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Volume transmission

Jingqi Zhu, Zuogang Xiong, Jiulong Zhang, Yuyou Qiu, Ting Hua, Guangyu Tang
BACKGROUND: This study aims to investigate the technical feasibility of semi-quantitative and quantitative dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) in the assessment of longitudinal changes of marrow perfusion in a rat osteoporosis model, using bone mineral density (BMD) measured by micro-computed tomography (micro-CT) and histopathology as the gold standards. METHODS: Fifty rats were randomly assigned to the control group (n=25) and ovariectomy (OVX) group whose bilateral ovaries were excised (n=25)...
November 14, 2017: BMC Musculoskeletal Disorders
Haixu Zhang, Jinian Shu, Bo Yang, Peng Zhang, Pengkun Ma
Many organic amines that comprise a benzene ring are policy-sensitive because of their toxicity and links to social harm. However, to date, detection of such compounds mainly relies on offline methods. This study proposes an online pptv (parts per trillion by volume) level of detection method for amines, using the recently-built vacuum ultraviolet photoionization mass spectrometer (VUV-PIMS) combined with a new doping technique. Thus, the dichloromethane doping-assisted photoionization mass spectra of aniline, benzylamine, phenethylamine, amphetamine, and their structural isomers were recorded...
February 1, 2018: Talanta
Yi Teng Fong, Chih-Hao Chen, Jyh-Ping Chen
By taking advantage of the pH-sensitive drug release property of graphene oxide (GO) after intracellular uptake, we prepared folic acid (FA)-conjugated GO (GOFA) for targeted delivery of the chemotherapeutic drug doxorubicin (DOX). GOFA-DOX was further encapsulated in an injectable in-situ forming thermo-sensitive hyaluronic acid-chitosan-g-poly(N-isopropylacrylamide) (HACPN) hydrogel for intratumoral delivery of DOX. As the degradation time of HACPN could be extended up to 3 weeks, intratumoral delivery of GOFA-DOX/HACPN could provide controlled and targeted delivery of DOX through slow degradation HACPN and subsequent cellular uptake of released GOFA-DOX by tumor cells through interactions of GOFA with folate receptors on the tumor cell's surface...
November 14, 2017: Nanomaterials
Murielle Schmitt, Ritu Toor, Renaud Denoyel, Mickaël Antoni
An experimental investigation of spontaneous emulsification is proposed with water drops pendant in a paraffin oil (PO) solution loaded with a surfactant (SPAN80). Optical microscopy in transmission mode is employed for high spatial resolution image recording. The kinetics of spontaneous emulsification is studied. It is shown to generate a darkening of the drops due to interface modification with a characteristic time that depends upon the SPAN80 concentration. For low concentrations, spontaneous emulsification is slow and produces micrometer sized droplets while for large concentrations, it is fast and bush-like microstructures are observed...
November 13, 2017: Langmuir: the ACS Journal of Surfaces and Colloids
Georges Raad, Mira Hazzouri, Silvia Bottini, Michele Trabucchi, Joseph Azoury, Valérie Grandjean
There is substantial evidence that paternal obesity is associated not only with an increased incidence of infertility, but also with an increased risk of metabolic disturbance in adult offspring. Apparently, several mechanisms may contribute to the sperm quality alterations associated with paternal obesity, such as physiological/hormonal alterations, oxidative stress, and epigenetic alterations. Along these lines, modifications of hormonal profiles namely reduced androgen levels and elevated estrogen levels, were found associated with lower sperm concentration and seminal volume...
2017: Basic and Clinical Andrology
Xiao-Xia Zhou, Yu-Jian Lai, Rui Liu, Shasha Li, Jing-Wen Xu, Jing-Fu Liu
Efficient separation and preconcentration of trace nanoparticulate silver (NAg) from large-volume environmental waters is a prerequisite for reliable analysis and therefore understanding the environmental processes of silver nanoparticles (AgNPs). Herein, we report the novel use of polyvinylidene fluoride (PVDF) filter membrane for disk-based solid phase extraction (SPE) of NAg in 1 L of water samples with the disk-based SPE system, which consists of a syringe pump and a syringe filter holder to embed the filter membrane...
