bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of methcathinone and 3-Cl-methcathinone (PAL-434) in cocaine discrimination or self-administration in rhesus monkeys
Authors: Kohut Stephen J. , Fivel Peter A. , Blough Bruce E. , Rothman Richard B. , Mello Nancy K.
Published: June 2013

Monoamine releasers with varying selectivity for dopamine (DA)/norepinephrine and serotonin (5-HT) release are potential treatment medications for cocaine abuse. Although DA-selective monoamine releasers effectively reduce cocaine abuse, their clinical usefulness is limited by abuse liability. It is hypothesized that increasing 5-HT neurotransmission may reduce the abuse-related effects of DA releasers, but the optimal DA:5-HT release ratio remains to be determined. This study in rhesus monkeys compared the effects of two compounds with differing potency for 5-HT release. Methcathinone and 3-Cl-methcathinone (PAL-434) have equal potency for DA release, but PAL-434 has 10-fold higher potency for 5-HT release. In drug discrimination studies, monkeys were trained to discriminate cocaine (0.4 mg/kg i.m.) from saline in a two-key, food-reinforced procedure. In drug self-administration studies, a separate group of monkeys was trained to respond for cocaine [0.01 mg/kg/injection (inj)] and food (1 g pellets) under a second order schedule of reinforcement [FR2(VR16:S)]. When responding was stable, methcathinone (0.1–0.56 mg/kg.h i.v.) or PAL-434 (0.32–1.8 mg/kg.h i.v.) was administered chronically (one injection every 20 min for 23 h/d) for 7–10 d. In discrimination studies, both compounds dose-dependently increased cocaine-like responding but with different potencies (cocaine=methcathinone >PAL-434). Chronic treatment with methcathinone or PAL-434 dose-dependently and selectively reduced cocaine self-administration. PAL-434 was about 4-fold and methcathinone about 1.6-fold more potent at decreasing cocaine-over food-maintained responding. These data suggest that compounds with moderate selectivity for DA vs. 5-HT release (8–15-fold) may be effective for the treatment of cocaine dependence.
Differential effect of lithium on spermidine/spermine N1-acetyltransferase expression in suicidal behaviour
Authors: Squassina Alessio , Manchia Mirko , Chillotti Caterina , Deiana Valeria , Congiu Donatella , Paribello Francesco , Roncada Paola , Soggiu Alessio , Piras Cristian , Urbani Andrea , Robertson George S. , Keddy Paul , Turecki Gustavo , Rouleau Guy A. , Alda Martin , Del Zompo Maria
Published: June 2013

An altered polyamine system has been suggested to play a key role in mood disorders and suicide, a hypothesis corroborated by the evidence that lithium inhibits the polyamine mediated stress response in the rat brain. Recent post-mortem studies have shown that spermidine/spermine N1-acetyltransferase (SAT1), the key regulator of cellular polyamine content, is under-expressed in brains from suicide victims compared to controls. In our study we tested the effect of in vitro lithium treatment on SAT1 gene and protein expression in B lymphoblastoid cell lines (BLCLs) from bipolar disorder (BD) patients who committed suicide (and for which BLCLs were collected prior to their death), BD patients with high and low risk of suicide and a sample of non-psychiatric controls. Baseline mRNA levels were similar in the four groups of subjects (p > 0.05). Lithium had no effect in suicide completers (p > 0.05) while it significantly increased SAT1 expression in the high risk (p < 0.001) and low risk (p < 0.01) groups as well as in controls (p < 0.001). Protein and mRNA levels were not correlated; lithium significantly reduced protein levels only in the control sample (p < 0.05). Our findings suggest that SAT1 transcription is influenced by lithium and that this effect is altered in BD patients who completed suicide, further supporting a role for polyamines in suicide.
My Experience as a Library Graduate Trainee in Law
Authors: Kent Natalie
Published: June 2013

Graduate traineeships are an excellent way for people to enter into a career in libraries, providing a vast range of relevant experience. In the following article, last year's Graduate Trainee at Lincoln's Inn Library Natalie Kent, describes her experience as a trainee in law, outlining her background, role, training and visits, and reflects on the profession more widely.
Exploring User Training Needs at Middle Temple Law Library
Authors: Gow Erin
Published: June 2013

This research, conducted by Erin Gow, aims to explore the information literacy and legal research training needs of users of the Middle Temple library.* In order to do this it focuses on the patterns of use of library resources by users, reasons for these patterns, previous training users have received, and general evidence of user training needs in law libraries. The research as a whole was generated in result of the recognition that many Middle Temple library users require further legal research skills training in order to confidently find and employ the extensive resources available through the library. Before such training could be developed, however, research needed to be conducted into the specific capabilities and needs of the unique user base at the library. As a result of the research the current habits of library users have been explored, their general training levels and needs identified, and recommendations made about how to structure training so as to address these needs and best serve users. It was discovered that Middle Temple library users generally visit the library frequently, and are already confident using certain materials such as textbooks. Despite confidence in using certain common materials, users struggle to take advantage of the full range of resources available, making training necessary. The difficulties many users currently face in the library stem from a general lack of information literacy and library skills training.
Integration of Latino/a cultural values into palliative health care: A culture centered model
Authors: Adames Hector Y. , Chavez-Dueñas Nayeli Y. , Fuentes Milton A. , Salas Silvia P. , Perez-Chavez Jessica G.
Published: June 2013

Objective:

Culture helps us grapple with, understand, and navigate the dying process. Although often overlooked, cultural values play a critical and influential role in palliative care. The purpose of the present study was two-fold: one, to review whether Latino/a cultural values have been integrated into the palliative care literature for Latinos/as; two, identify publications that provide recommendations on how palliative care providers can integrate Latino/a cultural values into the end-of-life care.

