bluuebunny/crossref_metadata_2025_split huggingface dataset:
Monte Carlo dosimetry modeling of focused kV x‐ray radiotherapy of eye diseases with potential nanoparticle dose enhancement
Authors: Yan Huagang , Ma Xiangyu , Sun Weiyuan , Mendez Stacy , Stryker Stefan , Starr‐Baier Sean , Delliturri Gianpiero , Zhu Dengsong , Nath Ravinder , Chen Zhe , Roberts Kenneth , MacDonald Carolyn A. , Liu Wu 
Published: August 2018

PurposeEye plaque brachytherapy is the most common approach for intraocular cancer treatment. It is, however, invasive and subject to large setup uncertainty due to the surgical operation. We propose a novel‐focused kV x‐ray technique with potential nanoparticle (NP) enhancement and evaluate its application in treating choroidal melanoma and iris melanoma by Monte Carlo (MC) dosimetry modeling.MethodsA polycapillary x‐ray lens was used to focus 45 kVp x rays to achieve pinpoint accuracy of dose delivery to small tumors near critical structures. In addition to allowing for beam focusing, the use of kV x rays takes advantage of the strong photoelectric absorption of metallic NPs in that energy regime and hence strong radiosensitization. We constructed an MC simulation program that takes into account the x‐ray optic modeling and used GEANT4 for dosimetric calculation. Extensive phantom measurements using a prototype‐focused x‐ray system were carried out. The MC simulation of simple geometry phantom irradiation was first compared to measurements to verify the x‐ray optic lens modeling in conjunction with the Geant4 dosimetric calculation. To simulate tumor treatment, a geometric eye model and two tumor models were constructed. Dose distributions of the simulated treatments were then calculated. NP radiosensitization was also simulated for two concentrations of 2 nm gold NP (AuNP) uniformly distributed in the tumor.ResultsThe MC‐simulated full width at half maximum (FWHM) and central‐axis depth dose of the focused kV x‐ray beam match those measured on EBT3 films within ~10% around the depth of focus of the beam. Dose distributions of the simulated ocular tumor treatments show that focused x‐ray beams can concentrate the high‐dose region in or close to the tumor plus margin. For the simulated posterior choroidal tumor treatment, with sufficient tumor coverage, the doses to the optic disc and fovea are substantially reduced with focused x‐ray therapy compared to eye plaque treatment (3.8 vs 39.8 Gy and 11.1 vs 53.8 Gy, respectively). The eye plaque treatment was calculated using an Eye Physics plaque with I‐125 seeds under TG43 assumption. For the energy spectrum used in this study, the average simulated dose enhancement ratios (DERs) are roughly 2.1 and 1.1 for 1.0% and 0.1% AuNP mass concentration in the tumor, respectively.ConclusionCompared to eye plaque brachytherapy, the proposed focused kV x‐ray technique is noninvasive and shows great advantage in sparing healthy critical organs without sacrificing the tumor control. The NP radiation dose enhancement is considerable at our proposed kV range even with a low NP concentration in the tumor, providing better critical structure protection and more flexibility for treatment planning.
Toward a novel dosimetry system using acrylic disk radiation sensor for proton pencil beam scanning
Authors: Cho Shinhaeng , Lee Nuri , Song Sanghyeon , Son Jaeman , Kim Haksoo , Jeong Jong Hwi , Lee Se Byeong , Lim Youngkyung , Moon Sunyoung , Yoon Myonggeun , Shin Dongho 
Published: August 2018

PurposeFabricate an acrylic disk radiation sensor (ADRS) and characterize the photoluminescence signal generated from the optical device as basis for the development and evaluation of a new dosimetry system for pencil beam proton therapy.MethodsBased on the characteristics of the proposed optical dosimetry sensor, we established the relation between the photoluminescence output and the applied dose using an ionization chamber. Then, we obtained the relative integral depth dose profiles using the photoluminescence signal generated by pencil beam irradiation at energies of 99.9 and 162.1 MeV, and compared the results with the curve measured using a Bragg peak ionization chamber.ResultsThe relation between the photoluminescence output and applied dose was linear. In addition, the ADRS was dose independent for beam currents up to 6 Gy/min, and the calibration factor for energy was close to 1. Hence, the energy dependence on the optical device can be disregarded. The integral depth dose profiles obtained for the ADRS suitable agreed with the curve measured in the Bragg peak ionization chamber without requiring correction.ConclusionsThese results suggest that the ADRS is suitable for dosimetry measurements in pencil beam scanning, and it will be employed as a low‐cost and versatile dosimetry sensor in upcoming developments.
Discourse analysis of health providers' experiences using service design
Authors: Eines Trude Fløystad , Angelo Elin , Vatne Solfrid 
Published: August 2018

