparticle

Science.gov (United States)

Tang, Hailin; Xie, Xinhua; Guo, Jiaoli; Wei, Weidong; Wu, Minqing; Liu, Peng; Kong, Yanan; Yang, Lu; Hung, Mien-Chie; Xie, Xiaoming

2014-01-01

There are few delivery agents that could deliver gene with high efficiency and low toxicity, especially for animal experiments. Therefore, creating vectors with good delivery efficiency and safety profile is a meaningful work. We have developed a self-assembled gene delivery system (XM001), which can more efficiently deliver DNA to multiple cell lines and breast tumor, as compared to commercial delivery agents. In addition, systemically administrated XM001-BikDD (BikDD is a mutant form of proapoptotic gene Bik) significantly inhibited the growth of human breast cancer cells and prolonged the life span in implanted nude mice. This study demonstrates that XM001 is an efficient and widespread transfection agent, which could be a promising tumor delivery vector for cancer targeted therapy.

Exploring information systems outsourcing in U.S. hospital-based health care delivery systems.

Science.gov (United States)

Diana, Mark L

2009-12-01

The purpose of this study is to explore the factors associated with outsourcing of information systems (IS) in hospital-based health care delivery systems, and to determine if there is a difference in IS outsourcing activity based on the strategic value of the outsourced functions. IS sourcing behavior is conceptualized as a case of vertical integration. A synthesis of strategic management theory (SMT) and transaction cost economics (TCE) serves as the theoretical framework. The sample consists of 1,365 hospital-based health care delivery systems that own 3,452 hospitals operating in 2004. The findings indicate that neither TCE nor SMT predicted outsourcing better than the other did. The findings also suggest that health care delivery system managers may not be considering significant factors when making sourcing decisions, including the relative strategic value of the functions they are outsourcing. It is consistent with previous literature to suggest that the high cost of IS may be the main factor driving the outsourcing decision.

Micelles As Delivery System for Cancer Treatment.

Science.gov (United States)

Keskin, Dilek; Tezcaner, Aysen

2017-01-01

Micelles are nanoparticles formed by the self-assembly of amphiphilic block copolymers in certain solvents above concentrations called critical micelle concentration (CMC). Micelles are used in different fields like food, cosmetics, medicine, etc. These nanosized delivery systems are under spotlight in the recent years with new achievements in terms of their in vivo stability, ability to protect entrapped drug, release kinetics, ease of cellular penetration and thereby increased therapeutic efficacy. Drug loaded micelles can be prepared by dialysis, oil-in-water method, solid dispersion, freezing, spray drying, etc. The aim of this review is to give an overview of the research on micelles (in vitro, in vivo and clinical) as delivery system for cancer treatment. Passive targeting is one route for accumulation of nanosized micellar drug formulations. Many research groups from both academia and industry focus on developing new strategies for improving the therapeutic efficacy of micellar systems (active targeting to the tumor site, designing multidrug delivery systems for overcoming multidrug resistance or micelles formed by prodrug conjugates, etc). There is only one micellar drug formulation in South Korea that has reached clinical practice. However, there are many untargeted anticancer drug loaded micellar formulations in clinical trials, which have potential for use in clinics. Many more products are expected to be on the market in the near future. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Exogenous and endogenous angiotensin-II decrease renal cortical oxygen tension in conscious rats by limiting renal blood flow.

Science.gov (United States)

Emans, Tonja W; Janssen, Ben J; Pinkham, Maximilian I; Ow, Connie P C; Evans, Roger G; Joles, Jaap A; Malpas, Simon C; Krediet, C T Paul; Koeners, Maarten P

2016-11-01

Our understanding of the mechanisms underlying the role of hypoxia in the initiation and progression of renal disease remains rudimentary. We have developed a method that allows wireless measurement of renal tissue oxygen tension in unrestrained rats. This method provides stable and continuous measurements of cortical tissue oxygen tension (PO2) for more than 2 weeks and can reproducibly detect acute changes in cortical oxygenation. Exogenous angiotensin-II reduced renal cortical tissue PO2 more than equi-pressor doses of phenylephrine, probably because it reduced renal oxygen delivery more than did phenylephrine. Activation of the endogenous renin-angiotensin system in transgenic Cyp1a1Ren2 rats reduced cortical tissue PO2; in this model renal hypoxia precedes the development of structural pathology and can be reversed acutely by an angiotensin-II receptor type 1 antagonist. Angiotensin-II promotes renal hypoxia, which may in turn contribute to its pathological effects during development of chronic kidney disease. We hypothesised that both exogenous and endogenous angiotensin-II (AngII) can decrease the partial pressure of oxygen (PO2) in the renal cortex of unrestrained rats, which might in turn contribute to the progression of chronic kidney disease. Rats were instrumented with telemeters equipped with a carbon paste electrode for continuous measurement of renal cortical tissue PO2. The method reproducibly detected acute changes in cortical oxygenation induced by systemic hyperoxia and hypoxia. In conscious rats, renal cortical PO2 was dose-dependently reduced by intravenous AngII. Reductions in PO2 were significantly greater than those induced by equi-pressor doses of phenylephrine. In anaesthetised rats, renal oxygen consumption was not affected, and filtration fraction was increased only in the AngII infused animals. Oxygen delivery decreased by 50% after infusion of AngII and renal blood flow (RBF) fell by 3.3 ml min -1 . Equi-pressor infusion of

Drug Delivery Systems for Imaging and Therapy of Parkinson's Disease.

Science.gov (United States)

Gunay, Mine Silindir; Ozer, A Yekta; Chalon, Sylvie

2016-01-01

Although a variety of therapeutic approaches are available for the treatment of Parkinson's disease, challenges limit effective therapy. Among these challenges are delivery of drugs through the blood brain barier to the target brain tissue and the side effects observed during long term administration of antiparkinsonian drugs. The use of drug delivery systems such as liposomes, niosomes, micelles, nanoparticles, nanocapsules, gold nanoparticles, microspheres, microcapsules, nanobubbles, microbubbles and dendrimers is being investigated for diagnosis and therapy. This review focuses on formulation, development and advantages of nanosized drug delivery systems which can penetrate the central nervous system for the therapy and/or diagnosis of PD, and highlights future nanotechnological approaches. It is esential to deliver a sufficient amount of either therapeutic or radiocontrast agents to the brain in order to provide the best possible efficacy or imaging without undesired degradation of the agent. Current treatments focus on motor symptoms, but these treatments generally do not deal with modifying the course of Parkinson's disease. Beyond pharmacological therapy, the identification of abnormal proteins such as α -synuclein, parkin or leucine-rich repeat serine/threonine protein kinase 2 could represent promising alternative targets for molecular imaging and therapy of Parkinson's disease. Nanotechnology and nanosized drug delivery systems are being investigated intensely and could have potential effect for Parkinson's disease. The improvement of drug delivery systems could dramatically enhance the effectiveness of Parkinson's Disease therapy and reduce its side effects.

The indium-oxygen system, ch. 5

International Nuclear Information System (INIS)

Dillen, A.J. van

1977-01-01

This chapter is divided into three sections: 1) a survey of the literature concerning the indiumoxygen system, 2) the adsorption of oxygen at pure and partially oxidized indium surfaces in the temperature range 20-180degC, and 3) the oxidation of indium at temperatures above 180degC. The oxygen uptake is determined volumetrically and gravimetrically. The influence of the melting point is considered and the results are compared with data from the literature. The oxide layer is amorphous at lower temperatures but above 350degC, crystallisation of In 2 O 3 takes place

Structured emulsion-based delivery systems: controlling the digestion and release of lipophilic food components.

Science.gov (United States)

McClements, David Julian; Li, Yan

2010-09-15

There is a need for edible delivery systems to encapsulate, protect and release bioactive and functional lipophilic constituents within the food and pharmaceutical industries. These delivery systems could be used for a number of purposes: controlling lipid bioavailability; targeting the delivery of bioactive components within the gastrointestinal tract; and designing food matrices that delay lipid digestion and induce satiety. Emulsion technology is particularly suited for the design and fabrication of delivery systems for lipids. In this article we provide an overview of a number of emulsion-based technologies that can be used as edible delivery systems by the food and other industries, including conventional emulsions, nanoemulsions, multilayer emulsions, solid lipid particles, and filled hydrogel particles. Each of these delivery systems can be produced from food-grade (GRAS) ingredients (e.g., lipids, proteins, polysaccharides, surfactants, and minerals) using relatively simple processing operations (e.g., mixing, homogenizing, and thermal processing). The structure, preparation, and utilization of each type of delivery system for controlling lipid digestion are discussed. This knowledge can be used to select the most appropriate emulsion-based delivery system for specific applications, such as encapsulation, controlled digestion, and targeted release. Copyright 2010 Elsevier B.V. All rights reserved.

Waste Feed Delivery Transfer System Analysis

Energy Technology Data Exchange (ETDEWEB)

JULYK, L.J.

2000-05-05

This document provides a documented basis for the required design pressure rating and pump pressure capacity of the Hanford Site waste-transfer system in support of the waste feed delivery to the privatization contractor for vitrification. The scope of the analysis includes the 200 East Area double-shell tank waste transfer pipeline system and the associated transfer system pumps for a11 Phase 1B and Phase 2 waste transfers from AN, AP, AW, AY, and A2 Tank Farms.

Waste Feed Delivery Transfer System Analysis

International Nuclear Information System (INIS)

JULYK, L.J.

2000-01-01

This document provides a documented basis for the required design pressure rating and pump pressure capacity of the Hanford Site waste-transfer system in support of the waste feed delivery to the privatization contractor for vitrification. The scope of the analysis includes the 200 East Area double-shell tank waste transfer pipeline system and the associated transfer system pumps for a11 Phase 1B and Phase 2 waste transfers from AN, AP, AW, AY, and A2 Tank Farms

Nanoscale Nutrient Delivery Systems for Food Applications: Improving Bioactive Dispersibility, Stability, and Bioavailability.

Science.gov (United States)

McClements, David Julian

2015-07-01

There has been a surge of interest in the development of nanoscale systems for the encapsulation, protection, and delivery of lipophilic nutrients, vitamins, and nutraceuticals. This review article highlights the challenges associated with incorporating these lipophilic bioactive components into foods, and then discusses potential nanoscale delivery systems that can be used to overcome these challenges. In particular, the desirable characteristics required for any nanoscale delivery system are presented, as well as methods of fabricating them and of characterizing them. An overview of different delivery systems is given, such as microemulsions, nanoemulsions, emulsions, microgels, and biopolymer nanoparticles, and their potential applications are discussed. Nanoscale delivery systems have considerable potential within the food industry, but they must be carefully formulated to ensure that they are safe, economically viable, and effective. Nanoscale delivery systems have numerous potential applications in the food industry for encapsulating, protecting, and releasing bioactive agents, such as nutraceuticals and vitamins. This review article highlights methods for designing, fabricating, characterizing, and utilizing edible nanoparticles from a variety of different food-grade ingredients. © 2015 Institute of Food Technologists®

Buccal mucosa as a route for systemic drug delivery: a review.

Science.gov (United States)

Shojaei, A H

1998-01-01

Within the oral mucosal cavity, the buccal region offers an attractive route of administration for systemic drug delivery. The mucosa has a rich blood supply and it is relatively permeable. It is the objective of this article to review buccal drug delivery by discussing the structure and environment of the oral mucosa and the experimental methods used in assessing buccal drug permeation/absorption. Buccal dosage forms will also be reviewed with an emphasis on bioadhesive polymeric based delivery systems

A Sample Delivery System for Planetary Missions

Data.gov (United States)

National Aeronautics and Space Administration — The project will develop, test and characterize the performance of a prototype /sample delivery system (SDS) implemented as an end effector on a robotic arm capable...

Evaluation of Additively Manufactured Metals for Use in Oxygen Systems Project

Science.gov (United States)

Tylka, Jonathan; Cooper, Ken; Peralta, Stephen; Wilcutt, Terrence; Hughitt, Brian; Generazio, Edward

2016-01-01

Space Launch System, Commercial Resupply, and Commercial Crew programs have published intent to use additively manufactured (AM) components in propulsion systems and are likely to include various life support systems in the future. Parts produced by these types of additive manufacturing techniques have not been fully evaluated for use in oxygen systems and the inherent risks have not been fully identified. Some areas of primary concern in the SLS process with respect to oxygen compatibility may be the porosity of the printed parts, fundamental differences in microstructure of an AM part as compared to traditional materials, or increased risk of shed metal particulate into an oxygen system. If an ignition were to occur the printed material could be more flammable than components manufactured from a traditional billet of raw material and/or present a significant hazards if not identified and rigorously studied in advance of implementation into an oxygen system.

Gradually Increased Oxygen Administration Improved Oxygenation and Mitigated Oxidative Stress after Resuscitation from Severe Hemorrhagic Shock.

Science.gov (United States)

Luo, Xin; Yin, Yujing; You, Guoxing; Chen, Gan; Wang, Ying; Zhao, Jingxiang; Wang, Bo; Zhao, Lian; Zhou, Hong

2015-11-01

The optimal oxygen administration strategy during resuscitation from hemorrhagic shock (HS) is still controversial. Improving oxygenation and mitigating oxidative stress simultaneously seem to be contradictory goals. To maximize oxygen delivery while minimizing oxidative damage, the authors proposed the notion of gradually increased oxygen administration (GIOA), which entails making the arterial blood hypoxemic early in resuscitation and subsequently gradually increasing to hyperoxic, and compared its effects with normoxic resuscitation, hyperoxic resuscitation, and hypoxemic resuscitation in severe HS. Rats were subjected to HS, and on resuscitation, the rats were randomly assigned to four groups (n = 8): the normoxic, the hyperoxic, the hypoxemic, and the GIOA groups. Rats were observed for an additional 1 h. Hemodynamics, acid-base status, oxygenation, and oxidative injury were observed and evaluated. Central venous oxygen saturation promptly recovered only in the hyperoxic and the GIOA groups, and the liver tissue partial pressure of oxygen was highest in the GIOA group after resuscitation. Oxidative stress in GIOA group was significantly reduced compared with the hyperoxic group as indicated by the reduced malondialdehyde content, increased catalase activity, and the lower histologic injury scores in the liver. In addition, the tumor necrosis factor-α and interleukin-6 expressions in the liver were markedly decreased in the GIOA group than in the hyperoxic and normoxic groups as shown by the immunohistochemical staining. GIOA improved systemic/tissue oxygenation and mitigated oxidative stress simultaneously after resuscitation from severe HS. GIOA may be a promising strategy to improve resuscitation from HS and deserves further investigation.

Drug delivery system and breast cancer cells

Science.gov (United States)

Colone, Marisa; Kaliappan, Subramanian; Calcabrini, Annarica; Tortora, Mariarosaria; Cavalieri, Francesca; Stringaro, Annarita

2016-06-01

Recently, nanomedicine has received increasing attention for its ability to improve the efficacy of cancer therapeutics. Nanosized polymer therapeutic agents offer the advantage of prolonged circulation in the blood stream, targeting to specific sites, improved efficacy and reduced side effects. In this way, local, controlled delivery of the drug will be achieved with the advantage of a high concentration of drug release at the target site while keeping the systemic concentration of the drug low, thus reducing side effects due to bioaccumulation. Various drug delivery systems such as nanoparticles, liposomes, microparticles and implants have been demonstrated to significantly enhance the preventive/therapeutic efficacy of many drugs by increasing their bioavailability and targetability. As these carriers significantly increase the therapeutic effect of drugs, their administration would become less cost effective in the near future. The purpose of our research work is to develop a delivery system for breast cancer cells using a microvector of drugs. These results highlight the potential uses of these responsive platforms suited for biomedical and pharmaceutical applications. At the request of all authors of the paper an updated version was published on 12 July 2016. The manuscript was prepared and submitted without Dr. Francesca Cavalieri's contribution and her name was added without her consent. Her name has been removed in the updated and re-published article.

Nursing Services Delivery Theory: an open system approach

Science.gov (United States)

Meyer, Raquel M; O’Brien-Pallas, Linda L

2010-01-01

meyer r.m. & o’brien-pallas l.l. (2010)Nursing services delivery theory: an open system approach. Journal of Advanced Nursing66(12), 2828–2838. Aim This paper is a discussion of the derivation of the Nursing Services Delivery Theory from the application of open system theory to large-scale organizations. Background The underlying mechanisms by which staffing indicators influence outcomes remain under-theorized and unmeasured, resulting in a ‘black box’ that masks the nature and organization of nursing work. Theory linking nursing work, staffing, work environments, and outcomes in different settings is urgently needed to inform management decisions about the allocation of nurse staffing resources in organizations. Data sources A search of CINAHL and Business Source Premier for the years 1980–2008 was conducted using the following terms: theory, models, organization, organizational structure, management, administration, nursing units, and nursing. Seminal works were included. Discussion The healthcare organization is conceptualized as an open system characterized by energy transformation, a dynamic steady state, negative entropy, event cycles, negative feedback, differentiation, integration and coordination, and equifinality. The Nursing Services Delivery Theory proposes that input, throughput, and output factors interact dynamically to influence the global work demands placed on nursing work groups at the point of care in production subsystems. Implications for nursing The Nursing Services Delivery Theory can be applied to varied settings, cultures, and countries and supports the study of multi-level phenomena and cross-level effects. Conclusion The Nursing Services Delivery Theory gives a relational structure for reconciling disparate streams of research related to nursing work, staffing, and work environments. The theory can guide future research and the management of nursing services in large-scale healthcare organizations. PMID:20831573

Sustained subconjunctival protein delivery using a thermosetting gel delivery system.

Science.gov (United States)

Rieke, Erin R; Amaral, Juan; Becerra, S Patricia; Lutz, Robert J

2010-02-01

An effective treatment modality for posterior eye diseases would provide prolonged delivery of therapeutic agents, including macromolecules, to eye tissues using a safe and minimally invasive method. The goal of this study was to assess the ability of a thermosetting gel to deliver a fluorescently labeled protein, Alexa 647 ovalbumin, to the choroid and retina of rats following a single subconjunctival injection of the gel. Additional experiments were performed to compare in vitro to in vivo ovalbumin release rates from the gel. The ovalbumin content of the eye tissues was monitored by spectrophotometric assays of tissue extracts of Alexa 647 ovalbumin from dissected sclera, choroid, and retina at time points ranging from 2 h to 14 days. At the same time points, fluorescence microscopy images of tissue samples were also obtained. Measurement of intact ovalbumin was verified by LDS-PAGE analysis of the tissue extract solutions. In vitro release of Alexa 488 ovalbumin into 37 degrees C PBS solutions from ovalbumin-loaded gel pellets was also monitored over time by spectrophotometric assay. In vivo ovalbumin release rates were determined by measurement of residual ovalbumin extracted from gel pellets removed from rat eyes at various time intervals. Our results indicate that ovalbumin concentrations can be maintained at measurable levels in the sclera, choroid, and retina of rats for up to 14 days using the thermosetting gel delivery system. The concentration of ovalbumin exhibited a gradient that decreased from sclera to choroid and to retina. The in vitro release rate profiles were similar to the in vivo release profiles. Our findings suggest that the thermosetting gel system may be a feasible method for safe and convenient sustained delivery of proteins to choroidal and retinal tissue in the posterior segments of the eye.

Nature engineered diatom biosilica as drug delivery systems.

Science.gov (United States)

Uthappa, U T; Brahmkhatri, Varsha; Sriram, G; Jung, Ho-Young; Yu, Jingxian; Kurkuri, Nikita; Aminabhavi, Tejraj M; Altalhi, Tariq; Neelgund, Gururaj M; Kurkuri, Mahaveer D

2018-05-14

Diatoms, unicellular photosynthetic algae covered with siliceous cell wall, are also called frustule. These are the most potential naturally available materials for the development of cost-effective drug delivery systems because of their excellent biocompatibility, high surface area, low cost and ease of surface modification. Mesoporous silica materials such as MCM-41 and SBA-15 have been extensively used in drug delivery area. Their synthesis is challenging, time consuming, requires toxic chemicals and are energy intensive, making the entire process expensive and non-viable. Therefore, it is necessary to explore alternative materials. Surprisingly, nature has provided some exciting materials called diatoms; biosilica is one such a material that can be potentially used as a drug delivery vehicle. The present review focuses on different types of diatom species used in drug delivery with respect to their structural properties, morphology, purification process and surface functionalization. In this review, recent advances along with their limitations as well as the future scope to develop them as potential drug delivery vehicles are discussed. Copyright © 2018. Published by Elsevier B.V.

Analysis and Design Information System Logistics Delivery Service in Pt Repex Wahana

Directory of Open Access Journals (Sweden)

Stephanie Surja

2015-12-01

Full Text Available Analysis and Design of Logistic Delivery System in PT Repex Wahana aims to analyze company’s need in existing business process of logistic delivery service. This will then be used in the development of an integrated system that can address the problems in the running process of sending and tracking the whereaboutsor status of the delivered goods which are the core business processes in the enterprise. The result then will be used as basis in the development of integrated information system in pursuit of corporate solution for process business automation, delivery process, inventory, and logistic delivery tracking, which is the core of the company business process, and it will be documented using Unified Modeling Language. The information system is meant to simplify the delivery and tracking process in the company, besides will minimize lost and error of data which is often happened because of the manual and unorganized transaction data processing.

