Desensitization in delayed drug hypersensitivity reactions -- an EAACI position paper of the Drug Allergy Interest Group.

Science.gov (United States)

Scherer, K; Brockow, K; Aberer, W; Gooi, J H C; Demoly, P; Romano, A; Schnyder, B; Whitaker, P; Cernadas, J S R; Bircher, A J

2013-07-01

Drug hypersensitivity may deprive patients of drug therapy, and occasionally no effective alternative treatment is available. Successful desensitization has been well documented in delayed drug hypersensitivity reactions. In certain situations, such as sulfonamide hypersensitivity in HIV-positive patients or hypersensitivity to antibiotics in patients with cystic fibrosis, published success rates reach 80%, and this procedure appears helpful for the patient management. A state of clinical tolerance may be achieved by the administration of increasing doses of the previously offending drug. However, in most cases, a pre-existent sensitization has not been proven by positive skin tests. Successful re-administration may have occurred in nonsensitized patients. A better understanding of the underlying mechanisms of desensitization is needed. Currently, desensitization in delayed hypersensitivity reactions is restricted to mild, uncomplicated exanthems and fixed drug eruptions. The published success rates vary depending on clinical manifestations, drugs, and applied protocols. Slower protocols tend to be more effective than rush protocols; however, underreporting of unsuccessful procedures is very probable. The decision to desensitize a patient must always be made on an individual basis, balancing risks and benefits. This paper reviews the literature and presents the expert experience of the Drug Hypersensitivity Interest Group of the European Academy of Allergy and Clinical Immunology. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

National Drug Control Strategy. Update.

Science.gov (United States)

Office of National Drug Control Policy, Washington, DC.

President Bush's new National Drug Control Strategy for 2003 focuses on three core priorities: stopping drug use before it starts; healing America's drug users; and disrupting the market. The 2003 strategy reports progress toward meeting the President's goals of reducing drug use by 10 percent over 2 years, and 25 percent over 5 years. With regard…

HPMA Copolymer-Drug Conjugates with Controlled Tumor-Specific Drug Release.

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Chytil, Petr; Koziolová, Eva; Etrych, Tomáš; Ulbrich, Karel

2018-01-01

Over the past few decades, numerous polymer drug carrier systems are designed and synthesized, and their properties are evaluated. Many of these systems are based on water-soluble polymer carriers of low-molecular-weight drugs and compounds, e.g., cytostatic agents, anti-inflammatory drugs, or multidrug resistance inhibitors, all covalently bound to a carrier by a biodegradable spacer that enables controlled release of the active molecule to achieve the desired pharmacological effect. Among others, the synthetic polymer carriers based on N-(2-hydroxypropyl) methacrylamide (HPMA) copolymers are some of the most promising carriers for this purpose. This review focuses on advances in the development of HPMA copolymer carriers and their conjugates with anticancer drugs, with triggered drug activation in tumor tissue and especially in tumor cells. Specifically, this review highlights the improvements in polymer drug carrier design with respect to the structure of a spacer to influence controlled drug release and activation, and its impact on the drug pharmacokinetics, enhanced tumor uptake, cellular trafficking, and in vivo antitumor activity. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

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.

Fragmentation of toxicologically relevant drugs in positive-ion liquid chromatography-tandem mass spectrometry.

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Niessen, W M A

2011-01-01

The identification of drugs and related compounds by LC-MS-MS is an important analytical challenge in several application areas, including clinical and forensic toxicology, doping control analysis, and environmental analysis. Although target-compound based analytical strategies are most frequently applied, at some point the information content of the MS-MS spectra becomes relevant. In this article, the positive-ion MS-MS spectra of a wide variety of drugs and related substances are discussed. Starting point was an MS-MS mass spectral library of toxicologically relevant compounds, available on the internet. The positive-ion MS-MS spectra of ∼570 compounds were interpreted by chemical and therapeutic class, thus involving a wide variety of drug compound classes, such benzodiazepines, beta-blockers, angiotensin-converting enzyme inhibitors, phenothiazines, dihydropyridine calcium channel blockers, diuretics, local anesthetics, vasodilators, as well as various subclasses of anti-diabetic, antidepressant, analgesic, and antihistaminic drugs. In addition, the scientific literature was searched for available MS-MS data of these compound classes and the interpretation thereof. The results of this elaborate study are presented in this article. For each individual compound class, the emphasis is on class-specific fragmentation, as discussing fragmentation of all individual compounds would take far too much space. The recognition of class-specific fragmentation may be quite informative in determining the compound class of a specific unknown, which may further help in the identification. In addition, knowledge on (class-specific) fragmentation may further help in the optimization of the selectivity in targeted analytical approaches of compounds of one particular class. Copyright © 2011 Wiley Periodicals, Inc.

Design, Characterization, and Optimization of Controlled Drug Delivery System Containing Antibiotic Drug/s

Directory of Open Access Journals (Sweden)

Apurv Patel

2016-01-01

Full Text Available The objective of this work was design, characterization, and optimization of controlled drug delivery system containing antibiotic drug/s. Osmotic drug delivery system was chosen as controlled drug delivery system. The porous osmotic pump tablets were designed using Plackett-Burman and Box-Behnken factorial design to find out the best formulation. For screening of three categories of polymers, six independent variables were chosen for Plackett-Burman design. Osmotic agent sodium chloride and microcrystalline cellulose, pore forming agent sodium lauryl sulphate and sucrose, and coating agent ethyl cellulose and cellulose acetate were chosen as independent variables. Optimization of osmotic tablets was done by Box-Behnken design by selecting three independent variables. Osmotic agent sodium chloride, pore forming agent sodium lauryl sulphate, and coating agent cellulose acetate were chosen as independent variables. The result of Plackett-Burman and Box-Behnken design and ANOVA studies revealed that osmotic agent and pore former had significant effect on the drug release up to 12 hr. The observed independent variables were found to be very close to predicted values of most satisfactory formulation which demonstrates the feasibility of the optimization procedure in successful development of porous osmotic pump tablets containing antibiotic drug/s by using sodium chloride, sodium lauryl sulphate, and cellulose acetate as key excipients.

How Drug Control Policy and Practice Undermine Access to Controlled Medicines.

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Burke-Shyne, Naomi; Csete, Joanne; Wilson, Duncan; Fox, Edward; Wolfe, Daniel; Rasanathan, Jennifer J K

2017-06-01

Drug conventions serve as the cornerstone for domestic drug laws and impose a dual obligation upon states to prevent the misuse of controlled substances while ensuring their adequate availability for medical and scientific purposes. Despite the mandate that these obligations be enforced equally, the dominant paradigm enshrined in the drug conventions is an enforcement-heavy criminal justice response to controlled substances that prohibits and penalizes their misuse. Prioritizing restrictive control is to the detriment of ensuring adequate availability of and access to controlled medicines, thereby violating the rights of people who need them. This paper argues that the drug conventions' prioritization of criminal justice measures-including efforts to prevent non-medical use of controlled substances-undermines access to medicines and infringes upon the right to health and the right to enjoy the benefits of scientific progress. While the effects of criminalization under drug policy limit the right to health in multiple ways, we draw on research and documented examples to highlight the impact of drug control and criminalization on access to medicines. The prioritization and protection of human rights-specifically the right to health and the right to enjoy the benefits of scientific progress-are critical to rebalancing drug policy.

Hydrophobic Drug-Loaded PEGylated Magnetic Liposomes for Drug-Controlled Release

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Hardiansyah, Andri; Yang, Ming-Chien; Liu, Ting-Yu; Kuo, Chih-Yu; Huang, Li-Ying; Chan, Tzu-Yi

2017-05-01

Less targeted and limited solubility of hydrophobic-based drug are one of the serious obstacles in drug delivery system. Thus, new strategies to enhance the solubility of hydrophobic drug and controlled release behaviors would be developed. Herein, curcumin, a model of hydrophobic drug, has been loaded into PEGylated magnetic liposomes as a drug carrier platform for drug controlled release system. Inductive magnetic heating (hyperthermia)-stimulated drug release, in vitro cellular cytotoxicity assay of curcumin-loaded PEGylated magnetic liposomes and cellular internalization-induced by magnetic guidance would be investigated. The resultant of drug carriers could disperse homogeneously in aqueous solution, showing a superparamagnetic characteristic and could inductive magnetic heating with external high-frequency magnetic field (HFMF). In vitro curcumin release studies confirmed that the drug carriers exhibited no significant release at 37 °C, whereas exhibited rapid releasing at 45 °C. However, it would display enormous (three times higher) curcumin releasing under the HFMF exposure, compared with that without HFMF exposure at 45 °C. In vitro cytotoxicity test shows that curcumin-loaded PEGylated magnetic liposomes could efficiently kill MCF-7 cells in parallel with increasing curcumin concentration. Fluorescence microscopy observed that these drug carriers could internalize efficiently into the cellular compartment of MCF-7 cells. Thus, it would be anticipated that the novel hydrophobic drug-loaded PEGylated magnetic liposomes in combination with inductive magnetic heating are promising to apply in the combination of chemotherapy and thermotherapy for cancer therapy.

Microencapsulation: A promising technique for controlled drug delivery.

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Singh, M N; Hemant, K S Y; Ram, M; Shivakumar, H G

2010-07-01

MICROPARTICLES OFFER VARIOUS SIGNIFICANT ADVANTAGES AS DRUG DELIVERY SYSTEMS, INCLUDING: (i) an effective protection of the encapsulated active agent against (e.g. enzymatic) degradation, (ii) the possibility to accurately control the release rate of the incorporated drug over periods of hours to months, (iii) an easy administration (compared to alternative parenteral controlled release dosage forms, such as macro-sized implants), and (iv) Desired, pre-programmed drug release profiles can be provided which match the therapeutic needs of the patient. This article gives an overview on the general aspects and recent advances in drug-loaded microparticles to improve the efficiency of various medical treatments. An appropriately designed controlled release drug delivery system can be a foot ahead towards solving problems concerning to the targeting of drug to a specific organ or tissue, and controlling the rate of drug delivery to the target site. The development of oral controlled release systems has been a challenge to formulation scientist due to their inability to restrain and localize the system at targeted areas of gastrointestinal tract. Microparticulate drug delivery systems are an interesting and promising option when developing an oral controlled release system. The objective of this paper is to take a closer look at microparticles as drug delivery devices for increasing efficiency of drug delivery, improving the release profile and drug targeting. In order to appreciate the application possibilities of microcapsules in drug delivery, some fundamental aspects are briefly reviewed.

Spirituality and adherence to antiretroviral drugs among HIV positive ...

African Journals Online (AJOL)

Method: It was an observational, longitudinal study in which 215 consenting HIV positive patients aged 18 to 65 years who were on antiretroviral drugs were recruited through systematic random sampling technique. Socio-demographic characteristics, clinical history and physical examination findings were documented for ...

Natural Non-Mulberry Silk Nanoparticles for Potential-Controlled Drug Release

Science.gov (United States)

Wang, Juan; Yin, Zhuping; Xue, Xiang; Kundu, Subhas C.; Mo, Xiumei; Lu, Shenzhou

2016-01-01

Natural silk protein nanoparticles are a promising biomaterial for drug delivery due to their pleiotropic properties, including biocompatibility, high bioavailability, and biodegradability. Chinese oak tasar Antheraea pernyi silk fibroin (ApF) nanoparticles are easily obtained using cations as reagents under mild conditions. The mild conditions are potentially advantageous for the encapsulation of sensitive drugs and therapeutic molecules. In the present study, silk fibroin protein nanoparticles are loaded with differently-charged small-molecule drugs, such as doxorubicin hydrochloride, ibuprofen, and ibuprofen-Na, by simple absorption based on electrostatic interactions. The structure, morphology and biocompatibility of the silk nanoparticles in vitro are investigated. In vitro release of the drugs from the nanoparticles depends on charge-charge interactions between the drugs and the nanoparticles. The release behavior of the compounds from the nanoparticles demonstrates that positively-charged molecules are released in a more prolonged or sustained manner. Cell viability studies with L929 demonstrated that the ApF nanoparticles significantly promoted cell growth. The results suggest that Chinese oak tasar Antheraea pernyi silk fibroin nanoparticles can be used as an alternative matrix for drug carrying and controlled release in diverse biomedical applications. PMID:27916946

Dual-controlled release system of drugs for bone regeneration.

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Kim, Yang-Hee; Tabata, Yasuhiko

2015-11-01

Controlled release systems have been noted to allow drugs to enhance their ability for bone regeneration. To this end, various biomaterials have been used as the release carriers of drugs, such as low-molecular-weight drugs, growth factors, and others. The drugs are released from the release carriers in a controlled fashion to maintain their actions for a long time period. Most research has been focused on the controlled release of single drugs to demonstrate the therapeutic feasibility. Controlled release of two combined drugs, so-called dual release systems, are promising and important for tissue regeneration. This is because the tissue regeneration process of bone formation is generally achieved by multiple bioactive molecules, which are produced from cells by other molecules. If two types of bioactive molecules, (i.e., drugs), are supplied in an appropriate fashion, the regeneration process of living bodies will be efficiently promoted. This review focuses on the bone regeneration induced by dual-controlled release of drugs. In this paper, various dual-controlled release systems of drugs aiming at bone regeneration are overviewed explaining the type of drugs and their release materials. Copyright © 2015 Elsevier B.V. All rights reserved.

Modulation of electrostatic interactions to improve controlled drug delivery from nanogels

Energy Technology Data Exchange (ETDEWEB)

Mauri, Emanuele; Chincarini, Giulia M.F.; Rigamonti, Riccardo; Magagnin, Luca; Sacchetti, Alessandro, E-mail: alessandro.sacchetti@polimi.it; Rossi, Filippo, E-mail: filippo.rossi@polimi.it

2017-03-01

The synthesis of nanogels as devices capable to maintain the drug level within a desired range for a long and sustained period of time is a leading strategy in controlled drug delivery. However, with respect to the good results obtained with antibodies and peptides there are a lot of problems related to the quick and uncontrolled diffusion of small hydrophilic molecules through polymeric network pores. For these reasons research community is pointing toward the use of click strategies to reduce release rates of the linked drugs to the polymer chains. Here we propose an alternative method that considers the electrostatic interactions between polymeric chains and drugs to tune the release kinetics from nanogel network. The main advantage of these systems lies in the fact that the carried drugs are not modified and no chemical reactions take place during their loading and release. In this work we synthesized PEG-PEI based nanogels with different protonation degrees and the release kinetics with charged and uncharged drug mimetics (sodium fluorescein, SF, and rhodamine B, RhB) were studied. Moreover, also the effect of counterion used to induce protonation was taken into account in order to build a tunable drug delivery system able to provide multiple release rates with the same device. - Highlights: • The design of nanogels as drug delivery systems based on electrostatic interaction among drug and polymers is proposed. • Nanogels can be synthetized tuning their positive charge density, according to the protonation of PEI at different pH. • No biorthogonal chemistry strategies are applied to the polymers or drugs. • Drug release is efficiently modulated by charge density of PEI chains. • The effect of counterion on nanogel synthesis is investigated and allows controlling the drug release.

Acid-fast bacilli culture positivity and drug resistance in abdominal tuberculosis in Mumbai, India.

Science.gov (United States)

Samant, Hrishikesh; Desai, Devendra; Abraham, Philip; Joshi, Anand; Gupta, Tarun; Rodrigues, Camilla; George, Siji

2014-09-01

Culture positivity for Mycobacterium tuberculosis complex (MTB) in abdominal tuberculosis (TB) using Lowenstein Jensen medium and Bactec system varies from 25 % to 36 %. Data on the prevalence of drug resistance in primary abdominal TB is scant. Our aim was to study the acid-fast bacilli (AFB) culture positivity rate in primary abdominal TB using Bactec Mycobacterial Growth Indicator Tubes (MGIT) system and the prevalence of drug resistance in these patients. Records of patients with abdominal TB (diagnosed on clinical features, endoscopy, histology, microbiology) seen during the period 2008 to 2013 were retrieved from the Gastroenterology and Microbiology departments. Patients with extra-abdominal TB (five pulmonary, two nodal), adnexal (one), and HIV (one) were excluded from analysis. Of 61 patients, 31 (50.8 %) had a positive AFB culture. In the 30 culture-negative patients, histology showed non-caseating granulomas in 25 patients. Drug sensitivity pattern was analyzed in 18 patients; resistance was detected in eight (14.3 % of all patients and 44.4 % of patients in whom drug sensitivity was done) including three (5.4 % of all subjects and 16.6 % in whom drug sensitivity was available) who were multidrug-resistant. The rate of AFB culture positivity in primary abdominal TB was 50.8 % using Bactec MGIT. Likelihood of drug resistance was seen in 14.3 %, of whom 5.4 % were multidrug-resistant.

Automatic positioning control device for automatic control rod exchanger

International Nuclear Information System (INIS)

Nasu, Seiji; Sasaki, Masayoshi.

1982-01-01

Purpose: To attain accurate positioning for a control rod exchanger. Constitution: The present position for an automatic control rod exchanger is detected by a synchro generator. An aimed stopping position for the exchanger, a stop instruction range depending on the distantial operation delay in the control system and the inertia-running distance of the mechanical system, and a coincidence confirmation range depending on the required positioning accuracy are previously set. If there is a difference between the present position and the aimed stopping position, the automatic exchanger is caused to run toward the aimed stopping position. A stop instruction is generated upon arrival at the position within said stop instruction range, and a coincidence confirmation signal is generated upon arrival at the position within the coincidence confirmation range. Since uncertain factors such as operation delay in the control system and the inertia-running distance of the mechanical system that influence the positioning accuracy are made definite by the method of actual measurement or the like and the stop instruction range and the coincidence confirmation range are set based on the measured data, the accuracy for the positioning can be improved. (Ikeda, J.)

Drug release control in delivery system for biodegradable polymer drugs by γ-radiation

International Nuclear Information System (INIS)

Yoshioka, Sumie; Azo, Yukio; Kojima, Shigeo

1997-01-01

Characterizations of the drug release from microsphere and hydrogel preparation made from biodegradable polymers were investigated aiming at development of a drug delivery system which allows an optimum drug delivery and the identification of the factors which control its delivery. Poly-lactic acid microspheres containing 10% of progesterone were produced from poly DL-lactic acid and exposed to γ-ray at 5-1000 kGy. And its glass transition temperature (Tg) was determined by differential scanning calorimetry. The temperature was gradually lowered with an increase in the dose of radiation. Tg of the microsphere exposed at 1000 kGy was lower by 10degC compared with the untreated one, showing that Tg control is possible without changing the size distribution of microsphere. Then, the amount of progesterone released from microsphere was determined. The release rate of the drug linearly increased with a square root of radiation time. These results indicate that the control of drug release rate is possible through controling the microsphere's Tg by γ-ray radiation. (M.N.)

Recreational drug use and related social factors among HIV-positive men in Japan.

Science.gov (United States)

Togari, Taisuke; Inoue, Yoji; Takaku, Yosuke; Abe, Sakurako; Hosokawa, Rikuya; Itagaki, Takashi; Yoshizawa, Shigeyuki; Oki, Sachiko; Katakura, Naoko; Yamauchi, Asae; Wakabayashi, Chihiro; Yajima, Takashi

2016-07-01

This study aims to determine the relationship between recreational drug use in HIV-positive males in the past year and socio-economic factors and/or social support networks in Japan. A national online survey in a cross-sectional study was conducted by HIV Futures Japan project from July 2013 to February 2014. Of the 1095 HIV-positive individuals who responded, 913 responses were determined to be valid; responses from the 875 males were analysed. A total of 282 participants used addictive drugs (32.2%) in past year. New psychoactive substances were used by 121 participants (13.8%), methamphetamine or amphetamine by 47 (5.4%), air dusters/sprays/gas by 31 (3.5%), 5-methoxy-N,N-diisopropyltryptamine (5MeO-DIPT) by 16 (1.8%) and cannabis (1.0%) by 9. Multiple logistic regression analysis was performed with the use of alkyl nitrites, addictive drugs, air dusters and thinners, which are low illegality, as dependent variables. We found that the odds ratio (95% confidence interval) for use among participants with full-time and temp/contracted/part-time employees compared to management/administration professions were 2.59 (0.99-6.77) and 2.61 (0.91-7.51). Also, a correlation was observed between alkyl nitrites and new psychoactive substances and usage rates in people engaged in few HIV-positive networks. It is necessary to develop targeted policies for drug use prevention and user support among HIV-positive men and to support and provide care for drug users who are isolated or have a narrow HIV/AIDS support network.

Prevalence and predictors of depressive symptoms among HIV-positive men who inject drugs in Vietnam.

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Levintow, Sara N; Pence, Brian W; Ha, Tran Viet; Minh, Nguyen Le; Sripaipan, Teerada; Latkin, Carl A; Vu, Pham The; Quan, Vu Minh; Frangakis, Constantine; Go, Vivian F

2018-01-01

HIV infection is common among people who inject drugs (PWID), and HIV-positive PWID may be particularly vulnerable to depression. This study measured the prevalence of depressive symptoms and the factors associated with severe symptoms among 455 HIV-positive PWID in Thai Nguyen, Vietnam. We used cross-sectional data from PWID in a randomized controlled trial of an intervention to reduce high-risk injecting and sexual behaviors in Thai Nguyen from 2009-2013. Depressive symptoms were measured with the Center for Epidemiologic Studies Depression Scale (CES-D). We used logistic regression to assess demographic, clinical, and psychosocial predictors of severe depressive symptoms (CES-D≥23) with prevalence odds ratios (POR) and 95% confidence intervals (CI). The prevalence of severe depressive symptoms (CES-D≥23) was 44%. 25% of participants had mild to moderate depressive symptoms (16≤CES-D<23), and 31% experienced no depressive symptoms (CES-D<16). Not being married, self-rated poor health, greater frequency of injection drug use, history of overdose, no alcohol use, and daily cigarette smoking were positively associated with severe depressive symptoms in unadjusted models and remained predictive in a multivariable model. The strongest predictors of depressive symptoms were self-reported poor health (POR = 2.94, 95% CI: 1.82, 4.76), no current alcohol use (POR = 2.35, 95% CI: 1.47, 3.77), and not currently married or cohabitating (POR = 2.21, 95% CI = 1.40, 3.47). Severe depressive symptoms were common among HIV-positive PWID in Thai Nguyen and were strongly associated with demographic, clinical, and psychosocial factors. Interventions that promote social support from family and reduce drug dependence may particularly benefit PWID experiencing severe depressive symptoms. Greater recognition and treatment of depressive symptoms has the potential to enhance quality of life and improve HIV clinical outcomes for PWID.

Initial Drug Dissolution from Amorphous Solid Dispersions Controlled by Polymer Dissolution and Drug-Polymer Interaction.

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Chen, Yuejie; Wang, Shujing; Wang, Shan; Liu, Chengyu; Su, Ching; Hageman, Michael; Hussain, Munir; Haskell, Roy; Stefanski, Kevin; Qian, Feng

2016-10-01

To identify the key formulation factors controlling the initial drug and polymer dissolution rates from an amorphous solid dispersion (ASD). Ketoconazole (KTZ) ASDs using PVP, PVP-VA, HMPC, or HPMC-AS as polymeric matrix were prepared. For each drug-polymer system, two types of formulations with the same composition were prepared: 1. Spray dried dispersion (SDD) that is homogenous at molecular level, 2. Physical blend of SDD (80% drug loading) and pure polymer (SDD-PB) that is homogenous only at powder level. Flory-Huggins interaction parameters (χ) between KTZ and the four polymers were obtained by Flory-Huggins model fitting. Solution (13)C NMR and FT-IR were conducted to investigate the specific drug-polymer interaction in the solution and solid state, respectively. Intrinsic dissolution of both the drug and the polymer from ASDs were studied using a Higuchi style intrinsic dissolution apparatus. PXRD and confocal Raman microscopy were used to confirm the absence of drug crystallinity on the tablet surface before and after dissolution study. In solid state, KTZ is completely miscible with PVP, PVP-VA, or HPMC-AS, demonstrated by the negative χ values of -0.36, -0.46, -1.68, respectively; while is poorly miscible with HPMC shown by a positive χ value of 0.23. According to solution (13)C NMR and FT-IR studies, KTZ interacts with HPMC-AS strongly through H-bonding and dipole induced interaction; with PVPs and PVP-VA moderately through dipole-induced interactions; and with HPMC weakly without detectable attractive interaction. Furthermore, the "apparent" strength of drug-polymer interaction, measured by the extent of peak shift on NMR or FT-IR spectra, increases with the increasing number of interacting drug-polymer pairs. For ASDs with the presence of considerable drug-polymer interactions, such as KTZ/PVPs, KTZ/PVP-VA, or KTZ /HPMC-AS systems, drug released at the same rate as the polymer when intimate drug-polymer mixing was ensured (i.e., the SDD systems

The stages of the international drug control system.

Science.gov (United States)

Carstairs, Catherine

2005-01-01

This paper argues that the history of the international drug control system of the League of Nations/United Nations can be divided into three cumulative stages. The first stage, the supply stage, dates back to early part of the 20th century, and aimed to reduce the supply of drugs through careful monitoring and trade regulations. This has remained the dominant control strategy. In the middle of the century, demand control, in the form of treatment and criminalization of the individual user, began to appear. This was the least successful stage. Finally, in the 1980s, the dangers of the drug traffic assumed an important place on the international agenda and measures to reduce drug-related organized crime were enacted. To date, this has been a process of proliferation of regulatory strategies. Recently, new challenges to the international drug control system have emerged, including well-funded non-governmental organizations critical of the war on drugs, and the adoption of harm reduction measures in national policies around the world.

Multi-drug-resistant tuberculosis in HIV positive patients in Eastern Europe.

Science.gov (United States)

Post, Frank A; Grint, Daniel; Werlinrud, Anne Marie; Panteleev, Alexander; Riekstina, Vieja; Malashenkov, Evgeniy A; Skrahina, Alena; Duiculescu, Dan; Podlekareva, Daria; Karpov, Igor; Bondarenko, Vasiliy; Chentsova, Nelly; Lundgren, Jens; Mocroft, Amanda; Kirk, Ole; Miro, Jose M

2014-03-01

Observational data from Eastern Europe on the management and outcome of multi-drug-resistant tuberculosis (MDR TB) in HIV positive populations remain sparse in the English-language literature. We compared clinical characteristics and outcomes of 55 patients who were diagnosed with HIV and MDR TB in Eastern Europe between 2004 and 2006 to 89 patients whose Mycobacterium tuberculosis isolates were susceptible to isoniazid and rifampicin. Patients with HIV and MDR TB were young and predominantly male with high rates of intravenous drug use, imprisonment and hepatitis C co-infection. Eighty-four per cent of patients with MDR TB had no history of previous TB drug exposure suggesting that the majority of MDR TB resulted from transmission of drug-resistant M. tuberculosis. The use of non-standardized tuberculosis treatment was common, and the use of antiretroviral therapy infrequent. Compared to those with susceptible tuberculosis, patients with MDR TB were less likely to achieve cure or complete tuberculosis treatment (21.8% vs. 62.9%, p < 0.0001), and they were more likely to die (65.5% vs. 27.0%, p < 0.0001). Our study documents suboptimal management and poor outcomes in HIV positive patients with MDR TB. Implementation of WHO guidelines, rapid TB diagnostics and TB drug susceptibility testing for all patients remain a priority in this region. Copyright © 2013 The British Infection Association. Published by Elsevier Ltd. All rights reserved.

The social context of controlled drug use amongst young people in a slum area in Makassar, Indonesia.

Science.gov (United States)

Nasir, Sudirman; Rosenthal, Doreen; Moore, Timothy

2011-11-01

There are few studies exploring the social context of controlled drug use amongst young people in Indonesia. This qualitative study examines the experience of young people in a slum area (lorong) in Makassar, eastern Indonesia, who use drugs but are not drug dependent and who employ various forms of self regulation to control their use. Semi-structured interviews were conducted with eight controlled drug users. The study found that whilst controlled drug users lived in a drug risk environment, they were not deeply embedded in the street culture, risk-taking practises and drug scene within their locality. Their employment, albeit in the informal economy and in low-paid jobs, facilitated their perspective that the status of rewa (a local construct of masculinity) and gaul (being sociable and up-to-date) could and should be accomplished through conventional means such as jobs and halal (legitimate) income. Their employment generated both direct benefit (legitimate income) and indirect benefit, including meaningful activities, structured time, positive identity and wider social networks (bridging social capital). This enabled them to have a stake in mainstream society and provided an incentive to control drug use. All factors which are protective against escalation into problematic drug use. The study showed the importance of sociological concepts of direct and indirect benefits of employment and of social capital in understanding the social context of controlled drug use amongst young people in the lorong. Additionally, drug policy should be more cognizant of the social vulnerability in the lorong and of the need to increase access to employment amongst young people in order to potentially decrease the likelihood of problematic drug use. Copyright © 2011 Elsevier B.V. All rights reserved.

Hybrid nanostructured drug carrier with tunable and controlled drug release

International Nuclear Information System (INIS)

Depan, D.; Misra, R.D.K.

2012-01-01

We describe here a transformative approach to synthesize a hybrid nanostructured drug carrier that exhibits the characteristics of controlled drug release. The synthesis of the nanohybrid architecture involved two steps. The first step involved direct crystallization of biocompatible copolymer along the long axis of the carbon nanotubes (CNTs), followed by the second step of attachment of drug molecule to the polymer via hydrogen bonding. The extraordinary inorganic–organic hybrid architecture exhibited high drug loading ability and is physically stable even under extreme conditions of acidic media and ultrasonic irradiation. The temperature and pH sensitive characteristics of the hybrid drug carrier and high drug loading ability merit its consideration as a promising carrier and utilization of the fundamental aspects used for synthesis of other promising drug carriers. The higher drug release response during the application of ultrasonic frequency is ascribed to a cavitation-type process in which the acoustic bubbles nucleate and collapse releasing the drug. Furthermore, the study underscores the potential of uniquely combining CNTs and biopolymers for drug delivery. - Graphical abstract: Block-copolymer crystallized on carbon nanotubes (CNTs). Nanohybrid drug carrier synthesized by attaching doxorubicin (DOX) to polymer crystallized CNTs. Crystallized polymer on CNTs provide mechanical stability. Triggered release of DOX. Highlights: ► The novel synthesis of a hybrid nanostructured drug carrier is described. ► The drug carrier exhibits high drug loading ability and is physically stable. ► The high drug release is ascribed to a cavitation-type process.

Microchips and controlled-release drug reservoirs.

Science.gov (United States)

Staples, Mark

2010-01-01

This review summarizes and updates the development of implantable microchip-containing devices that control dosing from drug reservoirs integrated with the devices. As the expense and risk of new drug development continues to increase, technologies that make the best use of existing therapeutics may add significant value. Trends of future medical care that may require advanced drug delivery systems include individualized therapy and the capability to automate drug delivery. Implantable drug delivery devices that promise to address these anticipated needs have been constructed in a variety of ways using micro- and nanoelectromechanical systems (MEMS or NEMS)-based technology. These devices expand treatment options for addressing unmet medical needs related to dosing. Within the last few years, advances in several technologies (MEMS or NEMS fabrication, materials science, polymer chemistry, and data management) have converged to enable the construction of miniaturized implantable devices for controlled delivery of therapeutic agents from one or more reservoirs. Suboptimal performance of conventional dosing methods in terms of safety, efficacy, pain, or convenience can be improved with advanced delivery devices. Microchip-based implantable drug delivery devices allow localized delivery by direct placement of the device at the treatment site, delivery on demand (emergency administration, pulsatile, or adjustable continuous dosing), programmable dosing cycles, automated delivery of multiple drugs, and dosing in response to physiological and diagnostic feedback. In addition, innovative drug-medical device combinations may protect labile active ingredients within hermetically sealed reservoirs. Copyright (c) 2010 John Wiley & Sons, Inc.

Risks, prices, and positions: A social network analysis of illegal drug trafficking in the world-economy.

Science.gov (United States)

Boivin, Rémi

2014-03-01

Illegal drug prices are extremely high, compared to similar goods. There is, however, considerable variation in value depending on place, market level and type of drugs. A prominent framework for the study of illegal drugs is the "risks and prices" model (Reuter & Kleiman, 1986). Enforcement is seen as a "tax" added to the regular price. In this paper, it is argued that such economic models are not sufficient to explain price variations at country-level. Drug markets are analysed as global trade networks in which a country's position has an impact on various features, including illegal drug prices. This paper uses social network analysis (SNA) to explain price markups between pairs of countries involved in the trafficking of illegal drugs between 1998 and 2007. It aims to explore a simple question: why do prices increase between two countries? Using relational data from various international organizations, separate trade networks were built for cocaine, heroin and cannabis. Wholesale price markups are predicted with measures of supply, demand, risks of seizures, geographic distance and global positioning within the networks. Reported prices (in $US) and purchasing power parity-adjusted values are analysed. Drug prices increase more sharply when drugs are headed to countries where law enforcement imposes higher costs on traffickers. The position and role of a country in global drug markets are also closely associated with the value of drugs. Price markups are lower if the destination country is a transit to large potential markets. Furthermore, price markups for cocaine and heroin are more pronounced when drugs are exported to countries that are better positioned in the legitimate world-economy, suggesting that relations in legal and illegal markets are directed in opposite directions. Consistent with the world-system perspective, evidence is found of coherent world drug markets driven by both local realities and international relations. Copyright © 2013 Elsevier B

Fractional-Order Control of Pneumatic Position Servosystems

Directory of Open Access Journals (Sweden)

Cao Junyi

2011-01-01

Full Text Available A fractional-order control strategy for pneumatic position servosystem is presented in this paper. The idea of the fractional calculus application to control theory was introduced in many works, and its advantages were proved. However, the realization of fractional-order controllers for pneumatic position servosystems has not been investigated. Based on the relationship between the pressure in cylinder and the rate of mass flow into the cylinder, the dynamic model of pneumatic position servo system is established. The fractional-order controller for pneumatic position servo and its implementation in industrial computer is designed. The experiments with fractional-order controller are carried out under various conditions, which include sine position signal with different frequency and amplitude, step position signal, and variety inertial load. The results show the effectiveness of the proposed scheme and verify their fine control performance for pneumatic position servo system.

Multi-drug-resistant tuberculosis in HIV positive patients in Eastern Europe

DEFF Research Database (Denmark)

Post, Frank A; Grint, Daniel; Efsen, Anne Marie Werlinrud

2014-01-01

Observational data from Eastern Europe on the management and outcome of multi-drug-resistant tuberculosis (MDR TB) in HIV positive populations remain sparse in the English-language literature.We compared clinical characteristics and outcomes of 55 patients who were diagnosed with HIV and MDR TB...... in Eastern Europe between 2004 and 2006 to 89 patients whose Mycobacterium tuberculosis isolates were susceptible to isoniazid and rifampicin.Patients with HIV and MDR TB were young and predominantly male with high rates of intravenous drug use, imprisonment and hepatitis C co-infection. Eighty-four per cent...... of patients with MDR TB had no history of previous TB drug exposure suggesting that the majority of MDR TB resulted from transmission of drug-resistant M. tuberculosis. The use of non-standardized tuberculosis treatment was common, and the use of antiretroviral therapy infrequent. Compared to those...

Narcotic Drug and Marihuana Controls.

Science.gov (United States)

Miller, Donald E.

As a background paper for the National Association of Student Personnel Administrators Drug Education Conference held in November, 1966, this paper focuses first on narcotic control in general, and second, on the reasons for insisting on marijuana control. Brief descriptions are given of the currently existing narcotics acts at federal and state…

Controlling fungal biofilms with functional drug delivery denture biomaterials.

Science.gov (United States)

Wen, Jianchuan; Jiang, Fuguang; Yeh, Chih-Ko; Sun, Yuyu

2016-04-01

Candida-associated denture stomatitis (CADS), caused by colonization and biofilm-formation of Candida species on denture surfaces, is a significant clinical concern. We show here that modification of conventional denture materials with functional groups can significantly increase drug binding capacity and control drug release rate of the resulting denture materials for potentially managing CADS. In our approach, poly(methyl methacrylate) (PMMA)-based denture resins were surface grafted with three kinds of polymers, poly(1-vinyl-2-pyrrolidinone) (PNVP), poly(methacrylic acid) (PMAA), and poly(2-hydroxyethyl methacrylate) (PHEMA), through plasma-initiated grafting polymerization. With a grafting yield as low as 2 wt%, the three classes of new functionalized denture materials showed significantly higher drug binding capacities toward miconazole, a widely used antifungal drug, than the original PMMA denture resin control, leading to sustained drug release and potent biofilm-controlling effects against Candida. Among the three classes of functionalized denture materials, PNVP-grafted resin provided the highest miconazole binding capability and the most powerful antifungal and biofilm-controlling activities. Drug binding mechanisms were studied. These results demonstrated the importance of specific interactions between drug molecules and functional groups on biomaterials, shedding lights on future design of CADS-managing denture materials and other related devices for controlled drug delivery. Copyright © 2015 Elsevier B.V. All rights reserved.

Stimuli-Responsive Liposomes for Controlled Drug Delivery

KAUST Repository

Li, Wengang

2014-01-01

Liposomes are promising drug delivery vesicles due to their biodegradibility, large volume and biocompatibility towards both hydrophilic and hydrophobic drugs. They suffer, however, from poor stability which limits their use in controlled delivery

A Brief History of American Drug Control.

Science.gov (United States)

Musto, David F.

1991-01-01

Traces the history of drug control in the United States from the extensive consumption of opium, heroin, and cocaine before World War I to the popularity of marijuana and LSD during the 1960s. Discusses public concern over drug use that seems to peak following periods of widespread drug use that is linked to foreign influences. (DK)

Factors associated with false-positive self-reported adherence to antihypertensive drugs.

Science.gov (United States)

Tedla, Y G; Bautista, L E

2017-05-01

Self-reported medication adherence is known to overestimate true adherence. However, little is known about patient factors that may contribute to the upward bias in self-reported medication adherence. The objective of this study is to examine whether demographic, behavioral, medication and mood factors are associated with being a false-positive self-reported adherer (FPA) to antihypertensive drug treatment. We studied 175 patients (mean age: 50 years; 57% men) from primary-care clinics starting antihypertensive drug treatment. Self-reported adherence (SRA) was measured with the Medication Adherence Report Scale (MARS) and by the number of drug doses missed in the previous week/month, and compared with pill count adherence ratio (PCAR) as gold standard. Data on adherence, demographic, behavioral, medication and mood factors were collected at baseline and every 3 months up to 1 year. FPA was defined as being a non-adherer by PCAR and an adherer by self-report. Mixed effect logistic regression was used for the analysis. Twenty percent of participants were FPA. Anxiety increased (odds ratio (OR): 3.00; P=0.01), whereas smoking (OR: 0.40; P=0.03) and drug side effects (OR: 0.46, P=0.03) decreased the probability for FPA by MARS. Education below high-school completion increased the probability of being an FPA as measured by missing doses in the last month (OR: 1.66; P=0.04) and last week (OR: 1.88; P=0.02). The validity of SRA varies significantly according to drug side effects, behavioral factors and patient's mood. Careful consideration should be given to the use of self-reported measures of adherence among patients likely to be false-positive adherers.

Validation of ISTTOK Plasma Position Controller

International Nuclear Information System (INIS)

Valcarcel, D. F.; Carvalho, I. S.; Carvalho, B. B.; Fernandes, H.; Silva, C.; Duarte, P.; Duarte, A.; Carvalho, P. J.; Pereira, T.

2008-01-01

Active control of plasma position on the ISTTOK tokamak is of extreme importance due to the inherent instability caused by an unfavourable curvature of the external equilibrium magnetic field. The consequences of this instability can be suppressed by applying a dynamic equilibrium field. A digital real-time plasma position control system for ISTTOK has been developed to perform this task. This system uses magnetic measurements to determine the plasma position and feeds the control signal to power supplies that generate the equilibrium fields. After commissioning, the results obtained have shown some discrepancies between the magnetic plasma position reconstruction and several other diagnostics, such as tomography. This discrepancy at some extent is due to the effect of the external magnetic fields on the poloidal magnetic measurements. This work presents a study that addresses this issue. In a future work it will lead to the development of a corrected plasma position algorithm, aiming at obtaining improved performance of plasma discharges and controlled plasma column displacements

Plasma position control on Alcator C

International Nuclear Information System (INIS)

Pribyl, P.A.

1981-05-01

The Alcator C MHD equilibrium is investigated from the standpoint of determining the plasma position. A review of equilibrium theory is presented, indicating that the central flux surfaces of the plasma should be displaced about 1 to 2 cm from the outermost. Further, the plasma should have a slightly noncircular cross-section. A comparison is made between the observed and predicted profiles. Flux loops sensitive to plasma position generate the error signal for the feedback control circuit. This measurement agrees with other position-sensitive diagnostics, such as limiter heating, and centroids of density, soft x-ray, and electron cyclotron emission. A linear model is developed for the position control feedback system, including the vertical field SCR supply, plasma, and feedback electronics. Operation of the control system agrees well with that predicted by the model, with acceptable plasma position being maintained for the duration of the discharge. The feedback control system is in daily use for Alcator C runs

Control rod position detection device

International Nuclear Information System (INIS)

Akita, Haruo; Ogiwara, Sakae.

1996-01-01

The device of the present invention is used in a back-up shut down system of an LMFBR type reactor which is easy for maintenance, has high reliability and can recognize the position of control rods accurately. Namely, a permanent magnet is disposed to a control rod extension tube connected to the lower portion of the control rod. The detector guide tube is disposed in the vicinity of the control rod extension tube. A detector having a detection coil is inserted into a detector tube. With such constitution, the control rod can be detected at one position using the following method. (1) the movement of the magnetic field of the permanent magnet is detected by the detection coil. (2) a plurality of grooves are formed on the control rod extension tube, and the movement of the grooves is detected. In addition, the detection coil is inserted into the detector guide tube, and the signals from the detection coil are inputted to a signal processing circuit disposed at the outside of the reactor vessel using an MI cable to enable the maintenance of the detector. Further, if the detector comprises a detection coil and an excitation coil, the position of a dropped control rod can be recognized at a plurality of points. (I.S.)

Active vibration control of clamped beams using positive position feedback controllers with moment pair

International Nuclear Information System (INIS)

Shin, Chang Joo; Jeong, Weui Bong; Hong, Chin Suk

2012-01-01

This paper investigates the active vibration control of clamp beams using positive position feedback (PPF) controllers with a sensor/ moment pair actuator. The sensor/moment pair actuator which is the non-collocated configuration leads to instability of the control system when using the direct velocity feedback (DVFB) control. To alleviate the instability problem, a PPF controller is considered in this paper. A parametric study of the control system with PPF controller is first conducted to characterize the effects of the design parameters (gain and damping ratio in this paper) on the stability and performance. The gain of the controller is found to affect only the relative stability. Increasing the damping ratio of the controller slightly improves the stability condition while the performance gets worse. In addition, the higher mode tuned PPF controller affects the system response at the lower modes significantly. Based on the characteristics of PPF controllers, a multi-mode controllable SISO PPF controller is then considered and tuned to different modes (in this case, three lowest modes) numerically and experimentally. The multi-mode PPF controller can be achieved to have a high gain margin. Moreover, it reduces the vibration of the beam significantly. The vibration levels at the tuned modes are reduced by about 11 dB

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.

Model-based drug administration : current status of target-controlled infusion and closed-loop control

NARCIS (Netherlands)

Kuizenga, Merel H.; Vereecke, Hugo E. M.; Struys, Michel M. R. F.

Purpose of review Drug administration might be optimized by incorporating pharmacokinetic-dynamic (PK/PD) principles and control engineering theories. This review gives an update of the actual status of target-controlled infusion (TCI) and closed-loop computer-controlled drug administration and the

HPMA copolymer-drug conjugates with controlled tumor-specific drug release

Czech Academy of Sciences Publication Activity Database

Chytil, Petr; Koziolová, Eva; Etrych, Tomáš; Ulbrich, Karel

2018-01-01

Roč. 18, č. 1 (2018), s. 1-15, č. článku 1700209. ISSN 1616-5187 R&D Projects: GA ČR(CZ) GA15-02986S; GA ČR(CZ) GA17-13283S; GA ČR(CZ) GA17-08084S; GA MŠk(CZ) LO1507 Institutional support: RVO:61389013 Keywords : biodegradable spacer * controlled drug release * drug delivery systems Subject RIV: CD - Macromolecular Chemistry OBOR OECD: Polymer science Impact factor: 3.238, year: 2016

Control rod position detector for nuclear reactor

International Nuclear Information System (INIS)

Kudo, Mitsuru; Fujiwara, Hiroshi.

1981-01-01

Purpose: To improve the reliability of a control rod position detector by detecting a reactive code with a combination of control rod position change signals produced from vertical and horizontal axis decoders, generation an error signal and thus simultaneously detecting the operation of more than two lead switches. Constitution: Horizontal and vertical axis position signals responsive to changes in the control rod position are applied from lead switches connected in a predetermined matrix connection corresponding to the notches of the positions of respective position detecting probes, the reactive output from the decoder is detected by a reactive code detecting circuit, which in turn generates a fault signal, and the control rod position code converted in a notch number generating circuit is converted to a predetermined value indicating invalidity. Accordingly, a fault caused by the simultaneous operation of a plurality of failed lead switches can be effectively detected. (Yoshino, Y.)

Quality control in diagnostic immunohistochemistry: integrated on-slide positive controls.

Science.gov (United States)

Bragoni, A; Gambella, A; Pigozzi, S; Grigolini, M; Fiocca, R; Mastracci, L; Grillo, F

2017-11-01

Standardization in immunohistochemistry is a priority in modern pathology and requires strict quality control. Cost containment has also become fundamental and auditing of all procedures must take into account both these principles. Positive controls must be routinely performed so that their positivity guarantees the appropriateness of the immunohistochemical procedure. The aim of this study is to develop a low cost (utilizing a punch biopsy-PB-tool) procedure to construct positive controls which can be integrated in the patient's tissue slide. Sixteen frequently used control blocks were selected and multiple cylindrical samples were obtained using a 5-mm diameter punch biopsy tool, separately re-embedding them in single blocks. For each diagnostic immunoreaction requiring a positive control, an integrated PB-control section (cut from the appropriate PB-control block) was added to the top right corner of the diagnostic slide before immunostaining. This integrated control technique permitted a saving of 4.75% in total direct lab costs and proved to be technically feasible and reliable. Our proposal is easy to perform and within the reach of all pathology labs, requires easily available tools, its application costs is less than using external paired controls and ensures that a specific control for each slide is always available.

Position paper from the Spanish Society of Rheumatology on biosimilar drugs.