AbstractBackgroundMunicipal healthcare organizations are facing increasing challenges to developing more cost‐effective organizations and services, particularly in nursing homes. The background for this article is an attempt in this concern; implementing service design in a nursing home.AimThe aim of the study is to explore nurses and nurse assistants' experiences using service design in a nursing home.DesignA qualitative design was applied.MethodData were collected through focus group interviews with 17 nurses and nurse assistants in 2015. Thematic discourse analysis was conducted to analyse their discussed experiences.ResultsThe employees had positive attitudes towards incorporating a service design approach that focused on the patients' needs, which thus encouraged creative solutions and promoted employee involvement. The study shows that involving service designers and employees in the entire process, from planning to implementation of new and innovative solutions, requires closer collaboration between the service designers, managers, and employees to achieve the final goal. We consider that the results of this study will be of relevance to the future development of health care and nursing in nursing homes.
SAHAquines, Novel Hybrids Based on SAHA and Primaquine Motifs, as Potential Cytostatic and Antiplasmodial Agents
Authors: Beus Maja , Rajić Zrinka , Maysinger Dusica , Mlinarić Zvonimir , Antunović Maja , Marijanović Inga , Fontinha Diana , Prudêncio Miguel , Held Jana , Olgen Sureyya , Zorc Branka 
Published: August 2018

AbstractWe report the synthesis of SAHAquines and related primaquine (PQ) derivatives. SAHAquines are novel hybrid compounds that combine moieties of suberoylanilide hydroxamic acid (SAHA), an anticancer agent with weak antiplasmodial activity, and PQ, an antimalarial drug with low antiproliferative activity. The preparation of SAHAquines is simple, cheap, and high yielding. It includes the following steps: coupling reaction between primaquine and a dicarboxylic acid monoester, hydrolysis, a new coupling reaction with O‐protected hydroxylamine, and deprotection. SAHAquines 5 a–d showed significant reduction in cell viability. Among the three human cancer cell lines (U2OS, HepG2, and MCF‐7), the most responsive were the MCF‐7 cells. The antibodies against acetylated histone H3K9/H3K14 in MCF‐7 cells revealed a significant enhancement following treatment with N‐hydroxy‐N′‐{4‐[(6‐methoxyquinolin‐8‐yl)amino]pentyl}pentanediamide (5 b). Ethyl (2E)‐3‐({4‐[(6‐methoxyquinolin‐8‐yl)amino]pentyl}carbamoyl)prop‐2‐enoate (2 b) and SAHAquines were the most active compounds against both the hepatic and erythrocytic stages of Plasmodium parasites, some of them at sub‐micromolar concentrations. The results of our research suggest that SAHAquines are promising leads for new anticancer and antimalarial agents.
Mechanisms and treatment of heart failure in diabetes
Authors: Timmons Joseph , Fisher Miles 
Published: August 2018

AbstractHeart failure is an increasingly common cause of cardiovascular morbidity and mortality in people with diabetes. The pathophysiology of heart failure in diabetes includes factors related to coronary heart disease, with myocardial ischaemia and myocardial scarring following myocardial infarction. Non‐ischaemic mechanisms are also important, including structural, metabolic, and biochemical abnormalities. Treatment of heart failure in people with diabetes is in essence the same as for other patients, along with optimised diabetic control. ACE inhibitors and beta blockers should be commenced in all patients with a diagnosis of heart failure with reduced ejection fraction regardless of NYHA class. Aldosterone antagonists, cardiac resynchronisation therapy and heart transplantation all have a role in management of patients of NYHA class III and IV. In patients with heart failure with preserved ejection fraction, which is more common in people with diabetes, there is unfortunately no evidence of benefit for these therapies and a diuretic‐based regimen is used to alleviate symptoms. Copyright © 2018 John Wiley & Sons.
Robust Synthesis of High‐Performance N‐Graphite Hollow Nanocatalysts Based on the Ostwald Ripening Mechanism for Oxygen Reduction Reaction Electrocatalysis
Authors: Ai Kelong , Li Zelun , Li Weiwei , Fan Jinchang , Cui Xiaoqiang , Zheng Weitao 
Published: August 2018