Approaches and Challenges of Engineering Implantable Microelectromechanical Systems (MEMS Drug Delivery Systems for in Vitro and in Vivo Applications

Directory of Open Access Journals (Sweden)

Ken-Tye Yong

2012-11-01

Full Text Available Despite the advancements made in drug delivery systems over the years, many challenges remain in drug delivery systems for treating chronic diseases at the personalized medicine level. The current urgent need is to develop novel strategies for targeted therapy of chronic diseases. Due to their unique properties, microelectromechanical systems (MEMS technology has been recently engineered as implantable drug delivery systems for disease therapy. This review examines the challenges faced in implementing implantable MEMS drug delivery systems in vivo and the solutions available to overcome these challenges.

Oral heparin delivery: design and in vivo evaluation of a stomach-targeted mucoadhesive delivery system.

Science.gov (United States)

Schmitz, Thierry; Leitner, Verena M; Bernkop-Schnürch, Andreas

2005-05-01

Low molecular weight heparin (LMWH) is an agent of choice in the anti-coagulant therapy and prophylaxis of thrombosis and coronary syndromes. However, the therapeutic use is partially limited due to a poor oral bioavailability. It was therefore the aim of this study to design and evaluate a highly efficient stomach-targeted oral delivery system for LMWH. In order to appraise the influence of the molecular weight on the oral bioavailability, mini-tablets comprising 3 kDa (279 IU) and 6 kDa (300 IU) LMWH, respectively, were generated and tested in vivo in rats. The potential of the test formulations based on thiolated polycarbophil, was evaluated in comparison to hydroxyethylcellulose (HEC) as control carrier matrix. The plasma levels of LMWH after oral versus subcutaneous administration were determined in order to calculate the relative bioavailability. With the delivery system containing 3 kDa LMWH (279 IU) a relative bioavailability of 19.1% was achieved, offering a significantly (p thiolated polymers are a promising tool for the non-invasive stomach-targeted systemic delivery of LMWH as model for a hydrophilic macromolecular polysaccharide. Copyright 2005 Wiley-Liss, Inc

Colon-targeted oral drug delivery systems: design trends and approaches.

Science.gov (United States)

Amidon, Seth; Brown, Jack E; Dave, Vivek S

2015-08-01

Colon-specific drug delivery systems (CDDS) are desirable for the treatment of a range of local diseases such as ulcerative colitis, Crohn's disease, irritable bowel syndrome, chronic pancreatitis, and colonic cancer. In addition, the colon can be a potential site for the systemic absorption of several drugs to treat non-colonic conditions. Drugs such as proteins and peptides that are known to degrade in the extreme gastric pH, if delivered to the colon intact, can be systemically absorbed by colonic mucosa. In order to achieve effective therapeutic outcomes, it is imperative that the designed delivery system specifically targets the drugs into the colon. Several formulation approaches have been explored in the development colon-targeted drug delivery systems. These approaches involve the use of formulation components that interact with one or more aspects of gastrointestinal (GI) physiology, such as the difference in the pH along the GI tract, the presence of colonic microflora, and enzymes, to achieve colon targeting. This article highlights the factors influencing colon-specific drug delivery and colonic bioavailability, and the limitations associated with CDDS. Further, the review provides a systematic discussion of various conventional, as well as relatively newer formulation approaches/technologies currently being utilized for the development of CDDS.

Transferosomes - A vesicular transdermal delivery system for enhanced drug permeation

Directory of Open Access Journals (Sweden)

Reshmy Rajan

2011-01-01

Full Text Available Transdermal administration of drugs is generally limited by the barrier function of the skin. Vesicular systems are one of the most controversial methods for transdermal delivery of active substances. The interest in designing transdermal delivery systems was relaunched after the discovery of elastic vesicles like transferosomes, ethosomes, cubosomes, phytosomes, etc. This paper presents the composition, mechanisms of penetration, manufacturing and characterization methods of transferosomes as transdermal delivery systems of active substances. For a drug to be absorbed and distributed into organs and tissues and eliminated from the body, it must pass through one or more biological membranes/barriers at various locations. Such a movement of drug across the membrane is called as drug transport. For the drugs to be delivered to the body, they should cross the membranous barrier. The concept of these delivery systems was designed in an attempt to concentrate the drug in the tissues of interest, while reducing the amount of drug in the remaining tissues. Hence, surrounding tissues are not affected by the drug. In addition, loss of drug does not happen due to localization of drug, leading to get maximum efficacy of the medication. Therefore, the phospholipid based carrier systems are of considerable interest in this era.

Can Oxygen Set Thermal Limits in an Insect and Drive Gigantism?

Science.gov (United States)

Verberk, Wilco C. E. P.; Bilton, David T.

2011-01-01

Background Thermal limits may arise through a mismatch between oxygen supply and demand in a range of animal taxa. Whilst this oxygen limitation hypothesis is supported by data from a range of marine fish and invertebrates, its generality remains contentious. In particular, it is unclear whether oxygen limitation determines thermal extremes in tracheated arthropods, where oxygen limitation may be unlikely due to the efficiency and plasticity of tracheal systems in supplying oxygen directly to metabolically active tissues. Although terrestrial taxa with open tracheal systems may not be prone to oxygen limitation, species may be affected during other life-history stages, particularly if these rely on diffusion into closed tracheal systems. Furthermore, a central role for oxygen limitation in insects is envisaged within a parallel line of research focussing on insect gigantism in the late Palaeozoic. Methodology/Principal Findings Here we examine thermal maxima in the aquatic life stages of an insect at normoxia, hypoxia (14 kPa) and hyperoxia (36 kPa). We demonstrate that upper thermal limits do indeed respond to external oxygen supply in the aquatic life stages of the stonefly Dinocras cephalotes, suggesting that the critical thermal limits of such aquatic larvae are set by oxygen limitation. This could result from impeded oxygen delivery, or limited oxygen regulatory capacity, both of which have implications for our understanding of the limits to insect body size and how these are influenced by atmospheric oxygen levels. Conclusions/Significance These findings extend the generality of the hypothesis of oxygen limitation of thermal tolerance, suggest that oxygen constraints on body size may be stronger in aquatic environments, and that oxygen toxicity may have actively selected for gigantism in the aquatic stages of Carboniferous arthropods. PMID:21818347

Can oxygen set thermal limits in an insect and drive gigantism?

Directory of Open Access Journals (Sweden)

Wilco C E P Verberk

Full Text Available BACKGROUND: Thermal limits may arise through a mismatch between oxygen supply and demand in a range of animal taxa. Whilst this oxygen limitation hypothesis is supported by data from a range of marine fish and invertebrates, its generality remains contentious. In particular, it is unclear whether oxygen limitation determines thermal extremes in tracheated arthropods, where oxygen limitation may be unlikely due to the efficiency and plasticity of tracheal systems in supplying oxygen directly to metabolically active tissues. Although terrestrial taxa with open tracheal systems may not be prone to oxygen limitation, species may be affected during other life-history stages, particularly if these rely on diffusion into closed tracheal systems. Furthermore, a central role for oxygen limitation in insects is envisaged within a parallel line of research focussing on insect gigantism in the late Palaeozoic. METHODOLOGY/PRINCIPAL FINDINGS: Here we examine thermal maxima in the aquatic life stages of an insect at normoxia, hypoxia (14 kPa and hyperoxia (36 kPa. We demonstrate that upper thermal limits do indeed respond to external oxygen supply in the aquatic life stages of the stonefly Dinocras cephalotes, suggesting that the critical thermal limits of such aquatic larvae are set by oxygen limitation. This could result from impeded oxygen delivery, or limited oxygen regulatory capacity, both of which have implications for our understanding of the limits to insect body size and how these are influenced by atmospheric oxygen levels. CONCLUSIONS/SIGNIFICANCE: These findings extend the generality of the hypothesis of oxygen limitation of thermal tolerance, suggest that oxygen constraints on body size may be stronger in aquatic environments, and that oxygen toxicity may have actively selected for gigantism in the aquatic stages of Carboniferous arthropods.

Leadership Perspectives on Operationalizing the Learning Health Care System in an Integrated Delivery System.

Science.gov (United States)

Psek, Wayne; Davis, F Daniel; Gerrity, Gloria; Stametz, Rebecca; Bailey-Davis, Lisa; Henninger, Debra; Sellers, Dorothy; Darer, Jonathan

2016-01-01

Healthcare leaders need operational strategies that support organizational learning for continued improvement and value generation. The learning health system (LHS) model may provide leaders with such strategies; however, little is known about leaders' perspectives on the value and application of system-wide operationalization of the LHS model. The objective of this project was to solicit and analyze senior health system leaders' perspectives on the LHS and learning activities in an integrated delivery system. A series of interviews were conducted with 41 system leaders from a broad range of clinical and administrative areas across an integrated delivery system. Leaders' responses were categorized into themes. Ten major themes emerged from our conversations with leaders. While leaders generally expressed support for the concept of the LHS and enhanced system-wide learning, their concerns and suggestions for operationalization where strongly aligned with their functional area and strategic goals. Our findings suggests that leaders tend to adopt a very pragmatic approach to learning. Leaders expressed a dichotomy between the operational imperative to execute operational objectives efficiently and the need for rigorous evaluation. Alignment of learning activities with system-wide strategic and operational priorities is important to gain leadership support and resources. Practical approaches to addressing opportunities and challenges identified in the themes are discussed. Continuous learning is an ongoing, multi-disciplinary function of a health care delivery system. Findings from this and other research may be used to inform and prioritize system-wide learning objectives and strategies which support reliable, high value care delivery.

Novel delivery systems with nonsteroidal anti-inflammatory drugs

Directory of Open Access Journals (Sweden)

Cvijić Sandra

2016-01-01

Full Text Available Chronic use of oral nonsteroidal anti-inflammatory drugs (NSAIDs is associated with increased risk of serious gastrointestinal side effects. Therefore, recent trends in the development of NSAIDs aim to reduce the incidence of side effects, and improve patient compliance. One of the strategies to improve efficacy and safety of oral NSAIDs is the development of combination products that contain gastroprotective agents. Several products containing NSAID in combination with proton pump inhibitors (ketoprofen/omeprazole, naproxen/esomeprazole, H2-receptor antagonists (ibuprofen/famotidine, and prostaglandin analogues (diclofenac/misoprostol are currently available on the market. Another approach refer to the special formulation design to allow dose reduction while preserving drug therapeutic efficacy. An example is SoluMatrix® technology, a manufacturing process that produce submicron-sized drug particles with enhanced dissolution and absorption properties. Patented SoluMatrix® technology has been successfully employed to develop low-dose diclofenac, meloxicam, indomethacin and naproxen products. Topical NSAID formulations enable drug delivery to target tissues, while reducing systemic exposure and concomitant side effects associated with oral NSAIDs. Dermal/transdermal NSAID delivery systems are subject of intensive investigation. So far, several 'advanced' drug delivery systems with diclofenac, ibuprofen and ketoprofen have been designed.

A clinical perspective on mucoadhesive buccal drug delivery systems

Science.gov (United States)

Gilhotra, Ritu M; Ikram, Mohd; Srivastava, Sunny; Gilhotra, Neeraj

2014-01-01

Mucoadhesion can be defined as a state in which two components, of which one is of biological origin, are held together for extended periods of time by the help of interfacial forces. Among the various transmucosal routes, buccal mucosa has excellent accessibility and relatively immobile mucosa, hence suitable for administration of retentive dosage form. The objective of this paper is to review the works done so far in the field of mucoadhesive buccal drug delivery systems (MBDDS), with a clinical perspective. Starting with a brief introduction of the mucoadhesive drug delivery systems, oral mucosa, and the theories of mucoadhesion, this article then proceeds to cover the works done so far in the field of MBDDS, categorizing them on the basis of ailments they are meant to cure. Additionally, we focus on the various patents, recent advancements, and challenges as well as the future prospects for mucoadhesive buccal drug delivery systems. PMID:24683406

Secondary fuel delivery system

Science.gov (United States)

Parker, David M.; Cai, Weidong; Garan, Daniel W.; Harris, Arthur J.

2010-02-23

A secondary fuel delivery system for delivering a secondary stream of fuel and/or diluent to a secondary combustion zone located in the transition piece of a combustion engine, downstream of the engine primary combustion region is disclosed. The system includes a manifold formed integral to, and surrounding a portion of, the transition piece, a manifold inlet port, and a collection of injection nozzles. A flowsleeve augments fuel/diluent flow velocity and improves the system cooling effectiveness. Passive cooling elements, including effusion cooling holes located within the transition boundary and thermal-stress-dissipating gaps that resist thermal stress accumulation, provide supplemental heat dissipation in key areas. The system delivers a secondary fuel/diluent mixture to a secondary combustion zone located along the length of the transition piece, while reducing the impact of elevated vibration levels found within the transition piece and avoiding the heat dissipation difficulties often associated with traditional vibration reduction methods.

Ophthalmic Drug Delivery Systems for Antibiotherapy—A Review

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Dubald, Marion; Bourgeois, Sandrine; Andrieu, Véronique; Fessi, Hatem

2018-01-01

The last fifty years, ophthalmic drug delivery research has made much progress, challenging scientists about the advantages and limitations of this drug delivery approach. Topical eye drops are the most commonly used formulation in ocular drug delivery. Despite the good tolerance for patients, this topical administration is only focus on the anterior ocular diseases and had a high precorneal loss of drugs due to the tears production and ocular barriers. Antibiotics are popularly used in solution or in ointment for the ophthalmic route. However, their local bioavailability needs to be improved in order to decrease the frequency of administrations and the side effects and to increase their therapeutic efficiency. For this purpose, sustained release forms for ophthalmic delivery of antibiotics were developed. This review briefly describes the ocular administration with the ocular barriers and the currently topical forms. It focuses on experimental results to bypass the limitations of ocular antibiotic delivery with new ocular technology as colloidal and in situ gelling systems or with the improvement of existing forms as implants and contact lenses. Nanotechnology is presently a promising drug delivery way to provide protection of antibiotics and improve pathway through ocular barriers and deliver drugs to specific target sites. PMID:29342879

Ophthalmic Drug Delivery Systems for Antibiotherapy—A Review

Directory of Open Access Journals (Sweden)

Marion Dubald

2018-01-01

Full Text Available The last fifty years, ophthalmic drug delivery research has made much progress, challenging scientists about the advantages and limitations of this drug delivery approach. Topical eye drops are the most commonly used formulation in ocular drug delivery. Despite the good tolerance for patients, this topical administration is only focus on the anterior ocular diseases and had a high precorneal loss of drugs due to the tears production and ocular barriers. Antibiotics are popularly used in solution or in ointment for the ophthalmic route. However, their local bioavailability needs to be improved in order to decrease the frequency of administrations and the side effects and to increase their therapeutic efficiency. For this purpose, sustained release forms for ophthalmic delivery of antibiotics were developed. This review briefly describes the ocular administration with the ocular barriers and the currently topical forms. It focuses on experimental results to bypass the limitations of ocular antibiotic delivery with new ocular technology as colloidal and in situ gelling systems or with the improvement of existing forms as implants and contact lenses. Nanotechnology is presently a promising drug delivery way to provide protection of antibiotics and improve pathway through ocular barriers and deliver drugs to specific target sites.

Adamantane in Drug Delivery Systems and Surface Recognition

OpenAIRE

Adela Štimac; Marina Šekutor; Kata Mlinarić-Majerski; Leo Frkanec; Ruža Frkanec

2017-01-01

The adamantane moiety is widely applied in design and synthesis of new drug delivery systems and in surface recognition studies. This review focuses on liposomes, cyclodextrins, and dendrimers based on or incorporating adamantane derivatives. Our recent concept of adamantane as an anchor in the lipid bilayer of liposomes has promising applications in the field of targeted drug delivery and surface recognition. The results reported here encourage the development of novel adamantane-based struc...

Solid Lipid Nanoparticles as Efficient Drug and Gene Delivery Systems: Recent Breakthroughs

Directory of Open Access Journals (Sweden)

Jafar Ezzati Nazhad Dolatabadi

2015-06-01

Full Text Available In recent years, nanomaterials have been widely applied as advanced drug and gene delivery nanosystems. Among them, solid lipid nanoparticles (SLNs have attracted great attention as colloidal drug delivery systems for incorporating hydrophilic or lipophilic drugs and various macromolecules as well as proteins and nucleic acids. Therefore, SLNs offer great promise for controlled and site specific drug and gene delivery. This article includes general information about SLN structures and properties, production procedures, characterization. In addition, recent progress on development of drug and gene delivery systems using SLNs was reviewed.

The transport of oxygen isotopes in hydrothermal systems

International Nuclear Information System (INIS)

McKibbin, R.; Absar, A.; Blattner, P.

1986-01-01

As groundwater passes through porous rocks, exchange of oxygen between the fluid and the solid matrix causes a change in the oxygen isotope concentrations in both water and rock. If the rate at which the exchange takes place can be estimated (as a function of the isotope concentrations and temperature) then the time taken for a rock/water system to come to equilibrium with respect to isotope concentration might be calculated. In this paper, the equation for isotope transport is derived using conservation laws, and a simple equation to describe the rate of isotope exchange is proposed. These are combined with the equations for fluid flow in a porous medium, to produce a general set of equations describing isotope transport in a hydrothermal system. These equations are solved numerically, using typical parameters, for the one-dimensional case. Oxygen isotope data from the basement rocks underlying Kawerau geothermal field are modelled. The results indicate that the time taken for exchange of 18 O to present-day values is less than the postulated age of hydrothermal alteration in that field. This suggests that, although controlled by similar parameters, oxygen isotope exchange, in felsic rocks at least, is much faster than hydrothermal alteration. This conclusion is consistent with the petrographic observations from the Kawerau system as well as other geothermal fields

14 CFR 25.1445 - Equipment standards for the oxygen distributing system.

Science.gov (United States)

2010-01-01

... distributing system. 25.1445 Section 25.1445 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT... Miscellaneous Equipment § 25.1445 Equipment standards for the oxygen distributing system. (a) When oxygen is supplied to both crew and passengers, the distribution system must be designed for either— (1) A source of...

Zein-alginate based oral drug delivery systems: Protection and release of therapeutic proteins.

Science.gov (United States)

Lee, Sungmun; Kim, Yeu-Chun; Park, Ji-Ho

2016-12-30

Reactive oxygen species (ROS) play an important role in the development of inflammatory bowel diseases. Superoxide dismutase (SOD) has a great therapeutic potential by scavenging superoxide that is one of ROS; however, in vivo application is limited especially when it is orally administered. SOD is easily degraded in vivo by the harsh conditions of gastrointestinal tract. Here, we design a zein-alginate based oral drug delivery system that protects SOD from the harsh conditions of gastrointestinal tract and releases it in the environment of the small intestine. SOD is encapsulated in zein-alginate nanoparticles (ZAN) via a phase separation method. We demonstrate that ZAN protect SOD from the harsh conditions of the stomach or small intestine condition. ZAN (200:40) at the weight ratio of 200mg zein to 40mg of alginate releases SOD in a pH dependent manner, and it releases 90.8±1.2% of encapsulated SOD at pH 7.4 in 2h, while only 11.4±0.4% of SOD was released at pH 1.3. The encapsulation efficiency of SOD in ZAN (200:40) was 62.1±2.0%. SOD in ZAN (200:40) reduced the intracellular ROS level and it saved 88.9±7.5% of Caco-2 cells from the toxic superoxide in 4 hours. Based on the results, zein-alginate based oral drug delivery systems will have numerous applications to drugs that are easily degradable in the harsh conditions of gastrointestinal tract. Copyright © 2016 Elsevier B.V. All rights reserved.

Waste feed delivery program systems engineering implementation plan

International Nuclear Information System (INIS)

O'Toole, S.M.; Hendel, B.J.

1998-01-01

This document defines the systems engineering processes and products planned by the Waste Feed Delivery Program to develop the necessary and sufficient systems to provide waste feed to the Privatization Contractor for Phase 1. It defines roles and responsibilities for the performance of the systems engineering processes and generation of products

Safe Active Scanning for Energy Delivery Systems Final Report

Energy Technology Data Exchange (ETDEWEB)

Helms, J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Salazar, B. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Scheibel, P. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Engels, M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Reiger, C. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

2017-09-30

The Department of Energy’s Cybersecurity for Energy Delivery Systems Program has funded Safe(r) Active Scanning for Energy Delivery Systems, led by Lawrence Livermore National Laboratory, to investigate and analyze the impacts of active scanning in the operational environment of energy delivery systems. In collaboration with Pacific Northwest National Laboratory and Idaho National Laboratory, active scans across three testbeds including 38 devices were performed. This report gives a summary of the initial literature survey performed on the SASEDS project as well as industry partner interview summaries and main findings from Phase 1 of the project. Additionally, the report goes into the details of scanning techniques, methodologies for testing, testbed descriptions, and scanning results, with appendices to elaborate on the specific scans that were performed. As a result of testing, a single device out of 38 exhibited problems when actively scanned, and a reboot was required to fix it. This single failure indicates that active scanning is not likely to have a detrimental effect on the safety and resilience of energy delivery systems. We provide a path forward for future research that could enable wide adoption of active scanning and lead utilities to incorporate active scanning as part of their default network security plans to discover and rectify rogue devices, adversaries, and services that may be on the network. This increased network visibility will allow operational technology cybersecurity practitioners to improve their situational awareness of networks and their vulnerabilities.