Science.gov (United States)

Abad Hernández, Miguel Ángel; Andreu, José Luis; Caracuel Ruiz, Miguel Ángel; Belmonte Serrano, Miguel Ángel; Díaz-González, Federico; Moreno Muelas, José Vicente

2015-01-01

A biosimilar (BS) is a biological drug that contains a version of the active substance of an already authorized original biological product. The BSs are marketed after patent period of the original drug has ended and once it has been demonstrated that the differences regarding the innovative medicine have no relevant effect on its safety or clinical efficacy. The Spanish Society of Rheumatology, in line with the European Medicines Agency, considers that because of its nature and complexity of production, a BS cannot be considered to be the same as a generic drug. The Spanish Society of Rheumatology expresses an unequivocal commitment to the sustainability of the health system in our country and our steadfast alignment with all measures designed to ensure continuity, without reducing the quality of care. Therefore, we believe that the advent of BSs will likely facilitate access of patients with rheumatic diseases to the biological drugs. This article reviews the European Medicines Agency requirements for authorization, the Spanish legal framework and controversies on BS and presents the position paper of the Spanish Society of Rheumatology on these drugs. Copyright © 2015 Elsevier España, S.L.U. All rights reserved.

"Thunderstruck": Plasma-Polymer-Coated Porous Silicon Microparticles As a Controlled Drug Delivery System.

Science.gov (United States)

McInnes, Steven J P; Michl, Thomas D; Delalat, Bahman; Al-Bataineh, Sameer A; Coad, Bryan R; Vasilev, Krasimir; Griesser, Hans J; Voelcker, Nicolas H

2016-02-01

Controlling the release kinetics from a drug carrier is crucial to maintain a drug's therapeutic window. We report the use of biodegradable porous silicon microparticles (pSi MPs) loaded with the anticancer drug camphothecin, followed by a plasma polymer overcoating using a loudspeaker plasma reactor. Homogenous "Teflon-like" coatings were achieved by tumbling the particles by playing AC/DC's song "Thunderstruck". The overcoating resulted in a markedly slower release of the cytotoxic drug, and this effect correlated positively with the plasma polymer coating times, ranging from 2-fold up to more than 100-fold. Ultimately, upon characterizing and verifying pSi MP production, loading, and coating with analytical methods such as time-of-flight secondary ion mass spectrometry, scanning electron microscopy, thermal gravimetry, water contact angle measurements, and fluorescence microscopy, human neuroblastoma cells were challenged with pSi MPs in an in vitro assay, revealing a significant time delay in cell death onset.

Delay discounting, self-control, and substance use among adult drug court participants.

Science.gov (United States)

Jones, Craig G A; Fearnley, Helen; Panagiotopoulos, Barbara; Kemp, Richard I

2015-08-01

The current study examined the relationship between two measures of impulsiveness and the odds of substance use among a sample of participants on an Australian drug court (n=80). Participants completed a computer-based delay discounting task, a paper-based delay discounting task, and a questionnaire-based measure of self-control. The delay discounting tasks measured individual differences in the value attributed to distal outcomes, which is one aspect of impulsive behavior that has been found to be over-represented among illicit drug users. The relationship between the measures of impulsiveness and the odds of substance use was assessed by fitting longitudinal panel regression models with adjustment for informative treatment dropout. Consistent with previous research, drug court participants were found to have higher discount rates (i.e. were more impulsive) than a noncriminal population of university students (n=101). Drug court participants also discounted delayed gains more than delayed losses. Delay discounting was not significantly associated with the odds of substance use on the drug court program. There was a positive relationship between the survey-based measure of impulsivity and the mean substance use frequency. The authors conclude that impulsivity is correlated with substance use among drug court participants but not when measuring impulsivity using a delay discounting paradigm.

Regulations And Control Of Food And Drugs

International Nuclear Information System (INIS)

Osuide, G.E.; Director General, National Agency For Food And Drugs Administration And Control, Federal Secretariat, Ikoyi, Lagos, Nigeria.

1996-01-01

Effective control of processed food and medicines is crucial for the maintenance of public health. Issues of wholesomeness, quality, efficacy and safety are of paramount concern to both consumers and regulatory agencies alike. Laws and regulatory are put in in place to ensure minimum standards of practice by the various operators in the food and pharmaceutical sub-sectors, such as will guarantee that the regulated products (food, drugs, cosmetics, medical devices, chemicals and bottled water) they deal in satisfy all the parameters of quality, wholesomeness, efficacy and safety. National Agency for Food and Drug Administration and Control (NAFDAC) was established to enforce all relevant laws and regulations on food and drugs among other-regulated products. NAFDAC has put in place appropriate administrative structures and procedures in its efforts to fulfill its mandate. Finally, the agency is in the process of extending its regulatory and control activities to cover irradiated food products in order to safeguard public health

Controlled drug release for tissue engineering.

Science.gov (United States)

Rambhia, Kunal J; Ma, Peter X

2015-12-10

Tissue engineering is often referred to as a three-pronged discipline, with each prong corresponding to 1) a 3D material matrix (scaffold), 2) drugs that act on molecular signaling, and 3) regenerative living cells. Herein we focus on reviewing advances in controlled release of drugs from tissue engineering platforms. This review addresses advances in hydrogels and porous scaffolds that are synthesized from natural materials and synthetic polymers for the purposes of controlled release in tissue engineering. We pay special attention to efforts to reduce the burst release effect and to provide sustained and long-term release. Finally, novel approaches to controlled release are described, including devices that allow for pulsatile and sequential delivery. In addition to recent advances, limitations of current approaches and areas of further research are discussed. Copyright © 2015 Elsevier B.V. All rights reserved.

[Incretin mimetic drugs: therapeutic positioning].

Science.gov (United States)

López Simarro, F

2014-07-01

Type 2 diabetes is a chronic and complex disease, due to the differences among affected individuals, which affect choice of treatment. The number of drug families has increased in the last few years, and these families have widely differing mechanisms of action, which contributes greatly to the individualization of treatment according to the patient's characteristics and comorbidities. The present article discusses incretin mimetic drugs. Their development has been based on knowledge of the effects of natural incretin hormones: GLP-1 (glucagon-like peptide 1), GIP (glucose-dependent insulinotropic peptide) and dipeptidyl peptidase enzyme 4 (DPP4), which rapidly degrade them in the systemic circulation. This group is composed of 2 different types of molecules: GLP-1 analogs and DPP4 enzyme inhibitors. The benefits of these molecules include a reduction in plasma glucose without the risk of hypoglycemias or weight gain. There are a series of questions that require new studies to establish a possible association between the use of these drugs and notification of cases of pancreatitis, as well as their relationship with pancreatic and thyroid cancer. Also awaited is the publication of several studies that will provide information on the relationship between these drugs and cardiovascular risk in people with diabetes. All these questions will probably be progressively elucidated with greater experience in the use of these drugs. Copyright © 2014 Elsevier España, S.L.U. y Sociedad Española de Medicina Rural y Generalista (SEMERGEN). All rights reserved.

Fractional-Order Control of Pneumatic Position Servosystems

OpenAIRE

Junyi, Cao; Binggang, Cao

2011-01-01

A fractional-order control strategy for pneumatic position servosystem is presented in this paper. The idea of the fractional calculus application to control theory was introduced in many works, and its advantages were proved. However, the realization of fractional-order controllers for pneumatic position servosystems has not been investigated. Based on the relationship between the pressure in cylinder and the rate of mass flow into the cylinder, the dynamic model of pneumatic position servo ...

Osmotically driven drug delivery through remote-controlled magnetic nanocomposite membranes

KAUST Repository

Zaher, A.

2015-09-29

Implantable drug delivery systems can provide long-term reliability, controllability, and biocompatibility, and have been used in many applications, including cancer pain and non-malignant pain treatment. However, many of the available systems are limited to zero-order, inconsistent, or single burst event drug release. To address these limitations, we demonstrate prototypes of a remotely operated drug delivery device that offers controllability of drug release profiles, using osmotic pumping as a pressure source and magnetically triggered membranes as switchable on-demand valves. The membranes are made of either ethyl cellulose, or the proposed stronger cellulose acetate polymer, mixed with thermosensitive poly(N-isopropylacrylamide) hydrogel and superparamagnetic iron oxide particles. The prototype devices\\' drug diffusion rates are on the order of 0.5–2 μg/h for higher release rate designs, and 12–40 ng/h for lower release rates, with maximum release ratios of 4.2 and 3.2, respectively. The devices exhibit increased drug delivery rates with higher osmotic pumping rates or with magnetically increased membrane porosity. Furthermore, by vapor deposition of a cyanoacrylate layer, a drastic reduction of the drug delivery rate from micrograms down to tens of nanograms per hour is achieved. By utilizing magnetic membranes as the valve-control mechanism, triggered remotely by means of induction heating, the demonstrated drug delivery devices benefit from having the power source external to the system, eliminating the need for a battery. These designs multiply the potential approaches towards increasing the on-demand controllability and customizability of drug delivery profiles in the expanding field of implantable drug delivery systems, with the future possibility of remotely controlling the pressure source.

Osmotically driven drug delivery through remote-controlled magnetic nanocomposite membranes

KAUST Repository

Zaher, Amir; Li, S.; Wolf, K. T.; Pirmoradi, F. N.; Yassine, Omar; Lin, L.; Khashab, Niveen M.; Kosel, Jü rgen

2015-01-01

Implantable drug delivery systems can provide long-term reliability, controllability, and biocompatibility, and have been used in many applications, including cancer pain and non-malignant pain treatment. However, many of the available systems are limited to zero-order, inconsistent, or single burst event drug release. To address these limitations, we demonstrate prototypes of a remotely operated drug delivery device that offers controllability of drug release profiles, using osmotic pumping as a pressure source and magnetically triggered membranes as switchable on-demand valves. The membranes are made of either ethyl cellulose, or the proposed stronger cellulose acetate polymer, mixed with thermosensitive poly(N-isopropylacrylamide) hydrogel and superparamagnetic iron oxide particles. The prototype devices' drug diffusion rates are on the order of 0.5–2 μg/h for higher release rate designs, and 12–40 ng/h for lower release rates, with maximum release ratios of 4.2 and 3.2, respectively. The devices exhibit increased drug delivery rates with higher osmotic pumping rates or with magnetically increased membrane porosity. Furthermore, by vapor deposition of a cyanoacrylate layer, a drastic reduction of the drug delivery rate from micrograms down to tens of nanograms per hour is achieved. By utilizing magnetic membranes as the valve-control mechanism, triggered remotely by means of induction heating, the demonstrated drug delivery devices benefit from having the power source external to the system, eliminating the need for a battery. These designs multiply the potential approaches towards increasing the on-demand controllability and customizability of drug delivery profiles in the expanding field of implantable drug delivery systems, with the future possibility of remotely controlling the pressure source.

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. 

Control of drug releasing from biodegradable polymer drug delivery system by gamma-ray irradiation

International Nuclear Information System (INIS)

Yoshioka, Sumie; Aso, Yukio; Kojima, Shigeo

1999-01-01

In order to introduce the drug to the target organ, we developed a gel to control the drug releasing velocity by response to change of temperature by means of γ-ray irradiation to gelatin-GMA modified dextran mixture aqueous solution. A certain level of molecular weight of drug is necessary. The response to the temperature (change of drug releasing velocity) was affected by the concentration of gelatin and the modification rate of GMA. The Higuchi equation was applied to the releasing of β-galactosidase from gelatin-dextran gel and the releasing velocity was calculated. The releasing velocity decreased with increasing GMA modification rate at 37degC and 15degC. The releasing velocity of β-galactosidase decreased with increasing the concentration of gelatin at 15degC, but the velocity increased with increasing the concentration at 37degC. These results indicated that the good drug releasing conditions are obtained by controlling the GMA modification rate and the concentration of gelatin. (S.Y.)

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...

A deterministic - approach controller design for electrohydraulic position servo control system

International Nuclear Information System (INIS)

Johari Osman

2000-01-01

This paper is concerned with the design of a tracking controller for controlling electrohydraulic position servo system based on a deterministic approach. The system is treated as an uncertain system with bounded uncertainties where the bounds are assumed known. It will be shown that the electrohydraulic position servo systems with the proposed controller is practically stable and tracks the desired position in spite of the uncertainties and nonlinearities present in the system (author)

Predictive IP controller for robust position control of linear servo system.

Science.gov (United States)

Lu, Shaowu; Zhou, Fengxing; Ma, Yajie; Tang, Xiaoqi

2016-07-01

Position control is a typical application of linear servo system. In this paper, to reduce the system overshoot, an integral plus proportional (IP) controller is used in the position control implementation. To further improve the control performance, a gain-tuning IP controller based on a generalized predictive control (GPC) law is proposed. Firstly, to represent the dynamics of the position loop, a second-order linear model is used and its model parameters are estimated on-line by using a recursive least squares method. Secondly, based on the GPC law, an optimal control sequence is obtained by using receding horizon, then directly supplies the IP controller with the corresponding control parameters in the real operations. Finally, simulation and experimental results are presented to show the efficiency of proposed scheme. Copyright © 2016 ISA. Published by Elsevier Ltd. All rights reserved.

Position control device for a control rod

International Nuclear Information System (INIS)

Ono, Takehiko; Kusaka, Shuji.

1976-01-01

Purpose: To reliably prevent dangerous operation in the control of the position of the control rod by checking for abnormal pulse motor coil excitation voltage and, at the time of occurrence of abnormality, immediately holding the control rod stationary lest it should be moved to an unsafe position, this being accomplished excitation from a compensating excitation system. Constitution: In an FBR reactor, a circuit for memorizing the correct output states of individual drive signals at arbitrary instants and consequtively producing the memorized results is provided, and the output of the circuit and the actual drive signal are compared at all times to discriminate whether the drive signal being compared is normal or not. When the actual drive signal is abnormal, a series signal varying after a predetermined pattern is shifted to enable replacement of the actual drive signal, so that irrespective of whether the problem drive signal is ''on'' or ''off'', a drive signal of the correct pattern may be supplied to the pulse motor to hold the control rod and prevent it from being moved toward the dangerous side due to its own weight or other causes. (Horiuchi, T.)

Upper limb position control in fibromyalgia

Directory of Open Access Journals (Sweden)

Bardal Ellen

2012-09-01

Full Text Available Abstract Background Motor problems are reported by patients with fibromyalgia (FM. However, the mechanisms leading to alterations in motor performance are not well understood. In this study, upper limb position control during sustained isometric contractions was investigated in patients with FM and in healthy controls (HCs. Methods Fifteen female FM patients and 13 HCs were asked to keep a constant upper limb position during sustained elbow flexion and shoulder abduction, respectively. Subjects received real-time visual feedback on limb position and both tasks were performed unloaded and while supporting loads (1, 2, and 3 kg. Accelerations of the dominant upper limb were recorded, with variance (SD of mean position and power spectrum analysis used to characterize limb position control. Normalized power of the acceleration signal was extracted for three frequency bands: 1–3 Hz, 4–7 Hz, and 8–12 Hz. Results Variance increased with load in both tasks (P 0.001 but did not differ significantly between patients and HCs (P > 0.17. Power spectrum analysis showed that the FM patients had a higher proportion of normalized power in the 1–3 Hz band, and a lower proportion of normalized power in the 8–12 Hz band compared to HCs (P 0.05. The results were consistent for all load conditions and for both elbow flexion and shoulder abduction. Conclusion FM patients exhibit an altered neuromuscular strategy for upper limb position control compared to HCs. The predominance of low-frequency limb oscillations among FM patients may indicate a sensory deficit.

United Nations International Drug Control Programme responds

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Michael Platzer

2002-01-01

Full Text Available [First paragraph] We would like to reply to the article written by Axel Klein entitled, "Between the Death Penalty and Decriminalization: New Directions for Drug Control in the Commonwealth Caribbean" published in NWIG 75 (3&4 2001. We have noted a number of factual inaccuracies as well as hostile comments which portray the United Nations International Drug Control Programme in a negative light. This reply is not intended to be a critique of the article, which we find unbalanced and polemical, but rather an alert to the tendentious statements about UNDCP, which we feel should be corrected.

Who Do You Think Is in Control in Addiction? A Pilot Study on Drug-related Locus of Control Beliefs.

Science.gov (United States)

Ersche, Karen D; Turton, Abigail J; Croudace, Tim; Stochl, Jan

2012-12-01

The drug-related locus of control scale (DR-LOC) is a new instrument for assessing a person's belief of "being in control" in situations involving drug abuse. It consists of 16-item pairs presented in a forced-choice format, based on the conceptual model outlined by Rotter. The model characterizes the extent to which a person believes that the outcome of an event is under their personal control (internal locus of control) or the influence of external circumstances (external locus of control). A total of 592 volunteers completed the DR-LOC and the Rotter's I-E scale. Approximately half of the respondents were enrolled in a drug treatment program for opiates, stimulants and/or alcohol dependence (n = 282), and the remainder (n = 310) had no history of drug dependence. Factor analysis of DR-LOC items revealed 2 factors reflecting control beliefs regarding (i) the successful recovery from addiction, and (ii) decisions to use drugs. The extent to which a person attributes control in drug-related situations is significantly influenced by their personal or professional experiences with drug addiction. Drug-dependent individuals have a greater internal sense of control with regard to addiction recovery or drug-taking behaviors than health professionals and/or non-dependent control volunteers. The DR-LOC has shown to effectively translate generalized expectancies of control into a measure of control expectancies for drug-related situations, making it more sensitive for drug-dependent individuals than Rotter's I-E scale. Further research is needed to demonstrate its performance at discriminating between heterogeneous clinical groups such as between treatment-seeking versus non-treatment-seeking drug users.

The application of nanomaterials in controlled drug delivery for bone regeneration.

Science.gov (United States)

Shi, Shuo; Jiang, Wenbao; Zhao, Tianxiao; Aifantis, Katerina E; Wang, Hui; Lin, Lei; Fan, Yubo; Feng, Qingling; Cui, Fu-zhai; Li, Xiaoming

2015-12-01

Bone regeneration is a complicated process that involves a series of biological events, such as cellular recruitment, proliferation and differentiation, and so forth, which have been found to be significantly affected by controlled drug delivery. Recently, a lot of research studies have been launched on the application of nanomaterials in controlled drug delivery for bone regeneration. In this article, the latest research progress in this area regarding the use of bioceramics-based, polymer-based, metallic oxide-based and other types of nanomaterials in controlled drug delivery for bone regeneration are reviewed and discussed, which indicates that the controlling drug delivery with nanomaterials should be a very promising treatment in orthopedics. Furthermore, some new challenges about the future research on the application of nanomaterials in controlled drug delivery for bone regeneration are described in the conclusion and perspectives part. Copyright © 2015 Wiley Periodicals, Inc.

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

Externally controlled triggered-release of drug from PLGA micro and nanoparticles.

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Xin Hua

Full Text Available Biofilm infections are extremely hard to eradicate and controlled, triggered and controlled drug release properties may prolong drug release time. In this study, the ability to externally control drug release from micro and nanoparticles was investigated. We prepared micro/nanoparticles containing ciprofloxacin (CIP and magnetic nanoparticles encapsulated in poly (lactic-co-glycolic acid PLGA. Both micro/nanoparticles were observed to have narrow size distributions. We investigated and compared their passive and externally triggered drug release properties based on their different encapsulation structures for the nano and micro systems. In passive release studies, CIP demonstrated a fast rate of release in first 2 days which then slowed and sustained release for approximately 4 weeks. Significantly, magnetic nanoparticles containing systems all showed ability to have triggered drug release when exposed to an external oscillating magnetic field (OMF. An experiment where the OMF was turned on and off also confirmed the ability to control the drug release in a pulsatile manner. The magnetically triggered release resulted in a 2-fold drug release increase compared with normal passive release. To confirm drug integrity following release, the antibacterial activity of released drug was evaluated in Pseudomonas aeruginosa biofilms in vitro. CIP maintained its antimicrobial activity after encapsulation and triggered release.

Externally controlled triggered-release of drug from PLGA micro and nanoparticles.

Science.gov (United States)

Hua, Xin; Tan, Shengnan; Bandara, H M H N; Fu, Yujie; Liu, Siguo; Smyth, Hugh D C

2014-01-01

Biofilm infections are extremely hard to eradicate and controlled, triggered and controlled drug release properties may prolong drug release time. In this study, the ability to externally control drug release from micro and nanoparticles was investigated. We prepared micro/nanoparticles containing ciprofloxacin (CIP) and magnetic nanoparticles encapsulated in poly (lactic-co-glycolic acid) PLGA. Both micro/nanoparticles were observed to have narrow size distributions. We investigated and compared their passive and externally triggered drug release properties based on their different encapsulation structures for the nano and micro systems. In passive release studies, CIP demonstrated a fast rate of release in first 2 days which then slowed and sustained release for approximately 4 weeks. Significantly, magnetic nanoparticles containing systems all showed ability to have triggered drug release when exposed to an external oscillating magnetic field (OMF). An experiment where the OMF was turned on and off also confirmed the ability to control the drug release in a pulsatile manner. The magnetically triggered release resulted in a 2-fold drug release increase compared with normal passive release. To confirm drug integrity following release, the antibacterial activity of released drug was evaluated in Pseudomonas aeruginosa biofilms in vitro. CIP maintained its antimicrobial activity after encapsulation and triggered release.

Positive deviance control-case life history: a method to develop grounded hypotheses about successful long-term avoidance of infection

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Sandoval Milagros

2008-03-01

developed to stay safe. Staying Safe methodology develops grounded hypotheses. These can be tested through cohort studies of incidence and prevention trials of hypothesis-based programs to help drug injectors make their injection and sexual careers safer for themselves and others. This positive deviance control-case life history method might be used to study avoiding other infections like genital herpes among sex workers.

pH-controlled drug loading and release from biodegradable microcapsules.

Science.gov (United States)

Zhao, Qinghe; Li, Bingyun

2008-12-01

Microcapsules made of biopolymers are of both scientific and technological interest and have many potential applications in medicine, including their use as controlled drug delivery devices. The present study makes use of the electrostatic interaction between polycations and polyanions to form a multilayered microcapsule shell and also to control the loading and release of charged drug molecules inside the microcapsule. Micron-sized calcium carbonate (CaCO3) particles were synthesized and integrated with chondroitin sulfate (CS) through a reaction between sodium carbonate and calcium nitrate tetrahydrate solutions suspended with CS macromolecules. Oppositely charged biopolymers were alternately deposited onto the synthesized particles using electrostatic layer-by-layer self-assembly, and glutaraldehyde was introduced to cross-link the multilayered shell structure. Microcapsules integrated with CS inside the multilayered shells were obtained after decomposition of the CaCO3 templates. The integration of a matrix (i.e., CS) permitted the subsequent selective control of drug loading and release. The CS-integrated microcapsules were loaded with a model drug, bovine serum albumin labeled with fluorescein isothiocyanate (FITC-BSA), and it was shown that pH was an effective means of controlling the loading and release of FITC-BSA. Such CS-integrated microcapsules may be used for controlled localized drug delivery as biodegradable devices, which have advantages in reducing systemic side effects and increasing drug efficacy.

A trend analysis of laboratory positive propoxyphene workplace urine drug screens before and after the product recall.

Science.gov (United States)

Price, James

2015-01-01

Propoxyphene was withdrawn from the US market in November 2010. This drug is still tested for in the workplace as part of expanded panel nonregulated testing. A convenience sample of urine specimens (n = 7838) were provided by workers from various industries. The percentage of positive specimens with 95% confidence intervals was calculated for each year of the study. Logistic regression was used to assess the impact of the year upon the propoxyphene result. The prevalence of positive propoxyphene tests was much higher before the product's withdrawal from the market. Logistic regression provided evidence of a decreasing linear trend (P < 0.000; β = -0.71). The odds ratio signifies that for every additional year the urine specimens were 0.49 times less likely to be positive for propoxyphene. This favors the determination that the change in propoxyphene positive drug test over the years is not by chance. The conclusion supports no longer performing nonregulated workplace propoxyphene urine drug testing for this population.

Cylinder Position Servo Control Based on Fuzzy PID

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Shibo Cai

2013-01-01

Full Text Available The arbitrary position control of cylinder has always been the hard challenge in pneumatic system. We try to develop a cylinder position servo control method by combining fuzzy PID with the theoretical model of the proportional valve-controlled cylinder system. The pressure differential equation of cylinder, pressure-flow equation of proportional valve, and moment equilibrium equation of cylinder are established. And the mathematical models of the cylinder driving system are linearized. Then fuzzy PID control algorithm is designed for the cylinder position control, including the detail analysis of fuzzy variables and domain, fuzzy logic rules, and defuzzification. The stability of the proposed fuzzy PID controller is theoretically proved according to the small gain theorem. Experiments for targets position of 250 mm, 300 mm, and 350 mm were done and the results showed that the absolute error of the position control is less than 0.25 mm. And comparative experiment between fuzzy PID and classical PID verified the advantage of the proposed algorithm.

Plasma position control in TCABR Tokamak

International Nuclear Information System (INIS)

Galvao, R.M.O.; Kuznetsov, Yu. K.; Nascimento, I.C.; Fonseca, A.M.M.; Silva, R.P. da; Ruchko, L.F.; Tuszel, A.G.; Reis, A.P. dos; Sanada, E.K.

1998-01-01

The plasma control position in the TCABR tokamak is described. The TCA tokamak was transferred from the Centre de Recherches en Physique des Plasmas, Lausanne, to the Institute of Physics of University of Sao Paulo, renamed TCABR (α=0.18 m, R = 0.62 m, B = 1 T,I p = 100 kA). The control system was reconstructed using mainly components obtained from the TCA tokamak. A new method of plasma position determination is used in TCABR to improve its accuracy. A more detailed theoretical analysis of the feed forward and feedback control is performed as compared with. (author)

The Predictive Role of Difficulties in Emotion Regulation and Self-Control with Susceptibility to Addiction in Drug-Dependent Individuals

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Mahmoud Shirazi

2015-06-01

Full Text Available Objective: The present study aimed to examine the predictive role of difficulties in emotion regulation and self-control in potential for addiction among drug-dependent individuals. Method: This was a correlational study which falls within the category of descriptive studies. The statistical population of the current study included all patients under treatment in outpatient health centers in Bam, among whom 315 individuals were selected through cluster sampling method as the participants of the study. Difficulties in Emotion Regulation Scale, Self-Control Scale, and Addiction Susceptibility Questionnaire were used for data collection purposes. Results: The results indicated that difficulties engaging in goal directed behavior, impulse control difficulties, lack of emotional awareness, and lack of emotional clarity (dimensions of difficulties in emotion regulation had a significant positive correlation with potential for addiction. In addition, there was a negative significant relationship between self-control and potential for addiction among drug-dependent individuals. Conclusion: In addition to common methods of abstinence from drug dependence, teaching self-control and emotional control techniques to addicted patients can help them reduce their dependence.

A case-control study of maternal periconceptual and pregnancy recreational drug use and fetal malformation using hair analysis.

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Anna L David

Full Text Available OBJECTIVE: Maternal recreational drug use may be associated with the development of fetal malformations such as gastroschisis, brain and limb defects, the aetiology due to vascular disruption during organogenesis. Using forensic hair analysis we reported evidence of recreational drug use in 18% of women with a fetal gastroschisis. Here we investigate this association in a variety of fetal malformations using the same method. METHODS: In a multi-centre study, women with normal pregnancies (controls and those with fetal abnormalities (cases gave informed consent for hair analysis for recreational drug metabolites using mass spectrometry. Hair samples cut at the root were tested in sections corresponding to 3 month time periods (pre and periconceptual period. RESULTS: Women whose fetus had gastroschisis, compared to women with a normal control fetus, were younger (mean age 23.78 ± SD4.79 years, 18-37 vs 29.79 ± SD6 years, 18-42, p = 0.00001, were more likely to have evidence of recreational drug use (15, 25.4% vs 21, 13%, OR2.27, 95thCI 1.08-4.78, p = 0.028, and were less likely to report periconceptual folic acid use (31, 53.4% vs 124, 77.5%, OR0.33, 95thCI 0.18-0.63, p = 0.001. Age-matched normal control women were no less likely to test positive for recreational drugs than women whose fetus had gastroschisis. After accounting for all significant factors, only young maternal age remained significantly associated with gastroschisis. Women with a fetus affected by a non-neural tube central nervous system (CNS anomaly were more likely to test positive for recreational drugs when compared to women whose fetus was normal (7, 35% vs 21, 13%, OR3.59, 95th CI1.20-10.02, p = 0.01. CONCLUSIONS: We demonstrate a significant association between non neural tube CNS anomalies and recreational drug use in the periconceptual period, first or second trimesters, but we cannot confirm this association with gastroschisis. We confirm the association of

Robust Position Control of Electro-mechanical Systems

OpenAIRE

Rong Mei; Mou Chen

2013-01-01

In this work, the robust position control scheme is proposed for the electro-mechanical system using the disturbance observer and backstepping control method. To the external unknown load of the electro-mechanical system, the nonlinear disturbance observer is given to estimate the external unknown load. Combining the output of the developed nonlinear disturbance observer with backstepping technology, the robust position control scheme is proposed for the electro-mechanical system. The stabili...

31 CFR 598.309 - Narcotic drug; controlled substance; listed chemical.

Science.gov (United States)

2010-07-01

...; listed chemical. 598.309 Section 598.309 Money and Finance: Treasury Regulations Relating to Money and... SANCTIONS REGULATIONS General Definitions § 598.309 Narcotic drug; controlled substance; listed chemical. The terms narcotic drug, controlled substance, and listed chemical have the meanings given those terms...

Estimated glomerular filtration rate, chronic kidney disease and antiretroviral drug use in HIV-positive patients

NARCIS (Netherlands)

Mocroft, Amanda; Kirk, Ole; Reiss, Peter; de Wit, Stephane; Sedlacek, Dalibor; Beniowski, Marek; Gatell, Jose; Phillips, Andrew N.; Ledergerber, Bruno; Lundgren, Jens D.; Losso, M.; Elias, C.; Vetter, N.; Zangerle, R.; Karpov, I.; Vassilenko, A.; Mitsura, V. M.; Suetnov, O.; Clumeck, N.; Poll, B.; Colebunders, R.; Vandekerckhove, L.; Hadziosmanovic, V.; Kostov, K.; Begovac, J.; Machala, L.; Rozsypal, H.; Sedlacek, D.; Nielsen, J.; Kronborg, G.; Benfield, T.; Larsen, M.; Gerstoft, J.; Katzenstein, T.; Hansen, A.-B. E.; Skinhøj, P.; Pedersen, C.; Oestergaard, L.; Zilmer, K.; Smidt, Jelena; Ristola, M.; Katlama, C.; Viard, J.-P.; Girard, P.-M.; Livrozet, J. M.; Vanhems, P.; Pradier, C.; Dabis, F.; Neau, D.; Rockstroh, J.

2010-01-01

Objectives: Chronic kidney disease (CKD) in HIV-positive persons might be caused by both HIV and traditional or non-HIV-related factors. Our objective was to investigate long-term exposure to specific antiretroviral drugs and CKD. Design: A cohort study including 6843 HIV-positive persons with at

The efficacy and safety of the targeted drug combined with adriamycin liposome solution for HER-2-positive breast cancer

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Zi-Ping Zhou

2017-05-01

Full Text Available Objective: To study the efficacy and safety of the targeted drug trastuzumab combined with adriamycin liposome solution for HER-2-positive breast cancer. Methods: A total of 112 patients with breast cancer who received chemotherapy in Department of Cardiothoracic Breast Surgery, Guangdong TongJiang Hospital between May 2014 and April 2016 were selected as the research subjects and divided into two groups by random number table, liposome group received trastuzumab + adriamycin liposome chemotherapy, and the control group received trastuzumab + adriamycin chemotherapy. Before chemotherapy as well as 4 weeks and 8 weeks after chemotherapy, serum levels of tumor markers, cytokines and myocardial injury indexes were detected, the electrocardiography was conducted and the degree of myocardial injury was determined. Results: 4 weeks and 8 weeks after chemotherapy, serum CEA, CA15-3, TPS, CTGF, TGF-β, TSGF, VEGF and MK levels of both groups were significantly lower than those before chemotherapy, serum CK-MB and cTnI levels were significantly higher than those before chemotherapy, limb leads QRS amplitudes and chest leads QRS amplitudes were significantly lower than those before chemotherapy, serum CEA, CA15-3, TPS, CTGF, TGF-β, TSGF, VEGF, MK, CK-MB and cTnI levels of liposome group were significantly lower than those of control group, and the limb leads QRS amplitudes and chest lead QRS amplitudes were significantly higher than those of control group. Conclusion: Targeted drug combined with adriamycin liposome therapy for HER-2-positive breast cancer can improve the curative effect and reduce the cardiotoxicity.

Optimizing weight control in diabetes: antidiabetic drug selection

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S Kalra

2010-08-01

Full Text Available S Kalra1, B Kalra1, AG Unnikrishnan2, N Agrawal3, S Kumar41Bharti Hospital, Karnal; 2Amrita Institute of Medical Science, Kochi; 3Medical College, Gwalior; 4Excel Life Sciences, Noida, IndiaDate of preparation: 18th August 2010Conflict of interest: SK has received speaker fees from Novo Nordisk, sanofi-aventis, MSD, Eli Lilly, BMS, and AstraZeneca.Clinical question: Which antidiabetic drugs provide optimal weight control in patients with type 2 diabetes?Results: Metformin reduces weight gain, and may cause weight loss, when given alone or in combination with other drugs. Pioglitazone and rosiglitazone use is associated with weight gain. Use of the glucagon-like peptide-1 (GLP-1 analogs, liraglutide and exenatide, is associated with weight loss. Dipeptidyl peptidase-4 (DPP-4 inhibitors are considered weight-neutral. Results with insulin therapy are conflicting. Insulin detemir provides weight control along with glycemic control.Implementation: • Weight gain is considered an inevitable part of good glycemic control using conventional modalities of treatment such as sulfonylureas.• Use of metformin, weight-sparing insulin analogs such as insulin detemir, and liraglutide, should be encouraged as monotherapy, or in combination with other drugs.Keywords: weight control, diabetes

Drug use and abuse: the ethical issues.

Science.gov (United States)

Almond, B

1992-01-01

Drug abuse is both a personal and a public issue, raising questions about individual rights and the boundaries of law, as well as about national sovereignty and international control. Ethical issues that arise under these headings may be related to certain broad ethical positions. The implications of adopting utilitarian assumptions may be contrasted with basing ethics on a theory of individual rights, closely related to a theory of human nature. Neither position justifies a libertarian presumption against control, for, first, an individual decision to expose one's mind and personality to the control of drugs cannot be ethically justified and, second, there are no ethical reasons, nor any compelling arguments from social and political theory, for decriminalizing non-medical drug use.

21 CFR 1401.2 - The Office of National Drug Control Policy-organization and functions.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 9 2010-04-01 2010-04-01 false The Office of National Drug Control Policy-organization and functions. 1401.2 Section 1401.2 Food and Drugs OFFICE OF NATIONAL DRUG CONTROL POLICY PUBLIC AVAILABILITY OF INFORMATION § 1401.2 The Office of National Drug Control Policy—organization and functions. (a) The Office of National Drug...

Predicting Drug-Target Interactions Based on Small Positive Samples.

Science.gov (United States)

Hu, Pengwei; Chan, Keith C C; Hu, Yanxing

2018-01-01

A basic task in drug discovery is to find new medication in the form of candidate compounds that act on a target protein. In other words, a drug has to interact with a target and such drug-target interaction (DTI) is not expected to be random. Significant and interesting patterns are expected to be hidden in them. If these patterns can be discovered, new drugs are expected to be more easily discoverable. Currently, a number of computational methods have been proposed to predict DTIs based on their similarity. However, such as approach does not allow biochemical features to be directly considered. As a result, some methods have been proposed to try to discover patterns in physicochemical interactions. Since the number of potential negative DTIs are very high both in absolute terms and in comparison to that of the known ones, these methods are rather computationally expensive and they can only rely on subsets, rather than the full set, of negative DTIs for training and validation. As there is always a relatively high chance for negative DTIs to be falsely identified and as only partial subset of such DTIs is considered, existing approaches can be further improved to better predict DTIs. In this paper, we present a novel approach, called ODT (one class drug target interaction prediction), for such purpose. One main task of ODT is to discover association patterns between interacting drugs and proteins from the chemical structure of the former and the protein sequence network of the latter. ODT does so in two phases. First, the DTI-network is transformed to a representation by structural properties. Second, it applies a oneclass classification algorithm to build a prediction model based only on known positive interactions. We compared the best AUROC scores of the ODT with several state-of-art approaches on Gold standard data. The prediction accuracy of the ODT is superior in comparison with all the other methods at GPCRs dataset and Ion channels dataset. Performance

Position of anticholinergic drugs in the treatment of childhood asthma

Directory of Open Access Journals (Sweden)

Stojković-Anđelković Anđelka

2010-01-01

Full Text Available Anticholinergic drugs block muscarinic effect of acetylcholine on the receptors of postjunctional membranes and so inhibit the answer of the postganglionic parasympathetic nerve. The loss of M2 muscarinic receptors function occurs in asthmatics and it contributes to bronchial hyperresponsiveness and it is not a chronic feature of asthma, instead it characterizes asthma exacerbation. The loss of M2 muscarinic receptor function in children and adults happens during antigen bronchoprovocation or during exposition of asthmatics to ozone. After inhalation, ipratropium bromide (IB can be found in a small quantity in circulation and it links less readily to muscarinic receptors on airway smooth muscles as related to its absorption after intravenous application. In the stepwise approach of asthma inhaled anticholinergics is recommended if the symptoms of the disease cannot be adequately controlled by a regular inhalation of antiinflammatory drugs with β2-agonist and oral steroids. The improvement of the airway inspiratory capacity is more elevated than the improvement of FEV1 after inhalation of IB. IB has similar effect as salbutamol and it is recommended to control a stable chronic obstructive disease. During our numerous investigations and up-to-date experience in the usage of 5-7 μg/kg/body mass of IB repeated every 4-6 hours in combination with salbutamol, we did not notice adverse effects of the drug in infants. IB is recommended for hospital treatment of children. .

Robust control design for the plasma horizontal position control on J-TEXT Tokamak

International Nuclear Information System (INIS)

Yu, W.Z.; Chen, Z.P.; Zhuang, G.; Wang, Z.J.

2013-01-01

It is extremely important for tokamak to control the plasma position during routine discharge. However, the model of plasma in tokamak usually contains much of the uncertainty, such as structured uncertainties and unmodeled dynamics. Compared with the traditional PID control approach, robust control theory is more suitable to handle this problem. In the paper, we propose a H ∞ robust control scheme to control the horizontal position of plasma during the flat-top phase of discharge on Joint Texas Experimental Tokamak (J-TEXT) tokamak. First, the model of our plant for plasma horizontal position control is obtained from the position equilibrium equations. Then the H ∞ robust control framework is used to synthesize the controller. Based on this, an H ∞ controller is designed to minimize the regulation/tracking error. Finally, a comparison study is conducted between the optimized H ∞ robust controller and the traditional PID controller in simulations. The simulation results of the H ∞ robust controller show a significant improvement of the performance with respect to those obtained with traditional PID controller, which is currently used on our machine

An ecological analysis of secondary school students' drug use in Hong Kong: A case-control study.

Science.gov (United States)

Tse, Samson; Zhu, Shimin; Yu, Chong Ho; Wong, Paul; Tsang, Sandra

2016-02-01

Youth drug use is a significant at-risk youth behaviour and remains as one of the top priorities for mental health services, researchers and policy planners. The ecological characteristics of secondary school students' behaviour in Hong Kong are understudied. To examine individual, familial, social and environmental correlates of drug use among secondary students in Hong Kong. Data were extracted from a school survey with 3078 students. Among the 3078 students, 86 students reported to have used drugs in the past 6 months. A total of 86 age- and gender-matched controls with no drug-use behaviour in the past 6 months were randomly selected from the remaining students. Multiple logistic analysis was used to examine differential correlates between those who used and did not use substance in the past 6 months. Positive school experience and perspective to school and parental support are protective factors of drug use. Lower self-esteem, lower self-efficacy against using drugs and higher level of permissive attitude towards drugs were associated with drug use. Students who were low in self-esteem and rather impulsive tend to use drugs. To prevent students from drug use, efforts in individual, family, school and community-levels should be addressed. © The Author(s) 2015.

Regulating khat--dilemmas and opportunities for the international drug control system.

Science.gov (United States)

Klein, Axel; Beckerleg, Susan; Hailu, Degol

2009-11-01

The regulation of khat, one of the most recent psychoactive drugs to become a globally traded commodity, remains hotly contested within different producer and consumer countries. As regimes vary, it has been possible to compare khat policies in Africa, Europe and North America from different disciplinary perspectives. Field research was conducted in East Africa and Europe, using a combination of semistructured interviews, participant observation and the analysis of trade statistics. The research established the significance of khat for rural producers, regional economies, as a tax base and source of foreign exchange. At the same time, khat as a psychoactive substance is associated with health and public safety problems that in turn are met with often ill-informed legislative responses. Bans have in turn lead to the criminalisation of users and sellers and illegal drug markets. The empirical work from Africa provides a strong argument for promoting evidence-based approaches to khat regulation, harnessing the positive aspects of the khat economy to develop a control model that incorporates the voices and respects the needs of rural producers. Ultimately, the framework for khat may provide both a model and an opportunity for revising the international treaties governing the control of other plant psychoactive-based substances.

Weighing the Consequences: Self-Disclosure of HIV-Positive Status among African American Injection Drug Users

Science.gov (United States)

Valle, Maribel; Levy, Judith

2009-01-01

Theorists posit that personal decisions to disclose being HIV positive are made based on the perceived consequences of that disclosure. This study examines the perceived costs and benefits of self-disclosure among African American injection drug users (IDUs). A total of 80 African American IDUs were interviewed in-depth subsequent to testing HIV…

Positively Charged Nanostructured Lipid Carriers and Their Effect on the Dissolution of Poorly Soluble Drugs

Directory of Open Access Journals (Sweden)

Kyeong-Ok Choi

2016-05-01

Full Text Available The objective of this study is to develop suitable formulations to improve the dissolution rate of poorly water soluble drugs. We selected lipid-based formulation as a drug carrier and modified the surface using positively charged chitosan derivative (HTCC to increase its water solubility and bioavailability. Chitosan and HTCC-coated lipid particles had higher zeta-potential values than uncoated one over the whole pH ranges and improved encapsulation efficiency. In vitro drug release showed that all NLC formulations showed higher in vitro release efficiency than drug particle at pH 7.4. Furthermore, NLC formulation prepared with chitosan or HTCC represented good sustained release property. The results indicate that chitosan and HTCC can be excellent formulating excipients of lipid-based delivery carrier for improving poorly water soluble drug delivery.

Positively Charged Nanostructured Lipid Carriers and Their Effect on the Dissolution of Poorly Soluble Drugs.

Science.gov (United States)

Choi, Kyeong-Ok; Choe, Jaehyeog; Suh, Seokjin; Ko, Sanghoon

2016-05-20

The objective of this study is to develop suitable formulations to improve the dissolution rate of poorly water soluble drugs. We selected lipid-based formulation as a drug carrier and modified the surface using positively charged chitosan derivative (HTCC) to increase its water solubility and bioavailability. Chitosan and HTCC-coated lipid particles had higher zeta-potential values than uncoated one over the whole pH ranges and improved encapsulation efficiency. In vitro drug release showed that all NLC formulations showed higher in vitro release efficiency than drug particle at pH 7.4. Furthermore, NLC formulation prepared with chitosan or HTCC represented good sustained release property. The results indicate that chitosan and HTCC can be excellent formulating excipients of lipid-based delivery carrier for improving poorly water soluble drug delivery.

Consensus positive position feedback control for vibration attenuation of smart structures

Science.gov (United States)

Omidi, Ehsan; Nima Mahmoodi, S.

2015-04-01

This paper presents a new network-based approach for active vibration control in smart structures. In this approach, a network with known topology connects collocated actuator/sensor elements of the smart structure to one another. Each of these actuators/sensors, i.e., agent or node, is enhanced by a separate multi-mode positive position feedback (PPF) controller. The decentralized PPF controlled agents collaborate with each other in the designed network, under a certain consensus dynamics. The consensus constraint forces neighboring agents to cooperate with each other such that the disagreement between the time-domain actuation of the agents is driven to zero. The controller output of each agent is calculated using state-space variables; hence, optimal state estimators are designed first for the proposed observer-based consensus PPF control. The consensus controller is numerically investigated for a flexible smart structure, i.e., a thin aluminum beam that is clamped at its both ends. Results demonstrate that the consensus law successfully imposes synchronization between the independently controlled agents, as the disagreements between the decentralized PPF controller variables converge to zero in a short time. The new consensus PPF controller brings extra robustness to vibration suppression in smart structures, where malfunctions of an agent can be compensated for by referencing the neighboring agents’ performance. This is demonstrated in the results by comparing the new controller with former centralized PPF approach.

Position Statement: Drug Holiday in Osteoporosis Treatment with Bisphosphonates in South Korea

Science.gov (United States)

Lee, Seung Hun; Gong, Hyun Sik; Kim, Tae-Hee; Park, Si Young; Shin, Jung-Ho; Cho, Sun Wook

2015-01-01

Bisphosphonates have been widely used in the treatment of osteoporosis with robust data from many placebo-controlled trials demonstrating its efficacy in fracture risk reduction over 3 to 5 years of treatment. Although bisphosphonates are generally safe and well tolerated, concerns have emerged about the adverse effects related to its long-term use, including osteonecrosis of the jaw and atypical femur fractures. Because bisphosphonates are incorporated into the skeleton and continue to exert an anti-resorptive effect for a period of time after the discontinuation of drugs, the concept of a "drug holiday" has emerged, whereby the risk of adverse effects might be decreased while the patient still benefits from anti-fracture efficacy. As randomized clinical trial evidence is not yet available on who may qualify for a drug holiday, there is considerable controversy regarding the selection of candidates for the drug holiday and monitoring during a drug holiday, both of which should be based on individual assessments of risk and benefit. This statement will provide suggestions for clinicians in South Korea on the identification of possible candidates and monitoring during a bisphosphonate drug holiday. PMID:26713307

Polyvinyl alcohol composite nanofibres containing conjugated levofloxacin-chitosan for controlled drug release

International Nuclear Information System (INIS)

Jalvandi, Javid; White, Max; Gao, Yuan; Truong, Yen Bach; Padhye, Rajiv; Kyratzis, Ilias Louis

2017-01-01

A range of biodegradable drug-nanofibres composite mats have been reported as drug delivery systems. However, their main disadvantage is the rapid release of the drug immediately after application. This paper reports an improved system based on the incorporation of drug conjugated-chitosan into polyvinyl alcohol (PVA) nanofibers. The results showed that controlled release of levofloxacin (LVF) could be achieved by covalently binding LVF to low molecular weight chitosan (CS) via a cleavable amide bond and then blending the conjugated CS with polyvinyl alcohol (PVA) nanofibres prior to electrospinning. PVA/LVF and PVA-CS/LVF nanofibres were fabricated as controls. The conjugated CS-LVF was characterized by FTIR, DSC, TGA and 1 H NMR. Scanning electron microscopy (SEM) showed that the blended CS-PVA nanofibres had a reduced fibre diameter compared to the controls. Drug release profiles showed that burst release was decreased from 90% in the control PVA/LVF electrospun mats to 27% in the PVA/conjugated CS-LVF mats after 8 h in phosphate buffer at 37 °C. This slower release is due to the cleavable bond between LVF and CS that slowly hydrolysed over time at neutral pH. The results indicate that conjugation of the drug to the polymer backbone is an effective way of minimizing burst release behaviour and achieving sustained release of the drug, LVF. - Highlights: • A novel drug delivery system for controlled release of drug was designed. • Composite PVA/conjugated CS-LVF nanofibres was fabricated by electrospinning. • Conjugated chitosan and composite nanofibres were characterized by various techniques. • Release profiles of drug were significantly improved in composite nanofibres containing drug conjugated chitosan.