Method:

A comprehensive systematic review on the area of Latino/a cultural values in palliative care was conducted via an electronic literature search of publications between 1930–2013. Five articles were identified for reviewing, discussing, or mentioning Latino/a cultural values and palliative care.

Results:

Only one article specifically addressed Latino/a cultural values in palliative care. The four remaining articles discuss or mention cultural values; however, the cultural values were not the main focus of each article's thesis.

Significance of results:

The results of the current study highlight the lack of literature specifically addressing the importance of integrating Latino/a cultural values into the delivery of palliative care. As a result, this article introduces the Culture-Centered Palliative Care Model (CCPC). The article defines five key traditional Latino/a cultural values (i.e.,familismo,personalismo,respeto,confianza, anddignidad), discusses the influence of each value on palliative health care, and ends with practical recommendations for service providers. Special attention is given to the stages of acculturation and ethnic identity.
Medical oncologist's commitment in end-of-life care of cancer patients
Authors: Bascioni Romeo , Giorgi Francesca , Esperide Barbara , Brugni Manuela , Basirat Farnoosh , Rastelli Francesca , De Signoribus Giorgio , Giustini Lucio
Published: June 2013

Objective:

Cancer patients and family members can feel abandoned by their oncologist at the transition to end-of-life (eoL) care. In this study, we evaluated the level of satisfaction of family caregivers when the oncology team assisted the patient until death.

Methods:

Two oncology units were reorganized to ensure continuity of care; oncologists trained in palliative care medicine assisted patients until death. Relatives who assisted the patient at home or at an inpatient hospice underwent a semi-structured phone interview >1 month after the patient's death. Satisfaction was measured using a five-point Likert scale ranging from very dissatisfied (score 0) to very satisfied (score 100).

Results:

Relatives of 65 patients were contacted, 55 accepted the interview. Patients were followed at home (41) or at an inpatient hospice (14), for 1–24 weeks (median 3 weeks). A specific question on the relevance of the oncologist having a role in EoL care produced a score of 82. The overall satisfaction score was higher than in our previous study in which a continuity of care model was not adopted, with a score improvement from 55/100 to 84/100 (p < 0.001).

Significance of results:

A care program where the oncologist is involved in EoL management improved the satisfaction of caregivers of cancer patients. When a longstanding and trusting relationship has been established, the connection between the patient and the oncologist should not be lost.
Mindfulness in informal caregivers of palliative patients
Authors: Kögler Monika , Brandstätter Monika , Borasio Gian Domenico , Fensterer Veronika , Küchenhoff Helmut , Fegg Martin Johannes
Published: June 2013

Objectives:

Mindfulness is a concept of growing impact on psychotherapy and has been shown to be effective for stress reduction and to improve psychological well-being. Existential Behavioural Therapy (EBT) was developed to support relatives of palliative care (PC) patients to cope with their situation during caregiving and bereavement. Mindfulness training was a core element of the intervention.

We investigated the relationship between mindfulness, mental distress, and psychological well-being in informal caregivers, and evaluated if the effects of the intervention were mediated by mindfulness.

Methods:

Relatives of PC inpatients took part in a randomized-controlled EBT trial and completed the Cognitive and Affective Mindfulness Scale-Revised, items from the Five Facets of Mindfulness as well as the Brief Symptom Inventory, the Satisfaction with Life Scale, the WHOQOL-BREF, a numerical rating scale on quality of life (range 0–10), and the Schedule for Meaning in Life Evaluation at pre- and post-intervention, and a 3- and 12-months follow-up.

Results:

One-hundred-and-thirty carers were included, most of them (71.6%) recently being bereaved at the beginning of the intervention. High correlations between mindfulness and mental distress (r = −0.51, p < 0.001) as well as life satisfaction (r = 0.52, p < 0.001) were found. Mindfulness was a significant predictor of improvement in psychological distress, meaning in life and quality of life three months after the intervention. The EBT effects were partly mediated by mindfulness.

