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https://www.readbyqxmd.com/read/28644905/a-realistic-phantom-for-validating-mri-based-synthetic-ct-images-of-the-human-skull
#1
Abraam S Soliman, Levi Burns, Amir Owrangi, Young Lee, William Y Song, Greg Stanisz, Brige P Chugh
PURPOSE: To introduce a new realistic human skull phantom for the validation of synthetic CT images of cortical bone from ultra-short echo-time (UTE) sequences. METHODS AND MATERIALS: A human skull of an adult female was utilized as a realistic representation of skull cortical bone. The skull was stabilized in a special acrylic container and was filled with contrast agents that have T1 and T2 relaxation times similar to human brain. The phantom was MR scanned at 3T with UTE and T2 -weighted sequences, followed by CT...
June 23, 2017: Medical Physics
https://www.readbyqxmd.com/read/28643281/removal-of-the-emerging-contaminant-bisphenol-a-by-an-ureasil-peo-hybrid-membrane-experimental-study-and-molecular-dynamic-simulation
#2
Lilian K de Oliveira, André L A Moura, Valdir Barbosa, Renato L T Parreira, Rodrigo S Banegas, Giovanni F Caramori, Katia J Ciuffi, Eduardo F Molina
This work reports the use of a cross-linked ureasil-PEO hybrid matrix (designated PEO800) as an efficient adsorbent to retain the emerging contaminant bisphenol A (BPA) from an aqueous medium. The in-deep experimental and theoretical results provide information about the interactions between PEO800 and BPA. The in situ UV-vis spectroscopy data and the pseudo-first order, pseudo-second order, Elovich, and Morris-Webber intraparticle diffusion models allowed us to propose a three-step mechanism for the adsorption of BPA onto PEO800...
June 22, 2017: Environmental Science and Pollution Research International
https://www.readbyqxmd.com/read/28640617/5-methylhydantoin-from-isolated-molecules-in-a-low-temperature-argon-matrix-to-solid-state-polymorphs-characterization
#3
Bernardo A Nogueira, Gulce O Ildiz, João Canotilho, M Ermelinda S Eusébio, Marta Sofia C Henriques, José A Paixão, Rui Fausto
The molecular structure, vibrational spectra and photochemistry of 5-methylhydantoin (C4H6N2O2; 5-MH) were studied by matrix isolation infrared spectroscopy and theoretical calculations at the DFT(B3LYP)/6-311++G(d,p) theory level. The Natural Bond Orbital (NBO) analysis approach was used to study in detail the electronic structure of the minimum energy structure of 5-MH, namely the specific characteristics of the σ and π electronic systems of the molecule, and the stabilizing orbital interactions. UV irradiation of 5-MH isolated in argon matrix resulted in its photofragmentation through a single photochemical pathway, yielding isocyanic acid, ethanimine and carbon monoxide, thus following a pattern already observed before for the parent hydantoin and 1-methylhydantoin molecules...
June 22, 2017: Journal of Physical Chemistry. A
https://www.readbyqxmd.com/read/28636046/lead-ii-soaps-crystal-structures-polymorphism-and-solid-and-liquid-mesophases
#4
F J Martínez-Casado, M Ramos-Riesco, J A Rodríguez-Cheda, M I Redondo-Yélamos, L Garrido, A Fernández-Martínez, J García-Barriocanal, I da Silva, M Durán-Olivencia, A Poulain
The long-chain members of the lead(ii) alkanoate series or soaps, from octanoate to octadecanoate, have been thoroughly characterized by means of XRD, PDF analysis, DSC, FTIR, ssNMR and other techniques, in all their phases and mesophases. The crystal structures at room temperature of all of the members of the series are now solved, showing the existence of two polymorphic forms in the room temperature crystal phase, different to short and long-chain members. Only nonanoate and decanoate present both forms, and this polymorphism is proven to be monotropic...