Polyvinyl alcohol composite nanofibres containing conjugated levofloxacin-chitosan for controlled drug release

Energy Technology Data Exchange (ETDEWEB)

Jalvandi, Javid, E-mail: Javid.jlv@gmail.com [CSIRO, Manufacturing Flagship, Bayview Ave, Clayton, Victoria 3168 (Australia); School of Fashion and Textiles, College of Design and Social Context, RMIT University, 25 Dawson Street, Brunswick, Victoria 3056 (Australia); White, Max, E-mail: tamrak@bigpond.com [School of Fashion and Textiles, College of Design and Social Context, RMIT University, 25 Dawson Street, Brunswick, Victoria 3056 (Australia); Gao, Yuan, E-mail: Yuan.Gao@csiro.au [CSIRO, Manufacturing Flagship, Bayview Ave, Clayton, Victoria 3168 (Australia); Truong, Yen Bach, E-mail: Yen.truong@csiro.au [CSIRO, Manufacturing Flagship, Bayview Ave, Clayton, Victoria 3168 (Australia); Padhye, Rajiv, E-mail: rajiv.padhye@rmit.edu.au [School of Fashion and Textiles, College of Design and Social Context, RMIT University, 25 Dawson Street, Brunswick, Victoria 3056 (Australia); Kyratzis, Ilias Louis, E-mail: Louis.kyratzis@csiro.au [CSIRO, Manufacturing Flagship, Bayview Ave, Clayton, Victoria 3168 (Australia)

2017-04-01

A range of biodegradable drug-nanofibres composite mats have been reported as drug delivery systems. However, their main disadvantage is the rapid release of the drug immediately after application. This paper reports an improved system based on the incorporation of drug conjugated-chitosan into polyvinyl alcohol (PVA) nanofibers. The results showed that controlled release of levofloxacin (LVF) could be achieved by covalently binding LVF to low molecular weight chitosan (CS) via a cleavable amide bond and then blending the conjugated CS with polyvinyl alcohol (PVA) nanofibres prior to electrospinning. PVA/LVF and PVA-CS/LVF nanofibres were fabricated as controls. The conjugated CS-LVF was characterized by FTIR, DSC, TGA and {sup 1}H NMR. Scanning electron microscopy (SEM) showed that the blended CS-PVA nanofibres had a reduced fibre diameter compared to the controls. Drug release profiles showed that burst release was decreased from 90% in the control PVA/LVF electrospun mats to 27% in the PVA/conjugated CS-LVF mats after 8 h in phosphate buffer at 37 °C. This slower release is due to the cleavable bond between LVF and CS that slowly hydrolysed over time at neutral pH. The results indicate that conjugation of the drug to the polymer backbone is an effective way of minimizing burst release behaviour and achieving sustained release of the drug, LVF. - Highlights: • A novel drug delivery system for controlled release of drug was designed. • Composite PVA/conjugated CS-LVF nanofibres was fabricated by electrospinning. • Conjugated chitosan and composite nanofibres were characterized by various techniques. • Release profiles of drug were significantly improved in composite nanofibres containing drug conjugated chitosan.

A concise review on smart polymers for controlled drug release.

Science.gov (United States)

Aghabegi Moghanjoughi, Arezou; Khoshnevis, Dorna; Zarrabi, Ali

2016-06-01

Design and synthesis of efficient drug delivery systems are of critical importance in health care management. Innovations in materials chemistry especially in polymer field allows introduction of advanced drug delivery systems since polymers could provide controlled release of drugs in predetermined doses over long periods, cyclic and tunable dosages. To this end, researchers have taken advantages of smart polymers since they can undergo large reversible, chemical, or physical fluctuations as responses to small changes in environmental conditions, for instance, in pH, temperature, light, and phase transition. The present review aims to highlight various kinds of smart polymers, which are used in controlled drug delivery systems as well as mechanisms of action and their applications.

Anti-Windup Scheme for Practical Control of Positioning Systems

Directory of Open Access Journals (Sweden)

Wahyudi Tarig Faisal and Abdulgani Albagul

2012-10-01

Full Text Available Positioning systems generally need a good controller to achieve high accuracy, fast response and robustness. In addition, ease of controller design and simplicity of controller structure are very important for practical application.  For satisfying these requirements, nominal characteristic trajectory following controller (NCTF has been proposed as a practical point-to-point (PTP positioning control. However, the effect of actuator saturation can not be completely compensated for due to the integrator windup as the plant parameters vary. This paper presents a method to improve the NCTF controller for overcoming the problem of integrator windup using simple and classical tracking anti-windup scheme. The improved NCTF controller is evaluated through simulation using a rotary positioning system. The results show that the improved NCTF controller is adequate to compensate for the effect of integrator windup. Keywords: Positioning, point-to-point, integrator windup, compensation, controller, robustness.

Control of plasma position in the CASTOR tokamak

International Nuclear Information System (INIS)

Valovic, M.

1988-11-01

A simple servo-system designed for plasma position control in the CASTOR tokamak is described. Both radial and vertical plasma displacements were minimized using two servo-loops consisting of detection coils, a conventional electric controller and an amplifier operated as an unipolar voltage-controlled current source. To ensure the optimum conditions in the start-up phase of the discharge, currents in the servo-systems were externally preprogrammed. The prescribed plasma position was maintained with the accuracy of 3 mm. The feedback control improves plasma parameters, e.g. it removes the positional disruption at the end of the tokamak discharge. (J.U.). 4 figs., 3 refs

X-ray Spectroscopy for Quality Control of Chemotherapy Drugs

International Nuclear Information System (INIS)

Greaves, E. D.; Barros, H.; Bermudez, J.; Sajo-Bohus, L.; Angeli-Greaves, M.

2007-01-01

We develop a method, employing Compton peak standardization and the use of matrix-matched spiked samples with Total Reflection X-ray Fluorescence (TXRF), for the determination of platinum plasma concentrations of patients undergoing chemotherapy with Pt-bearing drugs. Direct blood plasma analysis attains Pt detection limits of 70 ng/ml. Measurement results of prescribed drug doses are compared to achieved blood Pt concentrations indicating a lack of expected correlations. Direct analysis of Pt-containing infused drugs from a variety of suppliers indicates cases of abnormal concentrations which raises quality control issues. We demonstrate the potential usefulness of the method for pharmacokinetic studies or for routine optimization and quality control of Pt chemotherapy treatments

Robust hydraulic position controller by a fuzzy state controller

International Nuclear Information System (INIS)

Zhao, T.; Van der Wal, A.J.

1994-01-01

In nuclear industry, one of the most important design considerations of controllers is their robustness. Robustness in this context is defined as the ability of a system to be controlled in a stable way over a wide range of system parameters. Generally the systems to be controlled are linearized, and stability is subsequently proven for this idealized system. By combining classical control theory and fuzzy set theory, a new kind of state controller is proposed and successfully applied to a hydraulic position servo with excellent robustness against variation of system parameters

Sensorless SPMSM Position Estimation Using Position Estimation Error Suppression Control and EKF in Wide Speed Range

Directory of Open Access Journals (Sweden)

Zhanshan Wang

2014-01-01

Full Text Available The control of a high performance alternative current (AC motor drive under sensorless operation needs the accurate estimation of rotor position. In this paper, one method of accurately estimating rotor position by using both motor complex number model based position estimation and position estimation error suppression proportion integral (PI controller is proposed for the sensorless control of the surface permanent magnet synchronous motor (SPMSM. In order to guarantee the accuracy of rotor position estimation in the flux-weakening region, one scheme of identifying the permanent magnet flux of SPMSM by extended Kalman filter (EKF is also proposed, which formed the effective combination method to realize the sensorless control of SPMSM with high accuracy. The simulation results demonstrated the validity and feasibility of the proposed position/speed estimation system.

Real-time horizontal position control for Aditya-upgrade tokamak

International Nuclear Information System (INIS)

Kumar, Rohit; Ghosh, Joydeep; Tanna, Rakesh L.

2015-01-01

Position of plasma column is required to be controlled in real time for improved operation of any tokamak. A PID based system for real-time horizontal plasma position control has been designed for Aditya Upgrade tokamak. Modelling of transfer functions of actuators, plasma and diagnostic system are carried out for ADITYA-U tokamak. The PID controller is optimized using MATLAB-SIMULINK for horizontal position control. Further feed-forward loop is implemented where disturbance due to density variation is suppressed, which results in improved performance as compared to conventional PID operation. In this paper the detailed design of the whole system for real time control of plasma horizontal position in Aditya Upgrade tokamak is presented. (author)

Positive sliding mode control for blood glucose regulation

Science.gov (United States)

Menani, Karima; Mohammadridha, Taghreed; Magdelaine, Nicolas; Abdelaziz, Mourad; Moog, Claude H.

2017-11-01

Biological systems involving positive variables as concentrations are some examples of so-called positive systems. This is the case of the glycemia-insulinemia system considered in this paper. To cope with these physical constraints, it is shown that a positive sliding mode control (SMC) can be designed for glycemia regulation. The largest positive invariant set (PIS) is obtained for the insulinemia subsystem in open and closed loop. The existence of a positive SMC for glycemia regulation is shown here for the first time. Necessary conditions to design the sliding surface and the discontinuity gain are derived to guarantee a positive SMC for the insulin dynamics. SMC is designed to be positive everywhere in the largest closed-loop PIS of plasma insulin system. Two-stage SMC is employed; the last stage SMC2 block uses the glycemia error to design the desired insulin trajectory. Then the plasma insulin state is forced to track the reference via SMC1. The resulting desired insulin trajectory is the required virtual control input of the glycemia system to eliminate blood glucose (BG) error. The positive control is tested in silico on type-1 diabetic patients model derived from real-life clinical data.

Ibuprofen-loaded poly(lactic-co-glycolic acid films for controlled drug release

Directory of Open Access Journals (Sweden)

Pang JM

2011-04-01

Full Text Available Jianmei Pang1, Yuxia Luan1, Feifei Li1, Xiaoqing Cai1, Jimin Du2, Zhonghao Li31School of Pharmaceutical Science, Shandong University, Jinan, Shandong Province, PR China; 2School of Chemistry and Chemical Engineering, Anyang Normal University, Henan Province, PR China; 3School of Materials Science and Engineering, Shandong University, Jinan, Shandong Province, PR ChinaAbstract: Ibuprofen- (IBU loaded biocompatible poly(lactic-co-glycolic acid (PLGA films were prepared by spreading polymer/ibuprofen solution on the nonsolvent surface. By controlling the weight ratio of drug and polymer, different drug loading polymer films can be obtained. The synthesized ibuprofen-loaded PLGA films were characterized with scanning electron microscopy, powder X-ray diffraction, and differential scanning calorimetry. The drug release behavior of the as-prepared IBU-loaded PLGA films was studied to reveal their potential application in drug delivery systems. The results show the feasibility of the as-obtained films for controlling drug release. Furthermore, the drug release rate of the film could be controlled by the drug loading content and the release medium. The development of a biodegradable ibuprofen system, based on films, should be of great interest in drug delivery systems.Keywords: ibuprofen, controlled release, poly(lactic-co-glycolic acid, films

Nano positioning control for dual stage using minimum order observer

International Nuclear Information System (INIS)

Kim, Hong Gun

2012-01-01

A nano positioning control is developed using the ultra-precision positioning apparatus such as actuator, sensor, guide, power transmission element with an appropriate control method. Using established procedures, a single plane X-Y stage with ultra-precision positioning is manufactured. A global stage for materialization with robust system is combined by using an AC servo motor with a ball screw and rolling guide. An ultra-precision positioning system is developed using a micro stage with an elastic hinge and piezo element. Global and micro servos for positioning with nanometer accuracy are controlled simultaneously using an incremental encoder and a laser interferometer to measure displacement. Using established procedures, an ultra-precision positioning system (100 mm stroke and ±10 nm positioning accuracy) with a single plane X-Y stage is fabricated. Its performance is evaluated through simulation using Matlab. After analyzing previous control algorithms and adapting modern control theory, a dual servo algorithm is developed for a minimum order observer to secure the stability and priority on the controller. The simulations and experiments on the ultra precision positioning and the stability of the ultra-precision positioning system with single plane X-Y stage and the priority of the control algorithm are secured by using Matlab with Simulink and ControlDesk made in dSPACE

Nano positioning control for dual stage using minimum order observer

Energy Technology Data Exchange (ETDEWEB)

Kim, Hong Gun [Jeonju University, Jeonju (Korea, Republic of)

2012-03-15

A nano positioning control is developed using the ultra-precision positioning apparatus such as actuator, sensor, guide, power transmission element with an appropriate control method. Using established procedures, a single plane X-Y stage with ultra-precision positioning is manufactured. A global stage for materialization with robust system is combined by using an AC servo motor with a ball screw and rolling guide. An ultra-precision positioning system is developed using a micro stage with an elastic hinge and piezo element. Global and micro servos for positioning with nanometer accuracy are controlled simultaneously using an incremental encoder and a laser interferometer to measure displacement. Using established procedures, an ultra-precision positioning system (100 mm stroke and {+-}10 nm positioning accuracy) with a single plane X-Y stage is fabricated. Its performance is evaluated through simulation using Matlab. After analyzing previous control algorithms and adapting modern control theory, a dual servo algorithm is developed for a minimum order observer to secure the stability and priority on the controller. The simulations and experiments on the ultra precision positioning and the stability of the ultra-precision positioning system with single plane X-Y stage and the priority of the control algorithm are secured by using Matlab with Simulink and ControlDesk made in dSPACE.

From wanting to willing - controlled drug use as a treatment goal.

Science.gov (United States)

Järvinen, Margaretha

2017-03-01

This paper uses rational choice theory to analyse a new - and controversial - treatment approach to drug problems: services aimed at making clients capable of controlled use of illegal drugs. The paper highlights three mechanisms used in control-focused treatment: attempts to move drug use from the sphere of "wanting" to the sphere of "willing"; temporal framing of illegal drug use; and a therapeutic focus on clients' resources rather than their problems. Furthermore, the paper identifies some of the main challenges associated with this kind of treatment. The paper is based on 30 qualitative interviews with young people (aged 18-25) enrolled in drug treatment in Copenhagen, Denmark. Copyright © 2017 Elsevier Ltd. All rights reserved.

Optimising position control of a solar parabolic trough

Directory of Open Access Journals (Sweden)

Puramanathan Naidoo

2011-03-01

Full Text Available In today’s climate of growing energy needs and increasing environmental concerns, alternatives to the use of non-renewable and polluting fossil fuels have to be investigated. One such alternative is solar energy. This study is based on the implementation of a mathematical computation – the PSA (Plataforma Solar de Almeria computation developed at PSA (the European Test Centre for solar energy applications – embedded in a control algorithm to locate the position of the sun. Tests were conducted on a solar parabolic trough (SPT constructed at the Solar Thermal Applications Research Laboratory of the Mangosuthu University of Technology (Durban, South Africa for optimal position control using the PSA value. The designed control algorithm embedded in an industrial Siemens S7-314 C-2PtP programmable logic controller compared the PSA computation to a measured position of the SPT to optimally rotate the SPT to a desired position with the constant movement of the sun. The two main angles of the sun relative to the position of the SPT on earth, the zenith angle and the azimuth angle, both calculated in the PSA from the vertical and horizontal planes, respectively, were applied to the control algorithm to generate an appropriate final tracking angle within a 0.007 radian (0° 24′ 3.6″ tolerance, in accordance to the construction specifications and solar collector testing standards of the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE, 1991. These values, together with the longitude and latitude applicable to the geographical location of the SPT, were processed in the control software to rotate the SPT to an optimal position with respect to the position of the sun in its daily path, for solar-to-thermal conversion.

The context of HIV risk behaviours among HIV-positive injection drug users in Viet Nam: Moving toward effective harm reduction

Directory of Open Access Journals (Sweden)

Thanh Duong

2009-04-01

Full Text Available Abstract Background Injection drug users represent the largest proportion of all HIV reported cases in Viet Nam. This study aimed to explore the perceptions of risk and risk behaviours among HIV-positive injection drug users, and their experiences related to safe injection and safe sex practices. Methods This study used multiple qualitative methods in data collection including in-depth interviews, focus group discussions and participant observation with HIV-positive injection drug users. Results The informants described a change in the sharing practices among injection drug users towards more precautions and what was considered 'low risk sharing', like sharing among seroconcordant partners and borrowing rather than lending. However risky practices like re-use of injection equipment and 'syringe pulling' i.e. the use of left-over drugs in particular, were frequently described and observed. Needle and syringe distribution programmes were in place but carrying needles and syringes and particularly drugs could result in being arrested and fined. Fear of rejection and of loss of intimacy made disclosure difficult and was perceived as a major obstacle for condom use among recently diagnosed HIV infected individuals. Conclusion HIV-positive injection drug users continue to practice HIV risk behaviours. The anti-drug law and the police crack-down policy appeared as critical factors hampering ongoing prevention efforts with needle and syringe distribution programmes in Viet Nam. Drastic policy measures are needed to reduce the very high HIV prevalence among injection drug users.

Motivation enhances control of positive and negative emotional distractions.

Science.gov (United States)

Walsh, Amy T; Carmel, David; Harper, David; Grimshaw, Gina M

2018-01-03

Using cognitive control to ignore distractions is essential for successfully achieving our goals. In emotionally-neutral contexts, motivation can reduce interference from irrelevant stimuli by enhancing cognitive control. However, attention is commonly biased towards emotional stimuli, making them potent distractors. Can motivation aid control of emotional distractions, and does it do so similarly for positive and negative stimuli? Here, we examined how task motivation influences control of distraction from positive, negative, and neutral scenes. Participants completed a simple perceptual task while attempting to ignore task-irrelevant images. One group received monetary reward for fast and accurate task performance; another (control) group did not. Overall, both negative (mutilation) and positive (erotic) images caused greater slowing of responses than neutral images of people, but emotional distraction was reduced with reward. Crucially, despite the different motivational directions associated with negative and positive stimuli, reward reduced negative and positive distraction equally. Our findings suggest that motivation may encourage the use of a sustained proactive control strategy that can effectively reduce the impact of emotional distraction.

Refractometry for quality control of anesthetic drug mixtures.

Science.gov (United States)

Stabenow, Jennifer M; Maske, Mindy L; Vogler, George A

2006-07-01

Injectable anesthetic drugs used in rodents are often mixed and further diluted to increase the convenience and accuracy of dosing. We evaluated clinical refractometry as a simple and rapid method of quality control and mixing error detection of rodent anesthetic or analgesic mixtures. Dilutions of ketamine, xylazine, acepromazine, and buprenorphine were prepared with reagent-grade water to produce at least 4 concentration levels. The refraction of each concentration then was measured with a clinical refractometer and plotted against the percentage of stock concentration. The resulting graphs were linear and could be used to determine the concentration of single-drug dilutions or to predict the refraction of drug mixtures. We conclude that refractometry can be used to assess the concentration of dilutions of single drugs and can verify the mixing accuracy of drug combinations when the components of the mixture are known and fall within the detection range of the instrument.

Stimuli-Responsive Liposomes for Controlled Drug Delivery

KAUST Repository

Li, Wengang

2014-09-01

Liposomes are promising drug delivery vesicles due to their biodegradibility, large volume and biocompatibility towards both hydrophilic and hydrophobic drugs. They suffer, however, from poor stability which limits their use in controlled delivery applications. Herein, a novel method was devised for modification of liposomes with small molecules, polymers or nanoparticles to afford stimuli responsive systems that release on demand and stay relatively stable in the absence of the trigger.. This dissertation discusses thermosensitive, pH sensitive, light sensitive and magnetically triggered liposomes that have been prepared for controlled drug delivery application. RAFT polymerization was utilized for the preparation of thermosensitive liposomes (Cholesterol-PNIPAm) and acid-labile liposomes (DOPE-PAA). With low Mw Cholesterol-PNIPAm, the thermosensitive liposomes proved to be effective for controlled release and decreased the cytotoxicity of PNIPAm by eliciting the polymer doses. By crosslinking the DOPE-PAA on liposome surface with acid-labile diamine linkers, DOPE-PAA liposomes were verified to be sensitive at low pH. The effects of polymer structures (linear or hyperbranched) have also been studied for the stability and release properties of liposomes. Finally, a dual-responsive Au@SPIO embedded liposome hybrid (ALHs) was prepared with light-induced “on-and-off” function by photo-thermal process (visible light) and instant release properties triggered by alternating magnetic field, respectively. The ALH system would be further applied into the cellular imaging field as MRI contrast agent.

Control system design for nano-positioning using piezoelectric actuators

International Nuclear Information System (INIS)

Shan, Jinjun; Liu, Yanfang; Cui, Naigang; Gabbert, Ulrich

2016-01-01

This paper presents a systematic control system design for nano-positioning of a piezoelectric actuator (PEA). PEAs exhibit hysteresis nonlinearity, which can dramatically limit the application and performance of linear feedback control theory. Thus the hysteresis is compensated for based on the Maxwell resistive capacitor (MRC) model first. Then a proportional plus integral (PI) controller and a proportional double integral plus lead compensation (PII and L) controller are designed for the hysteresis-compensated PEA to account for model uncertainty, disturbance, and noise. The robust stability of both controllers is proved. The effectiveness of the proposed control scheme is demonstrated experimentally. Both controllers achieve fast precise positioning. The 2% settling times for the PI controller and the PII and L controller are 1.5 ms and 4.7 ms, respectively. The positioning resolution is upto 1 nm for both controllers. (paper)

Tracking control mechanisms for positioning automatic CRD exchanger

International Nuclear Information System (INIS)

Koizumi, Akira; Takada, Satoshi.

1984-01-01

Purpose: To enable completely automatic positioning for the automatic CRD (control rod drives) exchanger, as well as shorten the time for the exchanging operation and save the operator's labour. Constitution: Images of a target attached to the lower flange face of CRD are picked up by a fiber scope mounted to a mounting head. The images are converted through I.T.V. into electrical signals, passed through a cable and then sent to a pattern recognition mechanism. The position for the images of the target is calculated and the calculated position is sent to a drive control section, where the position for the images of the target is compared with a reference position for the images (exactly aligned position) and the moving amount of the mounting head is calculated to move the driving section and thereby complete the positioning. (Kawakami, Y.)

Plasma position control device for thermonuclear device

Energy Technology Data Exchange (ETDEWEB)

Onozuka, Masanori [Mitsubishi Heavy Industries Ltd., Tokyo (Japan); Fujita, Jun-ya; Ioki, Kimihiro

1995-10-03

The present invention concerns plasma position control coils having a feeder line structure not requiring high strength for the support portion. Namely, the coils are formed by twisting feeder lines extended from plasma position control coils in a vacuum vessel. The twisted feeder lines are supported using an appropriate structural member. Electromagnetic load is generated to the feeder lines being extended from the position control coils and traversing toroidal fields at a current introduction lines and at current delivery lines respectively. However, since the feeder lines have substantially spiral shape consisting of two twisted lines, the electromagnetic load and the moment caused by the generated load which are inversed to each other are off set. Accordingly, only extremely small force is exerted on the fittings which support the feeder lines. Therefore, small strength may suffice for the fittings and the gaps of mounting the fittings may be made longer. (I.S.).

Plasma position control device for thermonuclear device

International Nuclear Information System (INIS)

Onozuka, Masanori; Fujita, Jun-ya; Ioki, Kimihiro.

1995-01-01

The present invention concerns plasma position control coils having a feeder line structure not requiring high strength for the support portion. Namely, the coils are formed by twisting feeder lines extended from plasma position control coils in a vacuum vessel. The twisted feeder lines are supported using an appropriate structural member. Electromagnetic load is generated to the feeder lines being extended from the position control coils and traversing toroidal fields at a current introduction lines and at current delivery lines respectively. However, since the feeder lines have substantially spiral shape consisting of two twisted lines, the electromagnetic load and the moment caused by the generated load which are inversed to each other are off set. Accordingly, only extremely small force is exerted on the fittings which support the feeder lines. Therefore, small strength may suffice for the fittings and the gaps of mounting the fittings may be made longer. (I.S.)

Impulse position control algorithms for nonlinear systems

Energy Technology Data Exchange (ETDEWEB)

Sesekin, A. N., E-mail: sesekin@list.ru [Ural Federal University, 19 S. Mira, Ekaterinburg, 620002 (Russian Federation); Institute of Mathematics and Mechanics, Ural Division of Russian Academy of Sciences, 16 S. Kovalevskaya, Ekaterinburg, 620990 (Russian Federation); Nepp, A. N., E-mail: anepp@urfu.ru [Ural Federal University, 19 S. Mira, Ekaterinburg, 620002 (Russian Federation)

2015-11-30

The article is devoted to the formalization and description of impulse-sliding regime in nonlinear dynamical systems that arise in the application of impulse position controls of a special kind. The concept of trajectory impulse-sliding regime formalized as some limiting network element Euler polygons generated by a discrete approximation of the impulse position control This paper differs from the previously published papers in that it uses a definition of solutions of systems with impulse controls, it based on the closure of the set of smooth solutions in the space of functions of bounded variation. The need for the study of such regimes is the fact that they often arise when parry disturbances acting on technical or economic control system.

Impulse position control algorithms for nonlinear systems

Science.gov (United States)

Sesekin, A. N.; Nepp, A. N.

2015-11-01

The article is devoted to the formalization and description of impulse-sliding regime in nonlinear dynamical systems that arise in the application of impulse position controls of a special kind. The concept of trajectory impulse-sliding regime formalized as some limiting network element Euler polygons generated by a discrete approximation of the impulse position control This paper differs from the previously published papers in that it uses a definition of solutions of systems with impulse controls, it based on the closure of the set of smooth solutions in the space of functions of bounded variation. The need for the study of such regimes is the fact that they often arise when parry disturbances acting on technical or economic control system.

Optogenetic control of organelle transport and positioning

NARCIS (Netherlands)

van Bergeijk, Petra; Adrian, Max; Hoogenraad, Casper C; Kapitein, Lukas C

2015-01-01

Proper positioning of organelles by cytoskeleton-based motor proteins underlies cellular events such as signalling, polarization and growth. For many organelles, however, the precise connection between position and function has remained unclear, because strategies to control intracellular organelle

Car-Like Mobile Robot Oriented Positioning by Fuzzy Controllers

Directory of Open Access Journals (Sweden)

Noureddine Ouadah

2008-11-01

Full Text Available In this paper, fuzzy logic controllers (FLC are used to implement an efficient and accurate positioning of an autonomous car-like mobile robot, respecting final orientation. To accomplish this task, called "Oriented Positioning", two FLC have been developed: robot positioning controller (RPC and robot following controller (RFC. Computer simulation results illustrate the effectiveness of the proposed technique. Finally, real-time experiments have been made on an autonomous car-like mobile robot called "Robucar", developed to perform people transportation. Obtained results from experiments demonstrate the effectiveness of the proposed control strategy.

Plasmon resonant liposomes for controlled drug delivery

Science.gov (United States)

Knights-Mitchell, Shellie S.; Romanowski, Marek

2015-03-01

Nanotechnology use in drug delivery promotes a reduction in systemic toxicity, improved pharmacokinetics, and better drug bioavailability. Liposomes continue to be extensively researched as drug delivery systems (DDS) with formulations such as Doxil® and Ambisome® approved by FDA and successfully marketed in the United States. However, the limited ability to precisely control release of active ingredients from these vesicles continues to challenge the broad implementation of this technology. Moreover, the full potential of the carrier to sequester drugs until it can reach its intended target has yet to be realized. Here, we describe a liposomal DDS that releases therapeutic doses of an anticancer drug in response to external stimulus. Earlier, we introduced degradable plasmon resonant liposomes. These constructs, obtained by reducing gold on the liposome surface, facilitate spatial and temporal release of drugs upon laser light illumination that ultimately induces an increase in temperature. In this work, plasmon resonant liposomes have been developed to stably encapsulate and retain doxorubicin at physiological conditions represented by isotonic saline at 37o C and pH 7.4. Subsequently, they are stimulated to release contents either by a 5o C increase in temperature or by laser illumination (760 nm and 88 mW/cm2 power density). Successful development of degradable plasmon resonant liposomes responsive to near-infrared light or moderate hyperthermia can provide a new delivery method for multiple lipophilic and hydrophilic drugs with pharmacokinetic profiles that limit clinical utility.

International Drug Control Policy

Science.gov (United States)

2009-08-24

Common illegal drugs include cannabis, cocaine, opiates, and synthetic drugs. International trade in these drugs represents a lucrative and what...into effect, decriminalizing “personal use” amounts of marijuana , heroin, cocaine, methamphetamine, and other internationally sanctioned drugs.15 While...President Calls for Legalizing Marijuana ,”CNN.com, May 13, 2009. 15 “Mexico Legalizes Drug Possession,” Associated Press, August 21, 2009. 16 In support

Pain Control in the Presence of Drug Addiction.

Science.gov (United States)

Vadivelu, Nalini; Lumermann, Leandro; Zhu, Richard; Kodumudi, Gopal; Elhassan, Amir O; Kaye, Alan David

2016-05-01

Drug addiction is present in a significant proportion of the population in the USA and worldwide. Drug addiction can occur with the abuse of many types of substances including cocaine, marijuana, stimulants, alcohol, opioids, and tranquilizers. There is a high likelihood that clinicians will encounter patients with substance abuse disorders on a regular basis with the prevalence of the use of illicit substances and the high rate of abuse of prescription drugs. The use of abuse deterrent formulations of prescription opioid agents, pill counts, and urine drug abuse screenings are all useful strategies. Optimum pain management of patients with addiction in the outpatient and inpatient setting is essential to minimize pain states. Careful selection of medications and appropriate oversight, including drug agreements, can reduce drug-induced impairments, including sleep deficits and diminished physical, social, and sexual functioning. This review, therefore, discusses the prevalence of illicit and prescription drug addiction, the challenges of achieving optimum pain control, and the therapeutic approaches to be considered in this challenging population. More research is warranted to develop improved therapies and routes of treatments for optimum pain relief and to prevent the development of central sensitization, chronic pain, and impaired physical and social functioning in patients with drug addiction.

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

Science.gov (United States)

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.

Trauma exposure and heavy drinking and drug use among college students: Identifying the roles of negative and positive affect lability in a daily diary study.

Science.gov (United States)

Weiss, Nicole H; Bold, Krysten W; Contractor, Ateka A; Sullivan, Tami P; Armeli, Stephen; Tennen, Howard

2018-04-01

Trauma exposure is linked to heavy drinking and drug use among college students. Extant research reveals positive associations between negative affect lability and both trauma exposure and alcohol use. This study aimed to extend past research by using daily diary methods to test whether (a) individuals with (versus without) trauma exposure experience greater negative and positive affect lability, (b) negative and positive affect lability are associated with heavy drinking and drug use, and (c) negative and positive affect lability mediate the relations between trauma exposure and heavy drinking and drug use. Participants were 1640 college students (M age=19.2, 54% female, 80% European American) who provided daily diary data for 30days via online surveys. Daily diaries assessed negative and positive affect and substance use (i.e., percent days of heavy drinking, percent days of drug use, total number of drugs used). Individuals with (versus without) a history of trauma exposure demonstrated higher levels of negative and positive affect lability. Negative, but not positive, affect lability was associated with percent days of heavy drinking, percent days of drug use, and total number of drugs used, and mediated the associations between trauma exposure and heavy drinking and drug use outcomes. Findings provide support for the underlying role of negative affect lability in the relations between trauma exposure and heavy drinking and drug use among college students, suggesting that treatments targeting negative affect lability may potentially serve to reduce heavy drinking and drug use among trauma-exposed college students. Copyright © 2017 Elsevier Ltd. All rights reserved.

Development of the 'JFT-2' tokamak plasma position control system

International Nuclear Information System (INIS)

Fujisawa, Noboru; Matsuzaki, Yoshimi; Suzuki, Norio; Murai, Katsuji; Suzuki, Satoshi.

1980-01-01

Digital control technique was applied to control the plasma position in the JFT-2 tokamak experiment device. The detail of the JFT-2 is described elsewhere. The plasma position control system consists of a Hitachi control computer, HIDIC 80, and a Hitachi micro-computer, HIDIC 08E. The plasma position is detected by the position control computer, and compared with a preset value. Then, a reference signal is supplied to the micro-computer controlling power source, and the phase control of the thyristor controlling power source is performed. Since the behavior of plasma is very fast, the fast control is required. The control of the thyristor controlling power source is made by direct digital control (DDC). The main component of the hardware of the present system is the micro-computer HIDIC 08E. The software is the direct task system without the operating system (OS). The results of experiments showed that the feedback control of the system worked well. (Kato, T.)

Advanced control of piezoelectric micro-nano-positioning systems

CERN Document Server

Xu, Qingsong

2016-01-01

This book explores emerging methods and algorithms that enable precise control of micro-/nano-positioning systems. The text describes three control strategies: hysteresis-model-based feedforward control and hysteresis-model-free feedback control based on and free from state observation. Each paradigm receives dedicated attention within a particular part of the text. Readers are shown how to design, validate and apply a variety of new control approaches in micromanipulation: hysteresis modelling, discrete-time sliding-mode control and model-reference adaptive control. Experimental results are provided throughout and build up to a detailed treatment of practical applications in the fourth part of the book. The applications focus on control of piezoelectric grippers. Advanced Control of Piezoelectric Micro-/Nano-Positioning Systems will assist academic researchers and practising control and mechatronics engineers interested in suppressing sources of nonlinearity such as hysteresis and drift when combining positi...

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

OpenAIRE

Muhammad Zaman; Junaid Qureshi; Hira Ejaz; Rai Muhammad Sarfraz; Hafeez ullah Khan; Fazal Rehman Sajid; Muhammad Shafiq ur Rehman

2016-01-01

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 dif...

Coordinated joint motion control system with position error correction

Science.gov (United States)

Danko, George L.

2016-04-05

Disclosed are an articulated hydraulic machine supporting, control system and control method for same. The articulated hydraulic machine has an end effector for performing useful work. The control system is capable of controlling the end effector for automated movement along a preselected trajectory. The control system has a position error correction system to correct discrepancies between an actual end effector trajectory and a desired end effector trajectory. The correction system can employ one or more absolute position signals provided by one or more acceleration sensors supported by one or more movable machine elements. Good trajectory positioning and repeatability can be obtained. A two joystick controller system is enabled, which can in some cases facilitate the operator's task and enhance their work quality and productivity.

Automation of Aditya tokamak plasma position control DC power supply

Energy Technology Data Exchange (ETDEWEB)

Arambhadiya, Bharat, E-mail: bharat@ipr.res.in; Raj, Harshita; Tanna, R.L.; Edappala, Praveenlal; Rajpal, Rachana; Ghosh, Joydeep; Chattopadhyay, P.K.; Kalal, M.B.

2016-11-15

Highlights: • Plasma position control is very essential for obtaining repeatable high temperature, high-density discharges of longer durations in tokomak. • The present capacitor bank has limitations of maximum current capacity and position control beyond 200 ms. • The installation of a separate set of coils and a DC power supply can control the plasma position beyond 200 ms. • A high power thyristor (T588N1200) triggers for DC current pulse of 300 A fires precisely at required positions to modify plasma position. • The commissioning is done for the automated in-house, quick and reliable solution. - Abstract: Plasma position control is essential for obtaining repeatable high temperature, high-density discharges of longer duration in tokamaks. Recently, a set of external coils is installed in the vertical field mode configuration to control the radial plasma position in ADITYA tokamak. The existing capacitor bank cannot provide the required current pulse beyond 200 ms for position control. This motivated to have a DC power supply of 500 A to provide current pulse beyond 200 ms for the position control. The automatization of the DC power supply mandated interfaces with the plasma control system, Aditya Pulse Power supply, and Data acquisition system for coordinated discharge operation. A high current thyristor circuit and a timer circuit have been developed for controlling the power supply automatically for charging vertical field coils of Aditya tokamak. Key protection interlocks implemented in the development ensure machine and occupational safety. Fiber-optic trans-receiver isolates the power supply with other subsystems, while analog channel is optically isolated. Commissioning and testing established proper synchronization of the power supply with tokamak operation. The paper discusses the automation of the DC power supply with main circuit components, timing control, and testing results.

Oromucosal multilayer films for tailor-made, controlled drug delivery.

Science.gov (United States)

Lindert, Sandra; Breitkreutz, Jörg

2017-11-01

The oral mucosa has recently become increasingly important as an alternative administration route for tailor-made, controlled drug delivery. Oromucosal multilayer films, assigned to the monograph oromucosal preparations in the Ph.Eur. may be a promising dosage form to overcome the requirements related to this drug delivery site. Areas covered: We provide an overview of multilayer films as drug delivery tools, and discuss manufacturing processes and characterization methods. We focus on the suitability of characterization methods for particular requirements of multilayer films. A classification was performed covering indication areas and APIs incorporated in multilayer film systems for oromucosal use in order to provide a summary of data published in this field. Expert opinion: The shift in drug development to high molecular weight drugs will influence the field of pharmaceutical development and delivery technologies. For a high number of indication areas, such as hormonal disorders, cardiovascular diseases or local treatment of infections, the flexible layer design of oromucosal multilayer films provides a promising option for tailor-made, controlled delivery of APIs to or through defined surfaces in the oral cavity. However, there is a lack of discriminating or standardized testing methods to assess the quality of multilayer films in a reliable way.

Self-tuning control studies of the plasma vertical position problem

International Nuclear Information System (INIS)

Zheng, Guang Lin; Wellstead, P.E.; Browne, M.L.

1993-01-01

The plasma vertical position system in a tokamak device can be open-loop unstable with time-varying dynamics, such that the instability increases with system dynamical changes. Time-varying unstable dynamics makes the plasma vertical position a particularly difficult one to control with traditional fixed-coefficient controllers. A self-tuning technique offers a new solution of the plasma vertical position control problem by an adaptive control approach. Specifically, the self-tuning controller automatically tunes the controller parameters without an a priori knowledge of the system dynamics and continuously tracks dynamical changes within the system, thereby providing the system with auto-tuning and adaptive tuning capabilities. An overview of the self-tuning methods is given, and their applicability to a simulation of the Joint European Torus (JET) vertical plasma positions system is illustrated. Specifically, the applicability of pole-assignment and generalized predictive control self-tuning methods to the vertical plasma position system is demonstrated. 26 refs., 16 figs., 1 tab

A remotely operated drug delivery system with dose control

KAUST Repository

Yi, Ying; Kosel, Jü rgen

2017-01-01

include an effective actuation stimulus and a controllable dose release mechanism. This work focuses on remotely powering an implantable drug delivery system and providing a high degree of control over the released dose. This is accomplished by integration

Molecularly precise dendrimer-drug conjugates with tunable drug release for cancer therapy.

Science.gov (United States)

Zhou, Zhuxian; Ma, Xinpeng; Murphy, Caitlin J; Jin, Erlei; Sun, Qihang; Shen, Youqing; Van Kirk, Edward A; Murdoch, William J

2014-10-06

The structural preciseness of dendrimers makes them perfect drug delivery carriers, particularly in the form of dendrimer-drug conjugates. Current dendrimer-drug conjugates are synthesized by anchoring drug and functional moieties onto the dendrimer peripheral surface. However, functional groups exhibiting the same reactivity make it impossible to precisely control the number and the position of the functional groups and drug molecules anchored to the dendrimer surface. This structural heterogeneity causes variable pharmacokinetics, preventing such conjugates to be translational. Furthermore, the highly hydrophobic drug molecules anchored on the dendrimer periphery can interact with blood components and alter the pharmacokinetic behavior. To address these problems, we herein report molecularly precise dendrimer-drug conjugates with drug moieties buried inside the dendrimers. Surprisingly, the drug release rates of these conjugates were tailorable by the dendrimer generation, surface chemistry, and acidity. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Digital control of plasma position in Damavand tokamak

Energy Technology Data Exchange (ETDEWEB)

Emami, M.; Babazadeh, A.R.; Roshan, M.V.; Memarzadeh, M.; Habibi, H. [Atomic Energy Organization of Iran (AEOI), Tehran (Iran, Islamic Republic of). Nuclear Fusion Research Center. Plasma Physics Lab.

2002-03-01

Plasma position control is one of the important issues in the design and operation of tokamak fusion research device. Since a tokamak is basically an electrical system consisting of power supplies, coils, plasma and eddy currents, a model in which these components are treated as an electrical circuits is used in designing Damavand plasma position control system. This model is used for the simulation of the digital control system and its parameters have been verified experimentally. In this paper, the performance of a high-speed digital controller as well as a simulation study and its application to the Damavand tokamak is discussed. (author)

The Role of Internalized Stigma in the Disclosure of Injecting Drug Use Among People Who Inject Drugs and Self-Report as HIV-Positive in Kohtla-Järve, Estonia.

Science.gov (United States)

Johannson, Annika; Vorobjov, Sigrid; Heimer, Robert; Dovidio, John F; Uusküla, Anneli

2017-04-01

Disclosure of injecting drug use and its associations with stigma have received very little research attention. This cross-sectional study examined the role of internalized HIV and drug stigma (i.e., self-stigmatization) in the disclosure of injecting drug use among people who inject drugs (PWID) self-reporting as HIV-positive (n = 312) in Kohtla-Järve, Estonia. The internalization of both stigmas was relatively high. On average, PWID disclosed to three disclosure targets out of seven. Disclosure was highest to close friends and health care workers and lowest to employers and casual sex partners. Internalized drug stigma was negatively associated with disclosure to other family members (AOR = 0.48; 95% CI 0.30-0.77) and health care workers (AOR = 0.46; 95% CI 0.25-0.87). Internalized HIV stigma was positively associated with disclosure to health care workers (AOR = 2.26; 95% CI 1.27-4.00). No interaction effect of internalized stigmas on disclosures emerged. We concluded that effects of internalized stigmas on disclosures are few and not uniform.

Microfluidic synthesis of microfibers for magnetic-responsive controlled drug release and cell culture.

Directory of Open Access Journals (Sweden)

Yung-Sheng Lin

Full Text Available This study demonstrated the fabrication of alginate microfibers using a modular microfluidic system for magnetic-responsive controlled drug release and cell culture. A novel two-dimensional fluid-focusing technique with multi-inlets and junctions was used to spatiotemporally control the continuous laminar flow of alginate solutions. The diameter of the manufactured microfibers, which ranged from 211 µm to 364 µm, could be well controlled by changing the flow rate of the continuous phase. While the model drug, diclofenac, was encapsulated into microfibers, the drug release profile exhibited the characteristic of a proper and steady release. Furthermore, the diclofenac release kinetics from the magnetic iron oxide-loaded microfibers could be controlled externally, allowing for a rapid drug release by applying a magnetic force. In addition, the successful culture of glioblastoma multiforme cells in the microfibers demonstrated a good structural integrity and environment to grow cells that could be applied in drug screening for targeting cancer cells. The proposed microfluidic system has the advantages of ease of fabrication, simplicity, and a fast and low-cost process that is capable of generating functional microfibers with the potential for biomedical applications, such as drug controlled release and cell culture.

Natural and synthetic biomaterials for controlled drug delivery.

Science.gov (United States)

Kim, Jang Kyoung; Kim, Hyung Jin; Chung, Jee-Young; Lee, Jong-Hwan; Young, Seok-Beom; Kim, Yong-Hee

2014-01-01

A wide variety of delivery systems have been developed and many products based on the drug delivery technology are commercially available. The development of controlled-release technologies accelerated new dosage form design by altering pharmacokinetic and pharmacodynamics profiles of given drugs, resulting in improved efficacy and safety. Various natural or synthetic polymers have been applied to make matrix, reservoir or implant forms due to the characteristics of polymers, especially ease of control for modifications of biocompatibility, biodegradation, porosity, charge, mechanical strength and hydrophobicity/hydrophilicity. Hydrogel is a hydrophilic, polymeric network capable of imbibing large amount of water and biological fluids. This review article introduces various applications of natural and synthetic polymer-based hydrogels from pharmaceutical, biomedical and bioengineering points of view.

Positive affect improves working memory: implications for controlled cognitive processing.

Science.gov (United States)

Yang, Hwajin; Yang, Sujin; Isen, Alice M

2013-01-01

This study examined the effects of positive affect on working memory (WM) and short-term memory (STM). Given that WM involves both storage and controlled processing and that STM primarily involves storage processing, we hypothesised that if positive affect facilitates controlled processing, it should improve WM more than STM. The results demonstrated that positive affect, compared with neutral affect, significantly enhanced WM, as measured by the operation span task. The influence of positive affect on STM, however, was weaker. These results suggest that positive affect enhances WM, a task that involves controlled processing, not just storage processing. Additional analyses of recall and processing times and accuracy further suggest that improved WM under positive affect is not attributable to motivational differences, but results instead from improved controlled cognitive processing.

Considering the context: social factors in responses to drugs in humans.

Science.gov (United States)

de Wit, Harriet; Sayette, Michael

2018-04-01

Drugs are typically used in social settings. Here, we consider two factors that may contribute to this observation: (i) the presence of other people may enhance the positive mood effects of a drug, and conversely, (ii) drugs may enhance the value of social stimuli. We review evidence from controlled laboratory studies with human volunteers, which investigated either of these interactions between social factors and responses to drugs. We examine the bidirectional effects of social stimuli and single doses of alcohol, stimulants, opioids, and cannabis. All four classes of drugs interact with social contexts, but the nature of these interactions varies across drugs, and depends on whether the context is positive or negative. Alcohol and stimulant drugs enhance the attractiveness of social stimuli and the desire to socialize, and social contexts, in turn, enhance these drugs' effects. In contrast, opioids and cannabis have subtler effects on social interactions and their effects are less influenced by the presence of others. Overall, there is stronger evidence that drugs enhance positive social contexts than that they dampen the negativity of unpleasant social settings. Controlled research is needed to understand the interactions between drugs of abuse and social contexts, to model and understand the determinants of drug use outside the laboratory.

Plasma position and shape control for ITER

International Nuclear Information System (INIS)

Portone, A.; Gribov, Y.; Huguet, M.