Significance of results:

Mindfulness seems to be a promising concept in supporting informal caregivers of PC patients. Further research is needed to identify the required format and intensity of mindfulness practice necessary for improvement.
A Reality Check on Hardy–Weinberg
Authors: Stark Alan E. , Seneta Eugene
Published: June 2013

G. H. Hardy (1877–1947) and Wilhelm Weinberg (1862–1937) had very different lives, but in the minds of geneticists, the two are inextricably linked through the ownership of an apparently simple law called the Hardy–Weinberg law. We demonstrate that the simplicity is more apparent than real. Hardy derived the well-known trio of frequencies {q2, 2pq,p2} with a concise demonstration, whereas for Weinberg it was the prelude to an ingenious examination of the inheritance of twinning in man. Hardy's recourse to an identity relating to the distribution of types among offspring following random mating, rather than an identity relating to the mating matrix, may be the reason why he did not realize that Hardy–Weinberg equilibrium can be reached and sustained with non-random mating. The phrase ‘random mating’ always comes up in reference to the law. The elusive nature of this phrase is part of the reason for the misunderstandings that occur but also because, as we explain, mathematicians are able to use it in a different way from the man-in-the-street. We question the unthinking appeal to random mating as a model and explanation of the distribution of genotypes even when they are close to Hardy–Weinberg proportions. Such sustained proportions are possible under non-random mating.
Community Violence and Psychological Distress in South African and U.S. Children
Authors: Shields Nancy , Nadasen Kathy , Pierce Lois
Published: June 2013

This study compared the relation between exposure to community violence and psychological distress in children in the United States and the R.S.A. (South Africa). Interviews were conducted with 247 children (49% male) between the ages of 8 to 13 years from five Cape Town township schools, and 162 children (49% male) ages 7 to 13 in a summer day program in St. Louis, MO. The Nadel, Spellman, and Alvarez-Canino Victimization Scale ( H. Nadel, M. Spellman, T. Alvarez-Canino, L. Lausell-Bryant, and G. Landsberg, 1996 , The cycle of violence and victimization: A study of the school-based intervention of a multidisciplinary youth prevention program, American Journal of Preventive Medicine, Vol. 12, pp. 109–119) was used to measure exposure to violence and Richters, Martinez, and Valla’s (1990) instrument ( J. E. Richters, P. Martinez, and J. Valla, 1990 , Levonn: A cartooned-based structured interview for assessing young children’s distress symptoms. Rockville, MD: National Institute of Mental Health) was used to measure psychological distress. Reported exposure to community violence was generally higher in the R.S.A. sample than in the U.S. sample. However, children in the St. Louis sample reported more psychological distress. Interactions revealed that for young children and for low levels of witnessed school violence, U.S. children reported greater distress, with no sample differences at older ages, or at high levels of witnessed school violence. We suggest that children in the R.S.A. sample are experiencing less psychological distress because community violence is more normative in the R.S.A.
Lessons Learned From a Mindfulness-Based Intervention With Chronically Ill Youth
Authors: Lagor Anne F. , Williams Dahra Jackson , Lerner Jennifer Block , McClure Kelly S.
Published: June 2013

The purpose of this study was to take steps toward developing a mindfulness-based intervention for youth with chronic medical conditions, and, more importantly, to document lessons learned for increasing the effectiveness of similar interventions in real-world clinical settings. Thirteen children and adolescents attending a specialized school for youth with chronic illness completed the intervention. Students completed pre- and postintervention assessments of health-related quality of life, psychosocial functioning, and mindfulness. Students also provided verbal feedback regarding the intervention. The program was evaluated using the following criteria: (a) treatment acceptability, (b) recruitment and retention, (c) timing, and (d) preliminary outcomes. Data from treatment completers revealed statistically significant improvement in anxiety symptoms from pre- to postintervention; no other significant changes were found. Additionally, a number of important lessons were learned from this endeavor including the importance of the following: frequency and number of sessions, between-session practice, small group size, modular rather than cumulative/linear group format, groups based on age rather than gender, and external rewards for participation. Findings highlighted important areas for improvement and implications for implementation are discussed.
Case Studies in Clinical Practice in Pediatric Psychology: The “Why” and “How To”
Authors: Ernst Michelle M. , Barhight Lydia R. , Bierenbaum Melanie L. , Piazza-Waggoner Carrie , Carter Bryan D.
Published: June 2013

Case studies are an important venue for reporting clinical processes relevant to clinical care, research agendas, and interprofessional collaboration. Clinical Practice in Pediatric Psychology ( CPPP) is actively soliciting case studies to further the mission of promoting evidence-based practice, highlighting important areas for further empirical study related to biopsychosocial phenomena and advocating for the value and relevance of pediatric psychology in the current health care climate. This article highlights desired topic areas for case studies for CPPP, reviews methodological considerations, and provides recommendations for case study reporting. In addition, ethical considerations related to case study report methodology are reviewed. Our hope is that this article will promote submission and acceptance of case studies to Clinical Practice in Pediatric Psychology.
Cultural Beliefs, Intimate Partner Violence, and Mental Health Functioning Among Vietnamese Women
Authors: Do Khanh Ngoc , Weiss Bahr , Pollack Amie
Published: June 2013