Renal Blood Flow, Glomerular Filtration Rate, and Renal Oxygenation in Early Clinical Septic Shock.

Science.gov (United States)

Skytte Larsson, Jenny; Krumbholz, Vitus; Enskog, Anders; Bragadottir, Gudrun; Redfors, Bengt; Ricksten, Sven-Erik

2018-06-01

Data on renal hemodynamics, function, and oxygenation in early clinical septic shock are lacking. We therefore measured renal blood flow, glomerular filtration rate, renal oxygen consumption, and oxygenation in patients with early septic shock. Prospective comparative study. General and cardiothoracic ICUs. Patients with norepinephrine-dependent early septic shock (n = 8) were studied within 24 hours after arrival in the ICU and compared with postcardiac surgery patients without acute kidney injury (comparator group, n = 58). None. Data on systemic hemodynamics and renal variables were obtained during two 30-minute periods. Renal blood flow was measured by the infusion clearance of para-aminohippuric acid, corrected for renal extraction of para-aminohippuric acid. Renal filtration fraction was measured by renal extraction of chromium-51 labeled EDTA. Renal oxygenation was estimated from renal oxygen extraction. Renal oxygen delivery (-24%; p = 0.037) and the renal blood flow-to-cardiac index ratio (-21%; p = 0.018) were lower, renal vascular resistance was higher (26%; p = 0.027), whereas renal blood flow tended to be lower (-19%; p = 0.068) in the septic group. Glomerular filtration rate (-32%; p = 0.006) and renal sodium reabsorption (-29%; p = 0.014) were both lower in the septic group. Neither renal filtration fraction nor renal oxygen consumption differed significantly between groups. Renal oxygen extraction was significantly higher in the septic group (28%; p = 0.022). In the septic group, markers of tubular injury were elevated. In early clinical septic shock, renal function was lower, which was accompanied by renal vasoconstriction, a lower renal oxygen delivery, impaired renal oxygenation, and tubular sodium reabsorption at a high oxygen cost compared with controls.

Efficacy of a portable oxygen concentrator with pulsed delivery for treatment of hypoxemia during equine field anesthesia.

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Coutu, Paige; Caulkett, Nigel; Pang, Daniel; Boysen, Søren

2015-09-01

Hypoxemia is common during equine field anesthesia. Our hypothesis was that oxygen therapy from a portable oxygen concentrator would increase PaO2 during field anesthesia compared with the breathing of ambient air. Prospective clinical study. Fifteen yearling (250 - 400 kg) horses during field castration. Horses were maintained in dorsal recumbency during anesthesia with an intravenous infusion of 2000 mg ketamine and 500 mg xylazine in 1 L of 5% guaifenesin. Arterial samples for blood gas analysis were collected immediately post-induction (PI), and at 15 and 30 minutes PI. The control group (n = 6) breathed ambient air. The treatment group (n = 9) were administered pulsed-flow oxygen (192 mL per bolus) by nasal insufflation during inspiration for 15 minutes PI, then breathed ambient air. The study was performed at 1300 m above sea level. One-way and two-way repeated-measures anova with post-hoc Bonferroni tests were used for within and between-group comparisons, respectively. Significance was set at p ≤ 0.05. Mean ± SD PaO2 in controls at 0, 15 and 30 minutes PI were 46 ± 7 mmHg (6.1 ± 0.9 kPa), 42 ± 9 mmHg (5.6 ± 1.1 kPa), and 48 ± 7 mmHg (6.4 ± 0.1 kPa), respectively (p = 0.4). In treatment animals, oxygen administration significantly increased PaO2 at 15 minutes PI to 60 ± 13 mmHg (8.0 ± 1.7 kPa), compared with baseline values of 46 ± 8 mmHg (6.1 ± 1 kPa) (p = 0.007), and 30 minute PI values of 48 ± 7 mmHg (6.5 ± 0.9 kPa) (p = 0.003). These data show that a pulsed-flow delivery of oxygen can increase PaO2 in dorsally recumbent horses during field anesthesia with ketamine-xylazine-guaifenesin. The portable oxygen concentrator may help combat hypoxemia during field anesthesia in horses. © 2015 Association of Veterinary Anaesthetists and the American College of Veterinary Anesthesia and Analgesia.

Svelte Integrated Delivery System Performance Examined Through Diagnostic Catheter Delivery : The SPEED Registry

NARCIS (Netherlands)

Khattab, Ahmed A.; Nijhoff, Freek; Schofer, Joachim; Berland, Jacques; Meier, Bernhard; Nietlispach, Fabian; Agostoni, Pierfrancesco; Brucks, Steffen; Stella, Pieter

2015-01-01

Aims: The multi-center SPEED registry evaluated the procedural success and in-hospital clinical outcomes of direct stenting with the Svelte 'all-in-one' coronary stent Integrated Delivery System (IDS) through diagnostic catheters to identify the clinical indications for which this approach is

Regional Multiteam Systems in Cancer Care Delivery

Science.gov (United States)

Monson, John R.T.; Rizvi, Irfan; Savastano, Ann; Green, James S.A.; Sevdalis, Nick

2016-01-01

Teamwork is essential for addressing many of the challenges that arise in the coordination and delivery of cancer care, especially for the problems that are presented by patients who cross geographic boundaries and enter and exit multiple health care systems at various times during their cancer care journeys. The problem of coordinating the care of patients with cancer is further complicated by the growing number of treatment options and modalities, incompatibilities among the vast variety of technology platforms that have recently been adopted by the health care industry, and competing and misaligned incentives for providers and systems. Here we examine the issue of regional care coordination in cancer through the prism of a real patient journey. This article will synthesize and elaborate on existing knowledge about coordination approaches for complex systems, in particular, in general and cancer care multidisciplinary teams; define elements of coordination derived from organizational psychology and human factors research that are applicable to team-based cancer care delivery; and suggest approaches for improving multidisciplinary team coordination in regional cancer care delivery and avenues for future research. The phenomenon of the mobile, multisystem patient represents a growing challenge in cancer care. Paradoxically, development of high-quality, high-volume centers of excellence and the ease of virtual communication and data sharing by using electronic medical records have introduced significant barriers to effective team-based cancer care. These challenges urgently require solutions. PMID:27650833

Whey protein-derived biomaterials and their use as bioencapsulation and delivery systems

Directory of Open Access Journals (Sweden)

Subirade Muriel

2003-01-01

Full Text Available The emergence of bioactive food compounds (nutraceutical compounds with health benefits provides an excellent opportunity for improving public health. The incorporation of bioactive compounds into food systems is therefore of great interest to researchers in their efforts to develop innovative functional foods that may have physiological benefits or reduce the risk of disease beyond basic nutritional functions. However, the effectiveness of these products in preventing diseases relies on preserving the bioavailability of their active ingredients. This represents undoubtedly a great challenge since these molecules are generally sensitive to environmental conditions encountered in food processes (i.e., temperature oxygen, and light or in the gastrointestinal tract (i.e., pH, enzymes presence of other nutrients, which limit their activity and potential health benefits. However, bio- and microencapsulation can be used to overcome these limitations. Whey proteins, also known as the serum proteins of milk, are widely used in food products, because of their high nutritional value and their ability to form gels, emulsions, or foams. The aim of this article is to provide information on the different types of materials obtained from whey proteins and to examine their use as bioencapsulation and delivery systems.

Using grey literature to prepare pharmacy students for an evolving healthcare delivery system.

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Happe, Laura E; Walker, Desiree'

2013-05-13

To assess the impact of using "grey literature" (information internally produced in print or electronic format by agencies such as hospitals, government, businesses, etc) rather than a textbook in a course on healthcare delivery systems on students' perception of the relevance of healthcare delivery system topics and their ability to identify credible sources of this information. A reading from the grey literature was identified and assigned to the students for each topic in the course. Pre- and post-course survey instruments were used for the assessment. Students reported healthcare delivery systems topics to be moderately relevant to the profession of pharmacy on both the pre- and post-course survey instruments. Students' knowledge of current and credible sources of information on healthcare delivery system topics significantly improved based on self-reports and scores on objective assessments (pgrey literature in a course on healthcare delivery systems can be used to ensure that information in the pharmacy school curriculum is the most current and credible information available.

Intracellular antioxidants dissolve man-made antioxidant nanoparticles: using redox vulnerability of nanoceria to develop a responsive drug delivery system.

Science.gov (United States)

Muhammad, Faheem; Wang, Aifei; Qi, Wenxiu; Zhang, Shixing; Zhu, Guangshan

2014-01-01

Regeneratable antioxidant property of nanoceria has widely been explored to minimize the deleterious influences of reactive oxygen species. Limited information is, however, available regarding the biological interactions and subsequent fate of nanoceria in body fluids. This study demonstrates a surprising dissolution of stable and ultrasmall (4 nm) cerium oxide nanoparticles (CeO2 NPs) in response to biologically prevalent antioxidant molecules (glutathione, vitamin C). Such a redox sensitive behavior of CeO2 NPs is subsequently exploited to design a redox responsive drug delivery system for transporting anticancer drug (camptothecin). Upon exposing the CeO2 capped and drug loaded nanoconstruct to vitamin c or glutathione, dissolution-accompanied aggregation of CeO2 nanolids unleashes the drug molecules from porous silica to achieve a significant anticancer activity. Besides stimuli responsive drug delivery, immobilization of nanoceria onto the surface of mesoporous silica also facilitates us to gain a basic insight into the biotransformation of CeO2 in physiological mediums.

Application of mathematical modeling in sustained release delivery systems.

Science.gov (United States)

Grassi, Mario; Grassi, Gabriele

2014-08-01

This review, presenting as starting point the concept of the mathematical modeling, is aimed at the physical and mathematical description of the most important mechanisms regulating drug delivery from matrix systems. The precise knowledge of the delivery mechanisms allows us to set up powerful mathematical models which, in turn, are essential for the design and optimization of appropriate drug delivery systems. The fundamental mechanisms for drug delivery from matrices are represented by drug diffusion, matrix swelling, matrix erosion, drug dissolution with possible recrystallization (e.g., as in the case of amorphous and nanocrystalline drugs), initial drug distribution inside the matrix, matrix geometry, matrix size distribution (in the case of spherical matrices of different diameter) and osmotic pressure. Depending on matrix characteristics, the above-reported variables may play a different role in drug delivery; thus the mathematical model needs to be built solely on the most relevant mechanisms of the particular matrix considered. Despite the somewhat diffident behavior of the industrial world, in the light of the most recent findings, we believe that mathematical modeling may have a tremendous potential impact in the pharmaceutical field. We do believe that mathematical modeling will be more and more important in the future especially in the light of the rapid advent of personalized medicine, a novel therapeutic approach intended to treat each single patient instead of the 'average' patient.

An evaluation of oxygen systems for treatment of childhood pneumonia

Directory of Open Access Journals (Sweden)

Rudan Igor

2011-04-01

Full Text Available Abstract Background Oxygen therapy is recommended for all of the 1.5 – 2.7 million young children who consult health services with hypoxemic pneumonia each year, and the many more with other serious conditions. However, oxygen supplies are intermittent throughout the developing world. Although oxygen is well established as a treatment for hypoxemic pneumonia, quantitative evidence for its effect is lacking. This review aims to assess the utility of oxygen systems as a method for reducing childhood mortality from pneumonia. Methods Aiming to improve priority setting methods, The Child Health and Nutrition Research Initiative (CHNRI has developed a common framework to score competing interventions into child health. That framework involves the assessment of 12 different criteria upon which interventions can be compared. This report follows the proposed framework, using a semi-systematic literature review and the results of a structured exercise gathering opinion from experts (leading basic scientists, international public health researchers, international policy makers and representatives of pharmaceutical companies, to assess and score each criterion as their “collective optimism” towards each, on a scale from 0 to 100%. Results A rough estimate from an analysis of the literature suggests that global strengthening of oxygen systems could save lives of up to 122,000 children from pneumonia annually. Following 12 CHNRI criteria, the experts expressed very high levels of optimism (over 80% for answerability, low development cost and low product cost; high levels of optimism (60-80% for low implementation cost, likelihood of efficacy, deliverability, acceptance to end users and health workers; and moderate levels of optimism (40-60% for impact on equity, affordability and sustainability. The median estimate of potential effectiveness of oxygen systems to reduce the overall childhood pneumonia mortality was ~20% (interquartile range: 10-35%, min

Multi-Course Comparison of Traditional versus Web-based Course Delivery Systems

Directory of Open Access Journals (Sweden)

J. Michael Weber, PhD.,

2007-07-01

Full Text Available The purpose of this paper is to measure and compare the effectiveness of a Web-based course delivery system to a traditional course delivery system. The results indicate that a web-based course is effective and equivalent to a traditional classroom environment. As with the implementation of all new technologies, there are some pros and cons that should be considered. The significant pro is the element of convenience which eliminates the constrictive boundaries of space and time. The most notable con involves the impersonal nature of the online environment. Overall, we found the web-based course delivery system to be very successful in terms of learning outcomes and student satisfaction.

Microcomputer-based system for registration of oxygen tension in peripheral muscle.

Science.gov (United States)

Odman, S; Bratt, H; Erlandsson, I; Sjögren, L

1986-01-01

For registration of oxygen tension fields in peripheral muscle a microcomputer based system was designed on the M6800 microprocessor. The system was designed to record the signals from a multiwire oxygen electrode, MDO, which is a multiwire electrode for measuring oxygen on the surface of an organ. The system contained patient safety isolation unit built on optocopplers and the upper frequency limit was 0.64 Hz. Collected data were corrected for drift and temperature changes during the measurement by using pre- and after calibrations and a linear compensation technique. Measure drift of the electrodes were proved to be linear and thus the drift could be compensated for. The system was tested in an experiment on pig. To study the distribution of oxygen statistically mean, standard deviation, skewness and curtosis were calculated. To see changes or differences between histograms a Kolmogorv-Smirnov test was used.

Making the Invisible Visible: A Model for Delivery Systems in Adult Education

Science.gov (United States)

Alex, Jennifer L.; Miller, Elizabeth A.; Platt, R. Eric; Rachal, John R.; Gammill, Deidra M.

2007-01-01

Delivery systems are not well defined in adult education. Therefore, this article reviews the multiple components that overlap to affect the adult learner and uses them to create a model for a comprehensive delivery system in adult education with these individual components as sub-systems that are interrelated and inter-locked. These components…

A Prototype Educational Delivery System Using Water Quality Monitoring as a Model.

Science.gov (United States)

Glazer, Richard B.

This report describes the model educational delivery system used by Ulster County Community College in its water quality monitoring program. The educational delivery system described in the report encompasses the use of behavioral objectives as its foundation and builds upon this foundation to form a complete system whose outcomes can be measured,…

Protamine-based nanoparticles as new antigen delivery systems.

Science.gov (United States)

González-Aramundiz, José Vicente; Peleteiro Olmedo, Mercedes; González-Fernández, África; Alonso Fernández, María José; Csaba, Noemi Stefánia

2015-11-01

The use of biodegradable nanoparticles as antigen delivery vehicles is an attractive approach to overcome the problems associated with the use of Alum-based classical adjuvants. Herein we report, the design and development of protamine-based nanoparticles as novel antigen delivery systems, using recombinant hepatitis B surface antigen as a model viral antigen. The nanoparticles, composed of protamine and a polysaccharide (hyaluronic acid or alginate), were obtained using a mild ionic cross-linking technique. The size and surface charge of the nanoparticles could be modulated by adjusting the ratio of the components. Prototypes with optimal physicochemical characteristics and satisfactory colloidal stability were selected for the assessment of their antigen loading capacity, antigen stability during storage and in vitro and in vivo proof-of-concept studies. In vitro studies showed that antigen-loaded nanoparticles induced the secretion of cytokines by macrophages more efficiently than the antigen in solution, thus indicating a potential adjuvant effect of the nanoparticles. Finally, in vivo studies showed the capacity of these systems to trigger efficient immune responses against the hepatitis B antigen following intramuscular administration, suggesting the potential interest of protamine-polysaccharide nanoparticles as antigen delivery systems. Copyright © 2015 Elsevier B.V. All rights reserved.

Multi-Course Comparison of Traditional versus Web-Based Course Delivery Systems

Science.gov (United States)

Weber, J. Michael; Lennon, Ron

2007-01-01

The purpose of this paper is to measure and compare the effectiveness of a Web-based course delivery system to a traditional course delivery system. The results indicate that a web-based course is effective and equivalent to a traditional classroom environment. As with the implementation of all new technologies, there are some pros and cons that…

Electron Paramagnetic Resonance pO2 Image Tumor Oxygen-Guided Radiation Therapy Optimization.

Science.gov (United States)

Epel, Boris; Maggio, Matt; Pelizzari, Charles; Halpern, Howard J

2017-01-01

Modern standards for radiation treatment do not take into account tumor oxygenation for radiation treatment planning. Strong correlation between tumor oxygenation and radiation treatment success suggests that oxygen-guided radiation therapy (OGRT) may be a promising enhancement of cancer radiation treatment. We have developed an OGRT protocol for rodents. Electron paramagnetic resonance (EPR) imaging is used for recording oxygen maps with high spatial resolution and excellent accuracy better than 1 torr. Radiation is delivered with an animal intensity modulated radiation therapy (IMRT) XRAD225Cx micro-CT/ therapy system. The radiation plan is delivered in two steps. First, a uniform 15% tumor control dose (TCD 15 ) is delivered to the whole tumor. In the second step, an additional booster dose amounting to the difference between TCD 98 and TCD 15 is delivered to radio-resistant, hypoxic tumor regions. Delivery of the booster dose is performed using a multiport conformal beam protocol. For radiation beam shaping we used individual radiation blocks 3D-printed from tungsten infused ABS polymer. Calculation of beam geometry and the production of blocks is performed next to the EPR imager, immediately after oxygen imaging. Preliminary results demonstrate the sub-millimeter precision of the radiation delivery and high dose accuracy. The efficacy of the radiation treatment is currently being tested on syngeneic FSa fibrosarcoma tumors grown in the legs of C3H mice.

Ultrasound-mediated drug delivery by gas bubbles generated from a chemical reaction.

Science.gov (United States)

Lee, Sungmun; Al-Kaabi, Leena; Mawart, Aurélie; Khandoker, Ahsan; Alsafar, Habiba; Jelinek, Herbert F; Khalaf, Kinda; Park, Ji-Ho; Kim, Yeu-Chun

2018-02-01

Highly echogenic and ultrasound-responsive microbubbles such as nitrogen and perfluorocarbons have been exploited as ultrasound-mediated drug carriers. Here, we propose an innovative method for drug delivery using microbubbles generated from a chemical reaction. In a novel drug delivery system, luminol encapsulated in folate-conjugated bovine serum albumin nanoparticles (Fol-BSAN) can generate nitrogen gas (N 2 ) by chemical reaction when it reacts with hydrogen peroxide (H 2 O 2 ), one of reactive oxygen species (ROS). ROS plays an important role in the initiation and progression of cancer and elevated ROS have been observed in cancer cells both in vitro and in vivo. High-intensity focussed ultrasound (HIFU) is used to burst the N 2 microbubbles, causing site-specific delivery of anticancer drugs such as methotrexate. In this research, the drug delivery system was optimised by using water-soluble luminol and Mobil Composition of Matter-41 (MCM-41), a mesoporous material, so that the delivery system was sensitive to micromolar concentrations of H 2 O 2 . HIFU increased the drug release from Fol-BSAN by 52.9 ± 2.9% in 10 minutes. The cytotoxicity of methotrexate was enhanced when methotrexate is delivered to MDA-MB-231, a metastatic human breast cancer cell line, using Fol-BSAN with HIFU. We anticipate numerous applications of chemically generated microbubbles for ultrasound-mediated drug delivery.