1995-01-01

Key features and main results about the control of the plasma shape in ITER are presented. A control algorithm is designed to control up to 6 gaps between the plasma separatrix and the plasma facing components during the reference burn phase. Nonlinear simulations show the performances of the controller in the presence of plasma vertical position offsets, beta drops and power supply voltage saturation

10 CFR 707.7 - Random drug testing requirements and identification of testing designated positions.

Science.gov (United States)

2010-01-01

... contractor, to have the potential to significantly affect the environment, public health and safety, or... evidence of the use of illegal drugs of employees in testing designated positions identified in this... section shall provide for random tests at a rate equal to 30 percent of the total number of employees in...

Fractional-order positive position feedback compensator for active vibration control of a smart composite plate

Science.gov (United States)

Marinangeli, L.; Alijani, F.; HosseinNia, S. Hassan

2018-01-01

In this paper, Active Vibration Control (AVC) of a rectangular carbon fibre composite plate with free edges is presented. The plate is subjected to out-of-plane excitation by a modal vibration exciter and controlled by Macro Fibre Composite (MFC) transducers. Vibration measurements are performed by using a Laser Doppler Vibrometer (LDV) system. A fractional-order Positive Position Feedback (PPF) compensator is proposed, implemented and compared to the standard integer-order PPF. MFC actuator and sensor are positioned on the plate based on maximal modal strain criterion, so as to control the second natural mode of the plate. Both integer and fractional-order PPF allowed for the effective control of the second mode of vibration. However, the newly proposed fractional-order controller is found to be more efficient in achieving the same performance with less actuation voltage. Moreover, it shows promising performance in reducing spillover effect due to uncontrolled modes.

Laser-activated nano-biomaterials for tissue repair and controlled drug release

International Nuclear Information System (INIS)

Matteini, P; Ratto, F; Rossi, F; Pini, R

2014-01-01

We present recent achievements of minimally invasive welding of biological tissue and controlled drug release based on laser-activated nano-biomaterials. In particular, we consider new advancements in the biomedical application of near-IR absorbing gold nano-chromophores as an original solution for the photothermal repair of surgical incisions and as nanotriggers of controlled drug release from hybrid biopolymer scaffolds. (laser biophotonics)

Validation of Modifications to the ANSR for Listeria Method for Improved Internal Positive Control Performance.

Science.gov (United States)

Alles, Susan; Meister, Evan; Hosking, Edan; Tovar, Eric; Shaulis, Rebecca; Schonfeld, Mark; Zhang, Lei; Li, Lin; Biswas, Preetha; Mozola, Mark; Donofrio, Robert; Chen, Yi

2018-03-01

A study was conducted to validate a minor reagent formulation change to the ANSR for Listeria method, Performance Tested MethodSM 101202. This change involves increasing the master mix volume prelyophilization by 40% and addition of salmon sperm DNA (nontarget DNA) to the master mix. These changes improve the robustness of the internal positive control response and reduce the possibility of obtaining invalid results due to weak-positive control curves. When three foods (hot dogs, Mexican-style cheese, and cantaloupe) and sponge samples taken from a stainless steel surface were tested, no significant differences in performance between the ANSR and U.S. Food and Drug Administration Bacteriological Analytical Manual or U.S. Department of Agriculture-Food Safety and Inspection Service Microbiology Laboratory Guidebook reference culture procedures were observed for any of the matrixes as determined by probability of detection analysis. Inclusivity and exclusivity testing yielded 100% expected results for target and nontarget bacteria. Accelerated stability testing was carried out over a 7 week period and showed no decrease in assay performance over time.

Association of serum brain derived neurotropic factor with duration of drug-naive period and positive-negative symptom scores in drug naive schizophrenia.

Directory of Open Access Journals (Sweden)

Abdurrahim Bakirhan

Full Text Available The aim of this study was to compare the serum brain derived neurotropic factor (BNDF levels of patients with schizophrenia who had never received an antipsychotic treatment with those of a control group. Also, to analyze the relationship between the Positive and Negative Symptom Scale (PANSS scores and BDNF levels of the patients during the period they were drug-naive.The sample of the study comprised patients who presentedto the Psychiatry Clinic and were admitted after a distinctive schizophrenia diagnosis was made in accordance with the fourth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV-TR diagnosis classification and who were not using and never had any antipsychotic medicine. A total of 160 participants were included in the study, 80 of whom had schizophrenia patients and 80 constituted the age- and sex-matched healthy control group. Before the start of the treatment, the serum samples to be checked for the BDNF levels were collected from the patients.The difference between the average BDNF levels of the groups were statistically significant (t = -5.25; p˂.001. An analysis as to whether there was a relation between the BDNF levels and the drug-naïve duration indicated no correlations. An examination of the relationship between PANSS scores and BDNF levels of the patients yielded no correlations.Serum BDNF levels seem to be one of the indicators of schizophrenia and its progress; nevertheless, we still do not have sufficient information about this neurotropic factor. In light of our study, the neurodevelopmental changes that occur at disease onset of the illness prominently affect the progress of the illness, which highlights the importance of the treatment in the early stages.

Association of serum brain derived neurotropic factor with duration of drug-naive period and positive-negative symptom scores in drug naive schizophrenia.

Science.gov (United States)

Bakirhan, Abdurrahim; Yalcin Sahiner, Safak; Sahiner, Ismail Volkan; Safak, Yasir; Goka, Erol

2017-01-01

The aim of this study was to compare the serum brain derived neurotropic factor (BNDF) levels of patients with schizophrenia who had never received an antipsychotic treatment with those of a control group. Also, to analyze the relationship between the Positive and Negative Symptom Scale (PANSS) scores and BDNF levels of the patients during the period they were drug-naive. The sample of the study comprised patients who presentedto the Psychiatry Clinic and were admitted after a distinctive schizophrenia diagnosis was made in accordance with the fourth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV-TR) diagnosis classification and who were not using and never had any antipsychotic medicine. A total of 160 participants were included in the study, 80 of whom had schizophrenia patients and 80 constituted the age- and sex-matched healthy control group. Before the start of the treatment, the serum samples to be checked for the BDNF levels were collected from the patients. The difference between the average BDNF levels of the groups were statistically significant (t = -5.25; p˂.001). An analysis as to whether there was a relation between the BDNF levels and the drug-naïve duration indicated no correlations. An examination of the relationship between PANSS scores and BDNF levels of the patients yielded no correlations. Serum BDNF levels seem to be one of the indicators of schizophrenia and its progress; nevertheless, we still do not have sufficient information about this neurotropic factor. In light of our study, the neurodevelopmental changes that occur at disease onset of the illness prominently affect the progress of the illness, which highlights the importance of the treatment in the early stages.

Guidelines for controlled trials of drugs in tension-type headache: second edition

DEFF Research Database (Denmark)

Bendtsen, L; Bigal, M E; Cerbo, R

2010-01-01

and chronic tension-type headache have been published, providing new information on trial methodology for this disorder. Furthermore, the classification of the headaches, including tension-type headache, has been revised. These developments support the need for also revising the guidelines for drug treatments......The Clinical Trials Subcommittee of the International Headache Society published its first edition of the guidelines on controlled trials of drugs in tension-type headache in 1995. These aimed 'to improve the quality of controlled clinical trials in tension-type headache', because 'good quality...... controlled trials are the only way to convincingly demonstrate the efficacy of a drug, and form the basis for international agreement on drug therapy'. The Committee published similar guidelines for clinical trials in migraine and cluster headache. Since 1995 several studies on the treatment of episodic...

Contact lenses as drug controlled release systems: a narrative review

Directory of Open Access Journals (Sweden)

Helena Prior Filipe

2016-06-01

Full Text Available ABSTRACT Topically applied therapy is the most common way to treat ocular diseases, however given the anatomical and physiological constraints of the eye, frequent dosing is required with possible repercussions in terms of patient compliance. Beyond refractive error correction, contact lenses (CLs have, in the last few decades emerged as a potential ophthalmic drug controlled release system (DCRS. Extensive research is underway to understand how to best modify CLs to increase residence time and bioavailability of drugs within therapeutic levels on the ocular surface.These devices may simultaneously correct ametropia and have a role in managing ophthalmic disorders that can hinder CL wear such as dry eye, glaucoma, ocular allergy and cornea infection and injury. In this narrative review the authors explain how the ocular surface structures determine drug diffusion in the eye and summarize the strategies to enhance drug residence time and bioavailability. They synthesize findings and clinical applications of drug soaked CLs as DCRS combined with delivery diffusion barriers, incorporation of functional monomers, ion related controlled release, molecular imprinting, nanoparticles and layering. The authors draw conclusions about the impact of these novel ophthalmic agents delivery systems in improving drug transport in the target tissue and patient compliance, in reducing systemic absorption and undesired side effects, and discuss future perspectives.

Modeling And Position Control Of Scara Type 3D Printer

Directory of Open Access Journals (Sweden)

Ahmet Saygamp305n Ogulmuamp351

2015-08-01

Full Text Available In this work a scara robot type 3D printer system is dynamically modeled and position control of the system is realized. For this aim computer aided design model of three degrees of freedom robotic system is created using SolidWorks program then obtained model is exported to MATLABSimMechanics software for position control. Also mathematical model of servo motors used in robotic 3D printer system is included in control methodology to design proportional controllers. Uncontrolled and controlled position results are simulated and given in the form of the graphics.

Low energy nanoemulsification to design veterinary controlled drug delivery devices

Directory of Open Access Journals (Sweden)

Thierry F Vandamme

2010-10-01

Full Text Available Thierry F Vandamme, Nicolas Anton, University of Strasbourg, Faculty of Pharmacy, Illkirch Cedex, France; UMR CNRS 7199, Laboratoire de Conception et Application de Molécules Bioactives, équipe de Pharmacie Biogalénique, Illkirch Cedex, France,  This work is selected as Controlled Release Society Outstanding Veterinary Paper Award 2010Abstract: The unique properties of nanomaterials related to structural stability and quantum-scale reactive properties open up a world of possibilities that could be exploited to design and to target drug delivery or create truly microscale biological sensors for veterinary applications. We developed cost-saving and solvent-free nanoemulsions. Formulated with a low-energy method, these nanoemulsions can find application in the delivery of controlled amounts of drugs into the beverage of breeding animals (such as poultry, cattle, pigs or be used for the controlled release of injectable poorly water-soluble drugs.Keywords: nanoemulsion, nanomedicine, low-energy emulsification, veterinary, ketoprofen, sulfamethazine

Positive Exchange of Flight Controls Program

Science.gov (United States)

1995-03-10

This advisory circular provides guidance for all pilots, especially student pilots, flight instructors, and pilot examiners, on the recommended procedure to use for the positive exchange of flight controls between pilots when operating an aircraft.

[Wuling Capsule for climacteric patients with depression and anxiety state: a randomized, positive parallel controlled trial].

Science.gov (United States)

Wang, Xing-juan; Li, Ji; Zou, Qin-di; Jin, Ling

2009-11-01

The incidence of menopausal anxiety and depression is increasing. It can induce and aggravate a variety of somatic symptoms. Despite of the good effects of psychotropic drugs on the disease, patients' compliance is poor. Therefore, it is necessary to find a drug which is practical, effective, and easy for patients to take. To evaluate the efficacy of Wuling Capsule (WC), a Chinese herbal medicine, in treatment of female climacteric syndrome with depression and anxiety state. A total of 96 outpatients of female climacteric syndrome from Department of Gynecology of Integrated Traditional Chinese and Western Medicine, Huashan Hospital, Fudan University, Department of Gynecology of Traditional Chinese Medicine, Longhua Hospital, Shanghai University of Traditional Chinese Medicine, and Department of Traditional Chinese Medicine, Obstetrics and Gynecology Hospital, Fudan University were included. The study was designed as a randomized, positive drug parallel controlled trial. The patients were divided into WC group (64 cases) and control group (32 cases) and were orally administered Wuling Capsule and Gengnianan Tablet, respectively. The efficacy was evaluated with Kupperman menopausal index (KMI), Self-rating Depression Scale (SDS), and Self-rating Anxiety Scale (SAS) before treatment, and after 3-week and 6-week treatment. The total response rate was 89.66% (52/58) in the WC group, which was superior to that in the control group [76.67% (23/30)]. Ridit test showed that there was a significant difference between the two groups (Pstate. Wuling Capsule is more effective to alleviate depression and anxiety as compared with Gengnianan Tablet.

41 CFR 109-27.5008 - Control of drug substances and potable alcohol.

Science.gov (United States)

2010-07-01

..., and Guidelines § 109-27.5008 Control of drug substances and potable alcohol. Effective procedures and... 41 Public Contracts and Property Management 3 2010-07-01 2010-07-01 false Control of drug substances and potable alcohol. 109-27.5008 Section 109-27.5008 Public Contracts and Property Management...

Analysis of intentional drug poisonings using Ohio Poison Control Center Data, 2002-2014.

Science.gov (United States)

Pringle, Kelsey; Caupp, Sarah; Shi, Junxin; Wheeler, Krista K; Spiller, Henry A; Casavant, Marcel J; Xiang, Henry

2017-08-01

Pharmaceutical drug poisonings, especially those that are intentional, are a serious problem for adolescents and young adults. Poison control center data is a viable tool to track intentional drug poisonings in near real-time. To determine intentional drug poisoning rates among adolescents and young adults in Ohio using poison control center data. We analyzed data from 2002 to 2014 obtained by Ohio's three poison control centers. Inclusion variables were calls made to the centers that had appropriate subject age (10-29 years old), subject sex, involved substance (all drug classes), and medical outcome (no effect, minor effect, moderate effect, major effect, and death). Intentional drug poisoning reports were also separated into subgroups to compare suspected suicide reports to misuse and abuse reports. Finally, resident population estimates were used to generate 2014 intentional drug poisoning rates for each county in Ohio. The most common age group for intentional drug poisonings was 18-24. Females reported more suspected suicide drug poisonings while males reported more misuse/abuse drug poisonings. The most reported drug class across all ages was analgesics. Of the 88 counties in Ohio, Hamilton, Williams, Washington, and Guernsey counties had the highest rates of intentional drug poisonings. The high report rate of suspected suicides and analgesic class drugs demonstrates the need for preventative measures for adolescents and young adults in Ohio. Any interventions, along with legislative changes, will need to take place in our local communities.

Stemming the Escalating Cost of Prescription Drugs: A Position Paper of the American College of Physicians.

Science.gov (United States)

Daniel, Hilary

2016-03-29

This American College of Physicians position paper, initiated and written by its Health and Public Policy Committee and approved by the Board of Regents on 16 February 2016, reports policy recommendations from the American College of Physicians to address the escalating costs of prescription drugs in the United States. Prescription drugs play an important part in treating and preventing disease. However, the United States often pays more for some prescription drugs than other developed countries, and the high price and increasing costs associated with prescription medication is a major concern for patients, physicians, and payers. Pharmaceutical companies have considerable flexibility in how they price drugs, and the costs that payers and patients see are dependent on how payers are able to negotiate discounts or rebates. Beyond setting list prices are issues of regulatory approval, patents and intellectual property, assessment of value and cost-effectiveness, and health plan drug benefits. These issues are linked, and comprehensive efforts will be needed to affect how drugs are priced in the United States.

Control authorities of internal affairs bodies in the sphere of drug trafficking

Directory of Open Access Journals (Sweden)

О. М. Шевчук

2014-06-01

Full Text Available The article deals with control authorities of internal Affairs bodies in the sphere of turnover of narcotic drugs, psychotropic substances and precursors. Established the concept of the legal status of the Management of the fight against illegal circulation of drugs of the Ministry of interior of Ukraine and describes its features. The classification of control authorities of internal Affairs bodies in the sphere of turnover of narcotic drugs, psychotropic substances and precursors and analyzed for their content.

Precise control of the drug kinetics by means of non-invasive magnetic drug delivery system

International Nuclear Information System (INIS)

Chuzawa, M.; Mishima, F.; Akiyama, Y.; Nishijima, S.

2013-01-01

Highlights: ► We examined the kinetics of ferromagnetic drugs by simulation. ► We tried to accumulate the magnetic drug in the target part by rotating a magnet. ► Ferromagnetic drugs were accumulated in the target part along the rotating axis. ► Ferromagnetic drugs could be swept downstream in the off-axis part. -- Abstract: In order to solve the problems of the side effects and medical lowering, has been advanced a study on the drug delivery system (DDS) to accumulate the drugs locally in the body with minimum dosage. The DDS is a system that controls the drug kinetics in the body precisely and accumulates the drug locally at the target part, keeping the drugs at high density. Among the DDS, the magnetic drug delivery system (MDDS) is the one that we studied. This is a technique to accumulate drugs by using the magnetic force as the physical driving force. Our previous researches showed the possibility of the technique of MDDS to accumulate the drugs with higher accumulation rate and locality than the traditional methods. It is necessary to apply a strong external magnetic field and a high magnetic gradient to accumulate the ferromagnetic drugs at a deep diseased part non-invasively. However, by applying a static magnetic field from one direction, the drug accumulates only at the surface of the body locates near the magnet. In this study, we tried to change the magnetic field applied by a superconducting bulk magnet with time, in order to make a constant and strong magnetic field applied in the center of the body and to accumulate the ferromagnetic drugs at the deep target part in the body. First of all, the effect of the surface treatment of the ferromagnetic drugs to prevent its absorption in the normal tissue was examined. Then, to increase the accumulation rate of the ferromagnetic drugs at the target part, the distribution of magnetic field was changed, and the optimum spatial and temporal conditions of magnetic field were examined

Experimental Study on Position Control System Using Encoderless Magnetic Motion

Energy Technology Data Exchange (ETDEWEB)

Kim, Hong Youn; Heo, Hoon [Korea Univ., Seoul (Korea, Republic of); Yun, Young Min; Shim, Ho Keun; Kwon, Young Mok [TPC Mechatronics, Daejeon (Korea, Republic of)

2016-01-15

A position control system composed of the PMLSM(Permanent Magnet Linear Synchronous Motor), unlike conventional linear permanent magnet synchronous motor is fixed to the permanent magnet moving coil rails (permanent magnet = stator, coil = mover), the coil is fixed, moving the permanent magnet, we propose a position control system (permanent magnet = mover, coil = stator) structure. Position is measured not using conventional encoder or resolver but by adopting vector control method using 2 hall sensors generating rectangular signal. This method estimate the velocity and position of mover by using the quadruple of two hall sensor signal instead of encoder signal. Vector control of PMLSM using 2 hall sensor generating rectangular wave is proved to control the system stable and efficiently through simulation. Also hardware experiment reveals that the position control performance is measured within the range of 30-50μ in the accuracy of 10-20μ, which is improved twice to the conventional method. The proposed method exhibits its economical efficiency and practical usefulness. The vector control technique using two hall sensors can be installed in narrow place, accordingly it can be implemented on the system where the conventional encoder or resolver cannot operate.

Sol-gel encapsulation for controlled drug release and biosensing

Science.gov (United States)

Fang, Jonathan

The main focus of this dissertation is to investigate the use of sol-gel encapsulation of biomolecules for controlled drug release and biosensing. Controlled drug release has advantages over conventional therapies in that it maintains a constant, therapeutic drug level in the body for prolonged periods of time. The anti-hypertensive drug Captopril was encapsulated in sol-gel materials of various forms, such as silica xerogels and nanoparticles. The primary objective was to show that sol-gel silica materials are promising drug carriers for controlled release by releasing Captopril at a release rate that is within a therapeutic range. We were able to demonstrate desired release for over a week from Captopril-doped silica xerogels and overall release from Captopril-doped silica nanoparticles. As an aside, the antibiotic Vancomycin was also encapsulated in these porous silica nanoparticles and desired release was obtained for several days in-vitro. The second part of the dissertation focuses on immobilizing antibodies and proteins in sol-gel to detect various analytes, such as hormones and amino acids. Sol-gel competitive immunoassays on antibody-doped silica xerogels were used for hormone detection. Calibration for insulin and C-peptide in standard solutions was obtained in the nM range. In addition, NASA-Ames is also interested in developing a reagentless biosensor using bacterial periplasmic binding proteins (bPBPs) to detect specific biomarkers, such as amino acids and phosphate. These bPBPs were doubly labeled with two different fluorophores and encapsulated in silica xerogels. Ligand-binding experiments were performed on the bPBPs in solution and in sol-gel. Ligand-binding was monitored by fluorescence resonance energy transfer (FRET) between the two fluorophores on the bPBP. Titration data show that one bPBP has retained its ligand-binding properties in sol-gel.

Conductive polymer nanotube patch for fast and controlled ex vivo transdermal drug delivery.

Science.gov (United States)

Nguyen, Thao M; Lee, Sebin; Lee, Sang Bok

2014-10-01

To uptake and release hydrophilic model drugs and insulin in a novel conductive polymer (CP) nanotube transdermal patch. The externally controlled transdermal delivery of model drugs and insulin were tested ex vivo and results were compared with CP films. The unique intrinsic properties of CPs provide electrostatic interaction between the model drugs and polymer backbone. When a pulsed potential was applied, the drug delivery release profile mimics that of injection delivery. With a constant potential applied, the release rate constants of the patch system were up to three-times faster than the control (0 V) and released approximately 80% more drug molecules over 24 h. The CP nanotube transdermal patch represents a new and promising drug method, specifically for hydrophilic molecules, which have been a large obstacle for conventional transdermal drug delivery systems.

Position Control of a Pneumatic Muscle Actuator Using RBF Neural Network Tuned PID Controller

Directory of Open Access Journals (Sweden)

Jie Zhao

2015-01-01

Full Text Available Pneumatic Muscle Actuator (PMA has a broad application prospect in soft robotics. However, PMA has highly nonlinear and hysteretic properties among force, displacement, and pressure, which lead to difficulty in accurate position control. A phenomenological model is developed to portray the hysteretic behavior of PMA. This phenomenological model consists of linear component and hysteretic component force. The latter component is described by Duhem model. An experimental apparatus is built up and sets of experimental data are acquired. Based on the experimental data, parameters of the model are identified. Validation of the model is performed. Then a novel cascade position PID controller is devised for a 1-DOF manipulator actuated by PMA. The outer loop of the controller is to cope with position control whilst the inner loop deals with pressure dynamics within PMA. To enhance the adaptability of the PID algorithm to the high nonlinearities of the manipulator, PID parameters are tuned online using RBF Neural Network. Experiments are performed and comparison between position response of RBF Neural Network based PID controller and that of classic PID controller demonstrates the effectiveness of the novel adaptive controller on the manipulator.

Prospective associations of social self-control with drug use among youth from regular and alternative high schools

Directory of Open Access Journals (Sweden)

Sun Ping

2007-07-01

Full Text Available Abstract Background This study examined the one year prospective associations between adolescent social self-control and drug outcomes (cigarette use, alcohol use, marijuana use, hard drug use, and problem drug use among adolescents from regular and continuation high schools. In our previous cross-sectional study, poor social self-control was found to be associated with higher drug use, controlling for 12 personality disorder categories. In this study, we attempted to find out (a whether lack of social self-control predicted drug use one year later, and (b whether drug use at baseline predicted social self-control one year later. Methods We surveyed 2081 older adolescents from 9 regular (N = 1529 and 9 continuation (alternative (N = 552 high schools in the Los Angeles area. Data were collected at two time points in an interval of approximately 1 year. Results Past 30-day cigarette smoking, marijuana use, hard drug use, and problem drug use at baseline were found to predict lower social self-control at follow-up, controlling for baseline social self-control and demographic variables. The effect of problem drug use as a one-year predictor of social self-control was found to be moderated by school type (regular or continuation high school, such that the relationship was significant for continuation high school students only. Conversely, social self-control was found to predict past 30-day alcohol use, marijuana use, and problem drug use, controlling for baseline drug use and demographic variables. For alcohol use, marijuana use, and problem drug use outcomes, school type was not found to moderate the effects of social self-control, though an interaction effect was found regarding cigarette smoking. Social self-control was a significant predictor of cigarette use only at regular high school. Conclusion The results indicate that social self-control and drug use share a reciprocal relationship. Lack of social self-control in adolescents seems to

A comparative analysis of the impact of a positive list system on new chemical entity drugs and incrementally modified drugs in South Korea.

Science.gov (United States)

Ha, DongMun; Choi, Yong; Kim, Dae Up; Chung, Kyu Hyuck; Lee, Eui-Kyung

2011-07-01

Medical costs in South Korea have risen, in part due to increased demand and consumption of pharmaceutical products by an aging population and also because of the introduction of newer, more expensive drugs. In an effort to stabilize the financing of health insurance and alleviate the financial burden on individuals, the government implemented a policy changing the national health insurance drug-listing system from a negative list system to a positive list system (PLS). The goal of this study was to compare differences in drug-listing rates for new chemical entities (NCEs) and incrementally modified drugs (IMDs) after South Korea introduced the PLS in December 2006. Parameters significantly affecting NCE and IMD listings were also identified. New drug-listing data for 2007 and 2008 were obtained from the databases of the Health Insurance Review Agency and the Ministry of Health and Welfare. Descriptive analyses on the reimbursement rate and logistic regression analysis were conducted. Statistical significance was tested for all results, and P system by decreasing the drug-listing rate and lengthening the period for reimbursement determinations. These effects were more pronounced for NCE listings than for IMD listings. Crown Copyright © 2011. Published by EM Inc USA. All rights reserved.

Development of Vision Control Scheme of Extended Kalman filtering for Robot's Position Control

International Nuclear Information System (INIS)

Jang, W. S.; Kim, K. S.; Park, S. I.; Kim, K. Y.

2003-01-01

It is very important to reduce the computational time in estimating the parameters of vision control algorithm for robot's position control in real time. Unfortunately, the batch estimation commonly used requires too murk computational time because it is iteration method. So, the batch estimation has difficulty for robot's position control in real time. On the other hand, the Extended Kalman Filtering(EKF) has many advantages to calculate the parameters of vision system in that it is a simple and efficient recursive procedures. Thus, this study is to develop the EKF algorithm for the robot's vision control in real time. The vision system model used in this study involves six parameters to account for the inner(orientation, focal length etc) and outer (the relative location between robot and camera) parameters of camera. Then, EKF has been first applied to estimate these parameters, and then with these estimated parameters, also to estimate the robot's joint angles used for robot's operation. finally, the practicality of vision control scheme based on the EKF has been experimentally verified by performing the robot's position control

Glycemic control: a combination of lifestyle management and the use of drugs.

Science.gov (United States)

Standl, Eberhard; Erbach, Michael; Schnell, Oliver

2013-06-01

Some 30% of contemporary cardiology patients have coexisting known diabetes, and another 40% have either undiagnosed diabetes or prediabetes. There is still no final conclusive evidence of cardiovascular benefit by good glycemic control in type 2 diabetes, although studies like the United Kingdom Prospective Diabetes Study (UKPDS) and the Prospective Pioglitazone Clinical Trial in Macrovascular Events, and meta-analyses based on these and other randomized controlled trials of blood glucose-lowering therapies have been encouraging. On the other hand, microvascular disease is clearly reduced by good glycemic control. Structured education has remained a mandatory prerequisite of any successful treatment. Not only is appropriate weight management by diet and exercise able to revert new onset diabetes to normal, but it is also the foundation of any successful pharmacotherapy of diabetes. Aiming at normal fasting plasma glucose concentrations of 5.3 mmol/L or 95 mg/dL appears to be safe since publication of the long-term outcome results of the Outcome Reduction with an Initial Glargine INtervention trial. Individualized target glycosylated hemoglobin levels as near to normal as safely possible (i.e., type 2 diabetes, also in terms of preventing cardiovascular complications. An alternate first-line option in some parts of the world, especially Asian countries, is the class of alpha-glucosidase inhibitors. In most patients, combination therapies with two or three classes of drugs are warranted. Early combination are the golden strategy as type 2 diabetes is a multi-causal disease; the various classes of drugs have distinct and synergistic modes of action, and the blood glucose-lowering efficacy of these drugs is more or less fully maintained in combination. The recent joint American Diabetes Association/European Association for the Study of Diabetes position statement mentions five options as step two of the treatment algorithm for combination with metformin

Advances in research of targeting delivery and controlled release of drug-loaded nanoparticles

International Nuclear Information System (INIS)

Tan Zhonghua

2003-01-01

Biochemistry drug, at present, is still the main tool that human struggle to defeat the diseases. So, developing safe and efficacious technique of drug targeting delivery and controlled release is key to enhance curative effect, decrease drug dosage, and lessen its side effect. Drug-loaded nanoparticles, which is formed by conjugate between nanotechnology and modern pharmaceutics, is a new fashioned pharmic delivery carrier. Because of advantages in pharmic targeting transport and controlled or slow release and improving bioavailability, it has been one of developing trend of modern pharmaceutical dosage forms

Poly(dimethylsiloxane) coatings for controlled drug release--polymer modifications.

Science.gov (United States)

Schulze Nahrup, J; Gao, Z M; Mark, J E; Sakr, A

2004-02-11

Modifications of endhydroxylated poly(dimethylsiloxane) (PDMS) formulations were studied for their ability to be applied onto tablet cores in a spray-coating process and to control drug release in zero-order fashion. Modifications of the crosslinker from the most commonly used tetraethylorthosilicate (TEOS) to the trifunctional 3-(2,3-epoxypropoxy)propyltrimethoxysilane (SIG) and a 1:1 mixture of the two were undertaken. Addition of methylpolysiloxane-copolymers were studied. Lactose, microcrystalline cellulose (MCC) and polyethylene glycol 8000 (PEG) were the channeling agents applied. The effects on dispersion properties were characterized by particle size distribution and viscosity. Mechanical properties of resulting free films were studied to determine applicability in a pan-coating process. Release of hydrochlorothiazide (marker drug) was studied from tablets coated in a lab-size conventional coating pan. All dispersions were found suitable for a spray-coating process. Preparation of free films showed that copolymer addition was not possible due to great decline in mechanical properties. Tablets coated with formulations containing PEG were most suitable to control drug release, at only 5% coating weight. Constant release rates could be achieved for formulations with up to 25% PEG; higher amounts resulted in a non-linear release pattern. Upon adding 50% PEG, a drug release of 63% over 24 h could be achieved.

FPGA based Fuzzy Logic Controller for plasma position control in ADITYA Tokamak

International Nuclear Information System (INIS)

Suratia, Pooja; Patel, Jigneshkumar; Rajpal, Rachana; Kotia, Sorum; Govindarajan, J.

2012-01-01

Highlights: ► Evaluation and comparison of the working performance of FLC is done with that of PID Controller. ► FLC is designed using MATLAB Fuzzy Logic Toolbox, and validated on ADITYA RZIP model. ► FLC was implemented on a FPGA. The close-loop testing is done by interfacing FPGA to MATLAB/Simulink. ► Developed FLC controller is able to maintain the plasma column within required range of ±0.05 m and was found to give robust control against various disturbances and faster and smoother response compared to PID Controller. - Abstract: Tokamaks are the most promising devices for obtaining nuclear fusion energy from high-temperature, ionized gas termed as Plasma. The successful operation of tokamak depends on its ability to confine plasma at the geometric center of vacuum vessel with sufficient stability. The quality of plasma discharge in ADITYA Tokamak is strongly related to the radial position of the plasma column in the vacuum vessel. If the plasma column approaches too near to the wall of vacuum vessel, it leads to minor or complete disruption of plasma. Hence the control of plasma position throughout the entire plasma discharge duration is a fundamental requirement. This paper describes Fuzzy Logic Controller (FLC) which is designed for radial plasma position control. This controller is tested and evaluated on the ADITYA RZIP control model. The performance of this FLC was compared with that of Proportional–Integral–Derivative (PID) Controller and the response was found to be faster and smoother. FLC was implemented on a Field Programmable Gate Array (FPGA) chip with the use of a Very High-Speed Integrated-Circuits Hardware Description-Language (VHDL).

Factors influencing drug uptake during mass drug administration for control of lymphatic filariasis in rural and urban Tanzania.

Directory of Open Access Journals (Sweden)

William J Kisoka

Full Text Available BACKGROUND: In most countries of Sub-Saharan Africa, control of lymphatic filariasis (LF is based on annual mass drug administration (MDA with a combination of ivermectin and albendazole. Treatment coverages are however often suboptimal for programmes to reach the goal of transmission interruption within reasonable time. The present study aimed to identify predictors and barriers to individual drug uptake during MDA implementation by the National LF Elimination Programme in Tanzania. METHODS: A questionnaire based cross sectional household survey was carried out in two rural and two urban districts in Lindi and Morogoro regions shortly after the 2011 MDA. 3279 adults (≥15 years were interviewed about personal characteristics, socio-economic status, MDA drug uptake among themselves and their children, reasons for taking/not taking drugs, and participation in previous MDA activities for LF control. FINDINGS: The overall drug uptake rate was 55.1% (range of 44.5-75.6% between districts. There was no overall major difference between children (54.8% and adults (55.2% or between females (54.9% and males (55.8%, but the role of these and other predictors varied to some extent between study sites. Major overall predictors of drug uptake among the interviewed adults were increasing age and history of previous drug uptake. Being absent from home during drug distribution was the main reason for not taking the drugs (50.2% followed by clinical contraindications to treatment (10.8%, missing household visits of drug distributors (10.6%, and households not being informed about the distribution (9.0%. CONCLUSION: Drug uptake relied more on easily modifiable provider-related factors than on individual perceptions and practices in the target population. Limited investments in appropriate timing, dissemination of accurate timing information to recipients and motivation of drug distributors to visit all households (repeatedly when residents are absent are likely

PLGA-lecithin-PEG core-shell nanoparticles for controlled drug delivery.

Science.gov (United States)

Chan, Juliana M; Zhang, Liangfang; Yuet, Kai P; Liao, Grace; Rhee, June-Wha; Langer, Robert; Farokhzad, Omid C

2009-03-01

Current approaches to encapsulate and deliver therapeutic compounds have focused on developing liposomal and biodegradable polymeric nanoparticles (NPs), resulting in clinically approved therapeutics such as Doxil/Caelyx and Genexol-PM, respectively. Our group recently reported the development of biodegradable core-shell NP systems that combined the beneficial properties of liposomal and polymeric NPs for controlled drug delivery. Herein we report the parameters that alter the biological and physicochemical characteristics, stability, drug release properties and cytotoxicity of these core-shell NPs. We further define scalable processes for the formulation of these NPs in a reproducible manner. These core-shell NPs consist of (i) a poly(D,L-lactide-co-glycolide) hydrophobic core, (ii) a soybean lecithin monolayer, and (iii) a poly(ethylene glycol) shell, and were synthesized by a modified nanoprecipitation method combined with self-assembly. Preparation of the NPs showed that various formulation parameters such as the lipid/polymer mass ratio and lipid/lipid-PEG molar ratio controlled NP physical stability and size. We encapsulated a model chemotherapy drug, docetaxel, in the NPs and showed that the amount of lipid coverage affected its drug release kinetics. Next, we demonstrated a potentially scalable process for the formulation, purification, and storage of NPs. Finally, we tested the cytotoxicity using MTT assays on two model human cell lines, HeLa and HepG2, and demonstrated the biocompatibility of these particles in vitro. Our data suggest that the PLGA-lecithin-PEG core-shell NPs may be a useful new controlled release drug delivery system.

Car-Like Mobile Robot Oriented Positioning by Fuzzy Controllers

Directory of Open Access Journals (Sweden)

Noureddine Ouadah

2008-09-01

Full Text Available In this paper, fuzzy logic controllers (FLC are used to implement an efficient and accurate positioning of an autonomous car-like mobile robot, respecting final orientation. To accomplish this task, called “Oriented Positioning”, two FLC have been developed: robot positioning controller (RPC and robot following controller (RFC. Computer simulation results illustrate the effectiveness of the proposed technique. Finally, real-time experiments have been made on an autonomous car-like mobile robot called “Robucar”, developed to perform people transportation. Obtained results from experiments demonstrate the effectiveness of the proposed control strategy.

IONP-doped nanoparticles for highly effective NIR-controlled drug release and combination tumor therapy

Directory of Open Access Journals (Sweden)

Fu X

2017-05-01

Full Text Available Xudong Fu,1 Xinjun Wang,1 Shaolong Zhou,1 Yanyan Zhang2 1The Fifth Affiliated Hospital of Zhengzhou University, 2School of Basic Medical Sciences, Zhengzhou University, Zhengzhou, People’s Republic of China Abstract: Despite advances in controlled drug delivery, drug delivery systems (DDSs with controlled activated drug release and high spatial and temporal resolution are still required. Theranostic nanomedicine is capable of diagnosis, therapy, and monitoring the delivery and distribution of drug molecules and has received growing interest. In this study, a near-infrared light-controlled “off–on” DDS with magnetic resonance imaging and magnetic targeting properties was developed using a hybrid nanoplatform (carbon nanotubes [CNTs]-iron oxide nanoparticle. Doxorubicin (DOX and distearoyl-sn-glycero-3-phosphoethanolamine-PEG were adsorbed onto CNTs-iron oxide nanoparticle, and then to avoid the unexpected drug release during circulation, 1-myristyl alcohol was used to encapsulate the CNTs–drug complex. Herein, multifunctional DOX-loaded nanoparticles (NPs with “off–on” state were developed. DOX-NPs showed an obvious “off–on” effect (temperature increase, drug release controlled by near-infrared light in vitro and in vivo. In the in vivo and in vitro studies, DOX-NPs exhibited excellent magnetic resonance imaging ability, magnetic targeting property, high biosafety, and high antitumor combined therapeutic efficacy (hyperthermia combined with chemotherapy. These results highlight the great potential of DOX-NPs in the treatment of cancer. Keywords: controlled drug release, magnetic targeting, MRI, combination therapy

A compound control strategy combining velocity compensation with ADRC of electro-hydraulic position servo control system.

Science.gov (United States)

Gao, Bingwei; Shao, Junpeng; Yang, Xiaodong

2014-11-01

In order to enhance the anti-jamming ability of electro-hydraulic position servo control system at the same time improve the control precision of the system, a compound control strategy that combines velocity compensation with Active Disturbance Rejection Controller (ADRC) is proposed, and the working principle of the compound control strategy is given. ADRC controller is designed, and the extended state observer is used for observing internal parameters uncertainties and external disturbances, so that the disturbances of the system are suppressed effectively. Velocity compensation controller is designed and the compensation model is derived to further improve the positioning accuracy of the system and to achieve the velocity compensation without disturbance. The compound control strategy is verified by the simulation and experiment respectively, and the simulation and experimental results show that the electro-hydraulic position servo control system with ADRC controller can effectively inhibit the external disturbances, the precise positioning control is realized after introducing the velocity compensation controller, and verify that the compound control strategy is effective. Copyright © 2014 ISA. Published by Elsevier Ltd. All rights reserved.

Control of spool position of on/off solenoid operated hydraulic valve by sliding-mode controller

Energy Technology Data Exchange (ETDEWEB)

Lee, Jae Hak; Hong, Hyun Wook; Park, Myeong Kwan [Pusan National University, Busan (Korea, Republic of); Yun, Young Won [KHPS, Busan (Korea, Republic of)

2015-11-15

The use of on/off solenoid operated hydraulic valves instead of proportional valves has been attracting the interest of many researchers and engineers. However, there exist difficulties in controlling the on/off valve because of highly nonlinear characteristics including hysteresis and saturation. This paper considers the application of on/off solenoid operated hydraulic valves to control position of a hydraulic cylinder with the aim of evaluating, feasibility and practicability of their implementation and understanding the potential benefits when they are used in existing hydraulic systems. Assuming that only the current is measured, a sliding mode observer is designed to estimate the spool position and velocity. To alleviate the aforementioned difficulties in controlling the spool position, a nonlinear observer-based controller of an on/off solenoid valve is designed, taking into account the estimated values, based on a nonlinear model including hysteresis and saturation. The control objective is to track a desired spool trajectory. Simulation and experimental results illustrate the efficiency of the designed controller. The proposed controller is validated again in a single-rod hydraulic actuator. Experimental results show that the fluid flow through the valve orifice by controlling the spool position was successfully controlled.

Peer Positive Social Control and Men's Health-Promoting Behaviors.

Science.gov (United States)

Houle, Janie; Meunier, Sophie; Coulombe, Simon; Mercerat, Coralie; Gaboury, Isabelle; Tremblay, Gilles; de Montigny, Francine; Cloutier, Lyne; Roy, Bernard; Auger, Nathalie; Lavoie, Brigitte

2017-09-01

Men are generally thought to be less inclined to take care of their health. To date, most studies about men's health have focused on deficits in self-care and difficulties in dealing with this sphere of their life. The present study reframes this perspective, using a salutogenic strengths-based approach and seeking to identify variables that influence men to take care of their health, rather than neglect it. This study focuses on the association between peer positive social control and men's health behaviors, while controlling for other important individual and social determinants (sociodemographic characteristics, health self-efficacy, home neighborhood, spousal positive social control, and the restrictive emotionality norm). In a mixed-method study, 669 men answered a self-reported questionnaire, and interviews were conducted with a maximum variation sample of 31 men. Quantitative results indicated that, even after controlling for sociodemographic variables and other important factors, peer positive social control was significantly associated with the six health behaviors measured in the study (health responsibility, nutrition, physical activity, interpersonal relations, stress management, and spirituality). Interview results revealed that peer positive social control influenced men's health behaviors through three different mechanisms: shared activity, being inspired, and serving as a positive role model for others. In summary, friends and coworkers could play a significant role in promoting various health behaviors among adult men in their daily life. Encouraging men to socialize and discuss health, and capitalizing on healthy men as role models appear to be effective ways to influence health behavior adoption among this specific population.

Position Control of Linear Synchronous Motor Drives with Exploitation of Forced Dynamics Control Principles

Directory of Open Access Journals (Sweden)

Jan Vittek

2004-01-01

Full Text Available Closed-loop position control of mechanisms directly driven by linear synchronous motors with permanent magnets is presented. The control strategy is based on forced dynamic control, which is a form of feedback linearisation, yielding a non-liner multivariable control law to obtain a prescribed linear speed dynamics together with the vector control condition of mutal orthogonality between the stator current and magnetic flux vectors (assuming perfect estimates of the plant parameters. Outer position control loop is closed via simple feedback with proportional gain. Simulations of the design control sysstem, including the drive with power electronic switching, predict the intended drive performance.

Factors influencing drug uptake during mass drug administration for control of lymphatic filariasis in rural and urban Tanzania

DEFF Research Database (Denmark)

Kisoka, William J.; Simonsen, Paul Erik; Malecela, Mwelecele N.

2014-01-01

BACKGROUND: In most countries of Sub-Saharan Africa, control of lymphatic filariasis (LF) is based on annual mass drug administration (MDA) with a combination of ivermectin and albendazole. Treatment coverages are however often suboptimal for programmes to reach the goal of transmission interrupt......BACKGROUND: In most countries of Sub-Saharan Africa, control of lymphatic filariasis (LF) is based on annual mass drug administration (MDA) with a combination of ivermectin and albendazole. Treatment coverages are however often suboptimal for programmes to reach the goal of transmission...

Risk control and rational recreation: A qualitative analysis of synthetic drug use among young urbanites in China.

Science.gov (United States)

Lin, Shaozhen; Zhang, Yong-an

2014-07-01

To fight against the rapid growth of synthetic drugs, the Chinese government has strengthened the controls and regulation, incorporated synthetic drugs into the new detoxification system, and changed the inconsistent governance of synthetic and traditional drugs. This, however, has not stopped the spread of synthetic drugs among young urbanites. While scholars have focused on the loopholes and defects of specific drug control regulations, ethnographic inquiries illustrate how and why control does not work, or is even resisted by young drug users. In-depth qualitative interviews were conducted with 28 individuals aged between 20 and 35, recruited from a cohort of synthetic drug users in a Shanghai drug rehabilitation centre. Audio-recorded interviews elicited accounts of their daily experiences of drug use as well as their perspectives on the impact of the government's new drug control policies. The main themes voiced by our respondents include: (1) synthetic drugs are not addictive, and are used to feel 'high'; (2) synthetic drugs are used to achieve their goals, which are otherwise impossible through mainstream means; (3) users are confident that they will be able to manage the use of synthetic drugs without harm to themselves; (4) their worries concern administrative punishment rather than consequences to health. The participants of this study did not support the government's attempts to control the use of synthetic drugs. They viewed their use as rational recreation under the perceived boundaries of 'acceptable risks'. Even in the context of severe control, synthetic drugs have strong appeal to youths. Drug policy should acknowledge the experiences of users and consider the socio-cultural contexts of youth drug-taking. The personal experience of participants could help improve the Chinese Drug Control Act and regulations. Copyright © 2014 Elsevier B.V. All rights reserved.

Sol-gel Derived Warfarin - Silica Composites for Controlled Drug Release.

Science.gov (United States)

Dolinina, Ekaterina S; Parfenyuk, Elena V

2017-01-01

Warfarin, commonly used anticoagulant in clinic, has serious shortcomings due to its unsatisfactory pharmacodynamics. One of the efficient ways for the improvement of pharmacological and consumer properties of drugs is the development of optimal drug delivery systems. The aim of this work is to synthesize novel warfarin - silica composites and to study in vitro the drug release kinetics to obtain the composites with controlled release. The composites of warfarin with unmodified (UMS) and mercaptopropyl modified silica (MPMS) were synthesized by sol-gel method. The composite formation was confirmed by FTIR spectra. The concentrations of warfarin released to media with pH 1.6, 6.8 and 7.4 were measured using UV spectroscopy. The drug release profiles from the solid composites were described by a series of kinetic models which includes zero order kinetics, first order kinetics, the modified Korsmeyer-Peppas model and Hixson-Crowell model. The synthesized sol-gel composites have different kinetic behavior in the studied media. In contrast to the warfarin composite with unmodified silica, the drug release from the composite with mercaptopropyl modified silica follows zero order kinetics for 24 h irrespective to the release medium pH due to mixed mechanism (duffusion + degradation and/or disintegration of silica matrix). The obtained results showed that warfarin - silica sol-gel composites have a potential application for the development of novel oral formulation of the drug with controlled delivery. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Design of the Anti-tuberculosis Drugs induced Adverse Reactions in China National Tuberculosis Prevention and Control Scheme Study (ADACS

Directory of Open Access Journals (Sweden)

He Ping

2010-05-01

Full Text Available Abstract Background More than 1 million tuberculosis (TB patients are receiving the standard anti-TB treatment provided by China National Tuberculosis Prevention and Control Scheme (CNTS in China every year. Adverse reactions (ADRs induced by anti-TB drugs could both do harm to patients and lead to anti-TB treatment failure. The ADACS aimed to explore ADRs' incidences, prognoses, economical and public health impacts for TB patients and TB control, and build a DNA bank of TB patients. Methods/Design Multiple study designs were adopted. Firstly, a prospective cohort with 4488 sputum smears positive pulmonary tuberculosis patients was established. Patients were followed up for 6-9 months in 52 counties of four regions. Those suspected ADRs should be checked and confirmed by Chinese State Food and Drug Administration (SFDA. Secondly, if the suspected ADR was anti-TB drug induced liver injury (ATLI, a nested case-control study would be performed which comprised choosing a matched control and doing a plus questionnaire inquiry. Thirdly, health economical data of ADRs would be collected to analyze financial burdens brought by ADRs and cost-effectiveness of ADRs' treatments. Fourthly, a drop of intravenous blood for each patient was taken and saved in FTA card for DNA banking and genotyping. Finally, the demographic, clinical, environmental, administrative and genetic data would be merged for the comprehensive analysis. Discussion ADACS will give an overview of anti-TB drugs induced ADRs' incidences, risk factors, treatments, prognoses, and clinical, economical and public health impacts for TB patients applying CNTS regimen in China, and provide suggestions for individualized health care and TB control policy.