Intimate partner violence (IPV) against women occurs in all countries, with wide-ranging negative effects, including on mental health. However, IPV rates vary widely across countries, suggesting cultural factors may play a role in IPV. The primary purpose of the present study was to assess relations among IPV, mental health symptoms, and cultural beliefs among Vietnamese women, focusing on moderator effects of cultural beliefs on relations between IPV and mental health. IPV, anxious and depressive mental health symptoms, and culturally related beliefs about IPV were cross-sectionally assessed in 105 married adult Vietnamese women randomly selected from public population registries in five provinces. IPV was significantly correlated with anxiety, depression, and suicidal ideation. Relations were moderated by wives’ culturally related beliefs about abuse (e.g., relations between IPV and mental health symptoms were smaller for women who believed that nothing could be done about abuse). Findings suggest that when attempting to prevent or treat effects of IPV, it will be important to consider that certain beliefs about IPV generally viewed as maladaptive (e.g., nothing can be done about abuse) may have adaptive effects, at least in the short-term, on relations between IPV and mental health functioning.
Structure and function of Parkin E3 ubiquitin ligase reveals aspects of RING and HECT ligases
Authors: Riley B.E. , Lougheed J.C. , Callaway K. , Velasquez M. , Brecht E. , Nguyen L. , Shaler T. , Walker D. , Yang Y. , Regnstrom K. , Diep L. , Zhang Z. , Chiou S. , Bova M. , Artis D.R. , Yao N. , Baker J. , Yednock T. , Johnston J.A.
Published: June 2013

Parkin is a RING-between-RING E3 ligase that functions in the covalent attachment of ubiquitin to specific substrates, and mutations in Parkin are linked to Parkinson’s disease, cancer and mycobacterial infection. The RING-between-RING family of E3 ligases are suggested to function with a canonical RING domain and a catalytic cysteine residue usually restricted to HECT E3 ligases, thus termed ‘RING/HECT hybrid’ enzymes. Here we present the 1.58 Å structure of Parkin-R0RBR, revealing the fold architecture for the four RING domains, and several unpredicted interfaces. Examination of the Parkin active site suggests a catalytic network consisting of C431 and H433. In cells, mutation of C431 eliminates Parkin-catalysed degradation of mitochondria, and capture of an ubiquitin oxyester confirms C431 as Parkin’s cellular active site. Our data confirm that Parkin is a RING/HECT hybrid, and provide the first crystal structure of an RING-between-RING E3 ligase at atomic resolution, providing insight into this disease-related protein.
Vegetarian diet-induced increase in linoleic acid in serum phospholipids is associated with improved insulin sensitivity in subjects with type 2 diabetes
Authors: Kahleova H , Matoulek M , Bratova M , Malinska H , Kazdova L , Hill M , Pelikanova T
Published: June 2013

BACKGROUND AND AIMS:

Fatty acids are important cellular constituents that may affect many metabolic processes relevant for the development of diabetes and its complications. We showed previously that vegetarian diet leads to greater increase in metabolic clearance rate of glucose (MCR) than conventional hypocaloric diet. The aim of this secondary analysis was to explore the role of changes in fatty acid composition of serum phospholipids in diet- and exercise-induced changes in MCR in subjects with type 2 diabetes (T2D).

METHODS:

Subjects with T2D (n=74) were randomly assigned into a vegetarian group (VG, n=37) following vegetarian diet or a control group (CG, n=37) following a conventional diet. Both diets were calorie restricted (−500 kcal day–1). Participants were examined at baseline, 12 weeks of diet intervention and 24 weeks (subsequent 12 weeks of diet were combined with aerobic exercise). The fatty acid composition of serum phospholipids was measured by gas liquid chromatography. MCR was measured by hyperinsulinemic isoglycemic clamp. Visceral fat (VF) was measured by magnetic resonance imaging.

RESULTS:

Linoleic acid (LA; 18:2n6) increased in VG (P=0.04), whereas it decreased in CG (P=0.04) in response to dietary interventions. It did not change significantly after the addition of exercise in either group (group × time P<0.001). In VG, changes in 18:2n6 correlated positively with changes in MCR (r=+0.22; P=0.04) and negatively with changes in VF (r=−0.43; P=0.01). After adjustment for changes in body mass index, the association between 18:2n6 and MCR was no longer significant. The addition of exercise resulted in greater changes of phospholipid fatty acids composition in VG than in CG.

CONCLUSION:

We demonstrated that the insulin-sensitizing effect of a vegetarian diet might be related to the increased proportion of LA in serum phospholipids.
Magnetic-responsive Nanoparticles for Drug Delivery
Authors: Chen San-Yuan , Hu Shang-Hsiu , Liu Ting-Yu
Published: June 2013

Controlled drug release, especially stimuli-responsive drug-delivery systems, has received great attention worldwide. Compared to other triggering agents that require a physical or chemical contact, magnetic field permits a non-contact, remotely manageable control of the site and rate of the release, which is highly advantageous for clinical applications. Magnetic nanoparticles display some excellent advantages, such as magnetic-guiding, magnetic resonance image (MRI), hyperthermia and magnetic-triggered drug release upon a simple “on” and “off” magnetic switch mode. Therefore, magnetic-sensitive drug nanocarriers can be considered as a new biomedical nanoplatform for disease diagnosis and therapy. In this chapter, the physical basis of the effects of the magnetic field on magnetic nanocolloid solutions, the synthesis of magnetic nanoparticles and of nanostructures containing the magnetic nanoparticles (e.g. micelles, polymersomes, organic and inorganic networks) is described, and some relevant applications, including in vivo tests, for drug delivery in cancer, epilepsy and gene therapy, among others, are discussed.
Smart Carbon Nanotubes
Authors: Tobias Gerard , Flahaut Emmanuel
Published: June 2013