Liposomal drug delivery system from laboratory to clinic

Directory of Open Access Journals (Sweden)

Kshirsagar N

2005-01-01

Full Text Available The main objective of drug delivery systems is to deliver a drug effectively, specifically to the site of action and to achieve greater efficacy and minimise the toxic effects compared to conventional drugs. Amongst various carrier systems, liposomes have generated a great interest because of their versatility. Liposomes are vesicular concentric bilayered structures, which are biocompatible, biodegradable and nonimmumnogenic. They can control the delivery of drugs by targeting the drug to the site of action or by site avoidance drug delivery or by prolonged circulation of drugs. Amphotericin B (Amp B remains the drug of choice in most systemic mycoses and also as a second line treatment for Kala azar. However, its toxic effects often limit its use. Although the liposome delivery system has been tried for several drugs, only a few have been used in patients due to the slow development of necessary large-scale pharmaceutical procedures. This paper reviews the development of the technique for liposomal Amphotericin B (L-Amp-LRC-1, FungisomeTM drug delivery system in our laboratory in collaboration with the department of Biochemistry, Delhi University in India and proving the safety and efficacy of this preparation in clinical practice. It also attempts to compare the efficacy and benefits of our product for Indian patients with those of similar products and it includes facts from the publications that flowed from our work. As compared to conventional Amp B, Fungisome is infused over a much shorter period requiring a smaller volume and no premedication. It was found to be safe in patients who had developed serious unacceptable toxicity with conventional Amp B. In renal transplant patients, Fungisome did not produce any nephrotoxicity. Fungisome is effective in fungal infections resistant to fluconazole, conventional Amp B and in virgin and resistant cases of visceral leishmaniasis. The cost of any drug is of great significance, especially in India

Using DNA nanotechnology to produce a drug delivery system

International Nuclear Information System (INIS)

La, Thi Huyen; Nguyen, Thi Thu Thuy; Pham, Van Phuc; Nguyen, Thi Minh Huyen; Le, Quang Huan

2013-01-01

Drug delivery to cancer cells in chemotherapy is one of the most advanced research topics. The effectiveness of the current cancer treatment drugs is limited because they are not capable of distinguishing between cancer cells and normal cells so that they kill not only cancer cells but also normal ones. To overcome this disadvantage by profiting from the differences in physical and chemical properties between cancer and normal cells, nanoparticles (NPs) delivering a drug are designed in a specific manner such that they can distinguish the cancer cells from the normal ones and are targeted only to the cancer cells. Currently, there are various drug delivery systems with many advantages, but sharing some common disadvantages such as difficulty with controlling the size, low encapsulation capacity and low stability. With the development and success of DNA nanotechnology, DNA strands are used to create effective drug delivery NPs with precisely controlled size and structure, safety and high stability. This article presents our study on drug encapsulation in DNA nanostructure which loaded docetaxel and curcumin in a desire to create a new and effective drug delivery system with high biological compatibility. (paper)

Film forming systems for topical and transdermal drug delivery

Directory of Open Access Journals (Sweden)

Kashmira Kathe

2017-11-01

Full Text Available Skin is considered as an important route of administration of drugs for both local and systemic effects. The effectiveness of topical therapy depends on the physicochemical properties of the drug and adherence of the patient to the treatment regimen as well as the system's ability to adhere to skin during the therapy so as to promote drug penetration through the skin barrier. Conventional formulations for topical and dermatological administration of drugs have certain limitations like poor adherence to skin, poor permeability and compromised patient compliance. For the treatment of diseases of body tissues and wounds, the drug has to be maintained at the site of treatment for an effective period of time. Topical film forming systems are such developing drug delivery systems meant for topical application to the skin, which adhere to the body, forming a thin transparent film and provide delivery of the active ingredients to the body tissue. These are intended for skin application as emollient or protective and for local action or transdermal penetration of medicament for systemic action. The transparency is an appreciable feature of this polymeric system which greatly influences the patient acceptance. In the current discussion, the film forming systems are described as a promising choice for topical and transdermal drug delivery. Further the various types of film forming systems (sprays/solutions, gels and emulsions along with their evaluation parameters have also been reviewed.

Solubility enhancement and delivery systems of curcumin a herbal medicine: a review.

Science.gov (United States)

Hani, Umme; Shivakumar, H G

2014-01-01

Curcumin diferuloylmethane is a main yellow bioactive component of turmeric, possess wide spectrum of biological actions. It was found to have anti-inflammatory, antioxidant, anticarcinogenic, antimutagenic, anticoagulant, antifertility, antidiabetic, antibacterial, antifungal, antiprotozoal, antiviral, antifibrotic, antivenom, antiulcer, hypotensive and hypocholesteremic activities. However, the benefits are curtailed by its extremely poor aqueous solubility, which subsequently limits the bioavailability and therapeutic effects of curcumin. Nanotechnology is the available approach in solving these issues. Therapeutic efficacy of curcumin can be utilized effectively by doing improvement in formulation properties or delivery systems. Numerous attempts have been made to design a delivery system of curcumin. Currently, nanosuspensions, micelles, nanoparticles, nano-emulsions, etc. are used to improve the in vitro dissolution velocity and in vivo efficiency of curcumin. This review focuses on the methods to increase solubility of curcumin and various nanotechnologies based delivery systems and other delivery systems of curcumin.

Engaging Faculty in Telecommunications-Based Instructional Delivery Systems.

Science.gov (United States)

Swalec, John J.

In the design and development of telecommunications-based instructional delivery systems, attention to faculty involvement and training is often overlooked until the system is operational. The Waubonsee Telecommunications Instructional Consortium (TIC), in Illinois, is one network that benefited from early faculty input. Even before the first…

Immunological Risk of Injectable Drug Delivery Systems

NARCIS (Netherlands)

Jiskoot, W.; van Schie, R.M.F.; Carstens, M.G.; Schellekens, H.

2009-01-01

Injectable drug delivery systems (DDS) such as particulate carriers and water-soluble polymers are being used and developed for a wide variety of therapeutic applications. However, a number of immunological risks with serious clinical implications are associated with administration of DDS. These

Recent Advances in Ocular Drug Delivery Systems

Directory of Open Access Journals (Sweden)

Shinobu Fujii

2011-01-01

Full Text Available Transport of drugs applied by traditional dosage forms is restricted to the eye, and therapeutic drug concentrations in the target tissues are not maintained for a long duration since the eyes are protected by a unique anatomy and physiology. For the treatment of the anterior segment of the eye, various droppable products to prolong the retention time on the ocular surface have been introduced in the market. On the other hand, direct intravitreal implants, using biodegradable or non-biodegradable polymer technology, have been widely investigated for the treatment of chronic vitreoretinal diseases. There is urgent need to develop ocular drug delivery systems which provide controlled release for the treatment of chronic diseases, and increase patient’s and doctor’s convenience to reduce the dosing frequency and invasive treatment. In this article, progress of ocular drug delivery systems under clinical trials and in late experimental stage is reviewed.

[Advances of tumor targeting peptides drug delivery system with pH-sensitive activities].

Science.gov (United States)

Ma, Yin-yun; Li, Li; Huang, Hai-feng; Gou, San-hu; Ni, Jing-man

2016-05-01

The pH-sensitive peptides drug delivery systems, which target to acidic extracellular environment of tumor tissue, have many advantages in drug delivery. They exhibit a high specificity to tumor and low cytotoxicity, which significantly increase the efficacy of traditional anti-cancer drugs. In recent years the systems have received a great attention. The pH-sensitive peptides drug delivery systems can be divided into five types according to the difference in pH-responsive mechanism,type of peptides and carrier materials. This paper summarizes the recent progresses in the field with a focus on the five types of pH-sensitive peptides in drug delivery systems. This may provide a guideline to design and application of tumor targeting drugs.

Process development work plan for waste feed delivery system

International Nuclear Information System (INIS)

Papp, I.G.

1998-01-01

This work plan defines the process used to develop project definition for Waste Feed Delivery (WFD). Project definition provides the direction for development of definitive design media required for the ultimate implementation of operational processing hardware and software. Outlines for the major deliverables are attached as appendices. The implementation of hardware and software will accommodate requirements for safe retrieval and delivery of waste currently stored in Hanford's underground storage tanks. Operations and maintenance ensure the availability of systems, structures, and components for current and future planned operations within the boundary of the Tank Waste Remediation System (TWRS) authorization basis

Integrated delivery systems: the cure for fragmentation.

Science.gov (United States)

Enthoven, Alain C

2009-12-01

Our healthcare system is fragmented, with a misalignment of incentives, or lack of coordination, that spawns inefficient allocation of resources. Fragmentation adversely impacts quality, cost, and outcomes. Eliminating waste from unnecessary, unsafe care is crucial for improving quality and reducing costs--and making the system financially sustainable. Many believe this can be achieved through greater integration of healthcare delivery, more specifically via integrated delivery systems (IDSs). An IDS is an organized, coordinated, and collaborative network that links various healthcare providers to provide a coordinated, vertical continuum of services to a particular patient population or community. It is also accountable, both clinically and fiscally, for the clinical outcomes and health status of the population or community served, and has systems in place to manage and improve them. The marketplace already contains numerous styles and degrees of integration, ranging from Kaiser Permanente-style full integration, to more loosely organized individual practice associations, to public-private partnerships. Evidence suggests that IDSs can improve healthcare quality, improve outcomes, and reduce costs--especially for patients with complex needs--if properly implemented and coordinated. No single approach or public policy will fix the fragmented healthcare system, but IDSs represent an important step in the right direction.

Buccal Transmucosal Delivery System of Enalapril for Improved ...

African Journals Online (AJOL)

Methods: Transmucosal drug delivery systems of enalapril maleate were ... Index Medicus, JournalSeek, Journal Citation Reports/Science Edition, Directory of Open Access Journals. (DOAJ) ... investigated for various drugs including protein.

Nano-microdelivery systems for oral delivery of an active ingredient

DEFF Research Database (Denmark)

2014-01-01

A composition for oral delivery of one or more active ingredients in the form of a lipid nano-micro-delivery system comprising a lipid nano-micro-structure comprising at least one lipid and at least one active ingredient, said at least one active ingredient being immobilized in said lipid nano...

Community feedback on the JustMilk Nipple Shield Delivery System ...

African Journals Online (AJOL)

Background. Infant medication administration is a major public-health challenge, especially in rural or low-resource areas. The JustMilk Nipple Shield Delivery System (NSDS) is a novel method of infant medication delivery designed to address some of these challenges. Objective. To explore the acceptability of the JustMilk ...

Formulation and characterization of lipid-based drug delivery system of raloxifene-microemulsion and self-microemulsifying drug delivery system

Directory of Open Access Journals (Sweden)

Hetal Thakkar

2011-01-01

Full Text Available Background : Raloxifene, a second-generation selective estrogen receptor modulator (SERM used to prevent osteoporosis in postmenopausal women is administered orally in the form of a tablet. The absolute bioavailability of the drug is only 2% because of extensive hepatic first-pass metabolism. Lipid-based formulations are reported to reduce the first-pass metabolism by promoting its lymphatic uptake. Materials and Methods : In the present investigation, microemulsion and Self-Microemulsifying Drug Delivery System (SMEDDS formulations of Raloxifene were prepared. The prepared formulations were characterized for drug loading, size, transparency, zeta potential, Transmission Electron Microscopy (TEM and in vitro intestinal permeability. Results : The results indicated that high drug loading, optimum size and desired zeta potential and transparency could be achieved with both SMEDDS and microemulsion. The TEM studies indicated the absence of aggregation with both the systems. The in vitro intestinal permeability results showed that the permeation of the drug from the microemulsion and SMEDDs was significantly higher than that obtained from the drug dispersion and marketed formulation. Conclusion : Lipid based formulations such as microemulsion and Self Microemulsifying drug delivery systems are expected to increase the oral bioavailability as evidenced by the increased intestinal permeation.

Formulation and characterization of lipid-based drug delivery system of raloxifene-microemulsion and self-microemulsifying drug delivery system

Science.gov (United States)

Thakkar, Hetal; Nangesh, Jitesh; Parmar, Mayur; Patel, Divyakant

2011-01-01

Background: Raloxifene, a second-generation selective estrogen receptor modulator (SERM) used to prevent osteoporosis in postmenopausal women is administered orally in the form of a tablet. The absolute bioavailability of the drug is only 2% because of extensive hepatic first-pass metabolism. Lipid-based formulations are reported to reduce the first-pass metabolism by promoting its lymphatic uptake. Materials and Methods: In the present investigation, microemulsion and Self-Microemulsifying Drug Delivery System (SMEDDS) formulations of Raloxifene were prepared. The prepared formulations were characterized for drug loading, size, transparency, zeta potential, Transmission Electron Microscopy (TEM) and in vitro intestinal permeability. Results: The results indicated that high drug loading, optimum size and desired zeta potential and transparency could be achieved with both SMEDDS and microemulsion. The TEM studies indicated the absence of aggregation with both the systems. The in vitro intestinal permeability results showed that the permeation of the drug from the microemulsion and SMEDDs was significantly higher than that obtained from the drug dispersion and marketed formulation. Conclusion: Lipid based formulations such as microemulsion and Self Microemulsifying drug delivery systems are expected to increase the oral bioavailability as evidenced by the increased intestinal permeation. PMID:21966167

An Overview On Various Approaches And Recent Patents On Gastroretentive Drug Delivery Systems.

Science.gov (United States)

Kumar, Manoj; Kaushik, Deepak

2018-03-08

Drugs having absorption window in the stomach or upper small intestine has restricted bioavailability with conventional dosage forms. The gastric residence time of these dosage forms is usually short and they do not show drug release for prolonged period of time. To avoid these problems and to enhance the bioavailability and gastric retention time of these drugs, controlled drug delivery systems with prolonged gastric retention time are currently being developed. This review highlights the various pharmaceutical approaches for gastroretention such as floating drug delivery systems, mucoadhesive systems, high density systems, expandable and swelling systems, superporous hydrogels systems, magnetic systems, ion exchange resin system and recent patents filed or granted for these approaches. Recently some patents are also reported where a combination of various approaches are being employed to achieve very effective gastroretention. The various patent search sites were used to collect and analyze the information on gastroretentive drug delivery systems. The present study provides valuable information, advantages, limitations and future outlook of various gastroretentive drug delivery systems. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Magnetic microspheres as magical novel drug delivery system: A review

Directory of Open Access Journals (Sweden)

Satinder Kakar

2013-01-01

Full Text Available Magnetic microspheres hold great promise for reaching the goal of controlled and site specific drug delivery. Magnetic microspheres as an alternative to traditional radiation methods which uses highly penetrating radiations that is absorbed throughout the body. Its use is limited by toxicity and side effects. Now days, several targeted treatment systems including magnetic field, electric field, ultrasound, temperature, UV light and mechanical force are being used in many disease treatments (e.g. cancer, nerve damage, heart and artery, anti-diabetic, eye and other medical treatments. Among them, the magnetic targeted drug delivery system is one of the most attractive and promising strategy for delivering the drug to the specified site. Magnetically controlled drug targeting is one of the various possible ways of drug targeting. This technology is based on binding establish anticancer drug with ferrofluid that concentrate the drug in the area of interest (tumor site by means of magnetic fields. There has been keen interest in the development of a magnetically target drug delivery system. These drug delivery systems aim to deliver the drug at a rate directed by the needs of the body during the period of treatment, and target the activity entity to the site of action. Magnetic microspheres were developed to overcome two major problems encountered in drug targeting namely: RES clearance and target site specificity.

Formulation and Evaluation of Two-Pulse Drug Delivery System of ...

African Journals Online (AJOL)

Purpose: To develop a pH-controlled two-pulse drug delivery system of amoxicillin in order to overcome ... delivery have lately been applied in developing a .... Note: Each tablet contained 2 mg each of magnesium stearate and colloidal silicon dioxide; total weight of each ..... and Manufacture of Medicines, 3rd edn, Elsevier,.

SU-D-201-03: During-Treatment Delivery Monitoring System for TomoTherapy

Energy Technology Data Exchange (ETDEWEB)

Chen, Q; Read, P [University of Virginia, Charlottesville, VA (United States)

2016-06-15

Purpose: Multiple error pathways can lead to delivery errors during the treatment course that cannot be caught with pre-treatment QA. While in vivo solutions are being developed for linacs, no such solution exists for tomotherapy. The purpose of this study is to develop a near real-time system for tomotherapy that can monitor the delivery and dose accumulation process during the treatment-delivery, which enable the user to assess the impact of delivery variations and/or errors and to interrupt the treatment if necessary. Methods: A program running on a tomotherapy planning station fetches the raw DAS data during treatment. Exit detector data is extracted as well as output, gantry angle, and other machine parameters. For each sample, the MLC open-close state is determined. The delivered plan is compared with the original plan via a Monte Carlo dose engine which transports fluence deviations from a pre-treatment Monte Carlo run. A report containing the difference in fluence, dose and DVH statistics is created in html format. This process is repeated until the treatment is completed. Results: Since we only need to compute the dose for the difference in fluence for a few projections each time, dose with 2% statistical uncertainty can be computed in less than 1 second on a 4-core cpu. However, the current bottleneck in this near real-time system is the repeated fetching and processing the growing DAS data file throughout the delivery. The frame rate drops from 10Hz at the beginning of treatment to 5Hz after 3 minutes and to 2Hz after 10 minutes. Conclusion: A during-treatment delivery monitor system has been built to monitor tomotherapy treatments. The system improves patient safety by allowing operators to assess the delivery variations and errors during treatment delivery and adopt appropriate actions.

SU-D-201-03: During-Treatment Delivery Monitoring System for TomoTherapy

International Nuclear Information System (INIS)

Chen, Q; Read, P

2016-01-01

Purpose: Multiple error pathways can lead to delivery errors during the treatment course that cannot be caught with pre-treatment QA. While in vivo solutions are being developed for linacs, no such solution exists for tomotherapy. The purpose of this study is to develop a near real-time system for tomotherapy that can monitor the delivery and dose accumulation process during the treatment-delivery, which enable the user to assess the impact of delivery variations and/or errors and to interrupt the treatment if necessary. Methods: A program running on a tomotherapy planning station fetches the raw DAS data during treatment. Exit detector data is extracted as well as output, gantry angle, and other machine parameters. For each sample, the MLC open-close state is determined. The delivered plan is compared with the original plan via a Monte Carlo dose engine which transports fluence deviations from a pre-treatment Monte Carlo run. A report containing the difference in fluence, dose and DVH statistics is created in html format. This process is repeated until the treatment is completed. Results: Since we only need to compute the dose for the difference in fluence for a few projections each time, dose with 2% statistical uncertainty can be computed in less than 1 second on a 4-core cpu. However, the current bottleneck in this near real-time system is the repeated fetching and processing the growing DAS data file throughout the delivery. The frame rate drops from 10Hz at the beginning of treatment to 5Hz after 3 minutes and to 2Hz after 10 minutes. Conclusion: A during-treatment delivery monitor system has been built to monitor tomotherapy treatments. The system improves patient safety by allowing operators to assess the delivery variations and errors during treatment delivery and adopt appropriate actions.

Fabrication, Characterization, and Biological Activity of Avermectin Nano-delivery Systems with Different Particle Sizes

Science.gov (United States)

Wang, Anqi; Wang, Yan; Sun, Changjiao; Wang, Chunxin; Cui, Bo; Zhao, Xiang; Zeng, Zhanghua; Yao, Junwei; Yang, Dongsheng; Liu, Guoqiang; Cui, Haixin

2018-01-01

Nano-delivery systems for the active ingredients of pesticides can improve the utilization rates of pesticides and prolong their control effects. This is due to the nanocarrier envelope and controlled release function. However, particles containing active ingredients in controlled release pesticide formulations are generally large and have wide size distributions. There have been limited studies about the effect of particle size on the controlled release properties and biological activities of pesticide delivery systems. In the current study, avermectin (Av) nano-delivery systems were constructed with different particle sizes and their performances were evaluated. The Av release rate in the nano-delivery system could be effectively controlled by changing the particle size. The biological activity increased with decreasing particle size. These results suggest that Av nano-delivery systems can significantly improve the controllable release, photostability, and biological activity, which will improve efficiency and reduce pesticide residues.

Police and Community-partnered Delivery System to Address ...

International Development Research Centre (IDRC) Digital Library (Canada)

... Delivery System to Address Violence Against Women in the Punjab (India) ... Education, Scheduled Castes and Other Back Classes, and Land Rural Development. ... IWRA/IDRC webinar on climate change and adaptive water management.

Components of Maternal Healthcare Delivery System Contributing to ...

African Journals Online (AJOL)

Components of Maternal Healthcare Delivery System Contributing to Maternal Deaths ... transcripts were analyzed using a directed approach to content analysis. Excerpts were categorized according to three main components of the maternal ...

Texosome-based drug delivery system for cancer therapy: from past to present

International Nuclear Information System (INIS)

Mahmoodzadeh Hosseini, Hamideh; Halabian, Raheleh; Amin, Mohsen; Imani Fooladi, Abbas Ali

2015-01-01

Rising worldwide cancer incidence and resistance to current anti-cancer drugs necessitate the need for new pharmaceutical compounds and drug delivery system. Malfunction of the immune system, particularly in the tumor microenvironment, causes tumor growth and enhances tumor progression. Thus, cancer immunotherapy can be an appropriate approach to provoke the systemic immune system to combat tumor expansion. Texosomes, which are endogenous nanovesicles released by all tumor cells, contribute to cell-cell communication and modify the phenotypic features of recipient cells due to the texosomes’ ability to transport biological components. For this reason, texosome-based delivery system can be a valuable strategy for therapeutic purposes. To improve the pharmaceutical behavior of this system and to facilitate its use in medical applications, biotechnology approaches and mimetic techniques have been utilized. In this review, we present the development history of texosome-based delivery systems and discuss the advantages and disadvantages of each system

In vitro characterization of microcontainers as an oral drug delivery system

DEFF Research Database (Denmark)

Nielsen, Line Hagner; Keller, Stephan Sylvest; Jacobsen, J.

We here present in vitro studies showing the promise of microcontainers (fabricated in either SU-8 or Poly(lactic acid) (PLLA)) as an oral drug delivery system for the poorly watersoluble drug, furosemide.......We here present in vitro studies showing the promise of microcontainers (fabricated in either SU-8 or Poly(lactic acid) (PLLA)) as an oral drug delivery system for the poorly watersoluble drug, furosemide....