AbstractN‐doped carbon nanomaterials have received increasing attention as one of the most attractive candidates to replace Pt/C catalysts for the oxygen reduction reaction (ORR) in energy conversion and storage devices. The graphitization degree and the surface area are widely recognized as two fundamentally crucial factors for the catalytic performance of N‐doped carbon nanomaterials. However, there are no effective strategies to produce N‐doped carbon materials with a high degree of graphitization and a large surface area, simultaneously. As a result, currently studied N‐doped carbon materials exhibit much lower activity, durability, and stability than expected. Herein, an Ostwald ripening mechanism‐driven method to produce monodisperse N‐graphite hollow nanoparticles with significantly improved graphitization and a dramatically enlarged surface area is developed. Exhaustive measurements demonstrate that the N‐graphite hollow nanoparticles exhibit higher catalytic activity, stability, and methanol tolerance in the alkaline media, as compared to the commercial Pt/C. These nanoparticles are further assembled into a cell. Impressively, the cell shows a power density of 47.2 mW cm−2, which is almost twice the value of Pt/C‐based cell, and also much higher than those of previously reported nonprecious catalyst‐based cells. The N‐graphite hollow nanoparticles are expected to be a promising candidate for the next generation of ORR catalysts.
Advances in structure determination by cryo‐EM to unravel membrane‐spanning pore formation
Authors: Scott Harry , Huang Wei , Bann James G. , Taylor Derek J. 
Published: August 2018

AbstractThe beta pore‐forming proteins (β‐PFPs) are a large class of polypeptides that are produced by all Kingdoms of life to contribute to their species' own survival. Pore assembly is a sophisticated multi‐step process that includes receptor/membrane recognition and oligomerization events, and is ensued by large‐scale structural rearrangements, which facilitate maturation of a prepore into a functional membrane spanning pore. A full understanding of pore formation, assembly, and maturation has traditionally been hindered by a lack of structural data; particularly for assemblies representing differing conformations of functional pores. However, recent advancements in cryo‐electron microscopy (cryo‐EM) techniques have provided the opportunity to delineate the structures of such flexible complexes, and in different states, to near‐atomic resolution. In this review, we place a particular emphasis on the use of cryo‐EM to uncover the mechanistic details including architecture, activation, and maturation for some of the prominent members of this family.
“It doesn't make me any lessAboriginal”: The complex politics of translocal place‐making forIndigenous tertiary student migrants
Authors: Harris Desiree , Prout Quicke Sarah 
Published: August 2018

AbstractIndigenous migratory practices have never been comfortably explained using deterministic theories of migration. In this paper, we argue that translocalism offers new hopeful possibilities for building more robust and nuanced understandings of Indigenous migration and for extending theorisations of translocality in postcolonial settler‐states. Drawing on empirical evidence from a small‐scale exploratory study of Indigenous adults who migrated from rural/remote Australia, to Perth, Western Australia, to study at a university, we suggest that a particular politics of place‐making characterises Indigenous translocal subjectivities in settler states. These politics are evidenced by the ways in which the very act of movement from rural/remote areas to large cities for education can draw the authenticity of Indigenous identities into contestation. It also speaks to the resultant importance of translocal networks and places that provide relational spaces to share experiences of, and respond to, these contestations. The participants in this study made use of Indigenous student centres at their universities to develop a sense of place, build translocal networks, nurture their cultural identities, and contest settler assumptions that situate “authentic” Indigenous identities in a remote wilderness past.
Fidelity as a marker of topological phase transitions in 2D Dirac materials
Authors: Bolívar Juan Carlos , Cordero Nicolas A. , Nagy Ágnes , Romera Elvira 
Published: August 2018