Carbon-based nanomaterials combine a myriad of both physical and chemical properties that can be explored for target delivery and controlled release of drug payloads. Active agents can be attached to the surface of functionalized carbon nanotubes (CNTs) or can be encapsulated into the cavity of CNT nanocontainers. Smart delivery carriers combining a chosen drug, targeting agents and imaging moieties can thus be developed by using CNTs. General features of CNTs, approaches to functionalize their surface and to encapsulate materials inside, and both in vitro and in vivo studies of their suitability for the (targeted) delivery of drugs, are described in this chapter. Special emphasis is given to the toxicity and the potential environmental impact of CNTs.
Multiple Stimuli-responsive Hydrogels Based on α-Amino Acid Residues for Drug Delivery
Authors: Casolaro Mario , Casolaro Ilaria
Published: June 2013

Vinyl hydrogels containing α-amino-acid (l-valine, l-phenylalanine, l-histidine) residues are endowed with unique stimulus-responsive properties and undergo large changes in swelling degree as a function of temperature, pH and ionic strength conditions or the intensity of an electric field. These biocompatible smart hydrogels exhibit single or multiple stimuli-responsiveness potentially useful for biomedical applications, including controlled drug delivery, bioengineering or tissue engineering. This chapter focuses on recent developments and future trends of the α-amino-acid-based hydrogels as drug- (cisplatin, temsirolimus, pilocarpine) delivery systems for cancer and glaucoma therapy, and as platforms for lithium ion delivery to the brain for bipolar disorder management.
Intelligent Surfaces for Cell and Tissue Delivery
Authors: Takahashi Hironobu , Okano Teruo
Published: June 2013

Cell transplantation remains a powerful approach for promising numerous biomedical applications to promote tissue regeneration. Therefore, smart delivery systems of therapeutic cells, as well as therapeutic oligonucleotides and proteins, are required. Although cells have been conventionally delivered by direct injection to target sites, a number of clinical studies showed a limitation due to poor cell retention and survival at the sites, resulting in insufficient effect on tissue/organ repair. Therefore, at present, numerous delivery strategies have been developed, and a variety of polymeric materials play important roles. For example, encapsulation in semi-permeable membrane made from biocompatible polymers (e.g. alginate-poly(l-lysine)-alginate) allows xenograft islets to be delivered in vivo without immune suppression. With progress in tissue engineering, scaffold-based cell/tissue delivery reached the mainstream for regenerating damaged tissues. Various kinds of scaffolds have been fabricated from natural and synthetic polymers, such as collagen or poly(l-lactic-co-glycolic acid), and allowed to provide appropriate nutritional conditions and spatial organization for cell growth. Whereas these scaffolds produce reliable architectures to design cell/tissue delivery, scaffold-free cell/tissue delivery also has opened up a new class technology in the field of regenerative medicine. Thermo-responsive poly(N-isopropylacrylamide)-grafted surfaces allow one to fabricate tissue-like cell monolayers, “cell sheets”, and deliver the cell-dense tissue with associated extra-cellular matrix (ECM) to damaged sites without scaffold implantation. The chapter focuses on unique cell/tissue delivery techniques using the intelligent surfaces. This technology has already been applied to human clinical studies for tissue regeneration, and microfabricated thermo-responsive surfaces are further developing for delivering more complex tissue.
Drug/Medical Device Combination Products with Stimuli-responsive Eluting Surface
Authors: Alvarez-Lorenzo C. , Concheiro A.
Published: June 2013

Drug-eluting medical devices are designed to improve the primary function of the device and at the same time offer local release of drugs which otherwise might find it difficult to reach the insertion/implantation site. The incorporation of the drug enables the tuning of the host/microbial responses to the device and the management of device-related complications. On the other hand, the medical device acts as platform for the delivery of the drug for a prolonged period of time just at the site where it is needed and, consequently, the efficacy and the safety of the treatment, as well as its cost-effectiveness are improved. This chapter begins with an introduction to the combination products and then focuses on the techniques available (compounding, impregnation, coating, grafting of the drug or of polymers that interact with it) to endow medical devices with the ability to host drugs/biological products and to regulate their release. Furthermore, the methods for surface modification with stimuli-responsive polymers or networks are analyzed in detail and the performance of the modified materials as drug-delivery systems is discussed. A wide range of chemical-, irradiation- and plasma-based techniques for grafting of brushes and networks that are sensitive to changes in temperature, pH, light, ionic strength or concentration of certain biomarkers, from a variety of substrate materials, is currently available. Although in vivo tests are still limited, such a surface functionalization of medical devices has already been shown useful for the release on-demand of drugs and biological products, being switchable on/off as a function of the progression of certain physiological or pathological events (e.g. healing, body integration, biofouling or biofilm formation). Improved knowledge of the interactions among the medical device, the functionalized surface, the drug and the body are expected to pave the way to the design of drug-eluting medical devices with optimized and novel performances.
pH-sensitive Liposomes in Drug Delivery
Authors: Rai Paliwal Shivani , Paliwal Rishi , Vyas Suresh P
Published: June 2013