Towards an Innovative Web-Based Lab Delivery System for a Management Information Systems Course

Science.gov (United States)

Breimer, Eric; Cotler, Jami; Yoder, Robert

2011-01-01

While online systems are an essential component of distance learning, they can also play a critical role in improving the delivery of activities in a traditional laboratory setting. The quality and effectiveness of online course delivery is often compared to equivalent face-to-face alternatives. In our approach, we have harnessed what we feel to…

Chitosan magnetic nanoparticles for drug delivery systems.

Science.gov (United States)

Assa, Farnaz; Jafarizadeh-Malmiri, Hoda; Ajamein, Hossein; Vaghari, Hamideh; Anarjan, Navideh; Ahmadi, Omid; Berenjian, Aydin

2017-06-01

The potential of magnetic nanoparticles (MNPs) in drug delivery systems (DDSs) is mainly related to its magnetic core and surface coating. These coatings can eliminate or minimize their aggregation under physiological conditions. Also, they can provide functional groups for bioconjugation to anticancer drugs and/or targeted ligands. Chitosan, as a derivative of chitin, is an attractive natural biopolymer from renewable resources with the presence of reactive amino and hydroxyl functional groups in its structure. Chitosan nanoparticles (NPs), due to their huge surface to volume ratio as compared to the chitosan in its bulk form, have outstanding physico-chemical, antimicrobial and biological properties. These unique properties make chitosan NPs a promising biopolymer for the application of DDSs. In this review, the current state and challenges for the application magnetic chitosan NPs in drug delivery systems were investigated. The present review also revisits the limitations and commercial impediments to provide insight for future works.

Delivery systems for biopharmaceuticals. Part II: Liposomes, Micelles, Microemulsions and Dendrimers.

Science.gov (United States)

Silva, Ana C; Lopes, Carla M; Lobo, José M S; Amaral, Maria H

2015-01-01

Biopharmaceuticals are a generation of drugs that include peptides, proteins, nucleic acids and cell products. According to their particular molecular characteristics (e.g. high molecular size, susceptibility to enzymatic activity), these products present some limitations for administration and usually parenteral routes are the only option. To avoid these limitations, different colloidal carriers (e.g. liposomes, micelles, microemulsions and dendrimers) have been proposed to improve biopharmaceuticals delivery. Liposomes are promising drug delivery systems, despite some limitations have been reported (e.g. in vivo failure, poor long-term stability and low transfection efficiency), and only a limited number of formulations have reached the market. Micelles and microemulsions require more studies to exclude some of the observed drawbacks and guarantee their potential for use in clinic. According to their peculiar structures, dendrimers have been showing good results for nucleic acids delivery and a great development of these systems during next years is expected. This is the Part II of two review articles, which provides the state of the art of biopharmaceuticals delivery systems. Part II deals with liposomes, micelles, microemulsions and dendrimers.

Role of pressure-sensitive adhesives in transdermal drug delivery systems.

Science.gov (United States)

Lobo, Shabbir; Sachdeva, Sameer; Goswami, Tarun

2016-01-01

Transdermal drug delivery systems (TDDS) are employed for the delivery of drugs across skin into the systemic circulation. Pressure-sensitive adhesive (PSA) is one of the most critical components used in a TDDS. The primary function of PSA is to help in adhesion of patch to skin, but more importantly it acts as a matrix for the drug and other excipients. Hence, apart from adhesion of the patch, PSA also affects other critical quality attributes of the TDDS such as drug delivery, flux through skin and physical and chemical stability of the finished product. This review article provides a summary of the adhesives used in various types of TDDS. In particular, this review will cover the design types of TDDS, categories of PSAs and their evaluation and regulatory aspects.

Novel engineered systems for oral, mucosal and transdermal drug delivery.

Science.gov (United States)

Li, Hairui; Yu, Yuan; Faraji Dana, Sara; Li, Bo; Lee, Chi-Ying; Kang, Lifeng

2013-08-01

Technological advances in drug discovery have resulted in increasing number of molecules including proteins and peptides as drug candidates. However, how to deliver drugs with satisfactory therapeutic effect, minimal side effects and increased patient compliance is a question posted before researchers, especially for those drugs with poor solubility, large molecular weight or instability. Microfabrication technology, polymer science and bioconjugate chemistry combine to address these problems and generate a number of novel engineered drug delivery systems. Injection routes usually have poor patient compliance due to their invasive nature and potential safety concerns over needle reuse. The alternative non-invasive routes, such as oral, mucosal (pulmonary, nasal, ocular, buccal, rectal, vaginal), and transdermal drug delivery have thus attracted many attentions. Here, we review the applications of the novel engineered systems for oral, mucosal and transdermal drug delivery.

Using DNA nanotechnology to produce a drug delivery system

Science.gov (United States)

Huyen La, Thi; Thu Thuy Nguyen, Thi; Phuc Pham, Van; Huyen Nguyen, Thi Minh; Huan Le, Quang

2013-03-01

Drug delivery to cancer cells in chemotherapy is one of the most advanced research topics. The effectiveness of the current cancer treatment drugs is limited because they are not capable of distinguishing between cancer cells and normal cells so that they kill not only cancer cells but also normal ones. To overcome this disadvantage by profiting from the differences in physical and chemical properties between cancer and normal cells, nanoparticles (NPs) delivering a drug are designed in a specific manner such that they can distinguish the cancer cells from the normal ones and are targeted only to the cancer cells. Currently, there are various drug delivery systems with many advantages, but sharing some common disadvantages such as difficulty with controlling the size, low encapsulation capacity and low stability. With the development and success of DNA nanotechnology, DNA strands are used to create effective drug delivery NPs with precisely controlled size and structure, safety and high stability. This article presents our study on drug encapsulation in DNA nanostructure which loaded docetaxel and curcumin in a desire to create a new and effective drug delivery system with high biological compatibility. Invited talk at the 6th International Workshop on Advanced Materials Science and Nanotechnology, 30 October-2 November, 2012, Ha Long, Vietnam.

An emerging platform for drug delivery: aerogel based systems.

Science.gov (United States)

Ulker, Zeynep; Erkey, Can

2014-03-10

Over the past few decades, advances in "aerogel science" have provoked an increasing interest for these materials in pharmaceutical sciences for drug delivery applications. Because of their high surface areas, high porosities and open pore structures which can be tuned and controlled by manipulation of synthesis conditions, nanostructured aerogels represent a promising class of materials for delivery of various drugs as well as enzymes and proteins. Along with biocompatible inorganic aerogels and biodegradable organic aerogels, more complex systems such as surface functionalized aerogels, composite aerogels and layered aerogels have also been under development and possess huge potential. Emphasis is given to the details of the aerogel synthesis and drug loading methods as well as the influence of synthesis parameters and loading methods on the adsorption and release of the drugs. Owing to their ability to increase the bioavailability of low solubility drugs, to improve both their stability and their release kinetics, there are an increasing number of research articles concerning aerogels in different drug delivery applications. This review presents an up to date overview of the advances in all kinds of aerogel based drug delivery systems which are currently under investigation. Copyright © 2014 Elsevier B.V. All rights reserved.

Development of an oxygen saturation measuring system by using near-infrared spectroscopy

Science.gov (United States)

Kono, K.; Nakamachi, E.; Morita, Y.

2017-08-01

Recently, the hypoxia imaging has been recognized as the advanced technique to detect cancers because of a strong relationship with the biological characterization of cancer. In previous studies, hypoxia imaging systems for endoscopic diagnosis have been developed. However, these imaging technologies using the visible light can observe only blood vessels in gastric mucous membrane. Therefore, they could not detect scirrhous gastric cancer which accounts for 10% of all gastric cancers and spreads rapidly into submucous membrane. To overcome this problem, we developed a measuring system of blood oxygen saturation in submucous membrane by using near-infrared (NIR) spectroscopy. NIR, which has high permeability for bio-tissues and high absorbency for hemoglobin, can image and observe blood vessels in submucous membrane. NIR system with LED lights and a CCD camera module was developed to image blood vessels. We measured blood oxygen saturation using the optical density ratio (ODR) of two wavelengths, based on Lambert-Beer law. To image blood vessel clearly and measure blood oxygen saturation accurately, we searched two optimum wavelengths by using a multilayer human gastric-like phantom which has same optical properties as human gastric one. By using Monte Carlo simulation of light propagation, we derived the relationship between the ODR and blood oxygen saturation and elucidated the influence of blood vessel depth on measuring blood oxygen saturation. The oxygen saturation measuring methodology was validated with experiments using our NIR system. Finally, it was confirmed that our system can detect oxygen saturation in various depth blood vessels accurately.

A system for EPID-based real-time treatment delivery verification during dynamic IMRT treatment.

Science.gov (United States)

Fuangrod, Todsaporn; Woodruff, Henry C; van Uytven, Eric; McCurdy, Boyd M C; Kuncic, Zdenka; O'Connor, Daryl J; Greer, Peter B

2013-09-01

To design and develop a real-time electronic portal imaging device (EPID)-based delivery verification system for dynamic intensity modulated radiation therapy (IMRT) which enables detection of gross treatment delivery errors before delivery of substantial radiation to the patient. The system utilizes a comprehensive physics-based model to generate a series of predicted transit EPID image frames as a reference dataset and compares these to measured EPID frames acquired during treatment. The two datasets are using MLC aperture comparison and cumulative signal checking techniques. The system operation in real-time was simulated offline using previously acquired images for 19 IMRT patient deliveries with both frame-by-frame comparison and cumulative frame comparison. Simulated error case studies were used to demonstrate the system sensitivity and performance. The accuracy of the synchronization method was shown to agree within two control points which corresponds to approximately ∼1% of the total MU to be delivered for dynamic IMRT. The system achieved mean real-time gamma results for frame-by-frame analysis of 86.6% and 89.0% for 3%, 3 mm and 4%, 4 mm criteria, respectively, and 97.9% and 98.6% for cumulative gamma analysis. The system can detect a 10% MU error using 3%, 3 mm criteria within approximately 10 s. The EPID-based real-time delivery verification system successfully detected simulated gross errors introduced into patient plan deliveries in near real-time (within 0.1 s). A real-time radiation delivery verification system for dynamic IMRT has been demonstrated that is designed to prevent major mistreatments in modern radiation therapy.

Flexible power delivery system and its intelligent functions

International Nuclear Information System (INIS)

Glamochanin, Vlastimir; Andonov, Dragan

1996-01-01

This paper presents some of the features and capabilities of the novel energy distribution system called FRIENDS. The main FRIENDS objective is distribution system reliability, with flexible system structure reconfiguration, inclusion of dispersed energy generation systems. Altogether, it represents a new concept of reliable and economic electric power delivery to end users. The FRIENDS project is a challenge for future research and development, including new technology and devices for the implementation of such an integrated system. (author)

Inulin based glutathione-responsive delivery system for colon cancer treatment.

Science.gov (United States)

Wang, Dongdong; Sun, Feifei; Lu, Chunbo; Chen, Peng; Wang, Zhaojie; Qiu, Yuanhao; Mu, Haibo; Miao, Zehong; Duan, Jinyou

2018-05-01

Colorectal cancer is one of the most common types of tumor in the world. Here we developed a lipoic acid esterified polysaccharide (inulin) delivery system for tanshinone IIA to treat colorectal cancer in vitro. The release of tanshinone IIA in the system was highly responsive to glutathione, which is commonly abundant in cancer cells. In addition, this drug delivery system was proliferative to Bifidobacterium longum, the common inhabitant of human intestine. Thus, this strategy might be useful to improve colon cancer therapy efficacy of anticancer drugs and meanwhile promote the growth of beneficial commensal flora in the gut. Copyright © 2018 Elsevier B.V. All rights reserved.

Nursing Services Delivery Theory: an open system approach.

Science.gov (United States)

Meyer, Raquel M; O'Brien-Pallas, Linda L

2010-12-01

This paper is a discussion of the derivation of the Nursing Services Delivery Theory from the application of open system theory to large-scale organizations. The underlying mechanisms by which staffing indicators influence outcomes remain under-theorized and unmeasured, resulting in a 'black box' that masks the nature and organization of nursing work. Theory linking nursing work, staffing, work environments, and outcomes in different settings is urgently needed to inform management decisions about the allocation of nurse staffing resources in organizations. A search of CINAHL and Business Source Premier for the years 1980-2008 was conducted using the following terms: theory, models, organization, organizational structure, management, administration, nursing units, and nursing. Seminal works were included. The healthcare organization is conceptualized as an open system characterized by energy transformation, a dynamic steady state, negative entropy, event cycles, negative feedback, differentiation, integration and coordination, and equifinality. The Nursing Services Delivery Theory proposes that input, throughput, and output factors interact dynamically to influence the global work demands placed on nursing work groups at the point of care in production subsystems. THE Nursing Services Delivery Theory can be applied to varied settings, cultures, and countries and supports the study of multi-level phenomena and cross-level effects. The Nursing Services Delivery Theory gives a relational structure for reconciling disparate streams of research related to nursing work, staffing, and work environments. The theory can guide future research and the management of nursing services in large-scale healthcare organizations. © 2010 Blackwell Publishing Ltd.

Synthesis and characterization of modified starch/polybutadiene as novel transdermal drug delivery system.

Science.gov (United States)

Saboktakin, Mohammad Reza; Akhyari, Shahab; Nasirov, Fizuli A

2014-08-01

Transdermal drug delivery systems are topically administered medicaments in the form of patches that deliver drugs for systemic effects at a predetermined and controlled rate. It works very simply in which drug is applied inside the patch and it is worn on skin for long period of time. Polymer matrix, drug, permeation enhancers are the main components of transdermal drug delivery systems. The objective of the present study was to develop the modified starch and 1,4-cis polybutadiene nanoparticles as novel polymer matrix system. We have been studied the properties of a novel transdermal drug delivery system with clonidine as drug model. Copyright © 2014 Elsevier B.V. All rights reserved.

A clinician-driven home care delivery system.

Science.gov (United States)

August, D A; Faubion, W C; Ryan, M L; Haggerty, R H; Wesley, J R

1993-12-01

The financial, entrepreneurial, administrative, and legal forces acting within the home care arena make it difficult for clinicians to develop and operate home care initiatives within an academic setting. HomeMed is a clinician-initiated and -directed home care delivery system wholly owned by the University of Michigan. The advantages of a clinician-directed system include: Assurance that clinical and patient-based factors are the primary determinants of strategic and procedural decisions; Responsiveness of the system to clinician needs; Maintenance of an important role for the referring physician in home care; Economical clinical research by facilitation of protocol therapy in ambulatory and home settings; Reduction of lengths of hospital stays through clinician initiatives; Incorporation of outcome analysis and other research programs into the mission of the system; Clinician commitment to success of the system; and Clinician input on revenue use. Potential disadvantages of a clinician-based system include: Entrepreneurial, financial, and legal naivete; Disconnection from institutional administrative and data management resources; and Inadequate clinician interest and commitment. The University of Michigan HomeMed experience demonstrates a model of clinician-initiated and -directed home care delivery that has been innovative, profitable, and clinically excellent, has engendered broad physician, nurse, pharmacist, and social worker enthusiasm, and has supported individual investigator clinical protocols as well as broad outcomes research initiatives. It is concluded that a clinician-initiated and -directed home care program is feasible and effective, and in some settings may be optimal.

Novel electric power-driven hydrodynamic injection system for gene delivery: safety and efficacy of human factor IX delivery in rats.

Science.gov (United States)

Yokoo, T; Kamimura, K; Suda, T; Kanefuji, T; Oda, M; Zhang, G; Liu, D; Aoyagi, Y

2013-08-01

The development of a safe and reproducible gene delivery system is an essential step toward the clinical application of the hydrodynamic gene delivery (HGD) method. For this purpose, we have developed a novel electric power-driven injection system called the HydroJector-EM, which can replicate various time-pressure curves preloaded into the computer program before injection. The assessment of the reproducibility and safety of gene delivery system in vitro and in vivo demonstrated the precise replication of intravascular time-pressure curves and the reproducibility of gene delivery efficiency. The highest level of luciferase expression (272 pg luciferase per mg of proteins) was achieved safely using the time-pressure curve, which reaches 30 mm Hg in 10 s among various curves tested. Using this curve, the sustained expression of a therapeutic level of human factor IX protein (>500 ng ml(-1)) was maintained for 2 months after the HGD of the pBS-HCRHP-FIXIA plasmid. Other than a transient increase in liver enzymes that recovered in a few days, no adverse events were seen in rats. These results confirm the effectiveness of the HydroJector-EM for reproducible gene delivery and demonstrate that long-term therapeutic gene expression can be achieved by automatic computer-controlled hydrodynamic injection that can be performed by anyone.

Gamma- scintigraphy in the evaluation of drug delivery systems

International Nuclear Information System (INIS)

Shahhosseini, S.; Beiki, D.; Eftekhari, M.

2003-01-01

Gamma-scintigraphy is applied extensively in the development and evaluation of pharmaceutical delivery systems, particularly for monitoring formulations in the gastrointestinal and respiratory tracts. The radiolabelling is generally achieved by the incorporation of an appropriate radionuclide such as technetium-99m or indium-111 into the formulation or by addition of a non- radioactive isotope such as samarium-152 followed by neutron activation of the final product. Drug delivery systems can be tested in vitro using various techniques like dissolution rate. Since in vitro testing methods are not predictive of in vivo results, such systems should be evaluated in vivo using animal models, especially oral dosage forms. Altered gastrointestinal transit due to individual variation, physiologic factors, or the presence of food may influence bioavailability. Distribution or drug release may be premature or delayed in vivo. Similarly, altered deposition or clearance from other routes of administration such as nasal, ocular, or inhalation may explain drug absorption anomalies. Therefore, there is a growing tendency for new drug delivery systems to be tested, whenever possible, in human subjects in a so called phase 1 clinical evaluation. Gamma- scintigraphy combined with knowledge of physiological and dosage from design can help to identify some of these variables. the resulting insight can be used to accelerate the formulation development process and to ensure success in early clinical trials

A computer-controlled conformal radiotherapy system. III: graphical simulation and monitoring of treatment delivery

International Nuclear Information System (INIS)

Kessler, Marc L.; McShan, Daniel L.; Fraass, Benedick A.

1995-01-01

Purpose: Safe and efficient delivery of radiotherapy using computer-controlled machines requires new procedures to design and verify the actual delivery of these treatments. Graphical simulation and monitoring techniques for treatment delivery have been developed for this purpose. Methods and Materials: A graphics-based simulator of the treatment machine and a set of procedures for creating and manipulating treatment delivery scripts are used to simulate machine motions, detect collisions, and monitor machine positions during treatment. The treatment delivery simulator is composed of four components: a three-dimensional dynamic model of the treatment machine; a motion simulation and collision detection algorithm, user-interface widgets that mimic the treatment machine's control and readout devices; and an icon-based interface for creating and manipulating treatment delivery scripts. These components are used in a stand-alone fashion for interactive treatment delivery planning and integrated with a machine control system for treatment implementation and monitoring. Results: A graphics-based treatment delivery simulator and a set of procedures for planning and monitoring computer-controlled treatment delivery have been developed and implemented as part of a comprehensive computer-controlled conformal radiotherapy system. To date, these techniques have been used to design and help monitor computer-controlled treatments on a radiotherapy machine for more than 200 patients. Examples using these techniques for treatment delivery planning and on-line monitoring of machine motions during therapy are described. Conclusion: A system that provides interactive graphics-based tools for defining the sequence of machine motions, simulating treatment delivery including collision detection, and presenting the therapists with continual visual feedback from the treatment machine has been successfully implemented for routine clinical use as part of an overall system for computer

A system for EPID-based real-time treatment delivery verification during dynamic IMRT treatment

Energy Technology Data Exchange (ETDEWEB)

Fuangrod, Todsaporn [Faculty of Engineering and Built Environment, School of Electrical Engineering and Computer Science, the University of Newcastle, NSW 2308 (Australia); Woodruff, Henry C.; O’Connor, Daryl J. [Faculty of Science and IT, School of Mathematical and Physical Sciences, the University of Newcastle, NSW 2308 (Australia); Uytven, Eric van; McCurdy, Boyd M. C. [Division of Medical Physics, CancerCare Manitoba, 675 McDermot Avenue, Winnipeg, Manitoba R3E 0V9 (Canada); Department of Physics and Astronomy, University of Manitoba, Winnipeg, Manitoba R3T 2N2 (Canada); Department of Radiology, University of Manitoba, Winnipeg, Manitoba R3T 2N2 (Canada); Kuncic, Zdenka [School of Physics, University of Sydney, Sydney, NSW 2006 (Australia); Greer, Peter B. [Faculty of Science and IT, School of Mathematical and Physical Sciences, the University of Newcastle, NSW 2308, Australia and Department of Radiation Oncology, Calvary Mater Newcastle Hospital, Locked Bag 7, Hunter region Mail Centre, Newcastle, NSW 2310 (Australia)

2013-09-15

Purpose: To design and develop a real-time electronic portal imaging device (EPID)-based delivery verification system for dynamic intensity modulated radiation therapy (IMRT) which enables detection of gross treatment delivery errors before delivery of substantial radiation to the patient.Methods: The system utilizes a comprehensive physics-based model to generate a series of predicted transit EPID image frames as a reference dataset and compares these to measured EPID frames acquired during treatment. The two datasets are using MLC aperture comparison and cumulative signal checking techniques. The system operation in real-time was simulated offline using previously acquired images for 19 IMRT patient deliveries with both frame-by-frame comparison and cumulative frame comparison. Simulated error case studies were used to demonstrate the system sensitivity and performance.Results: The accuracy of the synchronization method was shown to agree within two control points which corresponds to approximately ∼1% of the total MU to be delivered for dynamic IMRT. The system achieved mean real-time gamma results for frame-by-frame analysis of 86.6% and 89.0% for 3%, 3 mm and 4%, 4 mm criteria, respectively, and 97.9% and 98.6% for cumulative gamma analysis. The system can detect a 10% MU error using 3%, 3 mm criteria within approximately 10 s. The EPID-based real-time delivery verification system successfully detected simulated gross errors introduced into patient plan deliveries in near real-time (within 0.1 s).Conclusions: A real-time radiation delivery verification system for dynamic IMRT has been demonstrated that is designed to prevent major mistreatments in modern radiation therapy.