June 21, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28633826/optimization-and-characterization-of-ultrasound-assisted-preparation-of-curcumin-loaded-solid-lipid-nanoparticles-application-of-central-composite-design-thermal-analysis-and-x-ray-diffraction-techniques
#5
Elham Sadati Behbahani, Mehrorang Ghaedi, Mohammadreza Abbaspour, Kobra Rostamizadeh
This study is devoted to preparation of novel solid lipid nanoparticles (SLNs) for the encapsulation of curcumin which is produced by micro-emulsion and ultrasonication using stearic acid and tripalmitin as solid lipids, tween80 and span80 as surfactants. The relation between particle size and entrapment efficiency of the produced SLNs was operated by central composite design (CCD) under response likes surface method (RSM). The variables including the ratio of lipids (X1), the ratio of surfactants (X2), drug/lipid ratio (X3), time of sonication (X4) and time of homogenization (X5)...
September 2017: Ultrasonics Sonochemistry
https://www.readbyqxmd.com/read/28633822/effects-of-pulsed-ultrasound-on-rheological-and-structural-properties-of-chicken-myofibrillar-protein
#6
Jing-Yu Wang, Yu-Ling Yang, Xiao-Zhi Tang, Wen-Xi Ni, Lei Zhou
The effects of pulsed ultrasound (PUS) (power: 240w) with varying time (0, 3, 6, 9, 12 and 15min) on rheological and structural properties of chicken myofibrillar protein (CMP) were examined. PUS treatment significantly caused a decrease in the viscosity coefficients (k) but an increase in the flow index (n) value of CMP solutions within short time (0-6min), while had no significant effect for longer time (9-15min). Besides, at 6min, the solubility and microstructure of CMP samples were optimum. The primary structure of CMP was not altered by PUS treatment...
September 2017: Ultrasonics Sonochemistry
https://www.readbyqxmd.com/read/28631252/synthesis-and-characterization-of-novel-carboxymethyl-assam-bora-rice-starch-for-the-controlled-release-of-cationic-anticancer-drug-based-on-electrostatic-interactions
#7
Sharmistha Mohapatra, Anees Ahmad Siddiqui, Mohammed Anwar, Neha Bhardwaj, Sohail Akhter, Farhan Jalees Ahmad
Carboxymethyl Assam Bora rice starch (CM-ABRS) was chemically synthesized in non-aqueous medium with the optimum degree of substitution (DS) of 1.23, and physicochemically characterized by FT-IR, DSC, XRD, and SEM analysis. Comparative evaluation of CM-ABRS with native starch (ABRS) for powder flow characteristics, swelling index, apparent solubility, rheological properties, textural properties, and mucoadhesive studies were carried out. The aim of the current work was to investigate the potential of CM-ABRS as a novel carrier for the water-soluble chemotherapeutic, doxorubicin hydrochloride (DOX)...
June 19, 2017: AAPS PharmSciTech
https://www.readbyqxmd.com/read/28631203/assessment-of-mri-contrast-agent-concentration-by-quantitative-susceptibility-mapping-qsm-application-to-estimation-of-cerebral-blood-volume-during-steady-state
#8
Emelie Lind, Linda Knutsson, Robin Kämpe, Freddy Ståhlberg, Ronnie Wirestam
OBJECTIVE: One major issue in dynamic susceptibility contrast MRI (DSC-MRI) is to accurately determine contrast agent (CA) concentration, since T2* relaxivity in vivo is generally unknown and varies between blood and tissue. In this study, quantitative susceptibility mapping (QSM) was used for quantification of CA concentration. MATERIALS AND METHODS: A DSC-MRI protocol, including phase data acquisition, was applied to 20 healthy volunteers in a test-retest study...