The pH-sensitive liposomes have been extensively studied in recent years as an advantageous alternative to conventional liposomes in effective targeting and accumulation of anticancer drugs in tumors. pH-sensitive liposomes usually contain phosphatidylethanolamine and stabilizing amphiphiles and can destabilize under acidic conditions of the endocytotic pathway. The drug loaded is thought to be delivered into the cytoplasm, probably through destabilization of or fusion with the endosome membrane. This fusogenic property makes the pH-sensitive liposomes more efficient in delivering anticancer drugs than conventional liposomes. The intra-cellular release of drug/gene/diagnostic agents can be achieved without altering their therapeutic efficacy by means of the endosomal escape phenomenon. Cell surface targeting ligands, including antibodies, can be appended on the surface of pH-sensitive liposomes to target specific receptors on tumor cells. This chapter provides an introduction to pH-sensitive liposomes and examples of their therapeutic interest as smart drug-delivery systems.
Enzyme-responsive Drug-delivery Systems
Authors: Caponi Pier-Francesco , Ulijn Rein V.
Published: June 2013

This chapter offers an overview of recent advances in enzyme-responsive materials potentially useful for drug delivery. The systems already developed provide new insights into the chemical design rules and response dynamics achievable by exploiting enzymatic catalysis as selective triggers in controlled release. The first section provides a general introduction about the role of enzymes in diseased states and examples where molecular therapeutics have been developed specifically to interfere with biochemical processes. The parameters to consider in order to develop enzyme-responsive drug-delivery systems are then discussed. Different approaches to design hydrogels, micelles and silica nanocontainers with moieties that can be substrates of enzymes are described with the help of relevant examples that highlight their performance. The research in this area is gaining momentum at a significant pace and it is likely that the first therapeutic enzyme responsive materials will reach the clinic in the next decade.
Metabolic phenotypes of Saccharomyces cerevisiae mutants with altered trehalose 6-phosphate dynamics
Authors: Walther Thomas , Mtimet Narjes , Alkim Ceren , Vax Amélie , Loret Marie-Odile , Ullah Azmat , Gancedo Carlos , Smits Gertien J. , François Jean Marie
Published: June 2013

In Saccharomyces cerevisiae, synthesis of T6P (trehalose 6-phosphate) is essential for growth on most fermentable carbon sources. In the present study, the metabolic response to glucose was analysed in mutants with different capacities to accumulate T6P. A mutant carrying a deletion in the T6P synthase encoding gene, TPS1, which had no measurable T6P, exhibited impaired ethanol production, showed diminished plasma membrane H+-ATPase activation, and became rapidly depleted of nearly all adenine nucleotides which were irreversibly converted into inosine. Deletion of the AMP deaminase encoding gene, AMD1, in the tps1 strain prevented inosine formation, but did not rescue energy balance or growth on glucose. Neither the 90%-reduced T6P content observed in a tps1 mutant expressing the Tps1 protein from Yarrowia lipolytica, nor the hyperaccumulation of T6P in the tps2 mutant had significant effects on fermentation rates, growth on fermentable carbon sources or plasma membrane H+-ATPase activation. However, intracellular metabolite dynamics and pH homoeostasis were strongly affected by changes in T6P concentrations. Hyperaccumulation of T6P in the tps2 mutant caused an increase in cytosolic pH and strongly reduced growth rates on non-fermentable carbon sources, emphasizing the crucial role of the trehalose pathway in the regulation of respiratory and fermentative metabolism.
Design and digital implementation of voltage and current mode control for the quasi‐Z‐source converters
Authors: Liu HePing , Liu Ping , Zhang YuXin
Published: June 2013

Two strategies of peak dc‐link voltage control of the voltage‐fed quasi‐Z‐source converters (qZSC) are analysed and compared. Different from the currently available literatures, the peak dc‐link voltage is estimated by summing the two capacitor voltages of qZSC. The voltage mode and current mode controls are derived based on the fifth‐order small‐signal model of the quasi‐Z‐source network with inductive load. Both controllers are digitally implemented using a digital signal processor (DSP)‐based direct digital design approach, where the real‐time workshop is used for automatic real‐time code generation for a TMS320F2808 DSP. Digital compensators are tuned using Bode diagram and discrete frequency response approaches with a graphical MATLAB/single‐input single‐output tool. The performances of the proposed control strategies are verified by the experimental results during start‐up, input voltage and load disturbances.
Analytical winding foil thickness optimisation of inductors conducting harmonic currents
Authors: Wojda Rafal P. , Kazimierczuk Marian K.
Published: June 2013

This study presents analytical winding power loss minimisation of foil inductors conducting ac harmonic currents with and without dc offset. The approximated equation for the ac winding power loss is derived and used to determine the optimum foil thickness of inductors operating with multi‐harmonic ac currents. An approximated equation for the total winding power loss is also derived and used to determine the optimum foil thickness of inductors operating with multi‐harmonic ac currents superimposed on the dc current. The design procedure for inductors with minimum total winding power loss is presented for a pulsewidth‐modulated dc–dc boost converter operating in discontinuous conduction mode. The theoretical predictions have been verified by measurements of inductors with four different foil thicknesses.
Dynamic performance investigation of d–q model with PID controller‐based unified power‐flow controller
Authors: Kasinathan Pounraj , Vairamani Rajasekaran , Sundramoorthy Selvaperumal
Published: June 2013