A system for EPID-based real-time treatment delivery verification during dynamic IMRT treatment

International Nuclear Information System (INIS)

Fuangrod, Todsaporn; Woodruff, Henry C.; O’Connor, Daryl J.; Uytven, Eric van; McCurdy, Boyd M. C.; Kuncic, Zdenka; Greer, Peter B.

2013-01-01

Purpose: To design and develop a real-time electronic portal imaging device (EPID)-based delivery verification system for dynamic intensity modulated radiation therapy (IMRT) which enables detection of gross treatment delivery errors before delivery of substantial radiation to the patient.Methods: The system utilizes a comprehensive physics-based model to generate a series of predicted transit EPID image frames as a reference dataset and compares these to measured EPID frames acquired during treatment. The two datasets are using MLC aperture comparison and cumulative signal checking techniques. The system operation in real-time was simulated offline using previously acquired images for 19 IMRT patient deliveries with both frame-by-frame comparison and cumulative frame comparison. Simulated error case studies were used to demonstrate the system sensitivity and performance.Results: The accuracy of the synchronization method was shown to agree within two control points which corresponds to approximately ∼1% of the total MU to be delivered for dynamic IMRT. The system achieved mean real-time gamma results for frame-by-frame analysis of 86.6% and 89.0% for 3%, 3 mm and 4%, 4 mm criteria, respectively, and 97.9% and 98.6% for cumulative gamma analysis. The system can detect a 10% MU error using 3%, 3 mm criteria within approximately 10 s. The EPID-based real-time delivery verification system successfully detected simulated gross errors introduced into patient plan deliveries in near real-time (within 0.1 s).Conclusions: A real-time radiation delivery verification system for dynamic IMRT has been demonstrated that is designed to prevent major mistreatments in modern radiation therapy

Aerosol delivery and humidification with the Boussignac continuous positive airway pressure device.

Science.gov (United States)

Thille, Arnaud W; Bertholon, Jean-François; Becquemin, Marie-Hélène; Roy, Monique; Lyazidi, Aissam; Lellouche, François; Pertusini, Esther; Boussignac, Georges; Maître, Bernard; Brochard, Laurent

2011-10-01

A simple method for effective bronchodilator aerosol delivery while administering continuing continuous positive airway pressure (CPAP) would be useful in patients with severe bronchial obstruction. To assess the effectiveness of bronchodilator aerosol delivery during CPAP generated by the Boussignac CPAP system and its optimal humidification system. First we assessed the relationship between flow and pressure generated in the mask with the Boussignac CPAP system. Next we measured the inspired-gas humidity during CPAP, with several humidification strategies, in 9 healthy volunteers. We then measured the bronchodilator aerosol particle size during CPAP, with and without heat-and-moisture exchanger, in a bench study. Finally, in 7 patients with acute respiratory failure and airway obstruction, we measured work of breathing and gas exchange after a β(2)-agonist bronchodilator aerosol (terbutaline) delivered during CPAP or via standard nebulization. Optimal humidity was obtained only with the heat-and-moisture exchanger or heated humidifier. The heat-and-moisture exchanger had no influence on bronchodilator aerosol particle size. Work of breathing decreased similarly after bronchodilator via either standard nebulization or CPAP, but P(aO(2)) increased significantly only after CPAP aerosol delivery. CPAP bronchodilator delivery decreases the work of breathing as effectively as does standard nebulization, but produces a greater oxygenation improvement in patients with airway obstruction. To optimize airway humidification, a heat-and-moisture exchanger could be used with the Boussignac CPAP system, without modifying aerosol delivery.

Oxygen Supplementation to Stabilize Preterm Infants in the Fetal to Neonatal Transition: No Satisfactory Answer.

Science.gov (United States)

Torres-Cuevas, Isabel; Cernada, Maria; Nuñez, Antonio; Escobar, Javier; Kuligowski, Julia; Chafer-Pericas, Consuelo; Vento, Maximo

2016-01-01

Fetal life elapses in a relatively low oxygen environment. Immediately after birth with the initiation of breathing, the lung expands and oxygen availability to tissue rises by twofold, generating a physiologic oxidative stress. However, both lung anatomy and function and the antioxidant defense system do not mature until late in gestation, and therefore, very preterm infants often need respiratory support and oxygen supplementation in the delivery room to achieve postnatal stabilization. Notably, interventions in the first minutes of life can have long-lasting consequences. Recent trials have aimed to assess what initial inspiratory fraction of oxygen and what oxygen targets during this transitional period are best for extremely preterm infants based on the available nomogram. However, oxygen saturation nomogram informs only of term and late preterm infants but not on extremely preterm infants. Therefore, the solution to this conundrum may still have to wait before a satisfactory answer is available.

NOVEL APROACHES ON BUCCAL MUCOADHESIVE DRUG DELIVERY SYSTEM

OpenAIRE

Dibyalochan Mohanty* , C. Gurulatha, Dr.Vasudha Bakshi, B. Mavya

2018-01-01

Among novel drug delivery system ,Buccal mucoadhesive systems have attracted great attention in recent years due to their ability to adhere and remain on the oral mucosa and to release their drug content gradually ,bioadhesion refers to any bond formed between two biological surface or a bond between a biological and a systemic surface. Buccal mucosa is preferred for both systemic and local drug action. The mucosa has a rich blood supply and it relatively permeable. Buccal mucoadhesive films ...

No oxygen delivery limitation in hepatic encephalopathy

DEFF Research Database (Denmark)

Gjedde, Albert; Keiding, Susanne; Vilstrup, Hendrik

2010-01-01

to choose between cause and effect in three groups of volunteers, including healthy control subjects (HC), patients with cirrhosis of the liver without hepatic encephalopathy (CL), and patients with cirrhosis with acute hepatic encephalopathy. Compared to HC subjects, blood flow and energy metabolism had......Hepatic encephalopathy is a condition of reduced brain functioning in which both blood flow and brain energy metabolism declined. It is not known whether blood flow or metabolism is the primary limiting factor of brain function in this condition. We used calculations of mitochondrial oxygen tension...

Transdermal drug delivery

Science.gov (United States)

Prausnitz, Mark R.; Langer, Robert

2009-01-01

Transdermal drug delivery has made an important contribution to medical practice, but has yet to fully achieve its potential as an alternative to oral delivery and hypodermic injections. First-generation transdermal delivery systems have continued their steady increase in clinical use for delivery of small, lipophilic, low-dose drugs. Second-generation delivery systems using chemical enhancers, non-cavitational ultrasound and iontophoresis have also resulted in clinical products; the ability of iontophoresis to control delivery rates in real time provides added functionality. Third-generation delivery systems target their effects to skin’s barrier layer of stratum corneum using microneedles, thermal ablation, microdermabrasion, electroporation and cavitational ultrasound. Microneedles and thermal ablation are currently progressing through clinical trials for delivery of macromolecules and vaccines, such as insulin, parathyroid hormone and influenza vaccine. Using these novel second- and third-generation enhancement strategies, transdermal delivery is poised to significantly increase impact on medicine. PMID:18997767

Cellulose Nanocrystal Membranes as Excipients for Drug Delivery Systems

Directory of Open Access Journals (Sweden)

Ananda M. Barbosa

2016-12-01

Full Text Available In this work, cellulose nanocrystals (CNCs were obtained from flax fibers by an acid hydrolysis assisted by sonochemistry in order to reduce reaction times. The cavitation inducted during hydrolysis resulted in CNC with uniform shapes, and thus further pretreatments into the cellulose are not required. The obtained CNC exhibited a homogeneous morphology and high crystallinity, as well as typical values for surface charge. Additionally, CNC membranes were developed from CNC solution to evaluation as a drug delivery system by the incorporation of a model drug. The drug delivery studies were carried out using chlorhexidine (CHX as a drug and the antimicrobial efficiency of the CNC membrane loaded with CHX was examined against Gram-positive bacteria Staphylococcus aureus (S. Aureus. The release of CHX from the CNC membranes is determined by UV-Vis. The obtaining methodology of the membranes proved to be simple, and these early studies showed a potential use in antibiotic drug delivery systems due to the release kinetics and the satisfactory antimicrobial activity.

Development of high power chemical oxygen lodine laser

Energy Technology Data Exchange (ETDEWEB)

Kim, Cheol Jung; Choi, Y. D.; Chung, C. M.; Kim, M. S.; Baik, S. H.; Kwon, S. O.; Park, S. K.; Kim, T. S

2001-10-01

This project is directed to construct 10kW Chemical Oxygen Iodine Laser (COIL) for decommissioning of old nuclear facilities, and to get the key technology that can be used for the development of high energy laser weapon. COIL is possible up to MW class in proportion to the amount of chemical reaction. For this reason, high energy laser weapon including Airborne Laser (ABL) and Airborne Tactical Laser (ATL) has been developed as a military use in USA. Recently, many research group have been doing a development study of COIL for nuclear and industrial use in material processing such as cutting and decommissioning by combining laser beam delivery through optical fiber. The Chemical Oxygen Iodine Laser of 6 kW output power has been developed in this project. The main technologies of chemical reaction and supersonic fluid control were developed. This technology can be applied for construction of 10 kW laser system. This laser can be used for old nuclear facilities and heavy industry by combining laser beam delivery through optical fiber. The development of High Energy Laser (HEL) weapon is necessary as a military use, and we conclude that Airborne Tactical Laser should be developed in our country.

American Heart Association's Call to Action for Payment and Delivery System Reform.

Science.gov (United States)

Bufalino, Vincent J; Berkowitz, Scott A; Gardner, Timothy J; Piña, Ileana L; Konig, Madeleine

2017-08-15

The healthcare system is undergoing a transition from paying for volume to paying for value. Clinicians, as well as public and private payers, are beginning to implement alternative delivery and payment models, such as the patient-centered medical home, accountable care organizations, and bundled payment arrangements. Implementation of these new models will necessitate delivery system transformation and will actively involve all fields of medical care, in particular medicine and surgery. This call to action, on behalf of the American Heart Association's Expert Panel on Payment and Delivery System Reform, serves to offer support and direction for further involvement by the American Heart Association. In doing so, it (1) provides baseline review and definition of the present models and some of the early results of these delivery models, including outcomes; (2) initiates a conversation within the American Heart Association on the impact of payment and delivery system reform, as well as how the American Heart Association should engage in the interest of patients; (3) issues a call to action to our organization and to cardiovascular and stroke health professionals across the country to become educated about these models so to as to understand their impact on patient care; and (4) asks the government and other funding agencies, including the American Heart Association, to begin supporting and prioritizing meaningful research endeavors to further evaluate these models. © 2017 American Heart Association, Inc.

Mechanisms controlling the oxygen consumption in experimentally induced hypochloremic alkalosis in calves.

Science.gov (United States)

Cambier, Carole; Clerbaux, Thierry; Amory, Hélène; Detry, Bruno; Florquin, Sandra; Marville, Vincent; Frans, Albert; Gustin, Pascal

2002-01-01

The study was carried out on healthy Friesian calves (n = 10) aged between 10 and 30 days. Hypochloremia and alkalosis were induced by intravenous administration of furosemide and isotonic sodium bicarbonate. The venous and arterial blood samples were collected repeatedly. 2,3-diphosphoglycerate (2,3-DPG), hemoglobin and plasmatic chloride concentrations were determined. The red blood cell chloride concentration was also calculated. pH, PCO2 and PO2 were measured in arterial and mixed venous blood. The oxygen equilibrium curve (OEC) was measured in standard conditions. The correspondence of the OEC to the arterial and mixed venous compartments was calculated, taking blood temperature, pH and PCO2 values into account. The oxygen exchange fraction (OEF%), corresponding to the degree of blood desaturation between the arterial and mixed venous compartments and the amount of oxygen released at the tissue level by 100 mL of blood (OEF Vol%) were calculated from the arterial and mixed venous OEC, combined with PO2 and hemoglobin concentration. Oxygen delivery (DO2) was calculated using the arterial oxygen content, the cardiac output measured by thermodilution, and the body weight of the animal. The oxygen consumption (VO2) was derived from the cardiac output, OEF Vol% and body weight values. Despite the plasma hypochloremia, the erythrocyte chloride concentration was not influenced by furosemide and sodium bicarbonate infusion. Due to the alkalosis-induced increase in the 2,3-DPG, the standard OEC was shifted to the right, allowing oxygen to dissociate from hemoglobin more rapidly. These changes opposed the increased affinity of hemoglobin for oxygen induced by alkalosis. Moreover, respiratory acidosis, hemoconcentration, and the slight decrease in the partial oxygen pressure in mixed venous blood (Pvo2) tended to improve the OEF Vol% and maintain the oxygen consumption in a physiological range while the cardiac output, and the oxygen delivery were significantly decreased

Non-viral delivery systems for CRISPR/Cas9-based genome editing: Challenges and opportunities.

Science.gov (United States)

Li, Ling; Hu, Shuo; Chen, Xiaoyuan

2018-07-01

In recent years, CRISPR (clustered regularly interspaced short palindromic repeat)/Cas (CRISPR-associated) genome editing systems have become one of the most robust platforms in basic biomedical research and therapeutic applications. To date, efficient in vivo delivery of the CRISPR/Cas9 system to the targeted cells remains a challenge. Although viral vectors have been widely used in the delivery of the CRISPR/Cas9 system in vitro and in vivo, their fundamental shortcomings, such as the risk of carcinogenesis, limited insertion size, immune responses and difficulty in large-scale production, severely limit their further applications. Alternative non-viral delivery systems for CRISPR/Cas9 are urgently needed. With the rapid development of non-viral vectors, lipid- or polymer-based nanocarriers have shown great potential for CRISPR/Cas9 delivery. In this review, we analyze the pros and cons of delivering CRISPR/Cas9 systems in the form of plasmid, mRNA, or protein and then discuss the limitations and challenges of CRISPR/Cas9-based genome editing. Furthermore, current non-viral vectors that have been applied for CRISPR/Cas9 delivery in vitro and in vivo are outlined in details. Finally, critical obstacles for non-viral delivery of CRISPR/Cas9 system are highlighted and promising strategies to overcome these barriers are proposed. Published by Elsevier Ltd.

Gene delivery to skeletal muscle results in sustained expression and systemic delivery of a therapeutic protein.

Science.gov (United States)

Kessler, P D; Podsakoff, G M; Chen, X; McQuiston, S A; Colosi, P C; Matelis, L A; Kurtzman, G J; Byrne, B J

1996-11-26

Somatic gene therapy has been proposed as a means to achieve systemic delivery of therapeutic proteins. However, there is limited evidence that current methods of gene delivery can practically achieve this goal. In this study, we demonstrate that, following a single intramuscular administration of a recombinant adeno-associated virus (rAAV) vector containing the beta-galactosidase (AAV-lacZ) gene into adult BALB/c mice, protein expression was detected in myofibers for at least 32 weeks. A single intramuscular administration of an AAV vector containing a gene for human erythropoietin (AAV-Epo) into mice resulted in dose-dependent secretion of erythropoietin and corresponding increases in red blood cell production that persisted for up to 40 weeks. Primary human myotubes transduced in vitro with the AAV-Epo vector also showed dose-dependent production of Epo. These results demonstrate that rAAV vectors are able to transduce skeletal muscle and are capable of achieving sustained expression and systemic delivery of a therapeutic protein following a single intramuscular administration. Gene therapy using AAV vectors may provide a practical strategy for the treatment of inherited and acquired protein deficiencies.

Gene delivery to skeletal muscle results in sustained expression and systemic delivery of a therapeutic protein

Science.gov (United States)

Kessler, Paul D.; Podsakoff, Gregory M.; Chen, Xiaojuan; McQuiston, Susan A.; Colosi, Peter C.; Matelis, Laura A.; Kurtzman, Gary J.; Byrne, Barry J.

1996-01-01

Somatic gene therapy has been proposed as a means to achieve systemic delivery of therapeutic proteins. However, there is limited evidence that current methods of gene delivery can practically achieve this goal. In this study, we demonstrate that, following a single intramuscular administration of a recombinant adeno-associated virus (rAAV) vector containing the β-galactosidase (AAV-lacZ) gene into adult BALB/c mice, protein expression was detected in myofibers for at least 32 weeks. A single intramuscular administration of an AAV vector containing a gene for human erythropoietin (AAV-Epo) into mice resulted in dose-dependent secretion of erythropoietin and corresponding increases in red blood cell production that persisted for up to 40 weeks. Primary human myotubes transduced in vitro with the AAV-Epo vector also showed dose-dependent production of Epo. These results demonstrate that rAAV vectors are able to transduce skeletal muscle and are capable of achieving sustained expression and systemic delivery of a therapeutic protein following a single intramuscular administration. Gene therapy using AAV vectors may provide a practical strategy for the treatment of inherited and acquired protein deficiencies. PMID:8943064

Control of oxygen tension recapitulates zone-specific functions in human liver microphysiology systems.

Science.gov (United States)

Lee-Montiel, Felipe T; George, Subin M; Gough, Albert H; Sharma, Anup D; Wu, Juanfang; DeBiasio, Richard; Vernetti, Lawrence A; Taylor, D Lansing

2017-10-01

This article describes our next generation human Liver Acinus MicroPhysiology System (LAMPS). The key demonstration of this study was that Zone 1 and Zone 3 microenvironments can be established by controlling the oxygen tension in individual devices over the range of ca. 3 to 13%. The oxygen tension was computationally modeled using input on the microfluidic device dimensions, numbers of cells, oxygen consumption rates of hepatocytes, the diffusion coefficients of oxygen in different materials and the flow rate of media in the MicroPhysiology System (MPS). In addition, the oxygen tension was measured using a ratiometric imaging method with the oxygen sensitive dye, Tris(2,2'-bipyridyl) dichlororuthenium(II) hexahydrate (RTDP) and the oxygen insensitive dye, Alexa 488. The Zone 1 biased functions of oxidative phosphorylation, albumin and urea secretion and Zone 3 biased functions of glycolysis, α1AT secretion, Cyp2E1 expression and acetaminophen toxicity were demonstrated in the respective Zone 1 and Zone 3 MicroPhysiology System. Further improvements in the Liver Acinus MicroPhysiology System included improved performance of selected nonparenchymal cells, the inclusion of a porcine liver extracellular matrix to model the Space of Disse, as well as an improved media to support both hepatocytes and non-parenchymal cells. In its current form, the Liver Acinus MicroPhysiology System is most amenable to low to medium throughput, acute through chronic studies, including liver disease models, prioritizing compounds for preclinical studies, optimizing chemistry in structure activity relationship (SAR) projects, as well as in rising dose studies for initial dose ranging. Impact statement Oxygen zonation is a critical aspect of liver functions. A human microphysiology system is needed to investigate the impact of zonation on a wide range of liver functions that can be experimentally manipulated. Because oxygen zonation has such diverse physiological effects in the liver, we

Placental Gas Exchange and the Oxygen Supply to the Fetus

DEFF Research Database (Denmark)

Carter, Anthony M

2015-01-01

The oxygen supply of the fetus depends on the blood oxygen content and flow rate in the uterine and umbilical arteries and the diffusing capacity of the placenta. Oxygen consumption by the placenta is a significant factor and a potential limitation on availability to the fetus. The relevance...... anaerobic conditions and even the fetus is adapted to a low oxygen environment. Nevertheless, there is a reserve capacity, and during acute hypoxia the fetus can counter a 50% reduction in oxygen delivery by increasing fractional extraction. During sustained hypoxia, on the other hand, fetal growth...

How can innovative project delivery systems improve the overall efficiency of GDOT in transportation project delivery?

Science.gov (United States)

2013-04-01

The USDOT and Federal Highway Administration (FHWA) recommend the smart use of innovative project : delivery systems, such as design-build, to improve efficiency and effectiveness of developing transportation : projects. Although design-build provide...

Magnetic control of potential microrobotic drug delivery systems: nanoparticles, magnetotactic bacteria and self-propelled microjets.