June 19, 2017: Magma
https://www.readbyqxmd.com/read/28629804/zero-order-controlled-release-delivery-of-cholecalciferol-from-injectable-biodegradable-microsphere-in-vitro-characterization-and-in-vivo-pharmacokinetic-studies
#9
Lalit Vora, Sita V G, Pradeep Vavia
Poly(lactic-co-glycolic acid) microspheres loaded with cholecalciferol (CL), more bioactive form of vitamin D was developed as an injectable controlled drug release system and was evaluated for its feasibility of once a month delivery. The CL loaded microspheres (CL-MS) were prepared by simple oil in water (O/W) emulsion-solvent evaporation technique incorporated with a stabilizer, Tocopherol Succinate (TS). Different formulation as well as process parameters were investigated namely concentration of emulsifier, concentration of stabilizer and drug: polymer mass ratios...
June 16, 2017: European Journal of Pharmaceutical Sciences
https://www.readbyqxmd.com/read/28629215/unusual-interfacial-freezing-phenomena-in-hexacontane-silica-composites
#10
Xia Gao, Yunlan Su, Weiwei Zhao, Qingyun Qian, Xin Chen, Robert Wittenbrink, Dujin Wang
The crystallization behaviors of n-hexacontane (C60H122)/Stöber silica (SiO2) composites with various compositions were investigated by a combination of differential scanning calorimetry (DSC), solid-state (13)C nuclear magnetic resonance (solid-state (13)C NMR) and Proton NMR relaxation experiments. By means of DSC, C60H122 molecules in C60H122/silica composites were observed to be involved in the interfacial freezing not present in the free bulk C60H122. The orientation of C60H122 molecules, being preferentially normal to silica surface, was confirmed by grazing incidence X-ray diffraction experiments on thin n-hexacontane film adsorbed on the silicon wafer with a native SiO2 layer...
June 19, 2017: Journal of Physical Chemistry. B
https://www.readbyqxmd.com/read/28629099/instrumental-methods-and-techniques-for-structural-and-physicochemical-characterization-of-biomaterials-and-bone-tissue-a-review
#11
REVIEW
Žarko Mitić, Aleksandra Stolić, Sanja Stojanović, Stevo Najman, Nenad Ignjatović, Goran Nikolić, Miroslav Trajanović
A review of recent advances in instrumental methods and techniques for structural and physicochemical characterization of biomaterials and bone tissue is presented in this paper. In recent years, biomaterials attracted great attention primarily because of the wide range of biomedical applications. This paper focuses on the practical aspects of instrumental methods and techniques that were most often applied (X-ray methods, vibrational spectroscopy (IR and Raman), magnetic-resonance spectroscopy (NMR and ESR), mass spectrometry (MS), atomic absorption spectrometry (AAS) and inductively coupled plasma-atomic emission spectrometry (ICP-AES), thermogravimetry (TG), differential thermal analysis (DTA) and differential scanning calorimetry (DSC), scanning electron microscopy (SEM), transmission electron microscopy (TEM)) in the structural investigation and physicochemical characterization of biomaterials and bone tissue...
October 1, 2017: Materials Science & Engineering. C, Materials for Biological Applications
https://www.readbyqxmd.com/read/28629087/a-novel-candidate-for-wound-dressing-transparent-porous-maghemite-cellulose-nanocomposite-membranes-with-controlled-release-of-doxorubicin-from-a-simple-approach
#12
Hao Zhang, Xiaogang Luo, Hu Tang, Mingming Zheng, Fenghong Huang
The aim of this study is to develop transparent maghemite/cellulose nanocomposite membranes with high porosity, high adsorption capacity and controlled release of doxorubicin to be used as a candidate for wound dressing. The membranes were fabricated by a tape casting method through blending a homogeneous dispersion of citrate coated maghemite nanoparticles and cellulose in the NaOH/urea aqueous solution system. The prepared membranes were characterized by Light transmittance measurements, Scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), X-ray Diffractometry (XRD), Differential scanning calorimetry (DSC), Tensile tests and Vibrating sample magnetometer (VSM)...