Design of the Anti-tuberculosis Drugs induced Adverse Reactions in China National Tuberculosis Prevention and Control Scheme Study (ADACS)

Science.gov (United States)

2010-01-01

Background More than 1 million tuberculosis (TB) patients are receiving the standard anti-TB treatment provided by China National Tuberculosis Prevention and Control Scheme (CNTS) in China every year. Adverse reactions (ADRs) induced by anti-TB drugs could both do harm to patients and lead to anti-TB treatment failure. The ADACS aimed to explore ADRs' incidences, prognoses, economical and public health impacts for TB patients and TB control, and build a DNA bank of TB patients. Methods/Design Multiple study designs were adopted. Firstly, a prospective cohort with 4488 sputum smears positive pulmonary tuberculosis patients was established. Patients were followed up for 6-9 months in 52 counties of four regions. Those suspected ADRs should be checked and confirmed by Chinese State Food and Drug Administration (SFDA). Secondly, if the suspected ADR was anti-TB drug induced liver injury (ATLI), a nested case-control study would be performed which comprised choosing a matched control and doing a plus questionnaire inquiry. Thirdly, health economical data of ADRs would be collected to analyze financial burdens brought by ADRs and cost-effectiveness of ADRs' treatments. Fourthly, a drop of intravenous blood for each patient was taken and saved in FTA card for DNA banking and genotyping. Finally, the demographic, clinical, environmental, administrative and genetic data would be merged for the comprehensive analysis. Discussion ADACS will give an overview of anti-TB drugs induced ADRs' incidences, risk factors, treatments, prognoses, and clinical, economical and public health impacts for TB patients applying CNTS regimen in China, and provide suggestions for individualized health care and TB control policy. PMID:20492672

Methamphetamine functions as a positive and negative drug feature in a Pavlovian appetitive discrimination task.

Science.gov (United States)

Reichel, Carmela M; Wilkinson, Jamie L; Bevins, Rick A

2007-12-01

This research determined the ability of methamphetamine to serve as a positive or negative feature, and assessed the ability of bupropion, cocaine, and naloxone to substitute for the methamphetamine features. Rats received methamphetamine (0.5 mg/kg, intraperitoneally) or saline 15 min before a conditioning session. For the feature positive (FP) group, offset of 15-s cue lights was followed by access to sucrose on methamphetamine sessions; sucrose was withheld during saline sessions. For the feature negative (FN) group, the light offset was followed by sucrose on saline sessions; sucrose was withheld during methamphetamine sessions. During acquisition, the FP group had higher responding on methamphetamine sessions than on saline sessions. For the FN group, responding was higher on saline sessions than on methamphetamine sessions. Conditioned responding was sensitive to methamphetamine dose. For the FP group, bupropion and cocaine fully and partially substituted for methamphetamine, respectively. In contrast, both drugs fully substituted for methamphetamine in the FN group. Naloxone did not substitute in either set of rats. FP-trained rats were more sensitive to the locomotor stimulating effects of the test drugs than FN-trained rats. This research demonstrates that the pharmacological effects of methamphetamine function as a FP or FN in this Pavlovian discrimination task and that training history can affect conditioned responding and locomotor effects evoked by a drug.

A digital position-indication system for control rods

International Nuclear Information System (INIS)

Nishizawa, Yukio; Hayakawa, Toshifumi

1979-01-01

Systems that detect and indicate the position of the control rods that regulate the thermal output of a nuclear reactor play a particularly important role in monitoring its operational status. Conventionally, control rod position indication in pressurized water reactors has been of the analog type, utilizing the principle of the differential transformer. The present digital system was developed with the objective of achieving greater stability, greater accuracy, and higher reliability. The article gives a general description of the system and describes its advantages. (author)

Heroin and cocaine abusers have higher discount rates for delayed rewards than alcoholics or non-drug-using controls.

Science.gov (United States)

Kirby, Kris N; Petry, Nancy M

2004-04-01

To test a prediction of the discounting model of impulsiveness that discount rates would be positively associated with addiction. The delay-discount rate refers to the rate of reduction in the present value of a future reward as the delay to that reward increases. We estimated participants' discount rates on the basis of their pattern of choices between smaller immediate rewards ($11-80) and larger, delayed rewards ($25-85; at delays from 1 week to 6 months) in a questionnaire format. Participants had a one-in-six chance of winning a reward that they chose on one randomly selected trial. Heroin (n = 27), cocaine (n = 41) and alcohol (n = 33) abusers and non-drug-using controls (n = 44) were recruited from advertisements. They were tested in a drug abuse research clinic at a medical school. On average, the cocaine and heroin groups had higher rates than controls (both P rates for heroin abusers (P = 0.03), but not for cocaine or alcohol abusers (both P > 0.50). These data suggest that discount rates vary with the preferred drug of abuse, and that high discount rates should be considered in the development of substance abuse prevention and treatment efforts.

An examination of the Sport Drug Control Model with elite Australian athletes.

Science.gov (United States)

Gucciardi, Daniel F; Jalleh, Geoffrey; Donovan, Robert J

2011-11-01

This study presents an opportunistic examination of the theoretical tenets outlined in the Sport Drug Control Model(1) using questionnaire items from a survey of 643 elite Australian athletes. Items in the questionnaire that related to the concepts in the model were identified and structural equation modelling was employed to test the hypothesised model. Morality (cheating), benefit appraisal (performance), and threat appraisal (enforcement) evidenced the strongest relationships with attitude to doping, which in turn was positively associated with doping susceptibility. Self-esteem, perceptions of legitimacy and reference group opinions showed small non-significant associations with attitude to doping. The hypothesised model accounted for 30% and 11% of the variance in attitudes to doping and doping susceptibility, respectively. These present findings provide support for the model even though the questionnaire items were not constructed to specifically measure concepts contained in it. Thus, the model appears useful for understanding influences on doping. Nevertheless, there is a need to further explore individual and social factors that may influence athletes' use of performance enhancing drugs. Copyright © 2011 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

Incidence of adverse drug reactions in human immune deficiency virus-positive patients using highly active antiretroviral therapy

Directory of Open Access Journals (Sweden)

B Akshaya Srikanth

2012-01-01

Full Text Available To estimate the incidence of adverse drug reactions (ADRs in Human immune deficiency virus (HIV patients on highly active antiretroviral therapy (HAART. To identify the risk factors associated with ADRs in HIV patients. To analyze reported ADRs based on various parameters like causality, severity, predictability, and preventability. Retrospective case-control study. An 18-month retrospective case-control study of 208 patients newly registered in ART center, RIMS hospital, Kadapa, were intensively monitored for ADRs to HAART. Predictability was calculated based on the history of previous exposure to drug. Multivariate logistic regressions were used to identify the risk factors for ADRs. Data were analyzed using the chi-square test for estimating the correlation between ADRs and different variables. All statistical calculations were performed using EpiInfo version 3.5.3. Monitoring of 208 retrospective patients by active Pharmacovigilance identified 105 ADRs that were identified in 71 patients. Skin rash and anemia were the most commonly observed ADRs. The organ system commonly affected by ADR was skin and appendages (31.57%. The ADRs that were moderate were 90.14% of cases. The incidence of ADRs (53.52% was higher with Zidovudine + Lamivudine + Nevirapine combination. CD4 cell count less than <250 cells/μl were 80.28%, male gender were observed to be the risk factors for ADRs. Our study finding showed that there is a need of active pharmaceutical care with intensive monitoring for ADRs in Indian HIV-positive patients who are illiterate, of male and female gender, with CD4 count ≤250 cells/mm 3 with comorbid conditions.

INDOOR POSITIONING AND NAVIGATION BASED ON CONTROL SPHERECAL PANORAMIC IMAGES

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T.-C. Huang

2016-06-01

Full Text Available Continuous indoor and outdoor positioning and navigation is the goal to achieve in the field of mobile mapping technology. However, accuracy of positioning and navigation will be largely degraded in indoor or occluded areas, due to receiving weak or less GNSS signals. Targeting the need of high accuracy indoor and outdoor positioning and navigation for mobile mapping applications, the objective of this study is to develop a novel method of indoor positioning and navigation with the use of spherical panoramic image (SPI. Two steps are planned in the technology roadmap. First, establishing a control SPI database that contains a good number of well-distributed control SPIs pre-acquired in the target space. A control SPI means an SPI with known exterior orientation parameters, which can be solved with a network bundle adjustment of SPIs. Having a control SPI database, the target space will be ready to provide the service of positioning and navigation. Secondly, the position and orientation of a newly taken SPI can be solved by using overlapped SPIs searched from the control SPI database. The method of matching SPIs and finding conjugate image features will be developed and tested. Two experiments will be planned and conducted in this paper to test the feasibility and validate the test results of the proposed methods. Analysis of appropriate number and distribution of needed control SPIs will also be included in the experiments with respect to different test cases.

Conductive polymer nanotube patch for fast and controlled in vivo transdermal drug delivery

Science.gov (United States)

Nguyen, Thao M.

Transdermal drug delivery has created new applications for existing therapies and offered an alternative to the traditional oral route where drugs can prematurely metabolize in the liver causing adverse side effects. Opening the transdermal delivery route to large hydrophilic drugs is one of the greatest challenges due to the hydrophobicity of the skin. However, the ability to deliver hydrophilic drugs using a transdermal patch would provide a solution to problems of other delivery methods for hydrophilic drugs. The switching of conductive polymers (CP) between redox states cause simultaneous changes in the polymer charge, conductivity, and volume—properties that can all be exploited in the biomedical field of controlled drug delivery. Using the template synthesis method, poly(3,4-ethylenedioxythiophene (PEDOT) nanotubes were synthesized electrochemically and a transdermal drug delivery patch was successfully designed and developed. In vitro and in vivo uptake and release of hydrophilic drugs were investigated. The relationship between the strength of the applied potential and rate of drug release were also investigated. Results revealed that the strength of the applied potential is proportional to the rate of drug release; therefore one can control the rate of drug release by controlling the applied potential. The in vitro studies focused on the kinetics of the drug delivery system. It was determined that the drug released mainly followed zero-order kinetics. In addition, it was determined that applying a releasing potential to the transdermal drug delivery system lead to a higher release rate constant (up to 7 times greater) over an extended period of time (˜24h). In addition, over 24 hours, an average of 80% more model drug molecules were released with an applied potential than without. The in vivo study showed that the drug delivery system was capable of delivering model hydrophilic drugs molecules through the dermis layer of the skin within 30 minutes

Selective control of attention supports the positivity effect in aging.

Science.gov (United States)

Sasse, Laura K; Gamer, Matthias; Büchel, Christian; Brassen, Stefanie

2014-01-01

There is emerging evidence for a positivity effect in healthy aging, which describes an age-specific increased focus on positive compared to negative information. Life-span researchers have attributed this effect to the selective allocation of cognitive resources in the service of prioritized emotional goals. We explored the basic principles of this assumption by assessing selective attention and memory for visual stimuli, differing in emotional content and self-relevance, in young and old participants. To specifically address the impact of cognitive control, voluntary attentional selection during the presentation of multiple-item displays was analyzed and linked to participants' general ability of cognitive control. Results revealed a positivity effect in older adults' selective attention and memory, which was particularly pronounced for self-relevant stimuli. Focusing on positive and ignoring negative information was most evident in older participants with a generally higher ability to exert top-down control during visual search. Our findings highlight the role of controlled selectivity in the occurrence of a positivity effect in aging. Since the effect has been related to well-being in later life, we suggest that the ability to selectively allocate top-down control might represent a resilience factor for emotional health in aging.

Robust position control of induction motor using fuzzy logic control

International Nuclear Information System (INIS)

Kim, Sei Chan; Kim, Duk Hun; Yang, Seung Ho; Won, Chung Yuen

1993-01-01

In recent years, fuzzy logic or fuzzy set theory has reveived attention of a number of researchers in the area of power electronics and motion control. The paper describes a vector-controlled induction motor position servo drive where fuzzy control is used to get robustness against parameter variation and load torque disturbance effects. Both coarse and fine control with the help of look-up rule tables are used to improve transient response and system settling time. The performance characteristics are then compared with those of proportional-integral(PI) control. The simulation results clearly indicate the superiority of fuzzy control with larger number of rules. The fuzzy controller was implemented with a 16-bit microprocessor and tested in laboratory on a 3-hp IGBT inverter induction motor drive system. The test results verify the simulation performance. (Author)

Controlled delivery of antiangiogenic drug to human eye tissue using a MEMS device

KAUST Repository

Pirmoradi, Fatemeh Nazly; Ou, Kevin; Jackson, John K.; Letchford, Kevin; Cui, Jing; Wolf, Ki Tae; Graber, Florian; Zhao, Tom; Matsubara, Joanne A.; Burt, Helen; Chiao, Mu; Lin, Liwei

2013-01-01

We demonstrate an implantable MEMS drug delivery device to conduct controlled and on-demand, ex vivo drug transport to human eye tissue. Remotely operated drug delivery to human post-mortem eyes was performed via a MEMS device. The developed curved

Novel electro-hydraulic position control system for primary mirror supporting system

Directory of Open Access Journals (Sweden)

Xiongbin Peng

2016-05-01

Full Text Available In the field of modern large-scale telescope, primary mirror supporting system technology faces the difficulties of theoretically uniform output force request and bias compensation. Therefore, a novel position control system combining hydraulic system with servo motor system is introduced. The novel system ensures uniform output force on supporting points without complicating the mechanical structure. The structures of both primary mirror supporting system and novel position system are described. Then, the mathematical model of novel position control system is derived for controller selection. A proportional–derivative controller is adopted for simulations and experiments of step response and triangle path tracking. The results show that proportional–derivative controller guarantees the system with micrometer-level positioning ability. A modified proportional–derivative controller is utilized to promote system behavior with faster response overshoot. The novel position control system is then applied on primary mirror supporting system. Coupling effect is observed among actuator partitions, and relocation of virtual pivot supporting point is chosen as the decoupling measurement. The position keeping ability of the primary mirror supporting system is verified by rotating the mirror cell at a considerably high rate. The experiment results show that the decoupled system performs better with smaller bias and shorter recovery time.

Sustained and controlled release of lipophilic drugs from a self-assembling amphiphilic peptide hydrogel

DEFF Research Database (Denmark)

Briuglia, Maria-Lucia; Urquhart, Andrew; Lamprou, Dimitrios A.

2014-01-01

and one hydrophobic that are positioned in such a well-ordered fashion allowing precise assembly into a predetermined organization. A "smart" architecture in nanostructures can represent a good opportunity to use RADA16 as a carrier system for hydrophobic drugs solving problems of drugs delivery...

HIV infection and drugs of abuse: role of acute phase proteins.

Science.gov (United States)

Samikkannu, Thangavel; Rao, Kurapati V K; Arias, Adriana Y; Kalaichezian, Aarthi; Sagar, Vidya; Yoo, Changwon; Nair, Madhavan P N

2013-09-17

HIV infection and drugs of abuse such as methamphetamine (METH), cocaine, and alcohol use have been identified as risk factors for triggering inflammation. Acute phase proteins such as C-reactive protein (CRP) and serum amyloid A (SAA) are the biomarkers of inflammation. Hence, the interactive effect of drugs of abuse with acute phase proteins in HIV-positive subjects was investigated. Plasma samples were utilized from 75 subjects with METH use, cocaine use, alcohol use, and HIV-positive alone and HIV-positive METH, cocaine, and alcohol users, and age-matched control subjects. The plasma CRP and SAA levels were measured by ELISA and western blot respectively and the CD4 counts were also measured. Observed results indicated that the CRP and SAA levels in HIV-positive subjects who are METH, cocaine and alcohol users were significantly higher when compared with either drugs of abuse or HIV-positive alone. The CD4 counts were also dramatically reduced in HIV-positive with drugs of abuse subjects compared with only HIV-positive subjects. These results suggest that, in HIV-positive subjects, drugs of abuse increase the levels of CRP and SAA, which may impact on the HIV infection and disease progression.

Effects of organizational safety practices and perceived safety climate on PPE usage, engineering controls, and adverse events involving liquid antineoplastic drugs among nurses.

Science.gov (United States)

DeJoy, David M; Smith, Todd D; Woldu, Henok; Dyal, Mari-Amanda; Steege, Andrea L; Boiano, James M

2017-07-01

Antineoplastic drugs pose risks to the healthcare workers who handle them. This fact notwithstanding, adherence to safe handling guidelines remains inconsistent and often poor. This study examined the effects of pertinent organizational safety practices and perceived safety climate on the use of personal protective equipment, engineering controls, and adverse events (spill/leak or skin contact) involving liquid antineoplastic drugs. Data for this study came from the 2011 National Institute for Occupational Safety and Health (NIOSH) Health and Safety Practices Survey of Healthcare Workers which included a sample of approximately 1,800 nurses who had administered liquid antineoplastic drugs during the past seven days. Regression modeling was used to examine predictors of personal protective equipment use, engineering controls, and adverse events involving antineoplastic drugs. Approximately 14% of nurses reported experiencing an adverse event while administering antineoplastic drugs during the previous week. Usage of recommended engineering controls and personal protective equipment was quite variable. Usage of both was better in non-profit and government settings, when workers were more familiar with safe handling guidelines, and when perceived management commitment to safety was higher. Usage was poorer in the absence of specific safety handling procedures. The odds of adverse events increased with number of antineoplastic drugs treatments and when antineoplastic drugs were administered more days of the week. The odds of such events were significantly lower when the use of engineering controls and personal protective equipment was greater and when more precautionary measures were in place. Greater levels of management commitment to safety and perceived risk were also related to lower odds of adverse events. These results point to the value of implementing a comprehensive health and safety program that utilizes available hazard controls and effectively communicates

Anti-viral drug treatment along with immune activator IL-2: a control-based mathematical approach for HIV infection

Science.gov (United States)

Nath Chatterjee, Amar; Roy, Priti Kumar

2012-02-01

Recent development in antiretroviral treatment against HIV can help AIDS patients to fight against HIV. But the question that whether the disease is to be partially or totally eradicated from HIV infected individuals still remains unsolved. Usually, the most effective treatment for the disease is HAART which can only control the disease progression. But as the immune system becomes weak, the patients can not fight against other diseases. Immune cells are activated and proliferated by IL-2 after the identification of antigen. IL-2 production is impaired in HIV positive patients and intermitted administration of immune activator IL-2 together with HAART which is a more effective treatment to fight against the disease. Thus, its expediency is essential and is yet to be explored. In this article we anticipated a mathematical model of the effect of IL-2 together with RTIs therapy in HIV positive patients. Our analytical as well as numerical study shows that the optimal schedule of treatment for best result is to be obtained by systematic drug therapy. But at the last stage of treatment, the infection level raises again due to minimisation of drug dosage. Thus we study the perfect adherence of the drugs and found out if RTIs are taken with sufficient interval then for fixed interval of IL-2 therapy, certain amount of drug dosages may be able to sustain the immune system at pre-infection stage and the infected CD4+T cells are going towards extinction.

Category 3 and 4 Controlled Drugs Users' Perceptions of Participating in Drug-Abuse-Health Prevention Lectures in Taiwan.

Science.gov (United States)

Sun, Fan-Ko; Long, Ann; Yu, Pei-Jane; Huang, Hui-Man; Chiang, Chun-Ying; Yao, YuChun

2017-08-01

This study was designed to explore Category 3 and 4 controlled drug users' perceptions of participating in health-prevention lectures. A phenomenological approach was used. Twelve participants were interviewed after completing the lectures. Findings revealed five themes (1) mixed emotions; (2) self-development; (3) finding the lectures lacked practicality and relevance; (4) highlighting three stages for discontinuing drug-usage; and, (5) suggesting tips for the advancement of lectures. These findings could be used as a map to help health professionals understand drug users' perceptions of attending health prevention lectures and provide insight into how young people might stop using drugs. Copyright © 2017 Elsevier Inc. All rights reserved.

Antihypertensive drug use in resistant and nonresistant hypertension and in controlled and uncontrolled resistant hypertension.

Science.gov (United States)

de la Sierra, Alejandro; Armario, Pedro; Oliveras, Anna; Banegas, José R; Gorostidi, Manuel; Vinyoles, Ernest; de la Cruz, Juan J; Segura, Julián; Ruilope, Luis M

2018-07-01

Treatment-resistant hypertension (TRH) is associated with particular clinical features, nonadherence, and suboptimal treatment. We assessed possible associations of antihypertensive drug classes, specific agents inside each class, and types of combinations, with the presence of non-TRH vs. TRH, and with controlled vs. uncontrolled TRH. Comparisons were done in 14 264 patients treated with three drugs (non-TRH: 2988; TRH: 11 276) and in 6974 treated with at least four drugs (controlled TRH: 1383; uncontrolled TRH: 5591). Associations were adjusted for age, sex, and previous cardiovascular event. In both groups of patients treated with three or with at least four drugs, aldosterone antagonists among drug classes [adjusted odds ratio (OR): 1.82 and 1.41, respectively], and ramipril (OR: 1.28 and 1.30), olmesartan (OR: 1.31 and 1.37), and amlodipine (OR: 1.11 and 1.41) inside each class were significantly associated with blood pressure control (non-TRH or controlled TRH). In patients treated with three drugs, non-TRH was also associated with the use of chlorthalidone (OR: 1.50) and bisoprolol (OR: 1.19), whereas in patients treated with at least four drugs, controlled TRH was significantly associated with the triple combination of a renin-angiotensin system blocker, a calcium channel blocker, and a diuretic (OR: 1.17). The use of aldosterone antagonists is associated with blood pressure control in patients treated with three or more drugs. Similar results are observed with specific agents inside each class, being ramipril, olmesartan, chlorthalidone, amlodipine, and bisoprolol those exhibiting significant results. An increased use of these drugs might probably reduce the burden of TRH.

Hypnosis control based on the minimum concentration of anesthetic drug for maintaining appropriate hypnosis.

Science.gov (United States)

Furutani, Eiko; Nishigaki, Yuki; Kanda, Chiaki; Takeda, Toshihiro; Shirakami, Gotaro

2013-01-01

This paper proposes a novel hypnosis control method using Auditory Evoked Potential Index (aepEX) as a hypnosis index. In order to avoid side effects of an anesthetic drug, it is desirable to reduce the amount of an anesthetic drug during surgery. For this purpose many studies of hypnosis control systems have been done. Most of them use Bispectral Index (BIS), another hypnosis index, but it has problems of dependence on anesthetic drugs and nonsmooth change near some particular values. On the other hand, aepEX has an ability of clear distinction between patient consciousness and unconsciousness and independence of anesthetic drugs. The control method proposed in this paper consists of two elements: estimating the minimum effect-site concentration for maintaining appropriate hypnosis and adjusting infusion rate of an anesthetic drug, propofol, using model predictive control. The minimum effect-site concentration is estimated utilizing the property of aepEX pharmacodynamics. The infusion rate of propofol is adjusted so that effect-site concentration of propofol may be kept near and always above the minimum effect-site concentration. Simulation results of hypnosis control using the proposed method show that the minimum concentration can be estimated appropriately and that the proposed control method can maintain hypnosis adequately and reduce the total infusion amount of propofol.

Novel HER2 Aptamer Selectively Delivers Cytotoxic Drug to HER2-positive Breast Cancer Cells in Vitro

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Liu Zhe

2012-07-01

Full Text Available Abstract Background Aptamer-based tumor targeted drug delivery system is a promising approach that may increase the efficacy of chemotherapy and reduce the related toxicity. HER2 protein is an attractive target for tumor-specific drug delivery because of its overexpression in multiple malignancies, including breast, gastric, ovarian, and lung cancers. Methods In this paper, we developed a new HER2 aptamer (HB5 by using systematic evolution of ligands by exponential enrichment technology (SELEX and exploited its role as a targeting ligand for delivering doxorubicin (Dox to breast cancer cells in vitro. Results The selected aptamer was an 86-nucleotide DNA molecule that bound to an epitope peptide of HER2 with a Kd of 18.9 nM. The aptamer also bound to the extracellular domain (ECD of HER2 protein with a Kdof 316 nM, and had minimal cross reactivity to albumin or trypsin. In addition, the aptamer was found to preferentially bind to HER2-positive but not HER2-negative breast cancer cells. An aptamer-doxorubicin complex (Apt-Dox was formulated by intercalating Dox into the DNA structure of HB5. The Apt-Dox complex could selectively deliver Dox to HER2-positive breast cancer cells while reducing the drug intake by HER2-negative cells in vitro. Moreover, Apt-Dox retained the cytotoxicity of Dox against HER2-positive breast cancer cells, but reduced the cytotoxicity to HER2-negative cells. Conclusions The results suggest that the selected HER2 aptamer may have application potentials in targeted therapy against HER2-positive breast cancer cells.

Nanotechnology-based polymeric bio(muco)adhesive platforms for controlling drug delivery - properties, methodologies and applications

International Nuclear Information System (INIS)

Carvalho, Flavia Chiva; Chorilli, Marlus; Gremiao, Maria Palmira Daflon

2014-01-01

Studies using bio(muco)adhesive drug delivery systems have recently gained great interest, which can promote drug targeting and more specific contact of the drug delivery system with the various absorptive membranes of the body. This technological platform associated with nanotechnology offers potential for controlling drug delivery; therefore, they are excellent strategies to increase the bioavailability of drugs. The objective of this work was to study nanotechnology-based polymeric bio(muco)adhesive platforms for controlling drug delivery, highlighting their properties, how the bio(muco)adhesion can be measured and their potential applications for different routes of administration. (author)

Fabrication of silk fibroin nanoparticles for controlled drug delivery

Energy Technology Data Exchange (ETDEWEB)

Zhao Zheng; Chen Aizheng; Li Yi, E-mail: tcliyi@polyu.edu.hk; Hu Junyan; Liu Xuan; Li Jiashen; Zhang Yu; Li Gang; Zheng Zijian [Hong Kong Polytechnic University, Institute of Textiles and Clothing (Hong Kong)

2012-03-15

A novel solution-enhanced dispersion by supercritical CO{sub 2} (SEDS) was employed to prepare silk fibroin (SF) nanoparticles. The resulting SF nanoparticles exhibited a good spherical shape, a smooth surface, and a narrow particle size distribution with a mean particle diameter of about 50 nm. The results of X-ray powder diffraction, thermo gravimetry-differential scanning calorimetry, and Fourier transform infrared spectroscopy analysis of the SF nanoparticles before and after ethanol treatment indicated conformation transition of SF nanoparticles from random coil to {beta}-sheet form and thus water insolubility. The MTS assay also suggested that the SF nanoparticles after ethanol treatment imposed no toxicity. A non-steroidal anti-inflammatory drug, indomethacin (IDMC), was chosen as the model drug and was encapsulated in SF nanoparticles by the SEDS process. The resulting IDMC-SF nanoparticles, after ethanol treatment, possessed a theoretical average drug load of 20%, an actual drug load of 2.05%, and an encapsulation efficiency of 10.23%. In vitro IDMC release from the IDMC-SF nanoparticles after ethanol treatment showed a significantly sustained release over 2 days. These studies of SF nanoparticles indicated the suitability of the SF nanoparticles prepared by the SEDS process as a biocompatible carrier to deliver drugs and also the feasibility of using the SEDS process to reach the goal of co-precipitation of drug and SF as composite nanoparticles for controlled drug delivery.

Fabrication of silk fibroin nanoparticles for controlled drug delivery

International Nuclear Information System (INIS)

Zhao Zheng; Chen Aizheng; Li Yi; Hu Junyan; Liu Xuan; Li Jiashen; Zhang Yu; Li Gang; Zheng Zijian

2012-01-01

A novel solution-enhanced dispersion by supercritical CO 2 (SEDS) was employed to prepare silk fibroin (SF) nanoparticles. The resulting SF nanoparticles exhibited a good spherical shape, a smooth surface, and a narrow particle size distribution with a mean particle diameter of about 50 nm. The results of X-ray powder diffraction, thermo gravimetry-differential scanning calorimetry, and Fourier transform infrared spectroscopy analysis of the SF nanoparticles before and after ethanol treatment indicated conformation transition of SF nanoparticles from random coil to β-sheet form and thus water insolubility. The MTS assay also suggested that the SF nanoparticles after ethanol treatment imposed no toxicity. A non-steroidal anti-inflammatory drug, indomethacin (IDMC), was chosen as the model drug and was encapsulated in SF nanoparticles by the SEDS process. The resulting IDMC–SF nanoparticles, after ethanol treatment, possessed a theoretical average drug load of 20%, an actual drug load of 2.05%, and an encapsulation efficiency of 10.23%. In vitro IDMC release from the IDMC–SF nanoparticles after ethanol treatment showed a significantly sustained release over 2 days. These studies of SF nanoparticles indicated the suitability of the SF nanoparticles prepared by the SEDS process as a biocompatible carrier to deliver drugs and also the feasibility of using the SEDS process to reach the goal of co-precipitation of drug and SF as composite nanoparticles for controlled drug delivery.

Selective control of attention supports the positivity effect in aging.

Directory of Open Access Journals (Sweden)

Laura K Sasse

Full Text Available There is emerging evidence for a positivity effect in healthy aging, which describes an age-specific increased focus on positive compared to negative information. Life-span researchers have attributed this effect to the selective allocation of cognitive resources in the service of prioritized emotional goals. We explored the basic principles of this assumption by assessing selective attention and memory for visual stimuli, differing in emotional content and self-relevance, in young and old participants. To specifically address the impact of cognitive control, voluntary attentional selection during the presentation of multiple-item displays was analyzed and linked to participants' general ability of cognitive control. Results revealed a positivity effect in older adults' selective attention and memory, which was particularly pronounced for self-relevant stimuli. Focusing on positive and ignoring negative information was most evident in older participants with a generally higher ability to exert top-down control during visual search. Our findings highlight the role of controlled selectivity in the occurrence of a positivity effect in aging. Since the effect has been related to well-being in later life, we suggest that the ability to selectively allocate top-down control might represent a resilience factor for emotional health in aging.

Incentive-Rewarding Mechanism for User-position Control in Mobile Services

Science.gov (United States)

Yoshino, Makoto; Sato, Kenichiro; Shinkuma, Ryoichi; Takahashi, Tatsuro

When the number of users in a service area increases in mobile multimedia services, no individual user can obtain satisfactory radio resources such as bandwidth and signal power because the resources are limited and shared. A solution for such a problem is user-position control. In the user-position control, the operator informs users of better communication areas (or spots) and navigates them to these positions. However, because of subjective costs caused by subjects moving from their original to a new position, they do not always attempt to move. To motivate users to contribute their resources in network services that require resource contributions for users, incentive-rewarding mechanisms have been proposed. However, there are no mechanisms that distribute rewards appropriately according to various subjective factors involving users. Furthermore, since the conventional mechanisms limit how rewards are paid, they are applicable only for the network service they targeted. In this paper, we propose a novel incentive-rewarding mechanism to solve these problems, using an external evaluator and interactive learning agents. We also investigated ways of appropriately controlling rewards based on user contributions and system service quality. We applied the proposed mechanism and reward control to the user-position control, and demonstrated its validity.

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

NARCIS (Netherlands)

Khalil, I.S.M.; Magdanz, V.; Sanchez, Stefan; Sanchez, S.; Schmidt, O.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.

Position calibration of a 3-DOF hand-controller with hybrid structure

Science.gov (United States)

Zhu, Chengcheng; Song, Aiguo

2017-09-01

A hand-controller is a human-robot interactive device, which measures the 3-DOF (Degree of Freedom) position of the human hand and sends it as a command to control robot movement. The device also receives 3-DOF force feedback from the robot and applies it to the human hand. Thus, the precision of 3-DOF position measurements is a key performance factor for hand-controllers. However, when using a hybrid type 3-DOF hand controller, various errors occur and are considered originating from machining and assembly variations within the device. This paper presents a calibration method to improve the position tracking accuracy of hybrid type hand-controllers by determining the actual size of the hand-controller parts. By re-measuring and re-calibrating this kind of hand-controller, the actual size of the key parts that cause errors is determined. Modifying the formula parameters with the actual sizes, which are obtained in the calibrating process, improves the end position tracking accuracy of the device.

Controlled local drug delivery strategies from chitosan hydrogels for wound healing.

Science.gov (United States)

Elviri, Lisa; Bianchera, Annalisa; Bergonzi, Carlo; Bettini, Ruggero

2017-07-01

The main target of tissue engineering is the preparation and application of adequate materials for the design and production of scaffolds, that possess properties promoting cell adhesion, proliferation and differentiation. The use of natural polysaccharides, such as chitosan, to prepare hydrogels for wound healing and controlled drug delivery is a research topic of wide and increasing interest. Areas covered: This review presents the latest results and challenges in the preparation of chitosan and chitosan-based scaffold/hydrogel for wound healing applications. A detailed overview of their behavior in terms of controlled drug delivery, divided by drug categories, and efficacy was provided and critically discussed. Expert opinion: The need to establish and exploit the advantages of natural biomaterials in combination with active compounds is playing a pivotal role in the regenerative medicine fields. The challenges posed by the many variables affecting tissue repair and regeneration need to be standardized and adhere to recognized guidelines to improve the quality of evidence in the wound healing process. Currently, different methodologies are followed to prepare innovative scaffold formulations and structures. Innovative technologies such as 3D printing or bio-electrospray are promising to create chitosan-based scaffolds with finely controlled structures with customizable shape porosity and thickness. Chitosan scaffolds could be designed in combination with a variety of polysaccharides or active compounds with selected and reproducible spacial distribution, providing active wound dressing with highly tunable controlled drug delivery.

New approach for control rod position indication system for light water power reactor

International Nuclear Information System (INIS)

Bahuguna, Sushil; Dhage, Sangeeta; Nawaj, S.; Salek, C.; Lahiri, S.K.; Marathe, P.P.; Mukhopadhyay, S.; Taly, Y.K.

2015-01-01

Control rod position indication system is an important system in a nuclear power plant to monitor and display control rod position in all regimes of reactor operation. A new approach to design a control rod position indication system for sensing absolute position of control rod in Light Water Power Reactor has been undertaken. The proposed system employs an inductive type, hybrid measurement strategy providing both analog position as well as digital zone indication with built-in temperature compensation. The new design approach meets single failure criterion through redundancy in design without sacrificing measurement resolution. It also provides diversity in measurement technique by indirect position sensing based on analysis of drive coil current signature. Prototype development and qualification at room temperature of the control rod position indication system (CRPIS) has been demonstrated. The article presents the design philosophy of control rod position indication system, the new measurement strategy for sensing absolute position of control rod, position estimation algorithm for both direct and indirect sensing and a brief account associated processing electronics. (author)

Preliminary performance test of control rod position indicator for ballscrew type CEDM

International Nuclear Information System (INIS)

Yoo, J. Y.; Kim, J. H.; Hu, H.; Lee, J. S.; Kim, J. I.

2003-01-01

The reliability and accuracy of the information on control rod position are very important to the reactor safety and the design of the core protection system. A survey on the RSPT(Reed Switch Position Transmitter) type control rod position indication system and its actual implementation in the exiting nuclear power plants in Korea was performed first. The prototype of control rod position indicator having the high performance for the ballscrew type CEDM was developed on the basis of RSPT technology identified through the survey. The characteristics of control rod position indicator was defined and documented through design procedure and preliminary performance test

Dysregulated Translational Control: From Brain Disorders to Psychoactive Drugs

Directory of Open Access Journals (Sweden)

Emanuela eSantini

2011-11-01

Full Text Available In the last decade, a plethora of studies utilizing pharmacological, biochemical, and genetic approaches have shown that precise translational control is required for long-lasting synaptic plasticity and the formation of long-term memory. Moreover, more recent studies indicate that alterations in translational control are a common pathophysiological feature of human neurological disorders, including developmental disorders, neuropsychiatric disorders, and neurodegenerative diseases. Finally, translational control mechanisms are susceptible to modification by psychoactive drugs. Taken together, these findings point to a central role for translational control in the regulation of synaptic function and behavior.

Design and reliability analysis of DP-3 dynamic positioning control architecture

Science.gov (United States)

Wang, Fang; Wan, Lei; Jiang, Da-Peng; Xu, Yu-Ru

2011-12-01

As the exploration and exploitation of oil and gas proliferate throughout deepwater area, the requirements on the reliability of dynamic positioning system become increasingly stringent. The control objective ensuring safety operation at deep water will not be met by a single controller for dynamic positioning. In order to increase the availability and reliability of dynamic positioning control system, the triple redundancy hardware and software control architectures were designed and developed according to the safe specifications of DP-3 classification notation for dynamically positioned ships and rigs. The hardware redundant configuration takes the form of triple-redundant hot standby configuration including three identical operator stations and three real-time control computers which connect each other through dual networks. The function of motion control and redundancy management of control computers were implemented by software on the real-time operating system VxWorks. The software realization of task loose synchronization, majority voting and fault detection were presented in details. A hierarchical software architecture was planed during the development of software, consisting of application layer, real-time layer and physical layer. The behavior of the DP-3 dynamic positioning control system was modeled by a Markov model to analyze its reliability. The effects of variation in parameters on the reliability measures were investigated. The time domain dynamic simulation was carried out on a deepwater drilling rig to prove the feasibility of the proposed control architecture.

Structure of the automatic system for plasma equilibrium position control

International Nuclear Information System (INIS)

Gubarev, V.F.; Krivonos, Yu.G.; Samojlenko, Yu.I.; Snegur, A.A.

1978-01-01

Considered are the principles of construction of the automatic system for plasma filament equilibrium position control inside the discharge chamber for the installation of a tokamak type. The combined current control system in control winding is suggested. The most powerful subsystem creates current in the control winding according to the program calculated beforehand. This system provides plasma rough equilibrium along the ''big radius''. The subsystem performing the current change in small limits according to the principle of feed-back coupling is provided simultaneously. The stabilization of plasma position is achieved in the discharge chamber. The advantage of construction of such system is in decreasing of the automatic requlator power without lowering the requirements to the accuracy of equilibrium preservation. The subsystem of automatic control of plasma position over the vertical is put into the system. Such an approach to the construction of the automatic control system proves to be correct; it is based on the experience of application of similar devices for some existing thermonuclear plants

Heightened vulnerability to MDR-TB epidemics after controlling drug-susceptible TB.

Directory of Open Access Journals (Sweden)

Jason D Bishai

2010-09-01

Full Text Available Prior infection with one strain TB has been linked with diminished likelihood of re-infection by a new strain. This paper attempts to determine the role of declining prevalence of drug-susceptible TB in enabling future epidemics of MDR-TB.A computer simulation of MDR-TB epidemics was developed using an agent-based model platform programmed in NetLogo (See http://mdr.tbtools.org/. Eighty-one scenarios were created, varying levels of treatment quality, diagnostic accuracy, microbial fitness cost, and the degree of immunogenicity elicited by drug-susceptible TB. Outcome measures were the number of independent MDR-TB cases per trial and the proportion of trials resulting in MDR-TB epidemics for a 500 year period after drug therapy for TB is introduced.MDR-TB epidemics propagated more extensively after TB prevalence had fallen. At a case detection rate of 75%, improving therapeutic compliance from 50% to 75% can reduce the probability of an epidemic from 45% to 15%. Paradoxically, improving the case-detection rate from 50% to 75% when compliance with DOT is constant at 75% increases the probability of MDR-TB epidemics from 3% to 45%.The ability of MDR-TB to spread depends on the prevalence of drug-susceptible TB. Immunologic protection conferred by exposure to drug-susceptible TB can be a crucial factor that prevents MDR-TB epidemics when TB treatment is poor. Any single population that successfully reduces its burden of drug-susceptible TB will have reduced herd immunity to externally or internally introduced strains of MDR-TB and can experience heightened vulnerability to an epidemic. Since countries with good TB control may be more vulnerable, their self interest dictates greater promotion of case detection and DOTS implementation in countries with poor control to control their risk of MDR-TB.

Hysteresis Analysis and Positioning Control for a Magnetic Shape Memory Actuator

Science.gov (United States)

Lin, Jhih-Hong; Chiang, Mao-Hsiung

2015-01-01

Magnetic shape memory alloys (MSM alloys), a new kind of smart materials, have become a potential candidate in many engineering fields. MSMs have the advantage of bearing a huge strain, much larger than other materials. In addition, they also have fast response. These characteristics make MSM a good choice in micro engineering. However, MSMs display the obvious hysteresis phenomenon of nonlinear behavior. Thus the difficulty in using the MSM element as a positioning actuator is increased due to the hysteresis. In this paper, the hysteresis phenomenon of the MSM actuator is analyzed, and the closed-loop positioning control is also implemented experimentally. For that, a modified fuzzy sliding mode control (MFSMC) is proposed. The MFSMC and the PID control are used to design the controllers for realizing the positioning control. The experimental results are compared under different experimental conditions, such as different frequency, amplitude, and loading. The experimental results show that the precise positioning control of MFSMC can be achieved satisfactorily. PMID:25853405

Attentional control mediates the effect of social anxiety on positive affect☆

Science.gov (United States)

Morrison, Amanda S.; Heimberg, Richard G.

2015-01-01

The goal of the present studies was to examine whether attentional control, a self-regulatory attentional mechanism, mediates the effect of social anxiety on positive affect. We tested this mediation in two studies using undergraduate students selected to represent a broad range of severity of social anxiety. Self-report assessments of social anxiety, attentional control, and positive affect were collected in a cross-sectional design (Study 1) and in a longitudinal design with three assessment points (Study 2). Results of both studies supported the hypothesized mediational model. Specifically, social anxiety was inversely related to attentional control, which itself positively predicted positive affect. This mediation remained significant even when statistically controlling for the effects of depression. Additionally, the hypothesized model provided superior model fit to theoretically-grounded equivalent models in both studies. Implications of these findings for understanding diminished positive affect in social anxiety are discussed. PMID:23254261

Controlled Positioning of Cells in Biomaterials-Approaches Towards 3D Tissue Printing.

Science.gov (United States)

Wüst, Silke; Müller, Ralph; Hofmann, Sandra

2011-08-04

Current tissue engineering techniques have various drawbacks: they often incorporate uncontrolled and imprecise scaffold geometries, whereas the current conventional cell seeding techniques result mostly in random cell placement rather than uniform cell distribution. For the successful reconstruction of deficient tissue, new material engineering approaches have to be considered to overcome current limitations. An emerging method to produce complex biological products including cells or extracellular matrices in a controlled manner is a process called bioprinting or biofabrication, which effectively uses principles of rapid prototyping combined with cell-loaded biomaterials, typically hydrogels. 3D tissue printing is an approach to manufacture functional tissue layer-by-layer that could be transplanted in vivo after production. This method is especially advantageous for stem cells since a controlled environment can be created to influence cell growth and differentiation. Using printed tissue for biotechnological and pharmacological needs like in vitro drug-testing may lead to a revolution in the pharmaceutical industry since animal models could be partially replaced by biofabricated tissues mimicking human physiology and pathology. This would not only be a major advancement concerning rising ethical issues but would also have a measureable impact on economical aspects in this industry of today, where animal studies are very labor-intensive and therefore costly. In this review, current controlled material and cell positioning techniques are introduced highlighting approaches towards 3D tissue printing.

Controlled Positioning of Cells in Biomaterials—Approaches Towards 3D Tissue Printing

Directory of Open Access Journals (Sweden)

Sandra Hofmann

2011-08-01

Full Text Available Current tissue engineering techniques have various drawbacks: they often incorporate uncontrolled and imprecise scaffold geometries, whereas the current conventional cell seeding techniques result mostly in random cell placement rather than uniform cell distribution. For the successful reconstruction of deficient tissue, new material engineering approaches have to be considered to overcome current limitations. An emerging method to produce complex biological products including cells or extracellular matrices in a controlled manner is a process called bioprinting or biofabrication, which effectively uses principles of rapid prototyping combined with cell-loaded biomaterials, typically hydrogels. 3D tissue printing is an approach to manufacture functional tissue layer-by-layer that could be transplanted in vivo after production. This method is especially advantageous for stem cells since a controlled environment can be created to influence cell growth and differentiation. Using printed tissue for biotechnological and pharmacological needs like in vitro drug-testing may lead to a revolution in the pharmaceutical industry since animal models could be partially replaced by biofabricated tissues mimicking human physiology and pathology. This would not only be a major advancement concerning rising ethical issues but would also have a measureable impact on economical aspects in this industry of today, where animal studies are very labor-intensive and therefore costly. In this review, current controlled material and cell positioning techniques are introduced highlighting approaches towards 3D tissue printing.

Comparative analysis of three drug-drug interaction screening systems against probable clinically relevant drug-drug interactions: a prospective cohort study.

Science.gov (United States)

Muhič, Neža; Mrhar, Ales; Brvar, Miran

2017-07-01

Drug-drug interaction (DDI) screening systems report potential DDIs. This study aimed to find the prevalence of probable DDI-related adverse drug reactions (ADRs) and compare the clinical usefulness of different DDI screening systems to prevent or warn against these ADRs. A prospective cohort study was conducted in patients urgently admitted to medical departments. Potential DDIs were checked using Complete Drug Interaction®, Lexicomp® Online™, and Drug Interaction Checker®. The study team identified the patients with probable clinically relevant DDI-related ADRs on admission, the causality of which was assessed using the Drug Interaction Probability Scale (DIPS). Sensitivity, specificity, and positive and negative predictive values of screening systems to prevent or warn against probable DDI-related ADRs were evaluated. Overall, 50 probable clinically relevant DDI-related ADRs were found in 37 out of 795 included patients taking at least two drugs, most common of them were bleeding, hyperkalemia, digitalis toxicity, and hypotension. Complete Drug Interaction showed the best sensitivity (0.76) for actual DDI-related ADRs, followed by Lexicomp Online (0.50), and Drug Interaction Checker (0.40). Complete Drug Interaction and Drug Interaction Checker had positive predictive values of 0.07; Lexicomp Online had 0.04. We found no difference in specificity and negative predictive values among these systems. DDI screening systems differ significantly in their ability to detect probable clinically relevant DDI-related ADRs in terms of sensitivity and positive predictive value.