Reactive power compensation is a main problem in the control of electric power system. Reactive power from the source increases the transmission losses and reduces the power transmission ability of the transmission lines. In addition, reactive power must not be transmitted throughout the transmission line to a longer distance. Consequently, flexible ac transmission systems devices such as static compensator unified power‐flow controller (UPFC) and static volt‐ampere compensator are used to ease these harms. UPFC is the mainly adaptable and composite power electronic equipment that has emerged as the vital equipment for the control and optimisation of power flow in electrical power transmission system. In this study, a d–q model‐based UPFC is developed with proportional‐integral (PI) and PID controller. The above controllers are simulated using MATLAB and their performance is analysed. Outcome of the analysis shows the superiority of PID control over the PI control method. Also this study presents comparative evaluation (both controllers) of dynamic response when initial and final load disturbances.
Implementation of dual‐loop controller for positive output elementary Luo converter
Authors: Ravichandran Shama , Patnaik Sanjib Kumar
Published: June 2013

A two‐loop controller has been designed for a positive output elementary Luo (POEL) converter. An H∞ controller is used in the outer loop using the loop‐shaping concepts and a sliding mode control (SMC) in the inner loop for the regulation of the output voltage in spite of the perturbations in the line and load voltages. H∞ controller generates the current reference for the converter inductor current, whereas SMC forces the converter inductor current to follow the reference. A practical design that combines the loop‐shaping technique with SMC to enhance robustness and sliding performance is proposed. The closed‐loop characteristics of a typical low‐power POEL converter with the proposed controller implemented in the actual switched model is validated through computer simulations and experimental hardware. The proposed controller is found to be superior because of its low distortion property, good regulating performance and insensitivity to load variations.
Obstacle‐avoidance path planning of a mobile Beacon for localisation
Authors: Wang Yinglong , CUI Huanqing , GUO Qiang , SHU Minglei
Published: June 2013

Location is important for most wireless sensor network applications. A potential localisation method uses a mobile beacon instead of numerous static beacons. This method includes planning a beacon trajectory as a fundamental and interesting problem. Obstacles in practical scenarios often restrict the free locomotion of beacons. This study examines the obstacle‐avoidance path‐planning method, which consists of three stages. First, the network deployment region is partitioned into cells by adaptive cell decomposition, and the corresponding connectivity graph is constructed. Second, a modified max–min ant system algorithm is provided to obtain the approximate shortest global path that covers the connectivity graph. Finally, a sequence of concentric circles of adjustable radii is utilised as the local path within an obstacle‐free cell. We prove that all sensor nodes deployed in obstacle‐free cells can be localised by using the proposed path. Simulation results show that more than 90% of the sensor nodes in the obstacle‐free region can be localised by using the given trajectory.
Cooperative wideband spectrum sensing in suspicious cognitive radio network
Authors: Srinu Sesham , Sabat Samrat Lagnajeet
Published: June 2013

This study presents a cooperative wideband spectrum‐sensing technique based on the entropy of the received signal in the frequency domain. To enhance the efficiency of detection, multiple suspicious cognitive users are excluded from the network using generalised extreme studentised deviate test and sigma limit test. The performance of the proposed technique is compared with the energy detection technique under different channel environments. The simulation results demonstrate that the entropy detection method, with excluded suspicious users, has 9 dB improvement in performance compared to the energy detection technique in extremely low signal‐to‐noise ratio regime. This is a significant improvement for cognitive radio systems. The simulations were performed with false alarm probability and detection probability of 0.01 and 0.9, respectively. The hardware‐in‐the‐loop simulation of the proposed algorithm is further carried out in the Xilinx Virtex‐4 Field Programmable Gate Array.
Transmission scheduling for broadcasting with two energy‐harvesting switching transmitters
Authors: Zhou Fangfang , Chen Hongbin , Zhao Feng
Published: June 2013

To minimise transmission completion time in energy‐harvesting rechargeable communication systems, various transmission scheduling schemes have been proposed. However, they did not consider the issue where a transmitter may fail before completing the transmission. To resolve this issue, transmission scheduling for broadcasting with energy‐harvesting switching transmitters is studied. The broadcasting communication system consists of two transmitters and two users. The transmitters harvest energy independently and work alternately. The transmission scheduling problem is formulated as minimising the transmission completion time, under the energy causality constraint, the data transmission constraint, and the transmitter switching constraint. Transmitter switching is addressed by proving that a transmitter should not stop transmission before switching to the other transmitter and the switching threshold should be zero. Then, an optimal transmission policy is proposed based on earlier works on rate region and the transmitter switching mechanism. The proposed optimal transmission policy can achieve a larger rate region than several kinds of suboptimal transmission policies.
Routing protocol based on genetic algorithm for energy harvesting‐wireless sensor networks
Authors: Wu Yin , Liu Wenbo
Published: June 2013