October 1, 2017: Materials Science & Engineering. C, Materials for Biological Applications
https://www.readbyqxmd.com/read/28629086/enhancing-internalization-of-silica-particles-in-myocardial-cells-through-surface-modification
#13
Nancy Ornelas-Soto, Rodrigo Rubio-Govea, Carlos E Guerrero-Beltrán, Eduardo Vázquez-Garza, Judith Bernal-Ramírez, Alejandra García-García, Yuriana Oropeza-Almazán, Gerardo García-Rivas, Flavio F Contreras-Torres
Surface modification in nanostructured mesoporous silica particles (MSNs) can significantly increase the uptake in myocardial cells. Herein, MSNs particles were synthesized and chemically functionalized to further assess their biocompatibility in rat myocardial cell line H9c2. The surface modification resulted in particles with an enhanced cellular internallization (3-fold increase) with respect to pristine particles. Apoptosis events were not evident at all, while necrosis incidence was significant only at a higher doses (>500μg/mL)...
October 1, 2017: Materials Science & Engineering. C, Materials for Biological Applications
https://www.readbyqxmd.com/read/28629002/a-facile-synthesis-method-of-hydroxyethyl-cellulose-silver-nanoparticle-scaffolds-for-skin-tissue-engineering-applications
#14
Farah Hanani Zulkifli, Fathima Shahitha Jahir Hussain, Senait Sileshi Zeyohannes, Mohammad Syaiful Bahari Abdull Rasad, Mashitah M Yusuff
Green porous and ecofriendly scaffolds have been considered as one of the potent candidates for tissue engineering substitutes. The objective of this study is to investigate the biocompatibility of hydroxyethyl cellulose (HEC)/silver nanoparticles (AgNPs), prepared by the green synthesis method as a potential host material for skin tissue applications. The substrates which contained varied concentrations of AgNO3 (0.4%-1.6%) were formed in the presence of HEC, were dissolved in a single step in water. The presence of AgNPs was confirmed visually by the change of color from colorless to dark brown, and was fabricated via freeze-drying technique...
October 1, 2017: Materials Science & Engineering. C, Materials for Biological Applications
https://www.readbyqxmd.com/read/28628311/pushing-the-limits-of-oxygen-balance-in-1-3-4-oxadiazoles
#15
Qiong Yu, Ping Yin, Jiaheng Zhang, Chunlin He, Gregory H Imler, Damon A Parrish, Jean'ne M Shreeve
Gem-trinitromethyl groups were introduced into a 1,3,4-oxadiazole ring to give the first example of a bifunctionalized single five-membered ring with six nitro groups. 2,5-Bis(trinitromethyl)-1,3,4-oxadiazole (12) has a high calculated crystal density of 2.007 g cm(-3) at 150 K (1.941 g cm(-3) at 293 K) and a very high positive oxygen balance (39.12%), which makes it a strong candidate as a high energy dense oxidizer. The dihydroxylammonium and dihydrazinium salts of bis(trinitromethyl)-1,3,4-oxadiazole (5 and 6) exhibit excellent calculated detonation properties (5, vD = 9266 m s(-1), P = 38...
June 21, 2017: Journal of the American Chemical Society
https://www.readbyqxmd.com/read/28627751/synthesis-of-gem-dinitromethylated-and-fluorodinitromethylated-derivatives-of-5-5-dinitro-bis-1-2-4-triazole-as-promising-high-energy-density-materials
#16
Qinghua Zhang, Shi Huang, Junjun Tian, Xiujuan Tian, Kangcai Wang
The gem-dinitromethylated and fluorodinitromethylated 5,5'-dinitro-3,3'-bis-1,2,4-triazole (DNBT) (2 and 3) along with seven ionic derivatives (4-9) were successfully synthesized and characterized by NMR and IR spectroscopies, elemental analysis, single crystal X-ray diffraction (XRD), and differential scanning calorimetry (DSC). XRD revealed that compounds 2 and 3 were crystallized in the monoclinic P21/n space group and compound 5 was crystallized in the monoclinic P21/c space group. The physicochemical properties for the as-synthesized compounds 2-9 were investigated and the results indicated that compounds 3, 6 and 7 exhibited a good balance between high energy and low sensitivity, indicating their promise as new high-energy-density materials (HEDMs)...