Production and Investigation of Controlled Drug Release Properties of Tamoxifen Loaded Alginate-Gum Arabic Microbeads

Directory of Open Access Journals (Sweden)

Rukiye Yavaşer

2016-08-01

Full Text Available The entrapment of tamoxifen onto alginate-gum arabic beads and the production of controlled drug release was investigated in this study. The polymeric system that would provide the controlled release of tamoxifen was formed using alginate and gum arabic. In the first phase of the study, the optimization of the alginate-gum arabic beads production was conducted; then the study continued with drug entrapment experiments. Tamoxifen entrapment yield was found to be approximately 90% of initial tamoxifen concentration. In vitro drug release experiments were performed in simulated gastric juice and intestinal fluid where the tamoxifen release was 20% and 53% of the initial drug present, respectively. As a result of this study, it is expected that a valuable contribution to the field of controlled drug release system production is realized.

Integrated shell approach to vertical position control on PBX-M

International Nuclear Information System (INIS)

Hatcher, R.E.; Okabayashi, M.

1995-03-01

The PBX-M device produces highly shaped discharges that, because of the negative external magnetic field decay index required, are vertically unstable. Vertical positional stability in PBX-M has been achieved by directly controlling the n = 0 component of the eddy current in the passive shell instead of the commonly used function of magnetic flux signals. Because the active coil is controlled via currents in the passive shell we call this an ''integrated shell'' approach to vertical position control. We present results of these experiments and make comparisons between the two methods of control

Position Control of the Single Spherical Wheel Mobile Robot by Using the Fuzzy Sliding Mode Controller

Directory of Open Access Journals (Sweden)

Hamed Navabi

2017-01-01

Full Text Available A spherical wheel robot or Ballbot—a robot that balances on an actuated spherical ball—is a new and recent type of robot in the popular area of mobile robotics. This paper focuses on the modeling and control of such a robot. We apply the Lagrangian method to derive the governing dynamic equations of the system. We also describe a novel Fuzzy Sliding Mode Controller (FSMC implemented to control a spherical wheel mobile robot. The nonlinear nature of the equations makes the controller nontrivial. We compare the performance of four different fuzzy controllers: (a regulation with one signal, (b regulation and position control with one signal, (c regulation and position control with two signals, and (d FSMC for regulation and position control with two signals. The system is evaluated in a realistic simulation and the robot parameters are chosen based on a LEGO platform, so the designed controllers have the ability to be implemented on real hardware.

Natural material-decorated mesoporous silica nanoparticle container for multifunctional membrane-controlled targeted drug delivery

Directory of Open Access Journals (Sweden)

Hu Y

2017-11-01

Full Text Available Yan Hu,1 Lei Ke,2 Hao Chen,1 Ma Zhuo,1 Xinzhou Yang,1 Dan Zhao,1 Suying Zeng,1 Xincai Xiao1 1Department of Pharmaceutics, School of Pharmaceutical Science, South-Central University for Nationalities, 2Department of Medicinal Chemistry, School of Pharmacy, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, People’s Republic of China Abstract: To avoid the side effects caused by nonspecific targeting, premature release, weak selectivity, and poor therapeutic efficacy of current nanoparticle-based systems used for drug delivery, we fabricated natural material-decorated nanoparticles as a multifunctional, membrane-controlled targeted drug delivery system. The nanocomposite material coated with a membrane was biocompatible and integrated both specific tumor targeting and responsiveness to stimulation, which improved transmission efficacy and controlled drug release. Mesoporous silica nanoparticles (MSNs, which are known for their biocompatibility and high drug-loading capacity, were selected as a model drug container and carrier. The membrane was established by the polyelectrolyte composite method from chitosan (CS which was sensitive to the acidic tumor microenvironment, folic acid-modified CS which recognizes the folate receptor expressed on the tumor cell surface, and a CD44 receptor-targeted polysaccharide hyaluronic acid. We characterized the structure of the nanocomposite as well as the drug release behavior under the control of the pH-sensitive membrane switch and evaluated the antitumor efficacy of the system in vitro. Our results provide a basis for the design and fabrication of novel membrane-controlled nanoparticles with improved tumor-targeting therapy. Keywords: multifunctional, membrane-controlled, natural materials, mesoporous silica nanoparticles, targeted drug delivery

Drug and alcohol crash risk : a case-control study.

Science.gov (United States)

2016-12-01

This study used a case-control design to estimate the risk of crashes involving drivers using drugs, alcohol or both. Data was collected in Virginia Beach, Virginia, for 20 months. The study obtained biological measures on more than 3,000 crash...

Parasite control in the age of drug resistance and changing agricultural practices.

Science.gov (United States)

Molento, Marcelo Beltrão

2009-08-07

The benefits of using antiparasitic drugs in farm animals are unquestionable. However, despite anthelmintic use as the predominant control strategy, extreme parasite infection cases are appearing in sheep and goat production; these impact productivity and have show mortality rates reaching pre-drug use levels. This was a predictable situation resulting from the loss of efficacy by all available products, particularly when some products were used as the sole intervention. The concepts of agroecology and holistic agriculture, which advocate the use of integrated management strategies, such as target selected treatment, herbal medicine, and the application of other parasite control alternatives, are not completely new, but are undergoing a resurgence because of their more sustainable appeal. The objective of this review article is to examine the problem of parasite control in the face of parasite drug resistance and to outline some strategies that may be used in parasite control programmes. Before they are accepted and recommended by the WAAVP, agroecological methods such as those listed above and described in detail herein should be validated based on scientific evidence of their efficacy for parasite control and should be tested for both host and environmental safety.

Application of Adaptive Sliding Mode Position Controller with PI ...

African Journals Online (AJOL)

PISMC) techniques for controlling the rotor position of PMDC motor drive system. In particular, since SMC is robust in the presence of the matched uncertainties and external disturbances, the desired position is perfectly tracked. In addition, the ...

Nanocapsule@xerogel microparticles containing sodium diclofenac: a new strategy to control the release of drugs.

Science.gov (United States)

da Fonseca, Letícia Sias; Silveira, Rodrigo Paulo; Deboni, Alberto Marçal; Benvenutti, Edilson Valmir; Costa, Tânia M H; Guterres, Sílvia S; Pohlmann, Adriana R

2008-06-24

The aim of this work was to evaluate the potentiality to control the drug release of a new architecture of microparticles organized at the nanoscopic scale by assembling polymeric nanocapsules at the surface of drug-loaded xerogels. Xerogel was prepared by sol-gel method using sodium diclofenac, as hydrophilic drug model, and coated by spray-drying. After coating, the surface areas decreased from 82 to 28 m(2)/g, the encapsulation efficiency was 71% and SEM analysis showed irregular microparticles coated by the nanocapsules. Formulation showed satisfactory gastro-resistance presenting drug release lower than 3% (60 min) in acid medium. In water, the pure drug dissolved 92% after 5 min, uncoated drug-loaded xerogel released 60% and nanocapsule coated drug-loaded xerogel 36%. After 60 min, uncoated drug-loaded xerogel released 82% and nanocapsule coated drug-loaded xerogel 62%. In conclusion, the new system was able to control the release of the hydrophilic drug model.

Electrochemically controlled release of anticancer drug methotrexate using nanostructured polypyrrole modified with cetylpyridinium: Release kinetics investigation

International Nuclear Information System (INIS)

Alizadeh, Naader; Shamaeli, Ehsan

2014-01-01

A new simple strategy for direct electrochemical incorporation of chemotherapeutic methotrexate (MTX) into conductive polypyrrole (PPy) has been suggested for an electrochemically controlled loading and release system. Electropolymerization of MTX doped polypyrrole yielded poor quality with low efficiency of doping, but a well-doped, nanostructure and increased capacity of drug loading (24.5 mg g −1 ) has been obtained in the presence of cetylpyridinium (CP) as a modifier. When CP was preloaded onto PPy, the hydrophobic surface of the PPy serves as a backbone to which the hydrophobic chain of the CP can be attached. Electrostatic interaction between cationic CP with anionic MTX and aromatic interaction between pyridinium head of CP with pyrimidine and pyrazine rings of MTX increases drug doping. Then release kinetics were investigated at various applied potentials and temperatures. Kinetics analysis based on Avrami's equation showed that the drug release was controlled and accelerated by increasing temperature and negative potential and sustained by increasing positive potential. At open circuit condition, the release parameter (n) represented a diffusive mechanism and at applying electrochemical potentials, a first-order mode. Activation energy parameters (E a , ΔG ≠ , ΔH ≠ and ΔS ≠ ) and half-life time (t 1/2 ) of drug release are also analyzed as a function of applied potential. The nanostructured polymer films (PPy/CP/MTX) were characterized by several techniques: scanning electron microscopy, Furrier transforms Infrared, UV-vis spectroscopy. Overall, our results demonstrate that the PPy/CP/MTX films, combined with electrical stimulation, permit a programmable release of MTX by altering the interaction strength between the PPy/CP and MTX

21 CFR 212.70 - What controls and acceptance criteria must I have for my finished PET drug products?

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 4 2010-04-01 2010-04-01 false What controls and acceptance criteria must I have... POSITRON EMISSION TOMOGRAPHY DRUGS (Eff. 12-12-2011) Finished Drug Product Controls and Acceptance § 212.70 What controls and acceptance criteria must I have for my finished PET drug products? (a) Specifications...

Changing an automated drug inventory control system to a data base design.

Science.gov (United States)

Bradish, R A

1982-09-01

A pharmacy department's change from indexed sequential access files to a data base management system (DBMS) for purposes of automated inventory control is described. The DBMS has three main functional areas: (1) inventory ordering and accountability, (2) charging of interdepartmental and intradepartmental orders, and (3) data manipulation with report design for management control. There are seven files directly related to the inventory ordering and accountability area. Each record can be accessed directly or through another file. Information on the quantity of a drug on hand, drug(s) supplied by a specific vendor, status of a purchase order, or calculation of an estimated order quantity can be retrieved quickly. In the drug master file, two records contain a reorder point and safety-stock level that are determined by searching the entries in the order history file and vendor master file. The intradepartmental and interdepartmental orders section contains five files assigned to record and store information on drug distribution. All items removed from the stockroom and distributed are recorded, and reports can be generated for itemized bills, total cost by area, and as formatted files for the accounts payable department. The design, development, and implementation of the DBMS took approximately a year using a part-time pharmacist and minimal outside help, while the previous system required constant expensive help of a programmer/analyst. The DBMS has given the pharmacy department a flexible inventory management system with increased drug control, decreased operating expenses, increased use of department personnel, and the ability to develop and enhance other systems.

The politics of drug control in Nigeria: Exclusion, repression and obstacles to policy change.

Science.gov (United States)

Klantschnig, Gernot

2016-04-01

International agencies have viewed West Africa as a major player in the global trade in cocaine and heroin and in efforts to control that trade, as there have been reports of escalating arrests of drug smugglers, large-scale drug seizures and 'narco-states' in the subregion. It is claimed that a substantial share of the drugs available in Western markets transit through West Africa today and are increasingly used there as well. Notwithstanding this growing alarm, there is little serious scholarship addressing the issue of drugs and drug policy in West Africa. The article assesses and challenges some of the existing depictions of drugs and drug policy in West Africa through an empirical case study of drug control in Nigeria - one of West Africa's most notorious 'drug hubs' and recently hailed as a policy model by international experts. Based on previously inaccessible government documents, interviews with key officials in Nigeria, as well as ethnographic work at Nigeria's key drug agency, the article provides a unique insight into the politics of drug policy-making and implementation in West Africa. After describing the dominant official narratives of Nigeria's drug control, the article shows how the key political dynamics underlying drug policy remain obscured by these narratives. Nigerian drug policy has been characterised by a highly exclusive policy-making process, repression as the sole means of implementation and a strong bond with international drug agencies. This policy emerged in the 1980s and 1990s and has remained the unchallenged norm until today. The political processes underlying Nigerian drug policy also explain why policy reform has been and will be difficult to accomplish. These domestic political processes have largely been ignored in the existing depictions of drugs in West Africa, as they have mainly focused on externally driven drug threats and foreign policy responses. Most importantly, they have ignored the role played by the state. Rather

28 CFR 0.177 - Applications for orders under the Comprehensive Drug Abuse Prevention and Control Act.

Science.gov (United States)

2010-07-01

... Comprehensive Drug Abuse Prevention and Control Act. 0.177 Section 0.177 Judicial Administration DEPARTMENT OF... the Comprehensive Drug Abuse Prevention and Control Act. Notwithstanding the delegation of functions... authorized to exercise the authority vested in the Attorney General by section 514 of the Comprehensive Drug...

How the pill became a lifestyle drug: the pharmaceutical industry and birth control in the United States since 1960.

Science.gov (United States)

Watkins, Elizabeth Siegel

2012-08-01

Marketing decisions, rather than scientific innovations, have guided the development and positioning of contraceptive products in recent years. I review the stalled progress in contraceptive development in the decades following the advent of the Pill in 1960 and then examine the fine-tuning of the market for oral contraceptives in the 1990s and 2000s. Although birth control has been pitched in the United States as an individual solution, rather than a public health strategy, the purpose of oral contraceptives was understood by manufacturers, physicians, and consumers to be the prevention of pregnancy, a basic health care need for women. Since 1990, the content of that message has changed, reflecting a shift in the drug industry's view of the contraception business. Two factors contributed to bring about this change: first, the industry's move away from research and development in birth control and second, the growth of the class of medications known as lifestyle drugs.

Dissociable influences of reward motivation and positive emotion on cognitive control.

Science.gov (United States)

Chiew, Kimberly S; Braver, Todd S

2014-06-01

It is becoming increasingly appreciated that affective and/or motivational influences contribute strongly to goal-oriented cognition and behavior. An unresolved question is whether emotional manipulations (i.e., direct induction of affectively valenced subjective experience) and motivational manipulations (e.g., delivery of performance-contingent rewards and punishments) have similar or distinct effects on cognitive control. Prior work has suggested that reward motivation can reliably enhance a proactive mode of cognitive control, whereas other evidence is suggestive that positive emotion improves cognitive flexibility, but reduces proactive control. However, a limitation of the prior research is that reward motivation and positive emotion have largely been studied independently. Here, we directly compared the effects of positive emotion and reward motivation on cognitive control with a tightly matched, within-subjects design, using the AX-continuous performance task paradigm, which allows for relative measurement of proactive versus reactive cognitive control. High-resolution pupillometry was employed as a secondary measure of cognitive dynamics during task performance. Robust increases in behavioral and pupillometric indices of proactive control were observed with reward motivation. The effects of positive emotion were much weaker, but if anything, also reflected enhancement of proactive control, a pattern that diverges from some prior findings. These results indicate that reward motivation has robust influences on cognitive control, while also highlighting the complexity and heterogeneity of positive-emotion effects. The findings are discussed in terms of potential neurobiological mechanisms.

Chitosan/alginate based multilayers to control drug release fromophthalmic lens

OpenAIRE

Silva, Diana; Pinto, Luís F. V.; Bozukova, Dimitriya; Santos, Luís F.; Serro, Ana Paula; Saramago, Benilde

2016-01-01

In this study we investigated the possibility of using layer-by-layer deposition, based in natural polymers (chitosan and alginate), to control the release of different ophthalmic drugs from three types of lens materials: a silicone-based hydrogel recently proposed by our group as drug releasing soft contact lens (SCL) material and two commercially available materials: CI26Y for intraocular lens (IOLs) and Definitive 50 for SCLs. The optimised coating, consisting in one double layer of (algin...

Parental permissiveness, control, and affect and drug use among adolescents.

Science.gov (United States)

Becoña, Elisardo; Martínez, Úrsula; Calafat, Amador; Fernández-Hermida, José Ramón; Juan, Montse; Sumnall, Harry; Mendes, Fernando; Gabrhelík, Roman

2013-01-01

Parents play an important role in determining the risk of children's drug use. The aim of this study was to analyse how certain family-related variables (permissiveness toward drug use, and parental control and affect) were linked to the use of alcohol, tobacco and cannabis, based on young people's self-report of such variables. The sample was composed of 1,428 school children (51.8% males) aged between 11 and 19 from Mallorca (Spain). We found that the young people who perceived their parents as permissive and those who perceived less maternal control and higher levels of both paternal and maternal affect were more likely to use alcohol, tobacco and cannabis. Sex differences were found within this pattern. Variables of maternal affect and control were not influential among males, whereas the general pattern was maintained among females. This study highlights the importance of perceived permissiveness and the need of considering parent's and children's gender when providing control and affect, as fathers will influence male children whereas mothers will influence female children.

Sixty Years of Placebo-Controlled Antipsychotic Drug Trials in Acute Schizophrenia: Systematic Review, Bayesian Meta-Analysis, and Meta-Regression of Efficacy Predictors.

Science.gov (United States)

Leucht, Stefan; Leucht, Claudia; Huhn, Maximilian; Chaimani, Anna; Mavridis, Dimitris; Helfer, Bartosz; Samara, Myrto; Rabaioli, Matteo; Bächer, Susanne; Cipriani, Andrea; Geddes, John R; Salanti, Georgia; Davis, John M

2017-10-01

Antipsychotic drug efficacy may have decreased over recent decades. The authors present a meta-analysis of all placebo-controlled trials in patients with acute exacerbations of schizophrenia, and they investigate which trial characteristics have changed over the years and which are moderators of drug-placebo efficacy differences. The search included multiple electronic databases. The outcomes were overall efficacy (primary outcome); responder and dropout rates; positive, negative, and depressive symptoms; quality of life; functioning; and major side effects. Potential moderators of efficacy were analyzed by meta-regression. The analysis included 167 double-blind randomized controlled trials with 28,102 mainly chronic participants. The standardized mean difference (SMD) for overall efficacy was 0.47 (95% credible interval 0.42, 0.51), but accounting for small-trial effects and publication bias reduced the SMD to 0.38. At least a "minimal" response occurred in 51% of the antipsychotic group versus 30% in the placebo group, and 23% versus 14% had a "good" response. Positive symptoms (SMD 0.45) improved more than negative symptoms (SMD 0.35) and depression (SMD 0.27). Quality of life (SMD 0.35) and functioning (SMD 0.34) improved even in the short term. Antipsychotics differed substantially in side effects. Of the response predictors analyzed, 16 trial characteristics changed over the decades. However, in a multivariable meta-regression, only industry sponsorship and increasing placebo response were significant moderators of effect sizes. Drug response remained stable over time. Approximately twice as many patients improved with antipsychotics as with placebo, but only a minority experienced a good response. Effect sizes were reduced by industry sponsorship and increasing placebo response, not decreasing drug response. Drug development may benefit from smaller samples but better-selected patients.

DNA Nanotechnology for Precise Control over Drug Delivery and Gene Therapy.

Science.gov (United States)

Angell, Chava; Xie, Sibai; Zhang, Liangfang; Chen, Yi

2016-03-02

Nanomedicine has been growing exponentially due to its enhanced drug targeting and reduced drug toxicity. It uses the interactions where nanotechnological components and biological systems communicate with each other to facilitate the delivery performance. At this scale, the physiochemical properties of delivery systems strongly affect their capacities. Among current delivery systems, DNA nanotechnology shows many advantages because of its unprecedented engineering abilities. Through molecular recognition, DNA nanotechnology can be used to construct a variety of nanostructures with precisely controllable size, shape, and surface chemistry, which can be appreciated in the delivery process. In this review, different approaches that are currently used for the construction of DNA nanostructures are reported. Further, the utilization of these DNA nanostructures with the well-defined parameters for the precise control in drug delivery and gene therapy is discussed. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Cost Minimization Analysis of Hypnotic Drug: Target Controlled Inhalation Anesthesia (TCIA Sevoflurane and Target Controlled Infusion (TCI Propofol

Directory of Open Access Journals (Sweden)

Made Wiryana

2016-09-01

Full Text Available Background: Cost minimization analysis is a pharmaco-economic study used to compare two or more health interventions that have been shown to have the same effect, similar or equivalent. With limited health insurance budget from the Indonesian National Social Security System implementation in 2015, the quality control and the drug cost are two important things that need to be focused. The application of pharmaco-economic study results in the selection and use of drugs more effectively and efficiently. Objective: To determine cost minimization analysis of hypnotic drug between a target controlled inhalation anesthesia (TCIA sevoflurane and a target controlled infusion (TCI propofol in patients underwent a major oncologic surgery in Sanglah General Hospital. Methods: Sixty ASA physical status I-II patients underwent major oncologic surgery were divided into two groups. Group A was using TCIA sevoflurane and group B using TCI propofol. Bispectral index monitor (BIS index was used to evaluate the depth of anesthesia. The statistical tests used are the Shapiro-Wilk test, Lavene test, Mann-Whitney U test and unpaired t-test (α = 0.05. The data analysis used the Statistical Package for Social Sciences (SPSS for Windows. Results: In this study, the rate of drug used per unit time in group A was 0.12 ml sevoflurane per minute (± 0.03 and the group B was 7.25 mg propofol per minute (±0.98. Total cost of hypnotic drug in group A was IDR598.43 (IQR 112.47 per minute, in group B was IDR703.27 (IQR 156.73 per minute (p>0.05. Conclusions: There was no statistically significant difference from the analysis of the drug cost minimization hypnotic drug in a major oncologic surgery using TCIA sevoflurane and TCI propofol.

In vivo real-time monitoring system of electroporation mediated control of transdermal and topical drug delivery.

Science.gov (United States)

Blagus, Tanja; Markelc, Bostjan; Cemazar, Maja; Kosjek, Tina; Preat, Veronique; Miklavcic, Damijan; Sersa, Gregor

2013-12-28

Electroporation (EP) is a physical method for the delivery of molecules into cells and tissues, including the skin. In this study, in order to control the degree of transdermal and topical drug delivery, EP at different amplitudes of electric pulses was evaluated. A new in vivo real-time monitoring system based on fluorescently labeled molecules was developed, for the quantification of transdermal and topical drug delivery. EP of the mouse skin was performed with new non-invasive multi-array electrodes, delivering different amplitudes of electric pulses ranging from 70 to 570 V, between the electrode pin pairs. Patches, soaked with 4 kDa fluorescein-isothiocyanate labeled dextran (FD), doxorubicin (DOX) or fentanyl (FEN), were applied to the skin before and after EP. The new monitoring system was developed based on the delivery of FD to and through the skin. FD relative quantity was determined with fluorescence microscopy imaging, in the treated region of the skin for topical delivery and in a segment of the mouse tail for transdermal delivery. The application of electric pulses for FD delivery resulted in enhanced transdermal delivery. Depending on the amplitude of electric pulses, it increased up to the amplitude of 360 V, and decreased at higher amplitudes (460 and 570 V). Topical delivery steadily enhanced with increasing the amplitude of the delivered electric pulses, being even higher than after tape stripping used as a positive control. The non-invasive monitoring of the delivery of DOX, a fluorescent chemotherapeutic drug, qualitatively and quantitatively confirmed the effects of EP at 360 and 570 V pulse amplitudes on topical and transdermal drug delivery. Delivery of FEN at 360 and 570 V pulse amplitudes verified the observed effects as obtained with FD and DOX, by the measured physiological responses of the mice as well as FEN plasma concentration. This study demonstrates that with the newly developed non-invasive multi-array electrodes and with the

Continuous Drug Infusion for Diabetes Therapy: A Closed-Loop Control System Design

Directory of Open Access Journals (Sweden)

Jiming Chen

2008-03-01

Full Text Available While a typical way for diabetes therapy is discrete insulin infusion based on long-time interval measurement, in this paper, we design a closed-loop control system for continuous drug infusion to improve the traditional discrete methods and make diabetes therapy automatic in practice. By exploring the accumulative function of drug to insulin, a continuous injection model is proposed. Based on this model, proportional-integral-derivative (PID and fuzzy logic controllers are designed to tackle a control problem of the resulting highly nonlinear plant. Even with serious disturbance of glucose, such as nutrition absorption at meal time, the proposed scheme can perform well in simulation experiments.

Predicting abuse potential of stimulants and other dopaminergic drugs: overview and recommendations.

Science.gov (United States)

Huskinson, Sally L; Naylor, Jennifer E; Rowlett, James K; Freeman, Kevin B

2014-12-01

Examination of a drug's abuse potential at multiple levels of analysis (molecular/cellular action, whole-organism behavior, epidemiological data) is an essential component to regulating controlled substances under the Controlled Substances Act (CSA). We reviewed studies that examined several central nervous system (CNS) stimulants, focusing on those with primarily dopaminergic actions, in drug self-administration, drug discrimination, and physical dependence. For drug self-administration and drug discrimination, we distinguished between experiments conducted with rats and nonhuman primates (NHP) to highlight the common and unique attributes of each model in the assessment of abuse potential. Our review of drug self-administration studies suggests that this procedure is important in predicting abuse potential of dopaminergic compounds, but there were many false positives. We recommended that tests to determine how reinforcing a drug is relative to a known drug of abuse may be more predictive of abuse potential than tests that yield a binary, yes-or-no classification. Several false positives also occurred with drug discrimination. With this procedure, we recommended that future research follow a standard decision-tree approach that may require examining the drug being tested for abuse potential as the training stimulus. This approach would also allow several known drugs of abuse to be tested for substitution, and this may reduce false positives. Finally, we reviewed evidence of physical dependence with stimulants and discussed the feasibility of modeling these phenomena in nonhuman animals in a rational and practical fashion. This article is part of the Special Issue entitled 'CNS Stimulants'. Copyright © 2014 Elsevier Ltd. All rights reserved.

Skin test concentrations for systemically administered drugs -- an ENDA/EAACI Drug Allergy Interest Group position paper

DEFF Research Database (Denmark)

Brockow, K; Garvey, L H; Aberer, W

2013-01-01

Skin tests are of paramount importance for the evaluation of drug hypersensitivity reactions. Drug skin tests are often not carried out because of lack of concise information on specific test concentrations. The diagnosis of drug allergy is often based on history alone, which is an unreliable...... indicator of true hypersensitivity.To promote and standardize reproducible skin testing with safe and nonirritant drug concentrations in the clinical practice, the European Network and European Academy of Allergy and Clinical Immunology (EAACI) Interest Group on Drug Allergy has performed a literature...... search on skin test drug concentration in MEDLINE and EMBASE, reviewed and evaluated the literature in five languages using the GRADE system for quality of evidence and strength of recommendation. Where the literature is poor, we have taken into consideration the collective experience of the group...

Feedback control of plasma position in the HL-1 tokamak

International Nuclear Information System (INIS)

Yuan Baoshan; Jiao Boliang; Yang Kailing

1991-01-01

In the HL-1 tokamak with a thick copper shell, the control of plasma position is successfully performed by a feedback-feedforward system with dual mode regulator and the equilibrium field coils outside the shell. The plasma position can be controlled within ±2 mm in both vertical and horizontal directions under the condition that the iron core of transformer is not saturated

POSITION CONTROL OF BRUSHLESS DC MOTOR BASED ON DIGITAL SIGNAL PROCESSING

Directory of Open Access Journals (Sweden)

Çetin GENÇER

2006-01-01

Full Text Available Brushless DC Motors (BLDC have been used widely high performance control systems which are depended on to development of power electronic and control technology. In these motors to fed commutated supply, the control of position without oscilation has been required. In this study, position control of BLDC with digital signal processing has been implemented by a proportional-derivative (PD controller because of its simple structure. It has been seen that the controller which is proposed from simulation and experimental studies, has a quick dynamic responce with nonoscillation.

Signal differentiation in position tracking control of dc motors

International Nuclear Information System (INIS)

Beltran-Carbajal, F; Valderrabano-Gonzalez, A; Rosas-Caro, J C

2015-01-01

An asymptotic differentiation approach with respect to time is used for on-line estimation of velocity and acceleration signals in controlled dc motors. The attractive feature of this differentiator of signals is that it does not require any system mathematical model, which allows its use in engineering systems that require the signal differentiation for its control, identification, fault detection, among other applications. Moreover, it is shown that the differentiation approach can be applied for output signals showing a chaotic behavior. In addition a differential flatness control scheme with additional integral compensation of the output error is proposed for tracking tasks of position reference trajectories for direct current electric motors using angular position measurements only

Family Checkup: Positive Parenting Prevents Drug Abuse

Science.gov (United States)

... Alcohol Club Drugs Cocaine Fentanyl Hallucinogens Inhalants Heroin Marijuana MDMA (Ecstasy/Molly) Methamphetamine Opioids Over-the-Counter Medicines Prescription Medicines Steroids (Anabolic) Synthetic Cannabinoids (K2/Spice) Synthetic Cathinones (Bath Salts) Tobacco/ ...

Relationship between hunger, adherence to antiretroviral therapy and plasma HIV RNA suppression among HIV-positive illicit drug users in a Canadian setting.

Science.gov (United States)

Anema, Aranka; Kerr, Thomas; Milloy, M-J; Feng, Cindy; Montaner, Julio S G; Wood, Evan

2014-04-01

Food insecurity may be a barrier to achieving optimal HIV treatment-related outcomes among illicit drug users. This study therefore, aimed to assess the impact of severe food insecurity, or hunger, on plasma HIV RNA suppression among illicit drug users receiving antiretroviral therapy (ART). A cross-sectional Multivariate logistic regression model was used to assess the potential relationship between hunger and plasma HIV RNA suppression. A sample of n = 406 adults was derived from a community-recruited open prospective cohort of HIV-positive illicit drug users, in Vancouver, British Columbia (BC), Canada. A total of 235 (63.7%) reported "being hungry and unable to afford enough food," and 241 (59.4%) had plasma HIV RNA hunger was associated with lower odds of plasma HIV RNA suppression (Odds Ratio = 0.59, 95% confidence interval [CI]: 0.39-0.90, p = 0.015). In multivariate analyses, this association was no longer significant after controlling for socio-demographic, behavioral, and clinical characteristics, including 95% adherence (Adjusted Odds Ratio [AOR] = 0.65, 95% CI: 0.37-1.10, p = 0.105). Multivariate models stratified by 95% adherence found that the direction and magnitude of this association was not significantly altered by the adherence level. Hunger was common among illicit drug users in this setting. Although, there was an association between hunger and lower likelihood of plasma HIV RNA suppression, this did not persist in adjusted analyses. Further research is warranted to understand the social-structural, policy, and physical factors shaping the HIV outcomes of illicit drug users.

Positive predictive value of automated database records for diabetic ketoacidosis (DKA in children and youth exposed to antipsychotic drugs or control medications: a tennessee medicaid study

Directory of Open Access Journals (Sweden)

Bobo William V

2011-11-01

Full Text Available Abstract Background Diabetic ketoacidosis (DKA is a potentially life-threatening complication of treatment with some atypical antipsychotic drugs in children and youth. Because drug-associated DKA is rare, large automated health outcomes databases may be a valuable data source for conducting pharmacoepidemiologic studies of DKA associated with exposure to individual antipsychotic drugs. However, no validated computer case definition of DKA exists. We sought to assess the positive predictive value (PPV of a computer case definition to detect incident cases of DKA, using automated records of Tennessee Medicaid as the data source and medical record confirmation as a "gold standard." Methods The computer case definition of DKA was developed from a retrospective cohort study of antipsychotic-related type 2 diabetes mellitus (1996-2007 in Tennessee Medicaid enrollees, aged 6-24 years. Thirty potential cases with any DKA diagnosis (ICD-9 250.1, ICD-10 E1x.1 were identified from inpatient encounter claims. Medical records were reviewed to determine if they met the clinical definition of DKA. Results Of 30 potential cases, 27 (90% were successfully abstracted and adjudicated. Of these, 24 cases were confirmed by medical record review (PPV 88.9%, 95% CI 71.9 to 96.1%. Three non-confirmed cases presented acutely with severe hyperglycemia, but had no evidence of acidosis. Conclusions Diabetic ketoacidosis in children and youth can be identified in a computerized Medicaid database using our case definition, which could be useful for automated database studies in which drug-associated DKA is the outcome of interest.

Ingenious pH-sensitive dextran/mesoporous silica nanoparticles based drug delivery systems for controlled intracellular drug release.

Science.gov (United States)

Zhang, Min; Liu, Jia; Kuang, Ying; Li, Qilin; Zheng, Di-Wei; Song, Qiongfang; Chen, Hui; Chen, Xueqin; Xu, Yanglin; Li, Cao; Jiang, Bingbing

2017-05-01

In this work, dextran, a polysaccharide with excellent biocompatibility, is applied as the "gatekeeper" to fabricate the pH-sensitive dextran/mesoporous silica nanoparticles (MSNs) based drug delivery systems for controlled intracellular drug release. Dextran encapsulating on the surface of MSNs is oxidized by NaIO 4 to obtain three kinds of dextran dialdehydes (PADs), which are then coupled with MSNs via pH-sensitive hydrazone bond to fabricate three kinds of drug carriers. At pH 7.4, PADs block the pores to prevent premature release of anti-cancer drug doxorubicin hydrochloride (DOX). However, in the weakly acidic intracellular environment (pH∼5.5) the hydrazone can be ruptured; and the drug can be released from the carriers. The drug loading capacity, entrapment efficiency and release rates of the drug carriers can be adjusted by the amount of NaIO 4 applied in the oxidation reaction. And from which DOX@MSN-NH-N=C-PAD 10 is chosen as the most satisfactory one for the further in vitro cytotoxicity studies and cellular uptake studies. The results demonstrate that DOX@MSN-NH-N=C-PAD 10 with an excellent pH-sensitivity can enter HeLa cells to release DOX intracellular due to the weakly acidic pH intracellular and kill the cells. In our opinion, the ingenious pH-sensitive drug delivery systems have application potentials for cancer therapy. Copyright © 2017 Elsevier B.V. All rights reserved.

Prevalence and sunlight photolysis of controlled and chemotherapeutic drugs in aqueous environments

International Nuclear Information System (INIS)

Lin, Angela Yu-Chen; Lin, Yen-Ching; Lee, Wan-Ning

2014-01-01

This study addresses the occurrences and natural fates of chemotherapeutics and controlled drugs when found together in hospital effluents and surface waters. The results revealed the presence of 11 out of 16 drugs in hospital effluents, and the maximum detected concentrations were at the μg L −1 level in the hospital effluents and the ng L −1 level in surface waters. The highest concentrations corresponded to meperidine, morphine, 5-fluorouracil and cyclophosphamide. The sunlight photolysis of the target compounds was investigated, and the results indicated that morphine and codeine can be significantly attenuated, with half-lives of 0.27 and 2.5 h, respectively, in natural waters. Photolysis can lower the detected environmental concentrations, also lowering the estimated environmental risks of the target drugs to human health. Nevertheless, 5-fluorouracil and codeine were found to have a high risk quotient (RQ), demonstrating the high risks of directly releasing hospital wastewater into the environment. - Highlights: • High occurrence of chemotherapeutics and controlled substances in aqueous systems. • Photolysis lowers the detected concentrations of morphine and codeine. • 5-fluorouracil and codeine in hospital effluents have high risk quotients. - Chemotherapeutics and controlled drugs occur at significant levels in hospital effluents and surface waters. Natural sunlight photolysis reduces their environmental occurrence

Dynamic Positioning of Ships : A nonlinear control design study

NARCIS (Netherlands)

Muhammad, S.

2012-01-01

Dynamic positioning (DP) is relatively a new technique used to maintain the position and heading of ships in various offshore operations. Due to the features like better safety and operating efficiency, DP systems are becoming more and more popular. This thesis mainly focusses on the control system

Position and attitude tracking control for a quadrotor UAV.

Science.gov (United States)

Xiong, Jing-Jing; Zheng, En-Hui

2014-05-01

A synthesis control method is proposed to perform the position and attitude tracking control of the dynamical model of a small quadrotor unmanned aerial vehicle (UAV), where the dynamical model is underactuated, highly-coupled and nonlinear. Firstly, the dynamical model is divided into a fully actuated subsystem and an underactuated subsystem. Secondly, a controller of the fully actuated subsystem is designed through a novel robust terminal sliding mode control (TSMC) algorithm, which is utilized to guarantee all state variables converge to their desired values in short time, the convergence time is so small that the state variables are acted as time invariants in the underactuated subsystem, and, a controller of the underactuated subsystem is designed via sliding mode control (SMC), in addition, the stabilities of the subsystems are demonstrated by Lyapunov theory, respectively. Lastly, in order to demonstrate the robustness of the proposed control method, the aerodynamic forces and moments and air drag taken as external disturbances are taken into account, the obtained simulation results show that the synthesis control method has good performance in terms of position and attitude tracking when faced with external disturbances. Copyright © 2014 ISA. Published by Elsevier Ltd. All rights reserved.

Country-wide surveillance of molecular markers of antimalarial drug resistance in Senegal by use of positive Malaria Rapid Diagnostic Tests

DEFF Research Database (Denmark)

Ndiaye, Magatte; Sow, Doudou; Nag, Sidsel

2017-01-01

of drug resistance. Therefore, surveillance of drug resistance in the malaria parasites is essential. The objective of this pilot study was to test the feasibility of routinely sampled malaria rapid diagnostic tests (RDTs) at a national scale to assess the temporal changes in the molecular profiles...... of antimalarial drug resistance markers of Plasmodium falciparum parasites. Overall, 9,549 positive malaria RDTs were collected from 14 health facilities across the country. A limited random set of RDTs were analyzed regarding Pfcrt gene polymorphisms at codon 72-76. Overall, a high but varied prevalence (> 50...

Study of Globus-M Tokamak Poloidal System and Plasma Position Control

Science.gov (United States)

Dokuka, V. N.; Korenev, P. S.; Mitrishkin, Yu. V.; Pavlova, E. A.; Patrov, M. I.; Khayrutdinov, R. R.

2017-12-01

In order to provide efficient performance of tokamaks with vertically elongated plasma position, control systems for limited and diverted plasma configuration are required. The accuracy, stability, speed of response, and reliability of plasma position control as well as plasma shape and current control depend on the performance of the control system. Therefore, the problem of the development of such systems is an important and actual task in modern tokamaks. In this study, the measured signals from the magnetic loops and Rogowski coils are used to reconstruct the plasma equilibrium, for which linear models in small deviations are constructed. We apply methods of the H∞-optimization theory to the synthesize control system for vertical and horizontal position of plasma capable to working with structural uncertainty of the models of the plant. These systems are applied to the plasma-physical DINA code which is configured for the tokamak Globus-M plasma. The testing of the developed systems applied to the DINA code with Heaviside step functions have revealed the complex dynamics of plasma magnetic configurations. Being close to the bifurcation point in the parameter space of unstable plasma has made it possible to detect an abrupt change in the X-point position from the top to the bottom and vice versa. Development of the methods for reconstruction of plasma magnetic configurations and experience in designing plasma control systems with feedback for tokamaks provided an opportunity to synthesize new digital controllers for plasma vertical and horizontal position stabilization. It also allowed us to test the synthesized digital controllers in the closed loop of the control system with the DINA code as a nonlinear model of plasma.

Using Positive Deviance for Determining Successful Weight-Control Practices

Science.gov (United States)

Stuckey, Heather L.; Boan, Jarol; Kraschnewski, Jennifer L.; Miller-Day, Michelle; Lehman, Erik B.; Sciamanna, Christopher N.

2013-01-01

Based on positive deviance (examining the practices of successful individuals), we identified five primary themes from 36 strategies that help to maintain long-term weight loss (weight control) in 61 people. We conducted in-depth interviews to determine what successful individuals did and/or thought about regularly to control their weight. The themes included weight-control practices related to (a) nutrition: increase water, fruit, and vegetable intake, and consistent meal timing and content; (b) physical activity: follow and track an exercise routine at least 3×/week; (c) restraint: practice restraint by limiting and/or avoiding unhealthy foods; (d) self-monitor: plan meals, and track calories/weight progress; and (e) motivation: participate in motivational programs and cognitive processes that affect weight-control behavior. Using the extensive data involving both the practices and practice implementation, we used positive deviance to create a comprehensive list of practices to develop interventions for individuals to control their weight. PMID:20956609

Preparation and drug controlled release of porous octyl-dextran microspheres.

Science.gov (United States)

Hou, Xin; Liu, Yanfei

2015-01-01

In this work, porous octyl-dextran microspheres with excellent properties were prepared by two steps. Firstly, dextran microspheres were synthesized by reversed-phase suspension polymerization. Secondly, octyl-dextran microspheres were prepared by the reaction between dextran microspheres and ethylhexyl glycidyl ether and freezing-drying method. Porous structure of microspheres was formed through the interaction between octyl groups and organic solvents. The structure, morphology, dry density, porosity and equilibrium water content of porous octyl-dextran microspheres were systematically investigated. The octyl content affected the properties of microspheres. The results showed that the dry density of microspheres decreased from 2.35 to 1.21 g/ml, porosity increased from 80.68 to 95.05% with the octyl content increasing from 0.49 to 2.28 mmol/g. Meanwhile, the equilibrium water content presented a peak value (90.18%) when the octyl content was 2.25 mmol/g. Octyl-dextran microspheres showed high capacity. Naturally drug carriers play an important role in drug-delivery systems for their biodegradability, wide raw materials sources and nontoxicity. Doxorubicin (DOX) was used as a drug model to examine the drug-loading capacity of porous octyl-dextran microspheres. The drug-loading efficiency increased with the increase in microspheres/drug ratio, while the encapsulation efficiency decreased. When microspheres/drug mass ratio was 4/1, the drug-loading efficiency and encapsulation efficiency were 10.20 and 51.00%, respectively. The release rate of DOX increased as drug content and porosity increased. In conclusion, porous octyl-dextran microspheres were synthesized successfully and have the potential to serve as an effective delivery system in drug controlled release.

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.

Alcohol and Drug Use in Young Apprentices: Effect of Social Control in the Family.

Science.gov (United States)

Burcu, Esra

2003-01-01

Examined the social control used by families of young apprentices in Turkey in relation to deviant behaviors, such as alcohol and drug use. Data for 397 apprentices show that those who use alcohol are most frequently exposed to stringent controls and oral and physical violence, and those who use drugs frequently were exposed to battering by their…

Cardiovascular drugs and the risk of suicide: a nested case-control study

DEFF Research Database (Denmark)

Callréus, Torbjörn; Agerskov Andersen, Ulla; Hallas, Jesper

2007-01-01

OBJECTIVE: During the past 30 years, various cardiovascular drugs have been implicated as causes of depression or suicide. Although the evidence for causal relationships has generally been conflicting, both beta-blockers and angiotensin-converting-enzyme inhibitors (ACE-inhibitors) have been...... related to depression. Lipid-lowering therapies and calcium-channel blockers have also been linked to an increased risk of suicide. In this study, we investigated the possible association between the use of cardiovascular drugs and suicide using population-based register data. METHODS: We performed...... a nested case-control study in the county of Funen, Denmark, that consisted of 743 cases of completed suicide identified in a Death Registry for the period 1991-1998 and 14,860 age- and sex-matched controls. Information on previous drug use was retrieved from prescription data and the association between...

Variable pattern contamination control under positive pressure

International Nuclear Information System (INIS)

Philippi, H.M.

1997-01-01

Airborne contamination control in nuclear and biological laboratories is traditionally achieved by directing the space ventilation air at subatmospheric pressures in one fixed flow pattern. However, biological and nuclear contamination flow control in the new Biological Research Facility, to be commissioned at the Chalk River Laboratories in 1996, will have the flexibility to institute a number of contamination control patterns, all achieved at positive (above atmospheric) pressures. This flexibility feature, made possible by means of a digitally controlled ventilation system, changes the facility ventilation system from being a relatively rigid building service operated by plant personnel into a flexible building service which can be operated by the facility research personnel. This paper focuses on and describes the application of these unique contamination control features in the design of the new Biological Research Facility. 3 refs., 7 figs

Variable pattern contamination control under positive pressure

Energy Technology Data Exchange (ETDEWEB)

Philippi, H.M. [Chalk River Labs., Ontario (Canada)

1997-08-01

Airborne contamination control in nuclear and biological laboratories is traditionally achieved by directing the space ventilation air at subatmospheric pressures in one fixed flow pattern. However, biological and nuclear contamination flow control in the new Biological Research Facility, to be commissioned at the Chalk River Laboratories in 1996, will have the flexibility to institute a number of contamination control patterns, all achieved at positive (above atmospheric) pressures. This flexibility feature, made possible by means of a digitally controlled ventilation system, changes the facility ventilation system from being a relatively rigid building service operated by plant personnel into a flexible building service which can be operated by the facility research personnel. This paper focuses on and describes the application of these unique contamination control features in the design of the new Biological Research Facility. 3 refs., 7 figs.

Multi-Drug-Loaded Microcapsules with Controlled Release for Management of Parkinson's Disease.

Science.gov (United States)

Baek, Jong-Suep; Choo, Chee Chong; Qian, Cheng; Tan, Nguan Soon; Shen, Zexiang; Loo, Say Chye Joachim

2016-07-01

Parkinson's disease (PD) is a progressive disease of the nervous system, and is currently managed through commercial tablets that do not sufficiently enable controlled, sustained release capabilities. It is hypothesized that a drug delivery system that provides controlled and sustained release of PD drugs would afford better management of PD. Hollow microcapsules composed of poly-l-lactide (PLLA) and poly (caprolactone) (PCL) are prepared through a modified double-emulsion technique. They are loaded with three PD drugs, i.e., levodopa (LD), carbidopa (CD), and entacapone (ENT), at a ratio of 4:1:8, similar to commercial PD tablets. LD and CD are localized in both the hollow cavity and PLLA/PCL shell, while ENT is localized in the PLLA/PCL shell. Release kinetics of hydrophobic ENT is observed to be relatively slow as compared to the other hydrophilic drugs. It is further hypothesized that encapsulating ENT into PCL as a surface coating onto these microcapsules can aid in accelerating its release. Now, these spray-coated hollow microcapsules exhibit similar release kinetics, according to Higuchi's rate, for all three drugs. The results suggest that multiple drug encapsulation of LD, CD, and ENT in gastric floating microcapsules could be further developed for in vivo evaluation for the management of PD. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Performance estimation of control rod position indicator due to aging of magnet

International Nuclear Information System (INIS)

Yu, Je Yong; Kim, Ji Ho; Huh, Hyung; Choi, Myoung Hwan; Sohn, Dong Seong

2009-01-01

The Control Element Drive Mechanism (CEDM) for the integral reactor is designed to raise and lower the control rod in steps of 2mm in order to satisfy the design features of the integral reactor which are the soluble boron free operation and the use of a nuclear heating for the reactor start-up. The actual position of the control rod could be achieved to sense the magnet connected to the control rod by the position indicator around the upper pressure housing of CEDM. It is sufficient that the actual position information of control rod at 20mm interval from the position indicator is used for the core safety analysis. As the magnet moves upward along the position indicator assembly from the bottom to the top in the upper pressure housing, the output voltage increases linearly step-wise at 0.2VDC increments. Between every step there are transient areas which occur by a contact closing of three reed switches which is the 2-3-2 contact closing sequence. In this paper the output voltage signal corresponding to the position of control rod was estimated on the 2-1-2 contact closing sequence due to the aging of the magnet.

Positive and negative dimensions of weight control motivation.