Science.gov (United States)

Khalil, Islam S M; Magdanz, Veronika; Sanchez, Samuel; Schmidt, Oliver G; Abelmann, Leon; Misra, Sarthak

2013-01-01

Development of targeted drug delivery systems using magnetic microrobots increases the therapeutic indices of drugs. These systems have to be incorporated with precise motion controllers. We demonstrate closed-loop motion control of microrobots under the influence of controlled magnetic fields. Point-to-point motion control of a cluster of iron oxide nanoparticles (diameter of 250 nm) is achieved by pulling the cluster towards a reference position using magnetic field gradients. Magnetotactic bacterium (MTB) is controlled by orienting the magnetic fields towards a reference position. MTB with membrane length of 5 µm moves towards the reference position using the propulsion force generated by its flagella. Similarly, self-propelled microjet with length of 50 µm is controlled by directing the microjet towards a reference position by external magnetic torque. The microjet moves along the field lines using the thrust force generated by the ejecting oxygen bubbles from one of its ends. Our control system positions the cluster of nanoparticles, an MTB and a microjet at an average velocity of 190 µm/s, 28 µm/s, 90 µm/s and within an average region-of-convergence of 132 µm, 40 µm, 235 µm, respectively.

Transdermal drug delivery

OpenAIRE

Prausnitz, Mark R.; Langer, Robert

2008-01-01

Transdermal drug delivery has made an important contribution to medical practice, but has yet to fully achieve its potential as an alternative to oral delivery and hypodermic injections. First-generation transdermal delivery systems have continued their steady increase in clinical use for delivery of small, lipophilic, low-dose drugs. Second-generation delivery systems using chemical enhancers, non-cavitational ultrasound and iontophoresis have also resulted in clinical products; the ability ...

Conceptualizing the use of system products and system deliveries in the building industry

DEFF Research Database (Denmark)

Hvam, Lars; Mortensen, Niels Henrik; Thuesen, Christian

2013-01-01

on the product architecture and partly of the setup of the business processes by using e.g. Configure to Order processes and Engineer to Order processes. Furthermore the potential impacts from using system products and system deliveries are discussed based on the examples included....

New Delivery Systems for Local Anaesthetics—Part 2

Directory of Open Access Journals (Sweden)

Edward A. Shipton

2012-01-01

Full Text Available Part 2 of this paper deals with the techniques for drug delivery of topical and injectable local anaesthetics. The various routes of local anaesthetic delivery (epidural, peripheral, wound catheters, intra-nasal, intra-vesical, intra-articular, intra-osseous are explored. To enhance transdermal local anaesthetic permeation, additional methods to the use of an eutectic mixture of local anaesthetics and the use of controlled heat can be used. These methods include iontophoresis, electroporation, sonophoresis, and magnetophoresis. The potential clinical uses of topical local anaesthetics are elucidated. Iontophoresis, the active transportation of a drug into the skin using a constant low-voltage direct current is discussed. It is desirable to prolong local anaesthetic blockade by extending its sensory component only. The optimal release and safety of the encapsulated local anaesthetic agents still need to be determined. The use of different delivery systems should provide the clinician with both an extended range and choice in the degree of prolongation of action of each agent.

A high-density lipoprotein-mediated drug delivery system.

Science.gov (United States)

Mo, Zhong-Cheng; Ren, Kun; Liu, Xing; Tang, Zhen-Li; Yi, Guang-Hui

2016-11-15

High-density lipoprotein (HDL) is a comparatively dense and small lipoprotein that can carry lipids as a multifunctional aggregate in plasma. Several studies have shown that increasing the levels or improving the functionality of HDL is a promising target for treating a wide variety of diseases. Among lipoproteins, HDL particles possess unique physicochemical properties, including naturally synthesized physiological components, amphipathic apolipoproteins, lipid-loading and hydrophobic agent-incorporating characteristics, specific protein-protein interactions, heterogeneity, nanoparticles, and smaller size. Recently, the feasibility and superiority of using HDL particles as drug delivery vehicles have been of great interest. In this review, we summarize the structure, constituents, biogenesis, remodeling, and reconstitution of HDL drug delivery systems, focusing on their delivery capability, characteristics, applications, manufacturing, and drug-loading and drug-targeting characteristics. Finally, the future prospects are presented regarding the clinical application and challenges of using HDL as a pharmacodelivery carrier. Copyright © 2016 Elsevier B.V. All rights reserved.

Conceptual design report for the University of Rochester cryogenic target delivery system

International Nuclear Information System (INIS)

Fagaly, R.L.; Alexander, N.B.; Bourque, R.F.; Dahms, C.F.; Lindgren, J.R.; Miller, W.J.; Bittner, D.N.; Hendricks, C.D.

1993-05-01

The upgrade of the Omega laser at the University of Rochester's Laboratory for Laser Energetics (UR/LLE) will result in a need for large targets filled with D 2 or Dt and maintained at cryogenic temperatures. This mandates a cryogenic target delivery system capable of filling, layering, characterizing and delivering cryogenic targets to the Omega Upgrade target chamber. The program goal is to design, construct, and test the entire target delivery system by June 1996. When completed (including an operational demonstration), the system will be shipped to Rochester for reassembly and commissioning in time for the Omega Upgrade cryogenic campaign, scheduled to start in 1998. General Atomics has been assigned the task of developing the conceptual design for the cryogenic target delivery system. Design and fabrication activities will be closely coordinated with the University of Rochester, Lawrence Livermore National laboratory (LLNL) and Los Alamos National Laboratory (LANL), drawing upon their knowledge base in fuel layering and cryogenic characterization. The development of a target delivery system for Omega could also benefit experiments at Lawrence Livermore National Laboratory and the other ICF Laboratories in that the same technologies could be applied to NOVA, the National Ignition Facility or the future Laboratory Microfusion Facility

Conceptual design report for the University of Rochester cryogenic target delivery system

Energy Technology Data Exchange (ETDEWEB)

Fagaly, R.L.; Alexander, N.B.; Bourque, R.F.; Dahms, C.F.; Lindgren, J.R.; Miller, W.J. (General Atomics, San Diego, CA (United States)); Bittner, D.N.; Hendricks, C.D. (W.J. Schafer Associates, Livermore, CA (United States))

1993-05-01

The upgrade of the Omega laser at the University of Rochester's Laboratory for Laser Energetics (UR/LLE) will result in a need for large targets filled with D[sub 2] or Dt and maintained at cryogenic temperatures. This mandates a cryogenic target delivery system capable of filling, layering, characterizing and delivering cryogenic targets to the Omega Upgrade target chamber. The program goal is to design, construct, and test the entire target delivery system by June 1996. When completed (including an operational demonstration), the system will be shipped to Rochester for reassembly and commissioning in time for the Omega Upgrade cryogenic campaign, scheduled to start in 1998. General Atomics has been assigned the task of developing the conceptual design for the cryogenic target delivery system. Design and fabrication activities will be closely coordinated with the University of Rochester, Lawrence Livermore National laboratory (LLNL) and Los Alamos National Laboratory (LANL), drawing upon their knowledge base in fuel layering and cryogenic characterization. The development of a target delivery system for Omega could also benefit experiments at Lawrence Livermore National Laboratory and the other ICF Laboratories in that the same technologies could be applied to NOVA, the National Ignition Facility or the future Laboratory Microfusion Facility.

Conceptual design report for the University of Rochester cryogenic target delivery system

Energy Technology Data Exchange (ETDEWEB)

Fagaly, R.L.; Alexander, N.B.; Bourque, R.F.; Dahms, C.F.; Lindgren, J.R.; Miller, W.J. [General Atomics, San Diego, CA (United States); Bittner, D.N.; Hendricks, C.D. [W.J. Schafer Associates, Livermore, CA (US)

1993-05-01

The upgrade of the Omega laser at the University of Rochester`s Laboratory for Laser Energetics (UR/LLE) will result in a need for large targets filled with D{sub 2} or Dt and maintained at cryogenic temperatures. This mandates a cryogenic target delivery system capable of filling, layering, characterizing and delivering cryogenic targets to the Omega Upgrade target chamber. The program goal is to design, construct, and test the entire target delivery system by June 1996. When completed (including an operational demonstration), the system will be shipped to Rochester for reassembly and commissioning in time for the Omega Upgrade cryogenic campaign, scheduled to start in 1998. General Atomics has been assigned the task of developing the conceptual design for the cryogenic target delivery system. Design and fabrication activities will be closely coordinated with the University of Rochester, Lawrence Livermore National laboratory (LLNL) and Los Alamos National Laboratory (LANL), drawing upon their knowledge base in fuel layering and cryogenic characterization. The development of a target delivery system for Omega could also benefit experiments at Lawrence Livermore National Laboratory and the other ICF Laboratories in that the same technologies could be applied to NOVA, the National Ignition Facility or the future Laboratory Microfusion Facility.

Replacement of HCFC-225 Solvent for Cleaning NASA Propulsion Oxygen Systems

Science.gov (United States)

Mitchell, Mark A.; Lowrey, Nikki M.

2015-01-01

Since the 1990's, when the Class I Ozone Depleting Substance (ODS) chlorofluorocarbon-113 (CFC-113) was banned, NASA's rocket propulsion test facilities at Marshall Space Flight Center (MSFC) and Stennis Space Center (SSC) have relied upon hydrochlorofluorocarbon-225 (HCFC-225) to safely clean and verify the cleanliness of large scale propulsion oxygen systems. Effective January 1, 2015, the production, import, export, and new use of HCFC-225, a Class II ODS, was prohibited by the Clean Air Act. In 2012 through 2014, leveraging resources from both the NASA Rocket Propulsion Test Program and the Defense Logistics Agency - Aviation Hazardous Minimization and Green Products Branch, test labs at MSFC, SSC, and Johnson Space Center's White Sands Test Facility (WSTF) collaborated to seek out, test, and qualify a replacement for HCFC-225 that is both an effective cleaner and safe for use with oxygen systems. Candidate solvents were selected and a test plan was developed following the guidelines of ASTM G127, Standard Guide for the Selection of Cleaning Agents for Oxygen Systems. Solvents were evaluated for materials compatibility, oxygen compatibility, cleaning effectiveness, and suitability for use in cleanliness verification and field cleaning operations. Two solvents were determined to be acceptable for cleaning oxygen systems and one was chosen for implementation at NASA's rocket propulsion test facilities. The test program and results are summarized. This project also demonstrated the benefits of cross-agency collaboration in a time of limited resources.

Polymer based drug delivery systems for mycobacterial infections.

Science.gov (United States)

Pandey, Rajesh; Khuller, G K

2004-07-01

In the last decade, polymer based technologies have found wide biomedical applications. Polymers, whether synthetic (e.g. polylactide-co-glycolide or PLG) or natural (e.g. alginate, chitosan etc.), have the property of encapsulating a diverse range of molecules of biological interest and bear distinct therapeutic advantages such as controlled release of drugs, protection against the premature degradation of drugs and reduction in drug toxicity. These are important considerations in the long-duration treatment of chronic infectious diseases such as tuberculosis in which patient non-compliance is the major obstacle to successful chemotherapy. Antitubercular drugs, singly or in combination, have been encapsulated in polymers to provide controlled drug release and the system also offers the flexibility of selecting various routes of administration such as oral, subcutaneous and aerosol. The present review highlights the approaches towards the preparation of polymeric antitubercular drug delivery systems, emphasizing how the route of administration may influence drug bioavailability as well as the chemotherapeutic efficacy. In addition, the pros and cons of the various delivery systems are also discussed.

Biomaterials as novel penetration enhancers for transdermal and dermal drug delivery systems.

Science.gov (United States)

Chen, Yang; Wang, Manli; Fang, Liang

2013-01-01

The highly organized structure of the stratum corneum provides an effective barrier to the drug delivery into or across the skin. To overcome this barrier function, penetration enhancers are always used in the transdermal and dermal drug delivery systems. However, the conventional chemical enhancers are often limited by their inability to delivery large and hydrophilic molecules, and few to date have been routinely incorporated into the transdermal formulations due to their incompatibility and local irritation issues. Therefore, there has been a search for the compounds that exhibit broad enhancing activity for more drugs without producing much irritation. More recently, the use of biomaterials has emerged as a novel method to increase the skin permeability. In this paper, we present an overview of the investigations on the feasibility and application of biomaterials as penetration enhancers for transdermal or dermal drug delivery systems.

Significant role of cationic polymers in drug delivery systems.

Science.gov (United States)

Farshbaf, Masoud; Davaran, Soodabeh; Zarebkohan, Amir; Annabi, Nasim; Akbarzadeh, Abolfazl; Salehi, Roya

2017-11-06

Cationic polymers are characterized as the macromolecules that possess positive charges, which can be either inherently in the polymer side chains and/or its backbone. Based on their origins, cationic polymers are divided in two category including natural and synthetic, in which the possessed positive charges are as result of primary, secondary or tertiary amine functional groups that could be protonated in particular situations. Cationic polymers have been employed commonly as drug delivery agents due to their superior encapsulation efficacy, enhanced bioavailability, low toxicity and improved release profile. In this paper, we focus on the most prominent examples of cationic polymers which have been revealed to be applicable in drug delivery systems and we also discuss their general synthesis and surface modification methods as well as their controlled release profile in drug delivery.

Potential applications for halloysite nanotubes based drug delivery systems

Science.gov (United States)

Sun, Lin

Drug delivery refers to approaches, formulations, technologies, and systems for transporting a drug in the body. The purpose is to enhance the drug efficacy and to reduce side reactions, which can significantly improve treatment outcomes. Halloysite is a naturally occurred alumino-silicate clay with a tubular structure. It is a biocompatible material with a big surface area which can be used for attachment of targeted molecules. Besides, loaded molecules can present a sustained release manner in solution. These properties make halloysite nanotubes (HNTs) a good option for drug delivery. In this study, a drug delivery system was built based on halloysite via three different fabrication methods: physical adsorption, vacuum loading and layer-by-layer coating. Methotrexate was used as the model drug. Factors that may affect performance in both drug loading and release were tested. Results showed that methotrexate could be incorporated within the HNTs system and released in a sustained manner. Layer-by-layer coating showed a better potential than the other two methods in both MTX loading and release. Besides, lower pH could greatly improve MTX loading and release while the increased number of polyelectrolytes bilayers had a limited impact. Osteosarcoma is the most common primary bone malignancy in children and adolescents. Postoperative recurrence and metastasis has become one of the leading causes for patient death after surgical remove of the tumor mass. A strategy could be a sustained release of chemotherapeutics directly at the primary tumor sites where recurrence would mostly occur. Then, this HNTs based system was tested with osteosarcoma cells in vitro to show the potential of delivering chemotherapeutics in the treatment of osteosarcoma. Methotrexate was incorporated within HNTs with a layer-bylayer coating technique, and drug coated HNTs were filled into nylon-6 which is a common material for surgical sutures in industry. Results showed that (1) methotrexate

Nanotechnology-Based Drug Delivery Systems for Photodynamic Therapy of Cancer: A Review.

Science.gov (United States)

Calixto, Giovana Maria Fioramonti; Bernegossi, Jéssica; de Freitas, Laura Marise; Fontana, Carla Raquel; Chorilli, Marlus

2016-03-11

Photodynamic therapy (PDT) is a promising alternative approach for improved cancer treatment. In PDT, a photosensitizer (PS) is administered that can be activated by light of a specific wavelength, which causes selective damage to the tumor and its surrounding vasculature. The success of PDT is limited by the difficulty in administering photosensitizers (PSs) with low water solubility, which compromises the clinical use of several molecules. Incorporation of PSs in nanostructured drug delivery systems, such as polymeric nanoparticles (PNPs), solid lipid nanoparticles (SLNs), nanostructured lipid carriers (NLCs), gold nanoparticles (AuNPs), hydrogels, liposomes, liquid crystals, dendrimers, and cyclodextrin is a potential strategy to overcome this difficulty. Additionally, nanotechnology-based drug delivery systems may improve the transcytosis of a PS across epithelial and endothelial barriers and afford the simultaneous co-delivery of two or more drugs. Based on this, the application of nanotechnology in medicine may offer numerous exciting possibilities in cancer treatment and improve the efficacy of available therapeutics. Therefore, the aim of this paper is to review nanotechnology-based drug delivery systems for photodynamic therapy of cancer.

Nanotechnology-Based Drug Delivery Systems for Photodynamic Therapy of Cancer: A Review

Directory of Open Access Journals (Sweden)

Giovana Maria Fioramonti Calixto

2016-03-01

Full Text Available Photodynamic therapy (PDT is a promising alternative approach for improved cancer treatment. In PDT, a photosensitizer (PS is administered that can be activated by light of a specific wavelength, which causes selective damage to the tumor and its surrounding vasculature. The success of PDT is limited by the difficulty in administering photosensitizers (PSs with low water solubility, which compromises the clinical use of several molecules. Incorporation of PSs in nanostructured drug delivery systems, such as polymeric nanoparticles (PNPs, solid lipid nanoparticles (SLNs, nanostructured lipid carriers (NLCs, gold nanoparticles (AuNPs, hydrogels, liposomes, liquid crystals, dendrimers, and cyclodextrin is a potential strategy to overcome this difficulty. Additionally, nanotechnology-based drug delivery systems may improve the transcytosis of a PS across epithelial and endothelial barriers and afford the simultaneous co-delivery of two or more drugs. Based on this, the application of nanotechnology in medicine may offer numerous exciting possibilities in cancer treatment and improve the efficacy of available therapeutics. Therefore, the aim of this paper is to review nanotechnology-based drug delivery systems for photodynamic therapy of cancer.

Oxygen supplementation to stabilize preterm infants in the fetal to neonatal transition: no satisfactory answer.

Directory of Open Access Journals (Sweden)

Isabel eTorres-Cuevas

2016-04-01

Full Text Available Fetal life elapses in a relatively low oxygen environment. Immediately after birth with the initiation of breathing the lung expands and oxygen availability to tissue rises by twofold generating a physiologic oxidative stress. However, both lung anatomy and function and the antioxidant defense system do not mature until late in gestation and therefore very preterm infants often need respiratory support and oxygen supplementation in the delivery room to achieve postnatal stabilization. Notably, interventions in the first minutes of life can have long-lasting consequences. Recent trials have aimed to assess what initial inspiratory fraction of oxygen and what oxygen targets during this transitional period are best for extremely preterm infants based on the available nomogram. However, oxygen saturation nomogram informs only of term and late preterm infants but not on extremely preterm infants. Therefore, the solution to this conundrum may still have to wait before a satisfactory answer is available.

Effects of race and sex on cerebral hemodynamics, oxygen delivery and blood flow distribution in response to high altitude

Science.gov (United States)

Liu, Jie; Liu, Yang; Ren, Li-Hua; Li, Li; Wang, Zhen; Liu, Shan-Shan; Li, Su-Zhi; Cao, Tie-Sheng

2016-08-01

To assess racial, sexual, and regional differences in cerebral hemodynamic response to high altitude (HA, 3658 m). We performed cross-sectional comparisons on total cerebral blood flow (TCBF = sum of bilateral internal carotid and vertebral arterial blood flows = QICA + QVA), total cerebrovascular resistance (TCVR), total cerebral oxygen delivery (TCOD) and QVA/TCBF (%), among six groups of young healthy subjects: Tibetans (2-year staying) and Han (Han Chinese) at sea level, Han (2-day, 1-year and 5-year) and Tibetans at HA. Bilateral ICA and VA diameters and flow velocities were derived from duplex ultrasonography; and simultaneous measurements of arterial pressure, oxygen saturation, and hemoglobin concentration were conducted. Neither acute (2-day) nor chronic (>1 year) responses showed sex differences in Han, except that women showed lower TCOD compared with men. Tibetans and Han exhibited different chronic responses (percentage alteration relative to the sea-level counterpart value) in TCBF (-17% vs. 0%), TCVR (22% vs. 12%), TCOD (0% vs. 10%) and QVA/TCBF (0% vs. 2.4%, absolute increase), with lower resting TCOD found in SL- and HA-Tibetans. Our findings indicate racial but not sex differences in cerebral hemodynamic adaptations to HA, with Tibetans (but not Han) demonstrating an altitude-related change of CBF distribution.

The impact of a preloaded intraocular lens delivery system on operating room efficiency in routine cataract surgery.

Science.gov (United States)

Jones, Jason J; Chu, Jeffrey; Graham, Jacob; Zaluski, Serge; Rocha, Guillermo

2016-01-01

The aim of this study was to evaluate the operational impact of using preloaded intraocular lens (IOL) delivery systems compared with manually loaded IOL delivery processes during routine cataract surgeries. Time and motion data, staff and surgery schedules, and cost accounting reports were collected across three sites located in the US, France, and Canada. Time and motion data were collected for manually loaded IOL processes and preloaded IOL delivery systems over four surgery days. Staff and surgery schedules and cost accounting reports were collected during the 2 months prior and after introduction of the preloaded IOL delivery system. The study included a total of 154 routine cataract surgeries across all three sites. Of these, 77 surgeries were performed using a preloaded IOL delivery system, and the remaining 77 surgeries were performed using a manual IOL delivery process. Across all three sites, use of the preloaded IOL delivery system significantly decreased mean total case time by 6.2%-12.0% (Psystem also decreased surgeon lens time, surgeon delays, and eliminated lens touches during IOL preparation. Compared to a manual IOL delivery process, use of a preloaded IOL delivery system for cataract surgery reduced total case time, total surgeon lens time, surgeon delays, and eliminated IOL touches. The time savings provided by the preloaded IOL delivery system provide an opportunity for sites to improve routine cataract surgery throughput without impacting surgeon or staff capacity.

Efficient siRNA delivery system using carboxilated single-wall carbon nanotubes in cancer treatment.