AbstractSilicene, as other 2D buckled structures, is a gapped Dirac material with intrinsic spin‐orbit coupling whose band structure can be controlled by applying a perpendicular electric field. It presents a topological phase transition from a topological insulator to a band insulator at the charge neutrality point. We present in this article a characterization of this phase transition by using fidelity of Loschmidt echoes when a magnetic and two slightly different electric fields are applied by considering the time evolution of two kinds of wave packets, one with a single Gaussian profile and the other with a double Gaussian profile creating a cat state. We also show that Zitterbewegung, classical, and revival Loschmidt periods diverge close to but not exactly at the charge neutrality point and explain this behavior.
Quadrupole mass filter operation with dipole direct current and quadrupole radiofrequency excitation
Authors: Douglas Donald J. , Konenkov Nikolai V. 
Published: August 2018

RationaleFor mass analysis, a quadrupole mass filter (QMF) usually operates at the upper tip of the first stability region. We introduce a new mode of QMF operation with dipole direct current (dc) and with auxiliary quadrupole excitation. Before experimental investigation of this mode, we have carried out numerical simulations of this process.MethodsBased on the analytical description of the equations of ion motion and mapping of stability islands, ion trajectory calculations are used to calculate peak shapes or mass filter transmission contours. Ions are given Gaussian distributions of initial positions in x and y, and thermal initial velocity distributions. The effects of the dipole dc in the y direction and auxiliary quadrupole excitation in the x and y directions are modeled.ResultsWe find that, with dipole dc excitation, the working area of the first stability region decreases and a new y stability boundary follows a βy line. This allows control of the resolution with the removal of the low‐mass tail of a peak thereby improving the isotopic abundance sensitivity by about two orders of magnitude. The operation of a QMF with high resolution (about 5000) and high transmission (20–25%) and with a relatively short sorting time of ions n = 150 radiofrequency (rf) cycles based on the use of dipole dc and quadrupole excitation is shown.ConclusionsA new mode of QMF operation with dipole direct current (dc) and with an auxiliary quadrupole is discussed. Using dc excitation allows control of the resolution with the removal of the low‐mass tail of a peak. The method of operation of a quadrupole mass filter with high resolution (about 5000) and high transmission (20–25%) and a relatively short sorting time (150 rf cycles) based on the use of dipole dc and on quadrupole excitation is shown.
Child discipline and violence in Nigeria: A community‐based intervention programme to reduce violent discipline and other forms of negative parenting practices
Authors: Ofoha Dorothy , Ogidan Rotimi , Saidu Rosemary 
Published: August 2018

Despite the growing research that demonstrates that the use of corporal punishment with children is harmful, many Nigerian parents still utilise such methods without realising the implications. Because of lack of a strong evidence‐based programme to serve local needs, we developed a community‐based parenting education programme (PEP) to help parents reduce violent discipline and learn more positive strategies of dealing with children. Using a quasi‐experimental design in which six communities were selected from different regions across Nigeria, three as the intervention and three as the control, we tested the effectiveness of the programme with 300 parents of children aged 3–12. Parents in the intervention communities (n = 150) were exposed to 8‐week PEP intervention session on a 2‐hour weekly basis. Parents in the control communities (n = 150) were given a placebo treatment. Data were collected through questionnaires and observation. Findings revealed positive changes in parental beliefs, attitudes and practices about child‐rearing. Significant reductions were observed in the frequency with which parents used corporal punishment, and adopting more positive methods in dealing with their children including verbal praise and redirecting; a feat that was lacking prior to intervention. Effect sizes associated with the gains in parental outcomes were in the medium to large range (0.62—0.84). Comparison of means of pre‐, post‐ and delayed intervention measures showed greater gains by the intervention group. These findings provided empirical support for wider implementation of the PEP programme, which would help many more parents become more effective in their parenting in ways that support their children's optimal development.
Concise Review: Neural Stem Cell-Mediated Targeted Cancer Therapies
Authors: Mooney Rachael , Hammad Mohamed , Batalla-Covello Jennifer , Abdul Majid Asma , Aboody Karen S. 
Published: August 2018