Science.gov (United States)

Stotland, S; Larocque, M; Sadikaj, G

2012-01-01

This study examined weight control motivation among patients (N=5460 females and 547 males) who sought weight loss treatment with family physicians. An eight-item measure assessed the frequency of thoughts and feelings related to weight control "outcome" (e.g. expected physical and psychological benefits) and "process" (e.g. resentment and doubt). Factor analysis supported the existence of two factors, labeled Positive and Negative motivation. Positive motivation was high (average frequency of thoughts about benefits was 'every day') and stable throughout treatment, while Negative motivation declined rapidly and then stabilized. The determinants of changes in the Positive and Negative dimensions during treatment were examined within 3 time frames: first month, months 2-6, and 6-12. Maintenance of high scores on Positive motivation was associated with higher BMI and more disturbed eating habits. Early reductions in Negative motivation were greater for those starting treatment with higher weight and more disturbed eating habits, but less depression and stress, while later reductions in Negative motivation were predicted by improvements in eating habits, weight, stress and perfectionism. Clinicians treating obesity should be sensitive to fluctuations in both motivational dimensions, as they are likely to play a central role in determining long-term behavior and weight change. Copyright © 2011 Elsevier Ltd. All rights reserved.

Skin test concentrations for systemically administered drugs -- an ENDA/EAACI Drug Allergy Interest Group position paper

NARCIS (Netherlands)

Brockow, K.; Garvey, L. H.; Aberer, W.; Atanaskovic-Markovic, M.; Barbaud, A.; Bilo, M. B.; Bircher, A.; Blanca, M.; Bonadonna, B.; Campi, P.; Castro, E.; Cernadas, J. R.; Chiriac, A. M.; Demoly, P.; Grosber, M.; Gooi, J.; Lombardo, C.; Mertes, P. M.; Mosbech, H.; Nasser, S.; Pagani, M.; Ring, J.; Romano, A.; Scherer, K.; Schnyder, B.; Testi, S.; Torres, M.; Trautmann, A.; Terreehorst, I.

2013-01-01

Skin tests are of paramount importance for the evaluation of drug hypersensitivity reactions. Drug skin tests are often not carried out because of lack of concise information on specific test concentrations. The diagnosis of drug allergy is often based on history alone, which is an unreliable

Tunable drug loading and release from polypeptide multilayer nanofilms

Science.gov (United States)

Jiang, Bingbing; Li, Bingyun

2009-01-01

Polypeptide multilayer nanofilms were prepared using electrostatic layer-by-layer self-assembly nanotechnology. Small charged drug molecules (eg, cefazolin, gentamicin, and methylene blue) were loaded in polypeptide multilayer nanofilms. Their loading and release were found to be pH-dependent and could also be controlled by changing the number of film layers and drug incubation time, and applying heat-treatment after film formation. Antibioticloaded polypeptide multilayer nanofilms showed controllable antibacterial properties against Staphylococcus aureus. The developed biodegradable polypeptide multilayer nanofilms are capable of loading both positively- and negatively-charged drug molecules and promise to serve as drug delivery systems on biomedical devices for preventing biomedical device-associated infection, which is a significant clinical complication for both civilian and military patients. PMID:19421369

Transmission pattern of drug-resistant tuberculosis and its implication for tuberculosis control in eastern rural China.

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Yi Hu

Full Text Available OBJECTIVE: Transmission patterns of drug-resistant Mycobacterium tuberculosis (MTB may be influenced by differences in socio-demographics, local tuberculosis (TB endemicity and efficaciousness of TB control programs. This study aimed to investigate the impact of DOTS on the transmission of drug-resistant TB in eastern rural China. METHODS: We conducted a cross-sectional study of all patients diagnosed with drug-resistant TB over a one-year period in two rural Chinese counties with varying lengths of DOTS implementation. Counties included Deqing, with over 11 years' DOTS implementation and Guanyun, where DOTS was introduced 1 year prior to start of this study. We combined demographic, clinical and epidemiologic information with IS6110-based restricted fragment length polymorphism (RFLP and Spoligotyping analysis of MTB isolates. In addition, we conducted DNA sequencing of resistance determining regions to first-line anti-tuberculosis agents. RESULTS: Of the 223 drug-resistant isolates, 73(32.7% isolates were identified with clustered IS6110RFLP patterns. The clustering proportion among total drug-resistant TB was higher in Guanyun than Deqing (26/101.vs.47/122; p,0.04, but not significantly different among the 53 multidrug-resistant isolates (10/18.vs.24/35; p,0.35. Patients with cavitary had increased risk of clustering in both counties. In Guanyun, patients with positive smear test or previous treatment history had a higher clustering proportion. Beijing genotype and isolates resistant to isoniazid and/or rifampicin were more likely to be clustered. Of the 73 patients with clustered drug-resistant isolates, 71.2% lived in the same or neighboring villages. Epidemiological link (household and social contact was confirmed in 12.3% of the clustered isolates. CONCLUSION: Transmission of drug-resistant TB in eastern rural China is characterized by small clusters and limited geographic spread. Our observations highlight the need for supplementing DOTS

Nonlinear control of ships minimizing the position tracking errors

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Svein P. Berge

1999-07-01

Full Text Available In this paper, a nonlinear tracking controller with integral action for ships is presented. The controller is based on state feedback linearization. Exponential convergence of the vessel-fixed position and velocity errors are proven by using Lyapunov stability theory. Since we only have two control devices, a rudder and a propeller, we choose to control the longship and the sideship position errors to zero while the heading is stabilized indirectly. A Virtual Reference Point (VRP is defined at the bow or ahead of the ship. The VRP is used for tracking control. It is shown that the distance from the center of rotation to the VRP will influence on the stability of the zero dynamics. By selecting the VRP at the bow or even ahead of the bow, the damping in yaw can be increased and the zero dynamics is stabilized. Hence, the heading angle will be less sensitive to wind, currents and waves. The control law is simulated by using a nonlinear model of the Japanese training ship Shiojimaru with excellent results. Wind forces are added to demonstrate the robustness and performance of the integral controller.

Controlling drug delivery kinetics from mesoporous titania thin films by pore size and surface energy

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Karlsson J

2015-07-01

Full Text Available Johan Karlsson, Saba Atefyekta, Martin Andersson Department of Chemical and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden Abstract: The osseointegration capacity of bone-anchoring implants can be improved by the use of drugs that are administrated by an inbuilt drug delivery system. However, to attain superior control of drug delivery and to have the ability to administer drugs of varying size, including proteins, further material development of drug carriers is needed. Mesoporous materials have shown great potential in drug delivery applications to provide and maintain a drug concentration within the therapeutic window for the desired period of time. Moreover, drug delivery from coatings consisting of mesoporous titania has shown to be promising to improve healing of bone-anchoring implants. Here we report on how the delivery of an osteoporosis drug, alendronate, can be controlled by altering pore size and surface energy of mesoporous titania thin films. The pore size was varied from 3.4 nm to 7.2 nm by the use of different structure-directing templates and addition of a swelling agent. The surface energy was also altered by grafting dimethylsilane to the pore walls. The drug uptake and release profiles were monitored in situ using quartz crystal microbalance with dissipation (QCM-D and it was shown that both pore size and surface energy had a profound effect on both the adsorption and release kinetics of alendronate. The QCM-D data provided evidence that the drug delivery from mesoporous titania films is controlled by a binding–diffusion mechanism. The yielded knowledge of release kinetics is crucial in order to improve the in vivo tissue response associated to therapeutic treatments. Keywords: mesoporous titania, controlled drug delivery, release kinetics, alendronate, QCM-D

Robust Operation of Tendon-Driven Robot Fingers Using Force and Position-Based Control Laws

Science.gov (United States)

Abdallah, Muhammad E (Inventor); Platt, Jr., Robert J. (Inventor); Reiland, Matthew J (Inventor); Hargrave, Brian (Inventor); Diftler, Myron A (Inventor); Strawser, Philip A (Inventor); Ihrke, Chris A. (Inventor)

2013-01-01

A robotic system includes a tendon-driven finger and a control system. The system controls the finger via a force-based control law when a tension sensor is available, and via a position-based control law when a sensor is not available. Multiple tendons may each have a corresponding sensor. The system selectively injects a compliance value into the position-based control law when only some sensors are available. A control system includes a host machine and a non-transitory computer-readable medium having a control process, which is executed by the host machine to control the finger via the force- or position-based control law. A method for controlling the finger includes determining the availability of a tension sensor(s), and selectively controlling the finger, using the control system, via the force or position-based control law. The position control law allows the control system to resist disturbances while nominally maintaining the initial state of internal tendon tensions.

Fertility drug use and the risk of ovarian tumors in infertile women: a case-control study.

Science.gov (United States)

Asante, Albert; Leonard, Phoebe H; Weaver, Amy L; Goode, Ellen L; Jensen, Jani R; Stewart, Elizabeth A; Coddington, Charles C

2013-06-01

To assess the influence of infertility and fertility drugs on risk of ovarian tumors. Case-control study (Mayo Clinic Ovarian Cancer Study). Ongoing academic study of ovarian cancer. A total of 1,900 women (1,028 with ovarian tumors and 872 controls, frequency matched on age and region of residence) who had provided complete information in a self-report questionnaire about history of infertility and fertility drug use. None. Effect of infertility history, use of fertility drugs and oral contraception, and gravidity on the risk of ovarian tumor development, after controlling for potential confounders. Among women who had a history of infertility, use of fertility drugs was reported by 44 (24%) of 182 controls and 38 (17%) of 226 cases. Infertile women who used fertility drugs were not at increased risk of developing ovarian tumors compared with infertile women who did not use fertility drugs; the adjusted odds ratio was 0.64 (95% CI, 0.37, 1.11). The findings were similar when stratified by gravidity and when analyzed separately for borderline versus invasive tumors. We found no statistically significant association between fertility drug use and risk of ovarian tumors. Further larger, prospective studies are needed to confirm this observation. Published by Elsevier Inc.

77 FR 16123 - Draft Guidance for Industry and Food and Drug Administration Staff; Class II Special Controls...

Science.gov (United States)

2012-03-19

... Guidance for Industry and Food and Drug Administration Staff; Class II Special Controls Guidance Document... Drug Administration 21 CFR Part 866 Draft Guidance for Industry and Food and Drug Administration Staff; Class II Special Controls Guidance Document: Nucleic Acid-Based In Vitro Diagnostic Devices for the...

Mesoporous silica nanoparticles for stimuli-responsive controlled drug delivery: advances, challenges, and outlook

Directory of Open Access Journals (Sweden)

Song Y

2016-12-01

Full Text Available Yuanhui Song, Yihong Li, Qien Xu, Zhe Liu Wenzhou Institute of Biomaterials and Engineering (WIBE, Wenzhou Medical University, Wenzhou, Zhejiang, People’s Republic of China Abstract: With the development of nanotechnology, the application of nanomaterials in the field of drug delivery has attracted much attention in the past decades. Mesoporous silica nanoparticles as promising drug nanocarriers have become a new area of interest in recent years due to their unique properties and capabilities to efficiently entrap cargo molecules. This review describes the latest advances on the application of mesoporous silica nanoparticles in drug delivery. In particular, we focus on the stimuli-responsive controlled release systems that are able to respond to intracellular environmental changes, such as pH, ATP, GSH, enzyme, glucose, and H2O2. Moreover, drug delivery induced by exogenous stimuli including temperature, light, magnetic field, ultrasound, and electricity is also summarized. These advanced technologies demonstrate current challenges, and provide a bright future for precision diagnosis and treatment. Keywords: mesoporous silica nanoparticle, drug delivery system, controlled release, stimuli-responsive, chemotherapy

Identifying Demand Responses to Illegal Drug Supply Interdictions.

Science.gov (United States)

Cunningham, Scott; Finlay, Keith

2016-10-01

Successful supply-side interdictions into illegal drug markets are predicated on the responsiveness of drug prices to enforcement and the price elasticity of demand for addictive drugs. We present causal estimates that targeted interventions aimed at methamphetamine input markets ('precursor control') can temporarily increase retail street prices, but methamphetamine consumption is weakly responsive to higher drug prices. After the supply interventions, purity-adjusted prices increased then quickly returned to pre-treatment levels within 6-12 months, demonstrating the short-term effects of precursor control. The price elasticity of methamphetamine demand is -0.13 to -0.21 for self-admitted drug treatment admissions and between -0.24 and -0.28 for hospital inpatient admissions. We find some evidence of a positive cross-price effect for cocaine, but we do not find robust evidence that increases in methamphetamine prices increased heroin, alcohol, or marijuana drug use. This study can inform policy discussions regarding other synthesized drugs, including illicit use of pharmaceuticals. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

Patents associated with high-cost drugs in Australia.

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Andrew F Christie

Full Text Available Australia, like most countries, faces high and rapidly-rising drug costs. There are longstanding concerns about pharmaceutical companies inappropriately extending their monopoly position by "evergreening" blockbuster drugs, through misuse of the patent system. There is, however, very little empirical information about this behaviour. We fill the gap by analysing all of the patents associated with 15 of the costliest drugs in Australia over the last 20 years. Specifically, we search the patent register to identify all the granted patents that cover the active pharmaceutical ingredient of the high-cost drugs. Then, we classify the patents by type, and identify their owners. We find a mean of 49 patents associated with each drug. Three-quarters of these patents are owned by companies other than the drug's originator. Surprisingly, the majority of all patents are owned by companies that do not have a record of developing top-selling drugs. Our findings show that a multitude of players seek monopoly control over innovations to blockbuster drugs. Consequently, attempts to control drug costs by mitigating misuse of the patent system are likely to miss the mark if they focus only on the patenting activities of originators.

Patents associated with high-cost drugs in Australia.

Science.gov (United States)

Christie, Andrew F; Dent, Chris; McIntyre, Peter; Wilson, Lachlan; Studdert, David M

2013-01-01

Australia, like most countries, faces high and rapidly-rising drug costs. There are longstanding concerns about pharmaceutical companies inappropriately extending their monopoly position by "evergreening" blockbuster drugs, through misuse of the patent system. There is, however, very little empirical information about this behaviour. We fill the gap by analysing all of the patents associated with 15 of the costliest drugs in Australia over the last 20 years. Specifically, we search the patent register to identify all the granted patents that cover the active pharmaceutical ingredient of the high-cost drugs. Then, we classify the patents by type, and identify their owners. We find a mean of 49 patents associated with each drug. Three-quarters of these patents are owned by companies other than the drug's originator. Surprisingly, the majority of all patents are owned by companies that do not have a record of developing top-selling drugs. Our findings show that a multitude of players seek monopoly control over innovations to blockbuster drugs. Consequently, attempts to control drug costs by mitigating misuse of the patent system are likely to miss the mark if they focus only on the patenting activities of originators.

Immobilization and controlled release of drug using plasma polymerized thin film

Energy Technology Data Exchange (ETDEWEB)

Myung, Sung-Woon [Department of Dental Materials, School of Dentistry, MRC Center, Chosun University, 309 Pilmun-daero, Dong-gu, Gwangju (Korea, Republic of); Jung, Sang-Chul [Department of Environmental Engineering, Sunchon National University, Sunchon 540-742 (Korea, Republic of); Kim, Byung-Hoon, E-mail: kim5055@chosun.ac.kr [Department of Dental Materials, School of Dentistry, MRC Center, Chosun University, 309 Pilmun-daero, Dong-gu, Gwangju (Korea, Republic of)

2015-06-01

In this study, plasma polymerization of acrylic acid was employed to immobilize drug and control its release. Doxorubicin (DOX) was immobilized covalently on the glass surface deposited with plasma polymerized acrylic acid (PPAAc) thin film containing the carboxylic group. At first, the PPAAc thin film was coated on a glass surface at a pressure of 1.33 Pa and radio frequency (RF) discharge power of 20 W for 10 min. DOX was immobilized on the PPAAc deposition in a two environment of phosphate buffer saline (PBS) and dimethyl sulfoxide (DMSO) solutions. The DOX immobilized surface was characterized by scanning electron microscope, atomic force microscope and attenuated total reflection Fourier transform infrared spectroscopy. The DOX molecules were more immobilized in PBS than DMSO solution. The different immobilization and release profiles of DOX result from the solubility of hydrophobic DOX in aqueous and organic solutions. Second, in order to control the release of the drug, PPAAc thin film was covered over DOX dispersed layer. Different thicknesses and cross-linked PPAAc thin films by adjusting deposition time and RF discharge power were covered on the DOX layer dispersed. PPAAc thin film coated DOX layer reduced the release rate of DOX. The thickness control of plasma deposition allows controlling the release rate of drug. - Highlights: • Doxorubicin was immobilized on the surface of plasma polymerized acrylic acid thin film. • Release profile of doxorubicin was affected by aqueous and organic solutions. • Plasma polymerized acrylic acid thin film can be used to achieve controlled release.

Immobilization and controlled release of drug using plasma polymerized thin film

International Nuclear Information System (INIS)

Myung, Sung-Woon; Jung, Sang-Chul; Kim, Byung-Hoon

2015-01-01

In this study, plasma polymerization of acrylic acid was employed to immobilize drug and control its release. Doxorubicin (DOX) was immobilized covalently on the glass surface deposited with plasma polymerized acrylic acid (PPAAc) thin film containing the carboxylic group. At first, the PPAAc thin film was coated on a glass surface at a pressure of 1.33 Pa and radio frequency (RF) discharge power of 20 W for 10 min. DOX was immobilized on the PPAAc deposition in a two environment of phosphate buffer saline (PBS) and dimethyl sulfoxide (DMSO) solutions. The DOX immobilized surface was characterized by scanning electron microscope, atomic force microscope and attenuated total reflection Fourier transform infrared spectroscopy. The DOX molecules were more immobilized in PBS than DMSO solution. The different immobilization and release profiles of DOX result from the solubility of hydrophobic DOX in aqueous and organic solutions. Second, in order to control the release of the drug, PPAAc thin film was covered over DOX dispersed layer. Different thicknesses and cross-linked PPAAc thin films by adjusting deposition time and RF discharge power were covered on the DOX layer dispersed. PPAAc thin film coated DOX layer reduced the release rate of DOX. The thickness control of plasma deposition allows controlling the release rate of drug. - Highlights: • Doxorubicin was immobilized on the surface of plasma polymerized acrylic acid thin film. • Release profile of doxorubicin was affected by aqueous and organic solutions. • Plasma polymerized acrylic acid thin film can be used to achieve controlled release

Use of drugs, alcohol and tobacco by people with schizophrenia: case-control study.

Science.gov (United States)

McCreadie, Robin G

2002-10-01

Specialised services should be developed to help people with schizophrenia and associated substance misuse. The extent of the problem therefore needs to be known. To determine the use of drugs, alcohol and tobacco by people with schizophrenia drawn from rural, suburban and urban settings, and to compare use by general population control subjects. People with schizophrenia (n=316) and general population controls of similar gender distribution, age and postcode area of residence (n=250) were identified in rural, urban and suburban areas of Scotland. Use of drugs and alcohol was assessed by the Schedules for Clinical Assessment in Neuropsychiatry, and use of tobacco by a questionnaire. More patients than controls reported problem use of drugs in the past year (22 (7%) v. 5 (2%)) and at some time before then (50 (20%) v. 15 (6%)) and problem use of alcohol in the past year (42 (17%) v. 25 (10%)) but not at some time previously (99 (40%) v. 84 (34%)). More patients were current smokers (162 (65%) v. 99 (40%)). Problem use of drugs and alcohol by people with schizophrenia is greater than in the general population, but absolute numbers are small. Tobacco use is the greatest problem.

Chitosan/alginate based multilayers to control drug release from ophthalmic lens.

Science.gov (United States)

Silva, Diana; Pinto, Luís F V; Bozukova, Dimitriya; Santos, Luís F; Serro, Ana Paula; Saramago, Benilde

2016-11-01

In this study we investigated the possibility of using layer-by-layer deposition, based in natural polymers (chitosan and alginate), to control the release of different ophthalmic drugs from three types of lens materials: a silicone-based hydrogel recently proposed by our group as drug releasing soft contact lens (SCL) material and two commercially available materials: CI26Y for intraocular lens (IOLs) and Definitive 50 for SCLs. The optimised coating, consisting in one double layer of (alginate - CaCl2)/(chitosan+glyoxal) topped with a final alginate-CaCl2 layer to avoid chitosan degradation by tear fluid proteins, proved to have excellent features to control the release of the anti-inflammatory, diclofenac, while keeping or improving the physical properties of the lenses. The coating leads to a controlled release of diclofenac from SCL and IOL materials for, at least, one week. Due to its high hydrophilicity (water contact angle≈0) and biocompatibility, it should avoid the use of further surface treatments to enhance the useŕs comfort. However, the barrier effect of this coating is specific for diclofenac, giving evidence to the need of optimizing the chemical composition of the layers in view of the desired drug. Copyright © 2016 Elsevier B.V. All rights reserved.

Pneumatic Rotary Actuator Position Servo System Based on ADE-PD Control

Directory of Open Access Journals (Sweden)

Yeming Zhang

2018-03-01

Full Text Available In order to accurately control the rotation position of a pneumatic rotary actuator, the flow state of the gas and the motion state of the pneumatic rotary actuator in the pneumatic rotary actuator position servo system are analyzed in this paper. The mathematical model of the system and the experiment platform are established after that. An Adaptive Differential Evolution (ADE algorithm which adaptively ameliorates the scaling factor and crossover probability in the process of individual evolution is proposed and applied to the parameter optimization of PD controller. The experimental platform is used to compare the controller with Differential Evolution (DE algorithm and NCD-PID controller. Finally, the characteristics of the system are tested by increasing the inertial load. The experimental results illustrate that system using ADE-PD control strategy has greater position precision and faster response than using DE-PD and NCD-PID strategies, and shows great robustness.

Thermosensitive liposomes entrapping iron oxide nanoparticles for controllable drug release

International Nuclear Information System (INIS)

Tai, L-A; Wang, Y-C; Wang, Y-J; Yang, C-S; Tsai, P-J; Lo, L-W

2009-01-01

Iron oxide nanoparticles can serve as a heating source upon alternative magnetic field (AMF) exposure. Iron oxide nanoparticles can be mixed with thermosensitive nanovehicles for hyperthermia-induced drug release, yet such a design and mechanism may not be suitable for controllable drug release applications in which the tissues are susceptible to environmental temperature change such as brain tissue. In the present study, iron oxide nanoparticles were entrapped inside of thermosensitive liposomes for AMF-induced drug release while the environmental temperature was maintained at a constant level. Carboxyfluorescein was co-entrapped with the iron oxide nanoparticles in the liposomes as a model compound for monitoring drug release and environmental temperature was maintained with a water circulator jacket. These experiments have been successfully performed in solution, in phantom and in anesthetized animals. Furthermore, the thermosensitive liposomes were administered into rat forearm skeletal muscle, and the release of carboxylfluorescein triggered by the external alternative magnetic field was monitored by an implanted microdialysis perfusion probe with an on-line laser-induced fluorescence detector. In the future such a device could be applied to simultaneous magnetic resonance imaging and non-invasive drug release in temperature-sensitive applications.

Neural effects of positive and negative incentives during marijuana withdrawal.

Directory of Open Access Journals (Sweden)

Francesca M Filbey

Full Text Available In spite of evidence suggesting two possible mechanisms related to drug-seeking behavior, namely reward-seeking and harm avoidance, much of the addiction literature has focused largely on positive incentivization mechanisms associated with addiction. In this study, we examined the contributing neural mechanisms of avoidance of an aversive state to drug-seeking behavior during marijuana withdrawal. To that end, marijuana users were scanned while performing the monetary incentive delay task in order to assess positive and negative incentive processes. The results showed a group x incentive interaction, such that marijuana users had greater response in areas that underlie reward processes during positive incentives while controls showed greater response in the same areas, but to negative incentives. Furthermore, a negative correlation between withdrawal symptoms and response in the amygdala during negative incentives was found in the marijuana users. These findings suggest that although marijuana users have greater reward sensitivity and less harm avoidance than controls, that attenuated amygdala response, an area that underlies fear and avoidance, was present in marijuana users with greater marijuana withdrawal symptoms. This is concordant with models of drug addiction that involve multiple sources of reinforcement in substance use disorders, and suggests the importance of strategies that focus on respective mechanisms.

Synthesis, characterization and in vitro cytotoxicity analysis of a novel cellulose based drug carrier for the controlled delivery of 5-fluorouracil, an anticancer drug

Science.gov (United States)

Anirudhan, Thayyath S.; Nima, Jayachandran; Divya, Peethambaran L.

2015-11-01

The present investigation concerns the development and evaluation of a novel drug delivery system, aminated-glycidylmethacrylate grafted cellulose-grafted polymethacrylic acid-succinyl cyclodextrin (Cell-g-(GMA/en)-PMA-SCD) for the controlled release of 5-Fluorouracil, an anticancer drug. The prepared drug carrier was characterized by FT-IR, XRD and SEM techniques. Binding kinetics and isotherm studies of 5-FU onto Cell-g-(GMA/en)-PMA-SCD were found to follow pseudo-second-order and Langmuir model respectively. Maximum binding capacity of drug carrier was found to be 149.09 mg g-1 at 37 °C. Swelling studies, in vitro release kinetics, drug loading efficiency and encapsulation efficiency of Cell-g-(GMA/en)-PMA-SCD were studied. The release kinetics was analyzed using Ritger-Peppas equation at pH 7.4. Cytotoxicity analysis on MCF-7 (human breast carcinoma) cells indicated that the drug carrier shows sustained and controlled release of drug to the target site. Hence, it is evident from this investigation that Cell-g-(GMA/en)-PMA-SCD could be a promising carrier for 5-FU.

Montmorillonite/Poly (L-Lactide microcomposite spheres as reservoirs of antidepressant drugs and their controlled release property

Directory of Open Access Journals (Sweden)

Shalini Rajkumar

2015-10-01

Full Text Available This work evaluates intercalation of Nortriptyline (NT and Venlafaxine (VFX in an interlayer gallery of Na+-MMT (Montmorillonite, which was further compounded with Poly (L-Lactide (PLLA to form microcomposite spheres (MPs for oral controlled drug delivery. The XRD patterns, thermal and spectroscopic analyses indicated intercalation of drugs into the MMT interlayer that was stabilized by electrostatic interaction. No significant changes in structural and functional properties of drugs were found in the MMT layers. In vitro drug release studies showed controlled release pattern.

Formulation, quality control and shelf life of the experimental cytostatic drug cyclopentenyl cytosine

NARCIS (Netherlands)

Schimmel, Kirsten; Guchelaar, Henk-Jan; van Kan, Erik

2006-01-01

This paper describes the formulation and quality control of an aqueous sterilized formulation of the experimental cytostatic drug cyclopentenyl cytosine (CPEC) to be used in Phase I/II clinical trials. The raw drug substance was extensively tested. A High Pressure Liquid Chromotography (HPLC) method

Influenza vaccination of HIV-1-positive and HIV-1-negative former intravenous drug users.

Science.gov (United States)

Amendola, A; Boschini, A; Colzani, D; Anselmi, G; Oltolina, A; Zucconi, R; Begnini, M; Besana, S; Tanzi, E; Zanetti, A R

2001-12-01

The immunogenicity of an anti-influenza vaccine was assessed in 409 former intravenous drug user volunteers and its effect on the levels of HIV-1 RNA, proviral DNA and on CD4+ lymphocyte counts in a subset HIV-1-positive subjects was measured. HIV-1-positive individuals (n = 72) were divided into three groups on the basis of their CD4+ lymphocyte counts, while the 337 HIV-1-negative participants were allocated into group four. Haemagglutination inhibiting (HI) responses varied from 45.8 to 70% in the HIV-1-positive subjects and were significantly higher in group four (80.7% responses to the H1N1 strain, 81.6% to the H3N2 strain, and 83% to the B strain). The percentage of subjects with HI protective antibody titres (> or = 1:40) increased significantly after vaccination, especially in HIV-1 uninfected subjects. Immunization caused no significant changes in CD4+ counts and in neither plasma HIV-1 RNA nor proviral DNA levels. Therefore, vaccination against influenza may benefit persons infected by HIV-1. Copyright 2001 Wiley-Liss, Inc.

Drug-loaded poly (ε-caprolactone)/Fe3O4 composite microspheres for magnetic resonance imaging and controlled drug delivery

Science.gov (United States)

Wang, Guangshuo; Zhao, Dexing; Li, Nannan; Wang, Xuehan; Ma, Yingying

2018-06-01

In this study, poly (ε-caprolactone) (PCL) microspheres loading magnetic Fe3O4 nanoparticles and anti-cancer drug of doxorubicin hydrochloride (DOX) were successfully prepared by a modified solvent-evaporation method. The obtained magnetic composite microspheres exhibited dual features of magnetic resonance imaging and controlled drug delivery. The morphology, structure, thermal behavior and magnetic properties of the drug-loaded magnetic microspheres were investigated in detail by SEM, XRD, DSC and SQUID. The obtained composite microspheres showed superparamagnetic behavior and T2-weighted enhancement effect. The drug loading, encapsulation efficiency, releasing behavior and in vitro cytotoxicity of the drug-loaded composite microspheres were systematically investigated. It was found that the values of drug loading and encapsulation efficiency were 36.7% and 25.8%, respectively. The composite microspheres were sensitive to pH and released in a sustained way, and both the release curves under various pH conditions (4.0 and 7.4) were well satisfied with the biphase kinetics function. In addition, the magnetic response of the drug-loaded microspheres was studied and the results showed that the composite microspheres had a good magnetic stability and strong targeting ability.

RODMOD: a code for control rod positioning

International Nuclear Information System (INIS)

Vondy, D.R.; Fowler, T.B.

1978-11-01

The report documents a computer code which has been implemented to position control rods according to a prescribed schedule during the calculation of a reactor history. Control rods may be represented explicitly with or without internal black absorber conditions in selected energy groups, or fractional insertion may be done, or both, in a problem. There is provision for control rod follower, movement of materials through a series of zones in a closed loop, and shutdown rod insertion and subsequent removal to allow the reactor history calculation to be continued. This code is incorporated in the system containing the VENTURE diffusion theory neutronics and the BURNER exposure codes for routine use. The implemented automated procedures cause the prescribed control rod insertion schedule to be applied without the access of additional user input data during the calculation of a reactor operating history

21 CFR 212.90 - What actions must I take to control the distribution of PET drug products?

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 4 2010-04-01 2010-04-01 false What actions must I take to control the... POSITRON EMISSION TOMOGRAPHY DRUGS (Eff. 12-12-2011) Distribution § 212.90 What actions must I take to control the distribution of PET drug products? (a) Written distribution procedures. You must establish...

Controlled release of cortisone drugs from block copolymers synthetized by ATRP

Science.gov (United States)

Valenti, G.; La Carta, S.; Mazzotti, G.; Rapisarda, M.; Perna, S.; Di Gesù, R.; Giorgini, L.; Carbone, D.; Recca, G.; Rizzarelli, P.

2016-05-01

Diseases affecting posterior eye segment, like macular edema, infection and neovascularization, may cause visual impairment. Traditional treatments, such as steroidal-drugs intravitreal injections, involve chronic course of therapy usually over a period of years. Moreover, they can require frequent administrations of drug in order to have an adequately disease control. This dramatically reduce patient's compliance. Efforts have been made to develop implantable devices that offer an alternative therapeutic approach to bypass many challenges of conventional type of therapy. Implantable drug delivery systems (DDS) have been developed to optimize therapeutic properties of drugs and ensure their slow release in the specific site. Polymeric materials can play an essential role in modulating drug delivery and their use in such field has become indispensable. During last decades, acrylic polymers have obtained growing interest. Biocompatibility and chemical properties make them extremely versatile, allowing their use in many field such as biomedical. In particular, block methacrylate copolymer with a balance of hydrophilic and hydrophobic properties can be suitable for prolonged DDS in biomedical devices. In this work, we focused on the realization of a system for controlled and long term release of betamethasone 17,21-dipropionate (BDP), a cortisone drug, from methacrylic block copolymers, to be tested in the treatment of the posterior eye's diseases. Different series of methyl methacrylate/hydroxyethyl methacrylate (MMA/HEMA) block and random copolymers, with different monomer compositions (10-60% HEMA), were synthetized by Atom Transfer Radical Polymerization (ATRP) to find the best hydrophilic/hydrophobic ratio, able to ensure optimal kinetic release. Copolymer samples were characterized by NMR spectroscopy (1H-NMR, 13C-NMR, CosY), SEC, TGA and DSC. Monitoring of drug release from films loaded with BDP was carried out by HPLC analysis. Evaluation of different kinetic

Controlled release of cortisone drugs from block copolymers synthetized by ATRP

Energy Technology Data Exchange (ETDEWEB)

Valenti, G.; La Carta, S.; Rapisarda, M.; Carbone, D.; Recca, G.; Rizzarelli, P., E-mail: paola.rizzarelli@cnr.it [Istituto per i Polimeri, Compositi e Biomateriali, Consiglio Nazionale delle Ricerche Via P. Gaifami 18, 95129 Catania (Italy); Mazzotti, G.; Giorgini, L. [Dipartimento di Chimica Industriale «Toso Montanari», Università di Bologna Via Risorgimento 4, 40136 Bologna (Italy); Perna, S. [ST Microelectronics Srl, Stradale Primosole, 50–95121 Catania (Italy); Di Gesù, R. [Merck Serono S.p.A., Via L. Einaudi, 11–00012 Guidonia Montecelio, Rome (Italy)

2016-05-18

Diseases affecting posterior eye segment, like macular edema, infection and neovascularization, may cause visual impairment. Traditional treatments, such as steroidal-drugs intravitreal injections, involve chronic course of therapy usually over a period of years. Moreover, they can require frequent administrations of drug in order to have an adequately disease control. This dramatically reduce patient’s compliance. Efforts have been made to develop implantable devices that offer an alternative therapeutic approach to bypass many challenges of conventional type of therapy. Implantable drug delivery systems (DDS) have been developed to optimize therapeutic properties of drugs and ensure their slow release in the specific site. Polymeric materials can play an essential role in modulating drug delivery and their use in such field has become indispensable. During last decades, acrylic polymers have obtained growing interest. Biocompatibility and chemical properties make them extremely versatile, allowing their use in many field such as biomedical. In particular, block methacrylate copolymer with a balance of hydrophilic and hydrophobic properties can be suitable for prolonged DDS in biomedical devices. In this work, we focused on the realization of a system for controlled and long term release of betamethasone 17,21-dipropionate (BDP), a cortisone drug, from methacrylic block copolymers, to be tested in the treatment of the posterior eye’s diseases. Different series of methyl methacrylate/hydroxyethyl methacrylate (MMA/HEMA) block and random copolymers, with different monomer compositions (10–60% HEMA), were synthetized by Atom Transfer Radical Polymerization (ATRP) to find the best hydrophilic/hydrophobic ratio, able to ensure optimal kinetic release. Copolymer samples were characterized by NMR spectroscopy ({sup 1}H-NMR, {sup 13}C-NMR, CosY), SEC, TGA and DSC. Monitoring of drug release from films loaded with BDP was carried out by HPLC analysis. Evaluation of

Controlled release of cortisone drugs from block copolymers synthetized by ATRP

International Nuclear Information System (INIS)

Valenti, G.; La Carta, S.; Rapisarda, M.; Carbone, D.; Recca, G.; Rizzarelli, P.; Mazzotti, G.; Giorgini, L.; Perna, S.; Di Gesù, R.

2016-01-01

Diseases affecting posterior eye segment, like macular edema, infection and neovascularization, may cause visual impairment. Traditional treatments, such as steroidal-drugs intravitreal injections, involve chronic course of therapy usually over a period of years. Moreover, they can require frequent administrations of drug in order to have an adequately disease control. This dramatically reduce patient’s compliance. Efforts have been made to develop implantable devices that offer an alternative therapeutic approach to bypass many challenges of conventional type of therapy. Implantable drug delivery systems (DDS) have been developed to optimize therapeutic properties of drugs and ensure their slow release in the specific site. Polymeric materials can play an essential role in modulating drug delivery and their use in such field has become indispensable. During last decades, acrylic polymers have obtained growing interest. Biocompatibility and chemical properties make them extremely versatile, allowing their use in many field such as biomedical. In particular, block methacrylate copolymer with a balance of hydrophilic and hydrophobic properties can be suitable for prolonged DDS in biomedical devices. In this work, we focused on the realization of a system for controlled and long term release of betamethasone 17,21-dipropionate (BDP), a cortisone drug, from methacrylic block copolymers, to be tested in the treatment of the posterior eye’s diseases. Different series of methyl methacrylate/hydroxyethyl methacrylate (MMA/HEMA) block and random copolymers, with different monomer compositions (10–60% HEMA), were synthetized by Atom Transfer Radical Polymerization (ATRP) to find the best hydrophilic/hydrophobic ratio, able to ensure optimal kinetic release. Copolymer samples were characterized by NMR spectroscopy ("1H-NMR, "1"3C-NMR, CosY), SEC, TGA and DSC. Monitoring of drug release from films loaded with BDP was carried out by HPLC analysis. Evaluation of different

21 CFR 1404.635 - May the Office of National Drug Control Policy settle a debarment or suspension action?

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 9 2010-04-01 2010-04-01 false May the Office of National Drug Control Policy settle a debarment or suspension action? 1404.635 Section 1404.635 Food and Drugs OFFICE OF NATIONAL DRUG CONTROL POLICY GOVERNMENTWIDE DEBARMENT AND SUSPENSION (NONPROCUREMENT) General Principles Relating to Suspension and Debarment Actions § 1404.635...

Radiation as a microbiological contamination control of drugs, cosmetics and medical devices

International Nuclear Information System (INIS)

Ishizeki, Chuichi

1985-01-01

This paper deals with current status of radiation sterilization or disinfection of drugs, cosmetics, their materials, and medical devices, and with quality control as a tool for securing microbiological safety, especially current status of sterilization tests. Ointment containing tetracyclin, steroid hormones, gelatin, and enzymes are presented as drug samples to be irradiated, and explanations for radiation sterilization of these drugs are provided. An outline of the application of radiation in cosmetics and medical devices is given. Issues are also provided from the viewpoint of safey and effectiveness of radiation sterilization. (Namekawa, K.)

Sustained, Controlled and Stimuli-Responsive Drug Release Systems Based on Nanoporous Anodic Alumina with Layer-by-Layer Polyelectrolyte

Science.gov (United States)

Porta-i-Batalla, Maria; Eckstein, Chris; Xifré-Pérez, Elisabet; Formentín, Pilar; Ferré-Borrull, J.; Marsal, Lluis F.

2016-08-01

Controlled drug delivery systems are an encouraging solution to some drug disadvantages such as reduced solubility, deprived biodistribution, tissue damage, fast breakdown of the drug, cytotoxicity, or side effects. Self-ordered nanoporous anodic alumina is an auspicious material for drug delivery due to its biocompatibility, stability, and controllable pore geometry. Its use in drug delivery applications has been explored in several fields, including therapeutic devices for bone and dental tissue engineering, coronary stent implants, and carriers for transplanted cells. In this work, we have created and analyzed a stimuli-responsive drug delivery system based on layer-by-layer pH-responsive polyelectrolyte and nanoporous anodic alumina. The results demonstrate that it is possible to control the drug release using a polyelectrolyte multilayer coating that will act as a gate.

Tool position tracking control of a nonlinear uncertain flexible robot ...

Indian Academy of Sciences (India)

Robot manipulators have become progressively important in the field of flexible ... this research, tracking of tool position and minimization of motor torque are ...... and Menhaj M B 2013a Position and current control of a permanent-magnet syn-.

Perceptions of community and family level IDU and HIV related stigma, disclosure decisions and experiences with layered stigma among HIV positive injection drug users in Vietnam

OpenAIRE

Rudolph, A.E.; Davis, W.W.; Quan, V.M.; Ha, T.V.; Minh, N.L.; Gregowski, A.; Salter, Megan; Celentano, D.D.; Go, V.

2011-01-01

This paper explores how perceived stigma and layered stigma related to injection drug use and being HIV positive influence the decision to disclose one’s HIV status to family and community and experiences with stigma following disclosure among a population of HIV positive male injection drug users (IDUs) in Thai Nguyen, Vietnam. In qualitative interviews conducted between 2007 and 2008, 25 HIV positive male IDUs described layered stigma in their community but an absence of layered stigma with...

Plasma position control in a tokamak reactor around ignition

International Nuclear Information System (INIS)

Carretta, U.; Minardi, E.; Bacelli, N.

1986-01-01

Plasma position control in a tokamak reactor in the phase approaching ignition is closely related to burn control. If ignited burn corresponds to a thermally unstable situation the plasma becomes sensitive to the thermal instability already in the phase when ignition is approached so that the trajectory in the position-pressure (R,p) space becomes effectively unpredictable. For example, schemes involving closed cycles around ignition can be unstable in the heating-cooling phases, and the deviations may be cumulative in time. Reliable plasma control in pressure-position (p, R) space is achieved by beforehand constraining the p, R trajectory rigidly with suitable feedback vertical field stabilization, which is to be established already below ignition. A scheme in which ignition is approached in a stable and automatic way by feedback stabilization on the vertical field is proposed and studied in detail. The values of the gain coefficient ensuring stabilization and the associated p and R excursions are discussed both analytically, with a 0-D approximation including non-linear effects, and numerically with a 1-D code in cylindrical geometry. Profile effects increase the excursions, in particular above ignition. (author)

Fixed drug eruption: topical provocation and subsequent phenomena

Energy Technology Data Exchange (ETDEWEB)

Mahboob, A; Haroon, T S [Shaikh Zayed FPGMI, Lahore (Pakistan). Dept. of Dermatology; Haroon, T S [King Edward Medical Univ., Lahore (Pakistan). Dept. of Dematology; Iqbal, Z; Iqbal, F [Shaikh Zayed FPGMI, Lahore (Pakistan). Dept. of Medicine

2006-12-15

To determine the usefulness of topical provocation in detecting the incriminated drug causing fixed eruption. Three hundred and five, clinically diagnosed cases of Fixed Drug Eruption (FDE) of either gender and of any age were subjected to topical provocation with different drugs by using concentration of 1% (n=203), 2% (n=210) and 5% (n=235) in white soft paraffin. Drug ointment of one strength was applied one at a time on normal skin of flexor surface of right or left forearm. The effects of tests on involved and uninvolved skin were observed for 48 hours. The changes in lesions like erythema, hyperpigmentation, itching, burning or appearance of new lesion were considered a positive response. In case of no change, the patients (n=5) were subjected to oral provocation test, by giving half to full therapeutic dose of the suspected drug depending upon the severity of the initial attack. A patient who exhibited see-sawing phenomenon with 5% metamizole TPT was given oral challenge with same drug. Control topical tests were repeated in equal number of normal persons with various drug ointments and in patients of FDE with white soft paraffin on normal and affected skin. One hundred and thirty-seven patients were males and one hundred and sixty-eight patients were females. Maximum number of patients belonged to third decade. With 1% drug preparations 12 out of 316, with 2% drug preparations 28 out of 422 and with 5% drug preparations, 312 out of 523 TPTs were positive. The comparison revealed a highly significant association (Chi-square 448.1 and p<0.000) among various strengths of preparations and positive response. Sulphamethoxazole was found to be the most commonly incriminated cause of FDE applied in 5% concentration yielded sensitivity rate of 91% compared to 4% with lower concentrations. Positive patch test was also observed with oxytetracycline. Five patients who were given oral provocation with different drugs were found to be positive to tinidazole, dapsone

Fixed drug eruption: topical provocation and subsequent phenomena

International Nuclear Information System (INIS)

Mahboob, A.; Haroon, T.S.; Haroon, T.S.; Iqbal, Z.; Iqbal, F.

2006-01-01

To determine the usefulness of topical provocation in detecting the incriminated drug causing fixed eruption. Three hundred and five, clinically diagnosed cases of Fixed Drug Eruption (FDE) of either gender and of any age were subjected to topical provocation with different drugs by using concentration of 1% (n=203), 2% (n=210) and 5% (n=235) in white soft paraffin. Drug ointment of one strength was applied one at a time on normal skin of flexor surface of right or left forearm. The effects of tests on involved and uninvolved skin were observed for 48 hours. The changes in lesions like erythema, hyperpigmentation, itching, burning or appearance of new lesion were considered a positive response. In case of no change, the patients (n=5) were subjected to oral provocation test, by giving half to full therapeutic dose of the suspected drug depending upon the severity of the initial attack. A patient who exhibited see-sawing phenomenon with 5% metamizole TPT was given oral challenge with same drug. Control topical tests were repeated in equal number of normal persons with various drug ointments and in patients of FDE with white soft paraffin on normal and affected skin. One hundred and thirty-seven patients were males and one hundred and sixty-eight patients were females. Maximum number of patients belonged to third decade. With 1% drug preparations 12 out of 316, with 2% drug preparations 28 out of 422 and with 5% drug preparations, 312 out of 523 TPTs were positive. The comparison revealed a highly significant association (Chi-square 448.1 and p<0.000) among various strengths of preparations and positive response. Sulphamethoxazole was found to be the most commonly incriminated cause of FDE applied in 5% concentration yielded sensitivity rate of 91% compared to 4% with lower concentrations. Positive patch test was also observed with oxytetracycline. Five patients who were given oral provocation with different drugs were found to be positive to tinidazole, dapsone

Nanoparticle enabled transdermal drug delivery systems for enhanced dose control and tissue targeting

Science.gov (United States)

Palmer, Brian C.; DeLouise, Lisa A.

2017-01-01

Transdermal drug delivery systems have been around for decades, and current technologies (e.g. patches, ointments, and creams) enhance the skin permeation of low molecular weight, lipophilic drugs that are efficacious at low doses. The objective of current transdermal drug delivery research is to discover ways to enhance skin penetration of larger, hydrophilic drugs and macromolecules for disease treatment and vaccination. Nanocarriers made of lipids, metals, or polymers have been successfully used to increase penetration of drugs or vaccines, control drug release, and target drugs to specific areas of skin in vivo. While more research is needed to identify the safety of nanocarriers, this technology has the potential to expand the use of transdermal routes of administration to a wide array of therapeutics. Here, we review the current state of nanoparticle skin delivery systems with special emphasis on targeting skin diseases. PMID:27983701

Nanoparticle-Enabled Transdermal Drug Delivery Systems for Enhanced Dose Control and Tissue Targeting.

Science.gov (United States)

Palmer, Brian C; DeLouise, Lisa A

2016-12-15

Transdermal drug delivery systems have been around for decades, and current technologies (e.g., patches, ointments, and creams) enhance the skin permeation of low molecular weight, lipophilic drugs that are efficacious at low doses. The objective of current transdermal drug delivery research is to discover ways to enhance skin penetration of larger, hydrophilic drugs and macromolecules for disease treatment and vaccination. Nanocarriers made of lipids, metals, or polymers have been successfully used to increase penetration of drugs or vaccines, control drug release, and target drugs to specific areas of skin in vivo. While more research is needed to identify the safety of nanocarriers, this technology has the potential to expand the use of transdermal routes of administration to a wide array of therapeutics. Here, we review the current state of nanoparticle skin delivery systems with special emphasis on targeting skin diseases.