Science.gov (United States)

Neagoe, Ioana Berindan; Braicu, Cornelia; Matea, Cristian; Bele, Constantin; Florin, Graur; Gabriel, Katona; Veronica, Chedea; Irimie, Alexandru

2012-08-01

Several functionalized carbon nanotubes have been designed and tested for the purpose of nucleic acid delivery. In this study, the capacity of SWNTC-COOH for siRNA deliverey were investigated delivery in parallel with an efficient commercial system. Hep2G cells were reverse-transfected with 50 nM siRNA (p53 siRNA, TNF-alphasiRNA, VEGFsiRNA) using the siPORT NeoFX (Ambion) transfection agent in paralel with SWNTC-COOH, functionalised with siRNA. The highest level of gene inhibition was observed in the cases treated with p53 siRNA gene; in the case of transfection with siPort, the NeoFX value was 33.8%, while in the case of SWNTC-COOH as delivery system for p53 siRNA was 37.5%. The gene silencing capacity for VEGF was 53.7%, respectively for TNF-alpha 56.7% for siPORT NeoFX delivery systems versus 47.7% (VEGF) and 46.5% (TNF-alpha) for SWNTC-COOH delivery system. SWNTC-COOH we have been showed to have to be an efficient carrier system. The results from the inhibition of gene expresion for both transfection systems were confirmed at protein level. Overall, the lowest mRNA expression was confirmed at protein level, especially in the case of p53 siRNA and TNF-alpha siRNA transfection. Less efficient reduction protein expressions were observed in the case of VEGF siRNA, for both transfection systems at 24 h; only at 48 h, there was a statistically significant reduction of VEGF protein expression. SWCNT-COOH determined an efficient delivery of siRNA. SWNTC-COOH, combined with suitable tumor markers like p53 siRNA, TNFalpha siRNA or VEGF siRNA can be used for the efficient delivery of siRNA.

Controlled release of simvastatin from biomimetic β-TCP drug delivery system.

Directory of Open Access Journals (Sweden)

Joshua Chou

Full Text Available Simvastatin have been shown to induce bone formation and there is currently a urgent need to develop an appropriate delivery system to sustain the release of the drug to increase therapeutic efficacy whilst reducing side effects. In this study, a novel drug delivery system for simvastatin by means of hydrothermally converting marine exoskeletons to biocompatible beta-tricalcium phosphate was investigated. Furthermore, the release of simvastatin was controlled by the addition of an outer apatite coating layer. The samples were characterized by x-ray diffraction analysis, fourier transform infrared spectroscopy, scanning electron microscopy and mass spectroscopy confirming the conversion process. The in-vitro dissolution of key chemical compositional elements and the release of simvastatin were measured in simulated body fluid solution showing controlled release with reduction of approximately 25% compared with un-coated samples. This study shows the potential applications of marine structures as a drug delivery system for simvastatin.

Post delivery test report for light duty utility arm optical alignment system (OAS)

International Nuclear Information System (INIS)

Pardini, A.F.

1996-01-01

This report documents the post delivery testing of the Optical Alignment System (OAS) LDUA system, designed for use by the Light Duty Utility Arm (LDUA) project. The post delivery test shows by demonstration that the optical alignment system is fully operational to perform the task of aligning the LDUA arm and mast with the entry riser during deployment operations within a Hanford Site waste tank

Post delivery test report for light duty utility arm optical alignment system (OAS)

Energy Technology Data Exchange (ETDEWEB)

Pardini, A.F.

1996-04-18

This report documents the post delivery testing of the Optical Alignment System (OAS) LDUA system, designed for use by the Light Duty Utility Arm (LDUA) project. The post delivery test shows by demonstration that the optical alignment system is fully operational to perform the task of aligning the LDUA arm and mast with the entry riser during deployment operations within a Hanford Site waste tank.

Effect of hindpaw electrical stimulation on capillary flow heterogeneity and oxygen delivery (Conference Presentation)

Science.gov (United States)

Li, Yuandong; Wei, Wei; Li, Chenxi; Wang, Ruikang K.

2017-02-01

We report a novel use of optical coherence tomography (OCT) based angiography to visualize and quantify dynamic response of cerebral capillary flow pattern in mice upon hindpaw electrical stimulation through the measurement of the capillary transit-time heterogeneity (CTH) and capillary mean transit time (MTT) in a wide dynamic range of a great number of vessels in vivo. The OCT system was developed to have a central wavelength of 1310 nm, a spatial resolution of 8 µm and a system dynamic range of 105 dB at an imaging rate of 92 kHz. The mapping of dynamic cerebral microcirculations was enabled by optical microangiography protocol. From the imaging results, the spatial homogenization of capillary velocity (decreased CTH) was observed in the region of interest (ROI) corresponding to the stimulation, along with an increase in the MTT in the ROI to maintain sufficient oxygen exchange within the brain tissue during functional activation. We validated the oxygen consumption due to an increase of the MTT through demonstrating an increase in the deoxygenated hemoglobin (HbR) during the stimulation by the use of laser speckle contrast imaging.

Californium oxygen system for 1.50 < O/Cf < 1.72

International Nuclear Information System (INIS)

Turcotte, R.P.; Haire, R.G.

1975-01-01

The californium-oxygen system was studied as a function of temperature, oxygen pressure, and stoichiometry by manometric and x-ray diffraction methods. The results establish rhombohedral Cf 7 O 12 as the stable compound obtained by heating Cf 2 O 3 in air. The isobaric oxidation-reduction cycles Cf 2 O 3 → Cf 7 O 12 → Cf 2 O 3 , observed in constant rate of heating (cooling) experiments, occur with large hysteresis. A close parallel to other fluorite related lanthanide and actinide oxide systems is established. (auth)

Transdermal solid delivery of epigallocatechin-3-gallate using self-double-emulsifying drug delivery system as vehicle: Formulation, evaluation and vesicle-skin interaction.

Science.gov (United States)

Hu, Caibiao; Gu, Chengyu; Fang, Qiao; Wang, Qiang; Xia, Qiang

2016-02-01

The present study investigated a self-double-emulsifying drug delivery system loaded with epigallocatechin-3-gallate to improve epigallocatechin-3-gallate skin retention. The long chain solid lipids (cetostearyl alcohol) and macadamia oil were utilized as a carrier to deliver the bioactive ingredient. Response surface methodology was used to optimize the formulation, and the solid lipid to total lipid weight ratio, concentration of epigallocatechin-3-gallate and hydrophilic surfactant on skin retention were found to be the principal factors. The optimum formulation with high encapsulation efficiency (95.75%), self-double-emulsification performance (99.58%) and skin retention (87.24%) were derived from the fitted models and experimentally examined, demonstrating a reasonable agreement between experimental and predicted values. Epigallocatechin-3-gallate-self-double-emulsifying drug delivery system was found to be stable for 3 months. Transdermal studies could explain a higher skin diffusion of epigallocatechin-3-gallate from the self-double-emulsifying drug delivery system compared with EGCG aqueous solution. In vitro cytotoxicity showed that epigallocatechin-3-gallate-self-double-emulsifying drug delivery system did not exert hazardous effect on L929 cells up to 1:10. © The Author(s) 2015.

Non-utility generation and demand management reliability of customer delivery systems

International Nuclear Information System (INIS)

Hamoud, G.A.; Wang, L.

1995-01-01

A probabilistic methodology for evaluating the impact of non-utility generation (NUG) and demand management programs (DMP) on supply reliability of customer delivery systems was presented. The proposed method was based on the criteria that the supply reliability to the customers on the delivery system should not be affected by the integration of either NUG or DMPs. The method considered station load profile, load forecast, and uncertainty in size and availability of the nuio. Impacts on system reliability were expressed in terms of possible delays of the in-service date for new facilities or in terms of an increase in the system load carrying capability. Examples to illustrate the proposed methodology were provided. 10 refs., 8 tabs., 2 figs

Effects of whole body UV-irradiation on oxygen delivery from the erythrocyte

International Nuclear Information System (INIS)

Humpeler, E.; Mairbaeurl, H.; Hoenigsmann, H.

1982-01-01

In 16 healthy caucasian volunteers (mean age: 22.2 years) the influence of whole body UV-irradiation on the oxygen transport properties of erythrocytes was investigated. Four hours after irradiation with UV (using the minimal erythema dose, MED) no variation of haemoglobin concentration, hematocrit, mean corpuscular haemoglobin concentration, pH or standard bicarbonate could be found, whereas inorganic plasma phosphate (Psub(i)), calcium, the intraerythrocytic 2,3-diphosphoglycerate (2,3-DPG), the activity of erythrocytic phosphofructokinase (PFK) and pyruvatekinase (PK) increased significantly. The half saturation tension of oxygen (P 50 -value) tended to increase. The increase of Psub(i) causes - via a stimulation of the glycolytic pathway - an increase in 2,3-DPG concentration and thus results in a shift of the oxygen dissociation curve. It is therefore possible to enhance tissue oxygenation by whole body UV-irradiation. (orig.)

An in silico analysis of oxygen uptake of a mild COPD patient during rest and exercise using a portable oxygen concentrator

Directory of Open Access Journals (Sweden)

Katz I

2016-09-01

Full Text Available Ira Katz,1,2 Marine Pichelin,1 Spyridon Montesantos,1 Min-Yeong Kang,3 Bernard Sapoval,3,4 Kaixian Zhu,5 Charles-Philippe Thevenin,5 Robert McCoy,6 Andrew R Martin,7 Georges Caillibotte1 1Medical R&D, Air Liquide Santé International, Centre de Recherche Paris-Saclay, Les Loges-en-Josas, France; 2Department of Mechanical Engineering, Lafayette College, Easton, PA, USA; 3Physique de la Matière Condensée, CNRS, Ecole Polytechnique, Palaiseau, 4Centre de Mathématiques et de leurs Applications, CNRS, UniverSud, Cachan, 5Centre Explor!, Air Liquide Healthcare, Gentilly, France; 6Valley Inspired Products, Inc, Apple Valley, MN, USA; 7Department of Mechanical Engineering, University of Alberta, Edmonton, AB, Canada Abstract: Oxygen treatment based on intermittent-flow devices with pulse delivery modes available from portable oxygen concentrators (POCs depends on the characteristics of the delivered pulse such as volume, pulse width (the time of the pulse to be delivered, and pulse delay (the time for the pulse to be initiated from the start of inhalation as well as a patient’s breathing characteristics, disease state, and respiratory morphology. This article presents a physiological-based analysis of the performance, in terms of blood oxygenation, of a commercial POC at different settings using an in silico model of a COPD patient at rest and during exercise. The analysis encompasses experimental measurements of pulse volume, width, and time delay of the POC at three different settings and two breathing rates related to rest and exercise. These experimental data of device performance are inputs to a physiological-based model of oxygen uptake that takes into account the real dynamic nature of gas exchange to illustrate how device- and patient-specific factors can affect patient oxygenation. This type of physiological analysis that considers the true effectiveness of oxygen transfer to the blood, as opposed to delivery to the nose (or mouth, can be

First-in-human pilot study of a spatial frequency domain oxygenation imaging system

Science.gov (United States)

Gioux, Sylvain; Mazhar, Amaan; Lee, Bernard T.; Lin, Samuel J.; Tobias, Adam M.; Cuccia, David J.; Stockdale, Alan; Oketokoun, Rafiou; Ashitate, Yoshitomo; Kelly, Edward; Weinmann, Maxwell; Durr, Nicholas J.; Moffitt, Lorissa A.; Durkin, Anthony J.; Tromberg, Bruce J.; Frangioni, John V.

2011-08-01

Oxygenation measurements are widely used in patient care. However, most clinically available instruments currently consist of contact probes that only provide global monitoring of the patient (e.g., pulse oximetry probes) or local monitoring of small areas (e.g., spectroscopy-based probes). Visualization of oxygenation over large areas of tissue, without a priori knowledge of the location of defects, has the potential to improve patient management in many surgical and critical care applications. In this study, we present a clinically compatible multispectral spatial frequency domain imaging (SFDI) system optimized for surgical oxygenation imaging. This system was used to image tissue oxygenation over a large area (16×12 cm) and was validated during preclinical studies by comparing results obtained with an FDA-approved clinical oxygenation probe. Skin flap, bowel, and liver vascular occlusion experiments were performed on Yorkshire pigs and demonstrated that over the course of the experiment, relative changes in oxygen saturation measured using SFDI had an accuracy within 10% of those made using the FDA-approved device. Finally, the new SFDI system was translated to the clinic in a first-in-human pilot study that imaged skin flap oxygenation during reconstructive breast surgery. Overall, this study lays the foundation for clinical translation of endogenous contrast imaging using SFDI.

Chemistry, manufacturing and controls in passive transdermal drug delivery systems.

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Goswami, Tarun; Audett, Jay

2015-01-01

Transdermal drug delivery systems (TDDS) are used for the delivery of the drugs through the skin into the systemic circulation by applying them to the intact skin. The development of TDDS is a complex and multidisciplinary affair which involves identification of suitable drug, excipients and various other components. There have been numerous problems reported with respect to TDDS quality and performance. These problems can be reduced by appropriately addressing chemistry, manufacturing and controls requirements, which would thereby result in development of robust TDDS product and processes. This article provides recommendations on the chemistry, manufacturing and controls focusing on the unique technical aspects of TDDS.

A mucoadhesive in situ gel delivery system for paclitaxel.

Science.gov (United States)

Jauhari, Saurabh; Dash, Alekha K

2006-06-02

MUC1 gene encodes a transmembrane mucin glycoprotein that is overexpressed in human breast cancer and colon cancer. The objective of this study was to develop an in situ gel delivery system containing paclitaxel (PTX) and mucoadhesives for sustained and targeted delivery of anticancer drugs. The delivery system consisted of chitosan and glyceryl monooleate (GMO) in 0.33M citric acid containing PTX. The in vitro release of PTX from the gel was performed in presence and absence of Tween 80 at drug loads of 0.18%, 0.30%, and 0.54% (wt/wt), in Sorensen's phosphate buffer (pH 7.4) at 37 degrees C. Different mucin-producing cell lines (Calu-3>Caco-2) were selected for PTX transport studies. Transport of PTX from solution and gel delivery system was performed in side by side diffusion chambers from apical to basal (A-B) and basal to apical (B-A) directions. In vitro release studies revealed that within 4 hours, only 7.61% +/- 0.19%, 12.0% +/- 0.98%, 31.7% +/- 0.40% of PTX were released from 0.18%, 0.30%, and 0.54% drug-loaded gel formulation, respectively, in absence of Tween 80. However, in presence of surfactant (0.05% wt/vol) in the dissolution medium, percentages of PTX released were 28.1% +/- 4.35%, 44.2% +/- 6.35%, and 97.1% +/- 1.22%, respectively. Paclitaxel has shown a polarized transport in all the cell monolayers with B-A transport 2 to 4 times higher than in the A-B direction. The highest mucin-producing cell line (Calu-3) has shown the lowest percentage of PTX transport from gels as compared with Caco-2 cells. Transport of PTX from mucoadhesive gels was shown to be influenced by the mucin-producing capability of cell.

Determination of the Minimal Fresh Gas Flow to Maintain a Therapeutic Inspired Oxygen Concentration in a Semi-Closed Anesthesia Circle System Using an Oxygen Concentrator as the Oxygen Source

National Research Council Canada - National Science Library

Grano, Joan

2001-01-01

The purpose of this study was to determine the rate of oxygen dilution, resulting from argon accumulation, using 3 low fresh gas flow rates using an oxygen concentrator in a semi-closed anesthesia circle system...

Design and control of the oxygen partial pressure of UO2 in TGA using the humidification system

International Nuclear Information System (INIS)

Lee, S.; Knight, T.W.; Roberts, E.

2015-01-01

Highlights: • We focus on measurement of oxygen partial pressure and change of O/M ratio under specific conditions produced by the humidification system. • This shows that the humidification system is stable, accurate, and reliable enough to be used for experiments of the oxygen partial pressure measurement for the oxide fuels. • The humidification system has benefits of easy control and flexibility for producing various oxygen partial pressures with fixed hydrogen gas flow rate. - Abstract: The oxygen to uranium (O/U) ratio of UO 2±x is determined by the oxygen content of the sample and is affected by oxygen partial pressure (pO 2 ) of the surrounding gas. Oxygen partial pressure is controllable by several methods. A common method to produce different oxygen partial pressures is the use of equilibria of different reaction gases. There are two common methods: H 2 O/H 2 reaction and CO 2 /CO reaction. In this work, H 2 O/H 2 reaction using a humidifier was employed and investigated to ensure that this humidification system for oxygen partial pressure is stable and accurate for use in Thermogravimetric Analyzer (TGA) experiments with UO 2 . This approach has the further advantage of flexibility to make a wide range of oxygen partial pressure with fixed hydrogen gas flow rate only by varying temperature of water in the humidifier. The whole system for experiments was constructed and includes the humidification system, TGA, oxygen analyzer, and gas flow controller. Uranium dioxide (UO 2 ) samples were used for experiments and oxygen partial pressure was measured at the equilibrium state of stoichiometric UO 2.0 . Oxygen partial pressures produced by humidification (wet gas) system were compared to the approach using mixed dry gases (without humidification system) to demonstrate that the humidification system provides for more stable and accurate oxygen partial pressure control. This work provides the design, method, and analysis of a humidification system for

Novel Nanostructured Solid Materials for Modulating Oral Drug Delivery from Solid-State Lipid-Based Drug Delivery Systems.

Science.gov (United States)

Dening, Tahnee J; Rao, Shasha; Thomas, Nicky; Prestidge, Clive A

2016-01-01

Lipid-based drug delivery systems (LBDDS) have gained significant attention in recent times, owing to their ability to overcome the challenges limiting the oral delivery of poorly water-soluble drugs. Despite the successful commercialization of several LBDDS products over the years, a large discrepancy exists between the number of poorly water-soluble drugs displaying suboptimal in vivo performances and the application of LBDDS to mitigate their various delivery challenges. Conventional LBDDS, including lipid solutions and suspensions, emulsions, and self-emulsifying formulations, suffer from various drawbacks limiting their widespread use and commercialization. Accordingly, solid-state LBDDS, fabricated by adsorbing LBDDS onto a chemically inert solid carrier material, have attracted substantial interest as a viable means of stabilizing LBDDS whilst eliminating some of the various limitations. This review describes the impact of solid carrier choice on LBDDS performance and highlights the importance of appropriate solid carrier material selection when designing hybrid solid-state LBDDS. Specifically, emphasis is placed on discussing the ability of the specific solid carrier to modulate drug release, control lipase action and lipid digestion, and enhance biopharmaceutical performance above the original liquid-state LBDDS. To encourage the interested reader to consider their solid carrier choice on a higher level, various novel materials with the potential for future use as solid carriers for LBDDS are described. This review is highly significant in guiding future research directions in the solid-state LBDDS field and fostering the translation of these delivery systems to the pharmaceutical marketplace.

The Role of Oxygen Therapies in Carbon Monoxide Poisoning

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Suleyman Metin

2011-08-01

Full Text Available Due to climate and socio-economic issues in Turkey, the incidence of carbon monoxide (CO poisoning is high, especially in winter. Clinical manifestations may vary depending on the type of CO source, concentration and duration of exposure. The symptoms of CO poisoning predominantly manifest in lots of organs and systems with high oxygen utilization, especially the brain and the heart. The primary aim in oxygen therapy is to eliminate CO and to reduce its toxic effects. In this context, normobaric and hyperbaric oxygen therapy are used to achieve these goals. Normobaric oxygen (NBO treatment is an easily accessible and relatively not expensive modality, where hyperbaric oxygen (HBO therapy requires specific equipment, certified staff and is available only in some centers. Additionally, HBO treatment has several additional advantages over NBO treatment. Despite its benefits, it is compulsory to search for some criteria in selecting patients to be treated because of the limited availability and access of hyperbaric facilities. For an effective evaluation and an optimal treatment, advanced education of the healthcare professionals on the use of oxygen delivery modalities in the management of CO poisoning is imperative. In this review, it has been aimed to outline the significance of oxygen treatment modalities and to determine patient selection criteria for HBO treatment in the management of CO poisoning which continues to be an important threat to community health care. [TAF Prev Med Bull 2011; 10(4.000: 487-494

Silk Electrogel Based Gastroretentive Drug Delivery System

Science.gov (United States)

Wang, Qianrui

Gastric cancer has become a global pandemic and there is imperative to develop efficient therapies. Oral dosing strategy is the preferred route to deliver drugs for treating the disease. Recent studies suggested silk electro hydrogel, which is pH sensitive and reversible, has potential as a vehicle to deliver the drug in the stomach environment. The aim of this study is to establish in vitro electrogelation e-gel based silk gel as a gastroretentive drug delivery system. We successfully extended the duration of silk e-gel in artificial gastric juice by mixing silk solution with glycerol at different ratios before the electrogelation. Structural analysis indicated the extended duration was due to the change of beta sheet content. The glycerol mixed silk e-gel had good doxorubicin loading capability and could release doxorubicin in a sustained-release profile. Doxorubicin loaded silk e-gels were applied to human gastric cancer cells. Significant cell viability decrease was observed. We believe that with further characterization as well as functional analysis, the silk e-gel system has the potential to become an effective vehicle for gastric drug delivery applications.