June 19, 2017: Chemistry: a European Journal
https://www.readbyqxmd.com/read/28627453/design-and-development-of-multi-walled-carbon-nanotube-liposome-drug-delivery-platforms
#17
Natassa Pippa, Demetrios D Chronopoulos, Dimitris Stellas, Rodrigo Fernández-Pacheco, Raul Arenal, Costas Demetzos, Nikos Tagmatarchis
The aim of this study is to design and develop delivery platforms made of liposomes and multi-walled carbon nanotubes (MWCNTs). We used different lipids with different main transition temperature (Tm) and differently functionalized MWCNTs with organic addends possessing either positive or negative charge. The phospholipids used for the formulations were 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) (Tm=41°C) and L-α-phosphatidylcholine, hydrogenated Soy (HSPC) (Tm=53°C). By Differential Scanning Calorimetry (DSC), we studied the interaction between the DPPC and HSPC bilayers and MWCNTs...
June 13, 2017: International Journal of Pharmaceutics
https://www.readbyqxmd.com/read/28627282/gallic-acid-pamam-and-gallic-acid-phspholipid-conjugates-physicochemical-characterization-and-in-vivo-evaluation
#18
Ebtsam M Abdou, Marwa A Masoud
Gallic acid (GA) is a naturally occurring compound with valuable antioxidant activity. Its oral bioavailability is limited by its high metabolism and rapid clearance. In this paper, gallic acid (GA) was conjugated with two different materials, phosphatidylcholine (PC) and Polyamidoamine (PAMAM) dendrimer. The prepared conjugates were characterized by FTIR, DSC and SEM. Also, they were tested for drug content and in-vitro drug release. It was found that GA conjugation with both materials have significantly prolonged its release up to 12 hours...
June 19, 2017: Pharmaceutical Development and Technology
https://www.readbyqxmd.com/read/28625688/electrically-atomised-formulations-of-timolol-maleate-for-direct-and-on-demand-ocular-lens-coatings
#19
Prina Mehta, Ali Al-Kinani, Rita Haj-Ahmad, Muhammad Sohail Arshad, Ming-Wei Chang, G Raid Alany, Zeeshan Ahmad
Advances in nanotechnology have enabled solutions for challenging drug delivery targets. While the eye presents numerous emerging opportunities for delivery, analysis and sensing; issues persist for conventional applications. This includes liquid phase formulation localisation on the ocular surface once administered as formulated eye-drops; with the vast majority of dosage (>90%) escaping from the administered site due to tear production and various drainage mechanisms. The work presented here demonstrates a single needle electrohydrodynamic (EHD) engineering process to nano-coat (as an on demand and controllable fiber depositing method) the surface of multiple contact lenses rendering formulations to be stationary on the lens and at the bio-interface...
June 15, 2017: European Journal of Pharmaceutics and Biopharmaceutics
https://www.readbyqxmd.com/read/28625473/effect-of-dir-uncertainty-on-prostate-passive-scattering-proton-therapy-dose-accumulation
#20
Yoshitomo Abe, Noriyuki Kadoya, Kazuhiro Arai, Yoshiki Takayama, Takahiro Kato, Kanako Kimura, Takashi Ono, Tatsuya Nakamura, Hitoshi Wada, Yasuhiro Kikuchi, Keiichi Jingu
Deformable image registration (DIR) is important in dose accumulation. Currently, the impact of DIR-algorithm-associated uncertainties in proton therapy is unclear. Here, we quantify the effect of DIR uncertainties on prostate passive-scattering proton therapy (PSPT) dose accumulation. Ten patients with an intermediate risk for prostate cancer formerly treated by PSPT (PTV D95=78GyE) were studied. Dose distributions from all verification CT images (five images per patient) were warped and accumulated in the planning CT geometries with DIR...
June 15, 2017: Physica Medica: PM
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