Magnetic sensorless control of plasma position and shape in a tokamak

International Nuclear Information System (INIS)

Nakamura, K.; Luo, J.R.; Wang, H.Z.

2005-01-01

Magnetic sensorless sensing and control experiments of the plasma horizontal position have been carried out in the superconducting tokamak HT-7. The sensing is made focusing on the ripple frequency component of the power supply with thyristor and directly from them without time integration. There is no drift problem of integrator of magnetic sensors. Two kinds of control experiments were carried out, to keep the position constant and swing the position in a triangular waveform. And magnetic sensorless sensing of plasma shape is discussed. (author)

Acoustically Triggered Disassembly of Multilayered Polyelectrolyte Thin Films through Gigahertz Resonators for Controlled Drug Release Applications

Directory of Open Access Journals (Sweden)

Zhixin Zhang

2016-11-01

Full Text Available Controlled drug release has a high priority for the development of modern medicine and biochemistry. To develop a versatile method for controlled release, a miniaturized acoustic gigahertz (GHz resonator is designed and fabricated which can transfer electric supply to mechanical vibrations. By contacting with liquid, the GHz resonator directly excites streaming flows and induces physical shear stress to tear the multilayered polyelectrolyte (PET thin films. Due to the ultra-high working frequency, the shear stress is greatly intensified, which results in a controlled disassembling of the PET thin films. This technique is demonstrated as an effective method to trigger and control the drug release. Both theory analysis and controlled release experiments prove the thin film destruction and the drug release.

Control, communication and monitoring of intravaginal drug delivery in dairy cows.

Science.gov (United States)

Cross, Peter S; Künnemeyer, Rainer; Bunt, Craig R; Carnegie, Dale A; Rathbone, Michael J

2004-09-10

We present the design of an electronically controlled drug delivery system. The intravaginally located device is a low-invasive platform that can measure and react inside the cow vagina while providing external control and monitoring ability. The electronics manufactured from off the shelf components occupies 16 mL of a Theratron syringe. A microcontroller reads and logs sensor data and controls a gascell. The generated gas pressure propels the syringe piston and releases the formulation. A two way radio link allows communication between other devices or a base station. Proof of principle experiments confirm variable-rate, arbitrary profile drug delivery qualified by internal sensors. A total volume of 30 mL was dispensed over a 7-day-period with a volume error of +/- 1 mL or +/- 7% for larger volumes. Delivery was controlled or overridden via the wireless link, and proximity to other devices was detected and recorded. The results suggest that temperature and activity sensing or social grouping determined via proximity can be used to detect oestrus and trigger appropriate responses.

Research of Control Strategy in the Large Electric Cylinder Position Servo System

Directory of Open Access Journals (Sweden)

Yongguang Liu

2015-01-01

Full Text Available An ideal positioning response is very difficult to realize in the large electric cylinder system that is applied in missile launcher because of the presence of many nonlinear factors such as load disturbance, parameter variations, lost motion, and friction. This paper presents a piecewise control strategy based on the optimized positioning principle. The combined application of position interpolation method and modified incremental PID with dead band is proposed and applied into control system. The experimental result confirms that this combined control strategy is not only simple to be applied into high accuracy real-time control system but also significantly improves dynamic response, steady accuracy, and anti-interference performance, which has very important significance to improve the smooth control of the large electric cylinder.

Silk fibroin as an organic polymer for controlled drug delivery

NARCIS (Netherlands)

Hofmann, S.; Foo, S.; Rossetti, F.; Textor, M.; Vunjak-Novakovic, G.; Kaplan, D.L.; Merkle, H.P.; Meinel, L.

2006-01-01

The pharmaceutical utility of silk fibroin (SF) materials for drug delivery was investigated. SF films were prepared from aqueous solutions of the fibroin protein polymer and crystallinity was induced and controlled by methanol treatment. Dextrans of different molecular weights, as well as proteins,

Development of controlled drug release systems based on thiolated polymers.

Science.gov (United States)

Bernkop-Schnürch, A; Scholler, S; Biebel, R G

2000-05-03

The purpose of the present study was to generate mucoadhesive matrix-tablets based on thiolated polymers. Mediated by a carbodiimide, L-cysteine was thereby covalently linked to polycarbophil (PCP) and sodium carboxymethylcellulose (CMC). The resulting thiolated polymers displayed 100+/-8 and 1280+/-84 micromol thiol groups per gram, respectively (means+/-S.D.; n=6-8). In aqueous solutions these modified polymers were capable of forming inter- and/or intramolecular disulfide bonds. The velocity of this process augmented with increase of the polymer- and decrease of the proton-concentration. The oxidation proceeded more rapidly within thiolated PCP than within thiolated CMC. Due to the formation of disulfide bonds within thiol-containing polymers, the stability of matrix-tablets based on such polymers could be strongly improved. Whereas tablets based on the corresponding unmodified polymer disintegrated within 2 h, the swollen carrier matrix of thiolated CMC and PCP remained stable for 6.2 h (mean, n=4) and more than 48 h, respectively. Release studies of the model drug rifampicin demonstrated that a controlled release can be provided by thiolated polymer tablets. The combination of high stability, controlled drug release and mucoadhesive properties renders matrix-tablets based on thiolated polymers useful as novel drug delivery systems.

Controlled drug release from bifunctionalized mesoporous silica

Science.gov (United States)

Xu, Wujun; Gao, Qiang; Xu, Yao; Wu, Dong; Sun, Yuhan; Shen, Wanling; Deng, Feng

2008-10-01

Serial of trimethylsilyl-carboxyl bifunctionalized SBA-15 (TMS/COOH/SBA-15) have been studied as carriers for controlled release of drug famotidine (Famo). To load Famo with large capacity, SBA-15 with high content of carboxyl groups was successfully synthesized by one-pot synthesis under the assistance of KCl. The mesostructure of carboxyl functionalized SBA-15 (COOH/SBA-15) could still be kept even though the content of carboxyl groups was up to 57.2%. Increasing carboxyl content could effectively enhance the loading capacity of Famo. Compared with pure SBA-15, into which Famo could be hardly adsorbed, the largest drug loading capacity of COOH/SBA-15 could achieve 396.9 mg/g. The release of Famo from mesoporous silica was studied in simulated intestine fluid (SIF, pH=7.4). For COOH/SBA-15, the release rate of Famo decreased with narrowing pore size. After grafting TMS groups on the surface of COOH/SBA-15 with hexamethyldisilazane, the release of Famo was greatly delayed with the increasing content of TMS groups.

Design and performance analysis of position-based impedance control for an electrohydrostatic actuation system

Directory of Open Access Journals (Sweden)

Yongling FU

2018-03-01

Full Text Available Electrohydrostatic actuator (EHA is a type of power-by-wire actuator that is widely implemented in the aerospace industry for flight control, landing gears, thrust reversers, thrust vector control, and space robots. This paper presents the development and evaluation of position-based impedance control (PBIC for an EHA. Impedance control provides the actuator with compliance and facilitates the interaction with the environment. Most impedance control applications utilize electrical or valve-controlled hydraulic actuators, whereas this work realizes impedance control via a compact and efficient EHA. The structures of the EHA and PBIC are firstly introduced. A mathematical model of the actuation system is established, and values of its coefficients are identified by particle swarm optimization. This model facilitates the development of a position controller and the selection of target impedance parameters. A nonlinear proportional-integral position controller is developed for the EHA to achieve the accurate positioning requirement of PBIC. The controller compensates for the adverse effect of stiction, and a position accuracy of 0.08 mm is attained. Various experimental results are presented to verify the applicability of PBIC to the EHA. The compliance of the actuator is demonstrated in an impact test. Keywords: Actuation system, Aerospace, Electrohydrostatic actuator, Force control, Nonlinear dynamics, Particle swarm optimization, Position control

Clinical implications of antiretroviral drug interactions with warfarin: a case-control study.

Science.gov (United States)

Esterly, John S; Darin, Kristin M; Gerzenshtein, Lana; Othman, Fidah; Postelnick, Michael J; Scarsi, Kimberly K

2013-06-01

Warfarin, a frequently prescribed anticoagulant with a narrow therapeutic index, is susceptible to drug-drug interactions with antiretroviral therapy (ART). This study compared the warfarin maintenance dose (WMD) between patients receiving and not receiving ART and evaluated predictors of warfarin dosage among those on ART. This was a case-control (1:2) study. Cases were HIV-infected patients receiving warfarin and protease inhibitor (PI)- and/or non-nucleoside reverse transcriptase inhibitor (NNRTI)-based ART. Controls were randomly selected HIV-uninfected patients receiving warfarin. The WMD was compared between cases and controls and between cases on varying ART regimens. Bivariate comparisons were performed and a linear regression model was developed to identify predictors of WMD. We identified 18 case and 36 control patients eligible for inclusion. Cases were younger than controls (mean age: 45.8 versus 63.1 years, P African American (50.0% versus 22.2%, P=0.04). ART was classified as PI-based (n=9), NNRTI-based (n=7) and PI + NNRTI-based (n=2). The WMD (mean ± SD) differed between cases and controls (8.6  ±  3.4 mg versus 5.1 ± 1.5 mg, P ART regimens (PI: 8.8  ±  4.5 mg; NNRTI: 8.6   ± 1.8 mg; PI + NNRTI: 7.3  ±  3.3 mg; P = 0.86). Race and ritonavir dose were independent predictors of WMD, predicting an increase of 3.9 mg (95% CI: 0.88-6.98, P = 0.02) if a patient was African American or 3.7 mg (95% CI: 0.53-6.89, P = 0.03) if the total daily ritonavir dose was 200 mg. The required WMD was significantly higher in patients receiving ART. Prompt dose titration to achieve a higher WMD with vigilant monitoring may be required due to these drug-drug interactions.

Kinetically Controlled Drug Resistance

DEFF Research Database (Denmark)

Sun, Xin E.; Hansen, Bjarne Gram; Hedstrom, Lizbeth

2011-01-01

The filamentous fungus Penicillium brevicompactum produces the immunosuppressive drug mycophenolic acid (MPA), which is a potent inhibitor of eukaryotic IMP dehydrogenases (IMPDHs). IMPDH catalyzes the conversion of IMP to XMP via a covalent enzyme intermediate, E-XMP*; MPA inhibits by trapping E...... of resistance is not apparent. Here, we show that, unlike MPA-sensitive IMPDHs, formation of E-XMP* is rate-limiting for both PbIMPDH-A and PbIMPDH-B. Therefore, MPA resistance derives from the failure to accumulate the drug-sensitive intermediate....

Position and Attitude Alternate of Path Tracking Heading Control

Directory of Open Access Journals (Sweden)

Baocheng Tan

2014-03-01

Full Text Available The path tracking control algorithm is one of the key problems in the control system design of autonomous vehicle. In this paper, we have conducted dynamic modeling for autonomous vehicle, the relationship between course deviation and yaw rate and centroid deflection angle. From the angle of the dynamics and geometrical, this paper have described the path tracking problem, analyzed the emergence of the eight autonomous vehicles pose binding - position and attitude alternate control methods to identify the relationship between posture and the controlling variables, and design a controller, the experimental results verify the feasibility and effectiveness of this control method.

Drug assertiveness and sexual risk-taking behavior in a sample of HIV-positive, methamphetamine-using men who have sex with men.

Science.gov (United States)

Semple, Shirley J; Strathdee, Steffanie A; Zians, Jim; McQuaid, John R; Patterson, Thomas L

2011-10-01

Drug assertiveness skills have been demonstrated to be effective in reducing substance use behaviors among patients with alcohol or heroin use disorders. This study examined the association between drug assertiveness and methamphetamine use, psychological factors, and sexual risk behaviors in a sample of 250 HIV-positive men who have sex with men enrolled in a safer sex intervention in San Diego, CA. Less assertiveness in turning down drugs was associated with greater frequency and larger amounts of methamphetamine use, lower self-esteem, higher scores on a measure of sexual sensation seeking, and greater attendance at risky sexual venues. These data suggest that drug assertiveness training should be incorporated into drug abuse treatment programs and other risk reduction interventions for methamphetamine users. Copyright © 2011 Elsevier Inc. All rights reserved.

Surveillance of drug resistance for tuberculosis control: why and how?

Science.gov (United States)

Chaulet, P; Boulahbal, F; Grosset, J

1995-12-01

The resistance of Mycobacterium tuberculosis to antibiotics, which reflects the quality of the chemotherapy applied in the community, is one of the elements of epidemiological surveillance used in national tuberculosis programmes. Measurement of drug resistance poses problems for biologists in standardization of laboratory methods and quality control. The definition of rates of acquired and primary drug resistance also necessitates standardization in the methods used to collect information transmitted by clinicians. Finally, the significance of the rates calculated depends on the choice of the patients sample on which sensitivity tests have been performed. National surveys of drug resistance therefore require multidisciplinary participation in order to select the only useful indicators: rates of primary resistance and of acquired resistance. These indicators, gathered in representative groups of patients over a long period, are a measurement of the impact of modern chemotherapy regimens on bacterial ecology.

Overcoming drug-tolerant cancer cell subpopulations showing AXL activation and epithelial–mesenchymal transition is critical in conquering ALK-positive lung cancer

Science.gov (United States)

Nakamichi, Shinji; Seike, Masahiro; Miyanaga, Akihiko; Chiba, Mika; Zou, Fenfei; Takahashi, Akiko; Ishikawa, Arimi; Kunugi, Shinobu; Noro, Rintaro; Kubota, Kaoru; Gemma, Akihiko

2018-01-01

Anaplastic lymphoma kinase tyrosine kinase inhibitors (ALK-TKIs) induce a dramatic response in non–small cell lung cancer (NSCLC) patients with the ALK fusion gene. However, acquired resistance to ALK-TKIs remains an inevitable problem. In this study, we aimed to discover novel therapeutic targets to conquer ALK-positive lung cancer. We established three types of ALK-TKI (crizotinib, alectinib and ceritinib)-resistant H2228 NSCLC cell lines by high exposure and stepwise methods. We found these cells showed a loss of ALK signaling, overexpressed AXL with epithelial-mesenchymal transition (EMT), and had cancer stem cell-like (CSC) properties, suggesting drug-tolerant cancer cell subpopulations. Similarly, we demonstrated that TGF-β1 treated H2228 cells also showed AXL overexpression with EMT features and ALK-TKI resistance. The AXL inhibitor, R428, or HSP90 inhibitor, ganetespib, were effective in reversing ALK-TKI resistance and EMT changes in both ALK-TKI-resistant and TGF-β1-exposed H2228 cells. Tumor volumes of xenograft mice implanted with established H2228-ceritinib-resistant (H2228-CER) cells were significantly reduced after treatment with ganetespib, or ganetespib in combination with ceritinib. Some ALK-positive NSCLC patients with AXL overexpression showed a poorer response to crizotinib therapy than patients with a low expression of AXL. ALK signaling-independent AXL overexpressed in drug-tolerant cancer cell subpopulations with EMT and CSC features may be commonly involved commonly involved in intrinsic and acquired resistance to ALK-TKIs. This suggests AXL and HSP90 inhibitors may be promising therapeutic drugs to overcome drug-tolerant cancer cell subpopulations in ALK-positive NSCLC patients for the reason that ALK-positive NSCLC cells do not live through ALK-TKI therapy. PMID:29930762

A modern automatic Carriage-Trolley Position Control System for Dhruva fuelling machine

International Nuclear Information System (INIS)

Agrawal, Ankit; Hari Balakrishna; Narvekar, J.P.; Sanadhya, Vivek

2014-01-01

A fully automatic absolute encoder based position control system has been designed developed implemented and commissioned for the Dhruva Fuelling Machine A (FM/A). This supports both the coarse and fine positioning modes. Provision for fully manual positioning as a standby system has been retained. This system replaces the ageing peg counting based incremental positioner used briefly during the early period after the Dhruva FM/A was commissioned. The older system suffered from peg detection skipping problems; hence it was not being used. Only full manual positioning was being carried out. This paper describes the automatic Carriage Trolley Position Control System (CTPCS). (author)

Drug therapy in spinal tuberculosis.

Science.gov (United States)

Rajasekaran, S; Khandelwal, Gaurav

2013-06-01

Although the discovery of effective anti-tuberculosis drugs has made uncomplicated spinal tuberculosis a medical disease, the advent of multi-drug-resistant Mycobacterium tuberculosis and the co-infection of HIV with tuberculosis have led to a resurgence of the disease recently. The principles of drug treatment of spinal tuberculosis are derived from our experience in treating pulmonary tuberculosis. Spinal tuberculosis is classified to be a severe form of extrapulmonary tuberculosis and hence is included in Category I of the WHO classification. The tuberculosis bacilli isolated from patients are of four different types with different growth kinetics and metabolic characteristics. Hence multiple drugs, which act on the different groups of the mycobacteria, are included in each anti-tuberculosis drug regimen. Prolonged and uninterrupted chemotherapy (which may be 'short course' and 'intermittent' but preferably 'directly observed') is effective in controlling the infection. Spinal Multi-drug-resistant TB and spinal TB in HIV-positive patients present unique problems in management and have much poorer prognosis. Failure of chemotherapy and emergence of drug resistance are frequent due to the failure of compliance hence all efforts must be made to improve patient compliance to the prescribed drug regimen.

Could positive affect help engineer robot control systems?

Science.gov (United States)

Quirin, Markus; Hertzberg, Joachim; Kuhl, Julius; Stephan, Achim

2011-11-01

Emotions have long been seen as counteracting rational thought, but over the last decades, they have been viewed as adaptive processes to optimize human (but also animal) behaviour. In particular, positive affect appears to be a functional aspect of emotions closely related to that. We argue that positive affect as understood in Kuhl's PSI model of the human cognitive architecture appears to have an interpretation in state-of-the-art hybrid robot control architectures, which might help tackle some open questions in the field.

Multiple model predictive control for optimal drug administration of mixed immunotherapy and chemotherapy of tumours.

Science.gov (United States)

Sharifi, N; Ozgoli, S; Ramezani, A

2017-06-01

Mixed immunotherapy and chemotherapy of tumours is one of the most efficient ways to improve cancer treatment strategies. However, it is important to 'design' an effective treatment programme which can optimize the ways of combining immunotherapy and chemotherapy to diminish their imminent side effects. Control engineering techniques could be used for this. The method of multiple model predictive controller (MMPC) is applied to the modified Stepanova model to induce the best combination of drugs scheduling under a better health criteria profile. The proposed MMPC is a feedback scheme that can perform global optimization for both tumour volume and immune competent cell density by performing multiple constraints. Although current studies usually assume that immunotherapy has no side effect, this paper presents a new method of mixed drug administration by employing MMPC, which implements several constraints for chemotherapy and immunotherapy by considering both drug toxicity and autoimmune. With designed controller we need maximum 57% and 28% of full dosage of drugs for chemotherapy and immunotherapy in some instances, respectively. Therefore, through the proposed controller less dosage of drugs are needed, which contribute to suitable results with a perceptible reduction in medicine side effects. It is observed that in the presence of MMPC, the amount of required drugs is minimized, while the tumour volume is reduced. The efficiency of the presented method has been illustrated through simulations, as the system from an initial condition in the malignant region of the state space (macroscopic tumour volume) transfers into the benign region (microscopic tumour volume) in which the immune system can control tumour growth. Copyright © 2017 Elsevier B.V. All rights reserved.

Drug adherence in treatment resistant and in controlled hypertension-Results from the Swedish Primary Care Cardiovascular Database (SPCCD).

Science.gov (United States)

Holmqvist, Lina; Boström, Kristina Bengtsson; Kahan, Thomas; Schiöler, Linus; Qvarnström, Miriam; Wettermark, Björn; Hjerpe, Per; Hasselström, Jan; Manhem, Karin

2018-03-01

To assess drug adherence in patients treated with ≥3 antihypertensive drug classes, with both controlled and uncontrolled blood pressure and describe associated factors for nonadherence. Patients with hypertension, without cardiovascular comorbidity, aged >30 years treated with ≥3 antihypertensive drug classes were followed for 2 years. Both patients with treatment resistant hypertension (TRH) and patients with controlled hypertension were included. Clinical data were derived from a primary care database. Pharmacy refill data from the Swedish Prescribed drug registry was used to calculate proportion of days covered (PDC). Patients with a PDC level ≥ 80% were included. We found 5846 patients treated ≥3 antihypertensive drug classes, 3508 with TRH (blood pressure ≥ 140/90), and 2338 with controlled blood pressure (drug therapy had similar decline in adherence over time regardless of initial blood pressure control. Diabetes was associated with better adherence, which may imply that the structured caregiving of these patients enhances antihypertensive drug treatment. Copyright © 2018 John Wiley & Sons, Ltd.

The NARCONON™ drug education curriculum for high school students: A non-randomized, controlled prevention trial

Directory of Open Access Journals (Sweden)

Cecchini Marie A

2008-03-01

Full Text Available Abstract Background An estimated 13 million youths aged 12 to 17 become involved with alcohol, tobacco and other drugs annually. The number of 12- to 17-year olds abusing controlled prescription drugs increased an alarming 212 percent between 1992 and 2003. For many youths, substance abuse precedes academic and health problems including lower grades, higher truancy, drop out decisions, delayed or damaged physical, cognitive, and emotional development, or a variety of other costly consequences. For thirty years the Narconon program has worked with schools and community groups providing single educational modules aimed at supplementing existing classroom-based prevention activities. In 2004, Narconon International developed a multi-module, universal prevention curriculum for high school ages based on drug abuse etiology, program quality management data, prevention theory and best practices. We review the curriculum and its rationale and test its ability to change drug use behavior, perceptions of risk/benefits, and general knowledge. Methods After informed parental consent, approximately 1000 Oklahoma and Hawai'i high school students completed a modified Center for Substance Abuse Prevention (CSAP Participant Outcome Measures for Discretionary Programs survey at three testing points: baseline, one month later, and six month follow-up. Schools assigned to experimental conditions scheduled the Narconon curriculum between the baseline and one-month follow-up test; schools in control conditions received drug education after the six-month follow-up. Student responses were analyzed controlling for baseline differences using analysis of covariance. Results At six month follow-up, youths who received the Narconon drug education curriculum showed reduced drug use compared with controls across all drug categories tested. The strongest effects were seen in all tobacco products and cigarette frequency followed by marijuana. There were also significant

Controlling type I error rate for fast track drug development programmes.

Science.gov (United States)

Shih, Weichung J; Ouyang, Peter; Quan, Hui; Lin, Yong; Michiels, Bart; Bijnens, Luc

2003-03-15

The U.S. Food and Drug Administration (FDA) Modernization Act of 1997 has a Section (No. 112) entitled 'Expediting Study and Approval of Fast Track Drugs' (the Act). In 1998, the FDA issued a 'Guidance for Industry: the Fast Track Drug Development Programs' (the FTDD programmes) to meet the requirement of the Act. The purpose of FTDD programmes is to 'facilitate the development and expedite the review of new drugs that are intended to treat serious or life-threatening conditions and that demonstrate the potential to address unmet medical needs'. Since then many health products have reached patients who suffered from AIDS, cancer, osteoporosis, and many other diseases, sooner by utilizing the Fast Track Act and the FTDD programmes. In the meantime several scientific issues have also surfaced when following the FTDD programmes. In this paper we will discuss the concept of two kinds of type I errors, namely, the 'conditional approval' and the 'final approval' type I errors, and propose statistical methods for controlling them in a new drug submission process. Copyright 2003 John Wiley & Sons, Ltd.

Nanoparticle-Enabled Transdermal Drug Delivery Systems for Enhanced Dose Control and Tissue Targeting

Directory of Open Access Journals (Sweden)

Brian C. Palmer

2016-12-01

Full Text Available Transdermal drug delivery systems have been around for decades, and current technologies (e.g., patches, ointments, and creams enhance the skin permeation of low molecular weight, lipophilic drugs that are efficacious at low doses. The objective of current transdermal drug delivery research is to discover ways to enhance skin penetration of larger, hydrophilic drugs and macromolecules for disease treatment and vaccination. Nanocarriers made of lipids, metals, or polymers have been successfully used to increase penetration of drugs or vaccines, control drug release, and target drugs to specific areas of skin in vivo. While more research is needed to identify the safety of nanocarriers, this technology has the potential to expand the use of transdermal routes of administration to a wide array of therapeutics. Here, we review the current state of nanoparticle skin delivery systems with special emphasis on targeting skin diseases.

Evaluation of a needle social marketing strategy to control HIV among injecting drug users in China.

Science.gov (United States)

Wu, Zunyou; Luo, Wei; Sullivan, Sheena G; Rou, Keming; Lin, Peng; Liu, Wei; Ming, Zhongqiang

2007-12-01

To evaluate the effectiveness of a needle social marketing strategy to reduce needle sharing and hepatitis C Virus (HCV)/HIV transmission among injecting drug users (IDU) in China. Two-armed, prospective, community-randomized prevention trial. Four counties/townships in Guangxi and Guangdong provinces; one randomized to intervention the other to control in each province. Injecting drug users: 823 (443 intervention, 382 control) at baseline and 852 (415 intervention, 407 control) at the second cross-sectional survey 12 months later. A needle social marketing programme, including promotion of safe injection norms and increased access to clean needles over a 12 month period. Cross sectional surveys at baseline and follow-up compared changes in drug using behaviours and HIV and HCV rates in the intervention and control communities. Needle sharing behaviours were similar in the two groups at baseline (68.4 vs. 67.8%), and dropped significantly to 35.3% in the intervention community and remained relatively stable in the control community (62.3%; P marketing can reduce risky injecting behaviour and HIV/HCV transmission among injecting drug users in China and should be expanded.

A randomized controlled trial of positioning treatments in infants with positional head shape deformities.

Science.gov (United States)

Hutchison, B Lynne; Stewart, Alistair W; De Chalain, Tristan B; Mitchell, Edwin A

2010-10-01

Randomized controlled trials of treatment for deformational plagiocephaly and brachycephaly have been lacking in the literature. Infants (n = 126) presenting to a plagiocephaly clinic were randomized to either positioning strategies or to positioning plus the use of a Safe T Sleep™ positioning wrap. Head shape was measured using a digital photographic technique, and neck function was assessed. They were followed up at home 3, 6 and 12 months later. There was no difference in head shape outcomes for the two treatment groups after 12 months of follow-up, with 42% of infants having head shapes in the normal range by that time. Eighty per cent of children showed good improvement. Those that had poor improvement were more likely to have both plagiocephaly and brachycephaly and to have presented later to clinic. Most infants improved over the 12-month study period, although the use of a sleep positioning wrap did not increase the rate of improvement. © 2010 The Author(s)/Journal Compilation © 2010 Foundation Acta Paediatrica.

Results from the 2008 Drug and Alcohol Testing Survey

Science.gov (United States)

2010-01-01

This report summarizes the results of the 2008 Federal Motor Carrier Safety Administration Drug and Alcohol Testing Survey. This annual survey measures the percentage of drivers with commercial drivers licenses who test positive for controlled sub...

A novel and alternative approach to controlled release drug delivery system based on solid dispersion technique

Directory of Open Access Journals (Sweden)

Tapan Kumar Giri

2012-12-01

Full Text Available The solid dispersion method was originally used to improve the dissolution properties and the bioavailability of poorly water soluble drugs by dispersing them into water soluble carriers. In addition to the above, dissolution retardation through solid dispersion technique using water insoluble and water swellable polymer for the development of controlled release dosage forms has become a field of interest in recent years. Development of controlled release solid dispersion has a great advantage for bypassing the risk of a burst release of drug; since the structure of the solid dispersion is monolithic where drug molecules homogeneously disperse. Despite the remarkable potential and extensive research being conducted on controlled release solid dispersion system, commercialization and large scale production are limited. The author expects that recent technological advances may overcome the existing limitations and facilitate the commercial utilization of the techniques for manufacture of controlled release solid dispersions. This article begins with an overview of the different carriers being used for the preparation of controlled release solid dispersion and also different techniques being used for the purpose. Kinetics of drug release from these controlled release solid dispersions and the relevant mathematical modeling have also been reviewed in this manuscript.

Improved Position Sensor for Feedback Control of Levitation

Science.gov (United States)

Hyers, Robert; Savage, Larry; Rogers, Jan

2004-01-01

An improved optoelectronic apparatus has been developed to provide the position feedback needed for controlling the levitation subsystem of a containerless-processing system. As explained, the advantage of this apparatus over prior optoelectronic apparatuses that have served this purpose stems from the use of an incandescent lamp, instead of a laser, to illuminate the levitated object. In containerless processing, a small object to be processed is levitated (e.g., by use of a microwave, low-frequency electromagnetic, electrostatic, or acoustic field) so that it is not in contact with the wall of the processing chamber or with any other solid object during processing. In the case of electrostatic or low-frequency electromagnetic levitation, real-time measurement of the displacement of the levitated object from its nominal levitation position along the vertical axis (and, in some cases, along one or two horizontal axes) is needed for feedback control of the levitating field.

Automatic beam position control at Los Alamos Spallation Radiation Effects Facility (LASREF)

International Nuclear Information System (INIS)

Oothoudt, M.; Pillai, C.; Zumbro, M.

1997-01-01

Historically the Los Alamos Spallation Radiation Effects Facility (LASREF) has used manual methods to control the position of the 800 kW, 800 MeV proton beam on targets. New experiments, however, require more stringent position control more frequently than can be done manually for long periods of time. Data from an existing harp is used to automatically adjust steering magnets to maintain beam position to required tolerances

Angular Position Tracking Control of a Quadcopter

Directory of Open Access Journals (Sweden)

T. V. Glazkov

2017-01-01

Full Text Available The paper dwells on tracking the quad-copter angular position with desired quality parameters of transient processes. The aerial vehicle is considered as a rigid body with six degrees of freedom.  A full rigid body quad-copter mathematical model is considered without the assumption of smallness of the Euler angles.Among the most well known methods of non-linear stabilization are feedback linearization and backstepping. The backstepping approach allows us to have an effective solution of the stabilization problems with uncertainties available in the system. However, in synthesis of the feedback through backstepping, there is still an urgent issue: how to ensure desirable quality of transients in the closed-loop system. The paper presents a solution of this problem using as an example the tracking a given (programmed change of the angular position of a quad-copter.The control algorithms obtained in this paper are implemented using the Rolling Spider MATLAB Toolbox (ROSMAT tool package on the Parrot Rolling Spider quad-copter. A numerical simulation and experiments have shown the efficiency of obtained control laws, with the transient processes taking into account the desired quality indicators. However, the experiments showed that lack of terms in the mathematical model to describe the aerodynamic effects, resulted in the instability of the quad-copter flight near the obstacle (the effect of the reflected airflow.Further research can be aimed at solving the control problem in question using a mathematical model of the quad-copter motion that takes into account various aerodynamic effects.One of the potential application areas for the theoretical results, obtained in the paper, is to solve the problems of automatic control of unmanned aerial vehicles.

Anger-Control Group Counseling for Women Recovering from Alcohol or Drug Addiction

Science.gov (United States)

Gonzalez-Prendes, A. Antonio

2008-01-01

Two experimental conditions, a manualized cognitive-behavioral anger-control treatment incorporating empowerment strategies and a relapse-prevention treatment without the anger-control component, were compared to assess their impact on levels of trait anger and attributional styles of women recovering from alcohol and drug addiction. Participants…

A Relook at the National Drug Control Strategy: Supply versus Demand

National Research Council Canada - National Science Library

Cook, Virgil

1998-01-01

.... By reviewing the ends, ways, and means of past drug control strategies, this paper suggests that it is time for the federal government to shift existing resources from supply reduction to demand reduction programs...

Sensory systems for a control rod position using reed switches for the integral reactor

International Nuclear Information System (INIS)

Yu, J. Y.; Choi, S.; Kim, J. H.; Lee, D. J.

2007-01-01

The system-integrated modular advanced reactor (SMART) currently under development at the Korea Atomic Energy Research Institute is being designed with a soluble boron free operation and the use of nuclear heating for the reactor start-up. These design features require a Control Element Drive Mechanism (CEDM) for the SMART to have a fine-step movement capability as well as a high reliability for a fine reactivity control. Also the reliability and accuracy of the information for the control rod position is very important to the reactor safety as well as the design of the core protection system. The position indicator is classified as a Class 1E component because the rod position signal of the position indicator is used in the safety related systems. Therefore it will be separated from the control systems to the extent that a failure of any single control system component of a channel and shall have sufficient independence, redundancy, and testability to perform its safety functions assuming a single failure. The position indicator is composed of a permanent magnet, reed switches and a voltage divider. Four independent position indicators around the upper pressure housing provide an indication of the position of a control rod comprising of a permanent magnet with a magnetic field concentrator which moves with the extension shaft connected to the control rod. The zigzag arranged reed switches are positioned along a line parallel to the path of the movement of the permanent magnet and it is activated selectively when the permanent magnet passes by. A voltage divider electrically connected to the reed switches provides a signal commensurate with the position of the control rod. The signal may then be transmitted to a position indicating device. In order to monitor the operating condition of the rotary step motor of CEDM, the angular position detector was installed at the top of the rotary step motor by means of connecting between the planetary gear and the rotating

Positive and Negative Perfectionism in Migrainus Patients Compaired with Control Group

Directory of Open Access Journals (Sweden)

H Afshar

2008-01-01

Full Text Available ABSTRACT: Introduction & Objective: The positive and negative effects of perfectionism on human cognition, affection and behavior have been emphasized. Perfectionism has been conceptualized as a multidimensional construct, with both adaptive and maladaptive aspects, which is one of the common personality traits that cause lifelong stress in human and results in anxiety, depression and physical and mental distress.The aim of this study was to assess the positive and negative perfectionism in migrainus patients in comparison with control group. Materials & Methods: This is an analytical (Case-control study which was performed on 91 migraine patients and 88 healthy individuals. The pqtients and controls completed a standard 40 item questionnaire for perfectionism – PANPS (20 for positive and 20 for negative perfectionism . The patients in both groups were matched for gender and age. Mean of positive and negative perfectionism scores for two groups was statistically analysed using SPSS software. Results: Mean positive perfectionism score was 83.47±8.5 for migraine group and 65.47±7.54 for control group (p=0.0001. The difference between two groups was significant. Mean of negative perfectionism score was 74.12±10.6 for migraine group and 51.79±7.8 for control group(p=0.0001. Conclusion: The results show that migraine patients have higher mean of perfectionism scores than healthy individuals. Based on this study and other clinical experiences more attention to psychotherapy is necessary for better management of migraine and recognition of personality profile in migraine patient helps to reduce patient’s complaints.

Modulation of electrostatic interactions to improve controlled drug delivery from nanogels.

Science.gov (United States)

Mauri, Emanuele; Chincarini, Giulia M F; Rigamonti, Riccardo; Magagnin, Luca; Sacchetti, Alessandro; Rossi, Filippo

2017-03-01

The synthesis of nanogels as devices capable to maintain the drug level within a desired range for a long and sustained period of time is a leading strategy in controlled drug delivery. However, with respect to the good results obtained with antibodies and peptides there are a lot of problems related to the quick and uncontrolled diffusion of small hydrophilic molecules through polymeric network pores. For these reasons research community is pointing toward the use of click strategies to reduce release rates of the linked drugs to the polymer chains. Here we propose an alternative method that considers the electrostatic interactions between polymeric chains and drugs to tune the release kinetics from nanogel network. The main advantage of these systems lies in the fact that the carried drugs are not modified and no chemical reactions take place during their loading and release. In this work we synthesized PEG-PEI based nanogels with different protonation degrees and the release kinetics with charged and uncharged drug mimetics (sodium fluorescein, SF, and rhodamine B, RhB) were studied. Moreover, also the effect of counterion used to induce protonation was taken into account in order to build a tunable drug delivery system able to provide multiple release rates with the same device. Copyright © 2016 Elsevier B.V. All rights reserved.

Nonlinear control of marine vehicles using only position and attitude measurements

Energy Technology Data Exchange (ETDEWEB)

Paulsen, Marit Johanne

1996-12-31

This thesis presents new results on the design and analysis of nonlinear output feedback controllers for auto pilots and dynamic positioning systems for ships and underwater vehicles. Only position and attitude measurements of the vehicle are used in the control design. The underlying idea of the work is to use certain structural properties of the equations of motion in the controller design and analysis. New controllers for regulation and tracking have been developed and the stability of the resulting closed-loop systems has been rigorously established. The results are supported by simulations. The following problems have been investigated covering design of passive controller for regulation, comparison of two auto pilots, nonlinear damping compensation for tracking, tracking control for nonlinear ships, and output tracking control with wave filtering for multivariable models of possibly unstable vehicles. 97 refs., 32 figs.

Strategies for the plasma position and shape control in IGNITOR

International Nuclear Information System (INIS)

Ramogida, G.; Alladio, F.; Albanese, R.

2006-01-01

The control of the plasma position and shape is a crucial issue in IGNITOR as in every compact, high field, elongated tokamak. The capability of the Poloidal Field Coil system, as presently designed, to provide an effective vertical stabilization of the plasma has been investigated using the CREATE L response model [R. Albanese, F. Villone, '' The Linearized CREATE L Plasma Response Model for the Control of Current, Position and Shape in Tokamaks '', Nucl. Fus., vol. 38, p. 723 (1998)]. This linearized MHD model assumes an axisymmetric deformable plasma described by few global parameters. An optimization of the vertical position control strategy has been carried out and the most effective coil combination has been selected to stabilize the plasma while fulfilling engineering constraints on the coils and minimizing the required power and voltage. The two pairs of coils selected for the vertical control will be fed up with up-down anti-symmetric currents provided by a dedicated supply and overlapped to the scenario currents. The growth rate of the vertical instability and the power required by the active stabilization system have been estimated with this model, indicating that it is possible to design a control system able to guarantee a stability region that includes the most interesting operation conditions. An assessment of the requirements for the plasma cross section shape control has been carried out considering independent perturbations of the plasma global parameters as disturbances and showing that the undesired shape modification rejection is possible with the present PFC and power supply system. The PF coils have been ranked with respect to their capability to restore the shape modifications due to different plasma disturbances and the most effective coil combination, that minimizes recovery time and voltage required, has been selected. In order to have additional means to monitor and control the centre of the plasma column, under demanding conditions

21 CFR 1405.400 - What are my responsibilities as a(n) Office of National Drug Control Policy awarding official?

Science.gov (United States)

2010-04-01

...) Responsibilities of Office of National Drug Control Policy Awarding Officials § 1405.400 What are my... 21 Food and Drugs 9 2010-04-01 2010-04-01 false What are my responsibilities as a(n) Office of National Drug Control Policy awarding official? 1405.400 Section 1405.400 Food and Drugs OFFICE OF NATIONAL...

21 CFR 1404.610 - What procedures does the Office of National Drug Control Policy use in suspension and debarment...

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 9 2010-04-01 2010-04-01 false What procedures does the Office of National Drug Control Policy use in suspension and debarment actions? 1404.610 Section 1404.610 Food and Drugs OFFICE OF NATIONAL DRUG CONTROL POLICY GOVERNMENTWIDE DEBARMENT AND SUSPENSION (NONPROCUREMENT) General Principles Relating to Suspension and Debarment...

a positive control plasmid for reporter gene assay

African Journals Online (AJOL)

STORAGESEVER

2008-07-04

Jul 4, 2008 ... qualification as a positive control for luciferase reporter gene assays. Key words: Reporter gene plasmid, luciferase assay, cytomegalovirus promoter/enhancer, human melanoma cell line. INTRODUCTION. Reporter genes, often called reporters, have become a precious tool in studies of gene expression ...

Design Project on Controlled-Release Drug Delivery Devices: Implementation, Management, and Learning Experiences

Science.gov (United States)

Xu, Qingxing; Liang, Youyun; Tong, Yen Wah; Wang, Chi-Hwa

2010-01-01

A design project that focuses on the subject of controlled-release drug delivery devices is presented for use in an undergraduate course on mass transfer. The purpose of the project is to introduce students to the various technologies used in the fabrication of drug delivery systems and provide a practical design exercise for understanding the…

Sex, drugs and moral goals: reproductive strategies and views about recreational drugs

Science.gov (United States)

Kurzban, Robert; Dukes, Amber; Weeden, Jason

2010-01-01

Humans, unlike most other species, show intense interest in the activities of conspecifics, even when the activities in question pose no obvious fitness threat or opportunity. Here, we investigate one content domain in which people show substantial interest, the use of drugs for non-medical purposes. Drawing from two subject populations—one undergraduate and one Internet-based—we look at the relationships among (i) abstract political commitments; (ii) attitudes about sexuality; and (iii) views surrounding recreational drugs. Whereas some theories suggest that drug views are best understood as the result of abstract political ideology, we suggest that these views can be better understood in the context of reproductive strategy. We show that, as predicted by a strategic construal, drug attitudes are best predicted by sexual items rather than abstract political commitments and, further, that the relationship between factors such as political ideology and drugs, while positive, are reduced to zero or nearly zero when items assessing sexuality are controlled for. We conclude that considering morality from the standpoint of strategic interests is a potentially useful way to understand why humans care about third party behaviour. PMID:20554547

The control system position to the electric probe in the Tokamak Novillo

International Nuclear Information System (INIS)

Sanchez Garcia, A.M.

1993-01-01

The electric probe are used to determine the parameters of electronic temperatures, the electron density and the plasma potential in Tokamak machines. On this machines the electric probes are used only in the plasma edge due to the intensive flow of high energy particles. This is the region in which the plasma density and temperature are relatively low. It is showed, in this work, the design and construction of an electro mechanic system which is used to control the position of the probe into the discharge chamber. This system is called T he control system position to the electric probe in the tokamak Novillo . This controller is a minimum system that is in charge , by a programming, to rule a step motor by a logic sequence commutation. This is done with the purpose of slide the probe in a radial way with a milli metric precision into the discharge chamber. To this purpose it is used a step motor, due it is principal characteristic is the control of the end element position without a feedback needing of the wrong signal. The system function consist on reading, through a board, the corresponding data to the position where it is wanted to place the probe, it also displays by a numeric indicator the position in which the probe is located (in an interval from 0 to 100 mm), and provide the logic sequence commutation for the step motor. The minimum system is constituted by the micro controller 8748-8 that gives with all precision the control of the electric probe position in the Tokamak Novillo, by programming, associated circuits, amplification unit bi phase unipolar and switching power (they supply the power to the control circuit and to the step motor too), avoiding the destruction of the electric probe. (Author). 17 refs, 29 figs

Diagnosis and Fault-Tolerant Control for Thruster-Assisted Position Mooring System

DEFF Research Database (Denmark)

Nguyen, Trong Dong; Blanke, Mogens; Sørensen, Asgeir

2007-01-01

Development of fault-tolerant control systems is crucial to maintain safe operation of o®shore installations. The objective of this paper is to develop a fault- tolerant control for thruster-assisted position mooring (PM) system with faults occurring in the mooring lines. Faults in line......'s pretension or line breaks will degrade the performance of the positioning of the vessel. Faults will be detected and isolated through a fault diagnosis procedure. When faults are detected, they can be accommodated through the control action in which only parameter of the controlled plant has to be updated...... to cope with the faulty condition. Simulations will be carried out to verify the advantages of the fault-tolerant control strategy for the PM system....

Change in antihypertensive drug prescribing after guideline implementation: a controlled before and after study

Directory of Open Access Journals (Sweden)

Helin-Salmivaara Arja

2011-08-01

Full Text Available Abstract Background Antihypertensive drug choices and treatment levels are not in accordance with the existing guidelines. We aimed to assess the impact of a guideline implementation intervention on antihypertensive drug prescribing. Methods In this controlled before and after study, the effects of a multifaceted (education, audit and feedback, local care pathway quality programme was evaluated. The intervention was carried out in a health centre between 2002 and 2003. From each health care unit (n = 31, a doctor-nurse pair was trained to act as peer facilitators in the intervention. All antihypertensive drugs prescribed by 25 facilitator general practitioners (intervention GPs and 53 control GPs were retrieved from the nationwide Prescription Register for three-month periods in 2001 and 2003. The proportions of patients receiving specific antihypertensive drugs and multiple antihypertensive drugs were measured before and after the intervention for three subgroups of hypertension patients: hypertension only, with coronary heart disease, and with diabetes. Results In all subgroups, the use of multiple concurrent medications increased. For intervention patients with hypertension only, the odds ratio (OR was 1.12 (95% CI 0.99, 1.25; p = 0.06 and for controls 1.13 (1.05, 1.21; p = 0.002. We observed no statistically significant differences in the change in the prescribing of specific antihypertensive agents between the intervention and control groups. The use of agents acting on the renin-angiotensin-aldosterone system increased in all subgroups (hypertension only intervention patients OR 1.19 (1.06, 1.34; p = 0.004 and controls OR 1.24 (1.15, 1.34; p Conclusions A multifaceted guideline implementation intervention does not necessarily lead to significant changes in prescribing performance. Rigorous planning of the interventions and quality projects and their evaluation are essential.

Security, development and human rights: normative, legal and policy challenges for the international drug control system.

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Barrett, Damon

2010-03-01

This commentary addresses some of the challenges posed by the broader normative, legal and policy framework of the United Nations for the international drug control system. The 'purposes and principles' of the United Nations are presented and set against the threat based rhetoric of the drug control system and the negative consequences of that system. Some of the challenges posed by human rights law and norms to the international drug control system are also described, and the need for an impact assessment of the current system alongside alternative policy options is highlighted as a necessary consequence of these analyses. Copyright (c) 2010 Elsevier B.V. All rights reserved.

Significant role of cationic polymers in drug delivery systems.

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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.

Admissions of injection drug users to drug abuse treatment following HIV counseling and testing.

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McCusker, J; Willis, G; McDonald, M; Lewis, B F; Sereti, S M; Feldman, Z T

1994-01-01

The outcomes of counseling and testing programs related to human immunodeficiency virus (HIV) infection and risk of infection among injection drug users (IDUs) are not well known or understood. A counseling and testing outcome of potential public health importance is attaining admission to drug abuse treatment by those IDUs who are either infected or who are at high risk of becoming infected. The authors investigated factors related to admission to drug abuse treatment among 519 IDUs who received HIV counseling and testing from September 1987 through December 1990 at a men's prison and at community-based testing sites in Worcester, MA. By June 1991, 123 of the 519 IDUs (24 percent) had been admitted to treatment. Variables associated with their admission included a long history of drug injection, frequent recent drug injection, cleaning injection equipment using bleach, prior drug treatment, and a positive HIV test result. Logistic regression analyses, controlling for effects of recruitment site, year, sex, and area of residence, generally confirmed the associations. IDUs in the study population who were HIV-infected sought treatment or were admitted to treatment more frequently than those who were not infected. The results indicate that access to drug abuse treatment should be facilitated for high-risk IDUs and for those who have begun to inject drugs recently.

21 CFR 1404.630 - May the Office of National Drug Control Policy impute conduct of one person to another?

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