Abstract
Cancer is one of the leading causes of morbidity and mortality worldwide, with 1,688,780 new cancer cases and 600,920 cancer deaths projected to occur in 2017 in the U.S. alone. Conventional cancer treatments including surgical, chemo-, and radiation therapies can be effective, but are often limited by tumor invasion, off-target toxicities, and acquired resistance. To improve clinical outcomes and decrease toxic side effects, more targeted, tumor-specific therapies are being developed. Delivering anticancer payloads using tumor-tropic cells can greatly increase therapeutic distribution to tumor sites, while sparing non-tumor tissues therefore minimizing toxic side effects. Neural stem cells (NSCs) are tumor-tropic cells that can pass through normal organs quickly, localize to invasive and metastatic tumor foci throughout the body, and cross the blood-brain barrier to reach tumors in the brain. This review focuses on the potential use of NSCs as vehicles to deliver various anticancer payloads selectively to tumor sites. The use of NSCs in cancer treatment has been studied most extensively in the brain, but the findings are applicable to other metastatic solid tumors, which will be described in this review. Strategies include NSC-mediated enzyme/prodrug gene therapy, oncolytic virotherapy, and delivery of antibodies, nanoparticles, and extracellular vesicles containing oligonucleotides. Preclinical discovery and translational studies, as well as early clinical trials, will be discussed.
Study on the Anti‐Endometrial Cancer Activity of a Series of 4,6‐Diaryl‐2‐pyrimidinamine Derivatives against Endometrial Carcinoma Ishikawa Cell and Their Molecular Design
Authors: Yang Qi , Qu Ziwei , Selek Danibai , Zhang Shuping 
Published: August 2018

AbstractEndometrial cancer is a thorny issue that has affected the health of women all over the world. It is also an important public issue which needed to be solved in developing countries. In this article, our team studied on the anti‐endometrial cancer activity of a series of 4,6‐diaryl‐2‐pyrimidinamine derivatives by using CoMFA (comparative molecular field analysis) and CoMSIA (comparative molecular similarity indices analysis) models and designed new small molecules with anti‐endometrial cancer activity. Our group divided randomly a series of 4,6‐diaryl‐2‐pyrimidinamine derivatives into a training set and a test set to build and test the CoMFA and CoMSIA models. The Q2 ( cross‐validated correlation coefficient) and R2 (non‐cross‐validated correlation coefficient) of the CoMFA model and the CoMSIA model were 0.562 and 0.993, 0.55 and 0.958. The result indicated that the model had strong stability and good predictability. Based on the 3D contour maps, we designed several molecules with high anti‐endometrial cancer activity against endometrial carcinoma ishikawa cell.
Sugar γ‐Amino Acids as Building Blocks for the Synthesis of Cyclic Neoglycopeptides.
Authors: Richard Mylène , Ariztia Julen , Lamandé‐Langle Sandrine , Pellegrini Moïse Nadia 
Published: August 2018

AbstractAnomeric sugar γ‐amino acids efficiently obtained by nucleophilic addition of nitronate anion on sugar olefins are useful building blocks for the preparation of new cyclic glycopeptides. Cyclopeptides have interesting biological properties or find potential applications as templates for anchoring of a wide range of biomolecules or detection dyes. We report here the synthesis of two types of cyclic systems containing γ‐glyco amino acid and α‐amino acid units. A first example was prepared to demonstrate the feasibility of the cyclization of these original structures. To explore the feasibility with more functionalized structures, α‐amino acid and sugar amino‐acid moieties bearing additional functions were chosen as building blocks for the second macrocycle. Furthermore, we describe and explain some unexpected results obtained during deprotection of these new cyclic glycopeptides.
Thienopyrrolo[2, 3‐d]pyrimidines, New Tricyclic Nucleobase Analogues: Synthesis and Biological Activities
Authors: Tichý Michal , Smoleń Sabina , Deingruber Tomáš , Džubák Petr , Pohl Radek , Slavětínská Lenka Poštová , Hajdúch Marián , Hocek Michal 
Published: August 2018

AbstractThree isomeric series of 4‐substituted thieno‐fused 7‐deazapurine nucleobases were synthesized by palladium catalyzed couplings or nucleophilic substitutions from protected key‐intermediate 4‐chlorothienopyrrolopyrimidines. Most final nucleobases exerted micromolar activity against hepatitis C virus and respiratory syncytial virus, as well as some in vitro cytostatic activities against several cancer and leukemia cell lines. Three new nucleosides derived from 8H‐thieno[3′, 4′:4,5]pyrrolo[2, 3‐d]pyrimidine were also synthesized and were significantly more cytostatic than corresponding nucleobases, with activities in submicromolar range and low toxicity to normal cycling fibroblasts.