Traditional routing protocols are no longer suitable for the energy harvesting‐wireless sensor networks (EH‐WSN), which is powered by the energy harvested from environment instead of batteries. Rather than minimising the energy consumption and maximising the network lifetime, the main challenge in EH‐WSN is to maximise its working performance under energy harvesting constraints. In this study, the authors propose a centralised power efficient routing algorithm energy harvesting genetic‐based unequal clustering‐optimal adaptive performance routing algorithm (EHGUC‐OAPR) which contains two parts: (i) energy harvesting genetic‐based unequal clustering algorithm EHGUC and (ii) optimal adaptive performance routing algorithm (OAPR). First, the base station (BS) uses EHGUC algorithm to form clusters of unequal size and select associated cluster heads, in which the clusters closer to the BS have smaller size. Then, the BS adopts OAPR algorithm to construct an optimal routing among each cluster heads. The numerical results show that EHGUC‐OAPR is not only well applied to EH‐WSN, but also has a great improvement in network energy balance and data delivery ratio.
Band gap and function engineering for novel functional alloy semiconductors: Bloomed as magnetic properties at room temperature with α-(GaFe)2O3
Authors: Kaneko Kentaro , Kakeya Itsuhiro , Komori Sachio , Fujita Shizuo
Published: June 2013

Highly crystalline corundum structured α-(Ga0.42Fe0.58)2O3 alloy thin film showed magnetic properties at room temperature. Microstructure analysis of cross-sectional transmission electron microscope (TEM) observation and TEM energy dispersive X-ray spectroscopy measurement indicated that different crystal phase could not be detected as well as there is no remarkable phase separating area, that is, Fe and Ga ions are distributed uniformly in the film. Magnetic measurements were performed on α-(Ga1−xFex)2O3 (x = 0.24, 0.44, 0.58, 1.00) alloy thin films at 110 K. The induced magnetic moment per a Fe ion of α-(Ga0.42Fe0.58)2O3 at 5000 Oe is about 6 times larger than α-Fe2O3 thin film. Compared to the α-Fe2O3 thin films, the value of coercivity is also about 6 times in α-(Ga0.42Fe0.58)2O3, in contrast, there is no significant difference in value of coercivity of α-(Ga1−xFex)2O3 (x = 0.24, 0.44, 1.00) thin films. These means that the origin of magnetism is not the separation region of α-Fe2O3 in α-(Ga0.42Fe0.58)2O3 thin film.
Direct observation of charge transfer region at interfaces in graphene devices
Authors: Nagamura Naoka , Horiba Koji , Toyoda Satoshi , Kurosumi Shodai , Shinohara Toshihiro , Oshima Masaharu , Fukidome Hirokazu , Suemitsu Maki , Nagashio Kosuke , Toriumi Akira
Published: June 2013

Nanoscale spectromicroscopic characterizing technique is indispensable for realization of future high-speed graphene transistors. Highly spatially resolved soft X-ray photoelectron microscopy measurements have been performed using our “3D nano-ESCA” (three-dimensional nanoscale electron spectroscopy for chemical analysis) equipment in order to investigate the local electronic states at interfaces in a graphene device structure. We have succeeded in detecting a charge transfer region at the graphene/metal-electrode interface, which extends over ∼500 nm with the energy difference of 60 meV. Moreover, a nondestructive depth profiling reveals the chemical properties of the graphene/SiO2-substrate interface.
Features in chemical kinetics. I. Signatures of self-emerging dimensional reduction from a general format of the evolution law
Authors: Nicolini Paolo , Frezzato Diego
Published: June 2013

Simplification of chemical kinetics description through dimensional reduction is particularly important to achieve an accurate numerical treatment of complex reacting systems, especially when stiff kinetics are considered and a comprehensive picture of the evolving system is required. To this aim several tools have been proposed in the past decades, such as sensitivity analysis, lumping approaches, and exploitation of time scales separation. In addition, there are methods based on the existence of the so-called slow manifolds, which are hyper-surfaces of lower dimension than the one of the whole phase-space and in whose neighborhood the slow evolution occurs after an initial fast transient. On the other hand, all tools contain to some extent a degree of subjectivity which seems to be irremovable. With reference to macroscopic and spatially homogeneous reacting systems under isothermal conditions, in this work we shall adopt a phenomenological approach to let self-emerge the dimensional reduction from the mathematical structure of the evolution law. By transforming the original system of polynomial differential equations, which describes the chemical evolution, into a universal quadratic format, and making a direct inspection of the high-order time-derivatives of the new dynamic variables, we then formulate a conjecture which leads to the concept of an “attractiveness” region in the phase-space where a well-defined state-dependent rate function ω has the simple evolution \documentclass[12pt]{minimal}\begin{document}$\dot{\omega }= - \omega ^2$\end{document}ω̇=−ω2 along any trajectory up to the stationary state. This constitutes, by itself, a drastic dimensional reduction from a system of N-dimensional equations (being N the number of chemical species) to a one-dimensional and universal evolution law for such a characteristic rate. Step-by-step numerical inspections on model kinetic schemes are presented. In the companion paper [P. Nicolini and D. Frezzato, J. Chem. Phys. 138, 234102 (2013)]10.1063/1.4809593 this outcome will be naturally related to the appearance (and hence, to the definition) of the slow manifolds.