November 9, 2017: Environmental Science & Technology
James J Jun, Nicholas A Steinmetz, Joshua H Siegle, Daniel J Denman, Marius Bauza, Brian Barbarits, Albert K Lee, Costas A Anastassiou, Alexandru Andrei, Çağatay Aydın, Mladen Barbic, Timothy J Blanche, Vincent Bonin, João Couto, Barundeb Dutta, Sergey L Gratiy, Diego A Gutnisky, Michael Häusser, Bill Karsh, Peter Ledochowitsch, Carolina Mora Lopez, Catalin Mitelut, Silke Musa, Michael Okun, Marius Pachitariu, Jan Putzeys, P Dylan Rich, Cyrille Rossant, Wei-Lung Sun, Karel Svoboda, Matteo Carandini, Kenneth D Harris, Christof Koch, John O'Keefe, Timothy D Harris
Sensory, motor and cognitive operations involve the coordinated action of large neuronal populations across multiple brain regions in both superficial and deep structures. Existing extracellular probes record neural activity with excellent spatial and temporal (sub-millisecond) resolution, but from only a few dozen neurons per shank. Optical Ca(2+) imaging offers more coverage but lacks the temporal resolution needed to distinguish individual spikes reliably and does not measure local field potentials. Until now, no technology compatible with use in unrestrained animals has combined high spatiotemporal resolution with large volume coverage...
November 8, 2017: Nature
Hidehiro Watanabe, Nobuhiro Takaya
PURPOSE: The quantitation accuracy in proton magnetic resonance spectroscopy ((1)H MRS) improves at higher B0 field. However, a larger chemical shift displacement (CSD) and stronger B1 inhomogeneity exist. In this work, we evaluate the quantitation accuracy for the spectra of metabolite mixtures in phantom experiments at 4.7T. We demonstrate a position-dependent error in quantitation and propose a correction method by measuring water signals. MATERIALS AND METHODS: All experiments were conducted on a whole-body 4...
November 8, 2017: Magnetic Resonance in Medical Sciences: MRMS
Hao Wang, Hua Chen, Hengle Gu, Yan Shao, Xuwei Cai, Xiaolong Fu, Zhiyong Xu
Intensity-modulated radiotherapy (IMRT) is an important technology in cancer radiotherapy. In the current planning system, such as in the Pinnacle(3) system, jaw positions are automatically set to cover all target volumes, and many medical centers in developing countries are not equipped with linear accelerators with a jaw tracing function. As solitary lesions are often located in patients, the resulting radiation leakage and transmission increase the dose exposure in surrounding critical organs, although blocked by multileaf collimator (MLC) leaves...
October 27, 2017: Medical Dosimetry: Official Journal of the American Association of Medical Dosimetrists
Yun Li, Chaonan Huang, Jiajia Yang, Junyu Peng, Jing Jin, Huilian Ma, Jiping Chen
A mesoporous silica Santa Barbara Amorphous-15 (SBA-15) has been first functionalized with 3-[2-(2-aminoethylamino)ethylamino]propyl-trimethoxysilane (a silane with three amines) and then reacted with an excess of phenyl glycidyl ether to generate a mixed-mode anion-exchanger containing both anion-exchange (three amines) and reversed-phase (multiple ether-linked phenyls) functionalities in a single branched ligand. The resulting material has been characterized by scanning electron microscopy, transmission electron microscopy, nitrogen adsorption-desorption measurements, Fourier-transform infrared spectroscopy, and elemental analysis...
October 23, 2017: Journal of Chromatography. A
Chen Li, Gerlinde Habler, Lisa C Baldwin, Rainer Abart
Focused ion beam (FIB) sample preparation technique in plan-view geometry allows direct correlations of the atomic structure study via transmission electron microscopy with micrometer-scale property measurements. However, one main technical difficulty is that a large amount of material must be removed underneath the specimen. Furthermore, directly monitoring the milling process is difficult unless very large material volumes surrounding the TEM specimen site are removed. In this paper, a new cutting geometry is introduced for FIB lift-out sample preparation with plan-view geometry...
September 28, 2017: Ultramicroscopy
Dagny Fleischman, Luke A Sweatlock, Hirotaka Murakami, Harry Atwater
The subwavelength mode volumes of plasmonic filters are well matched to the small size of state-of-the-art active pixels in CMOS image sensor arrays used in portable electronic devices. Typical plasmonic filters exhibit broad (> 100 nm) transmission bandwidths suitable for RBG or CMYK color filtering. Dramatically reducing the peak width of filter transmission spectra would allow for the realization of CMOS image sensors with multi- and hyperspectral imaging capabilities. We find that the design of 5 layer metal-insulator-metal-insulator-metal structures gives rise to multi-mode interference phenomena that suppress spurious transmission features and give rise to single transmission bands as narrow as 17 nm...
October 30, 2017: Optics Express
Gregory B Rehm, Brooks T Kuhn, Jean-Pierre Delplanque, Edward C Guo, Monica K Lieng, Jimmy Nguyen, Nicholas R Anderson, Jason Y Adams
Lack of access to high-frequency, high-volume patient-derived data, such as mechanical ventilator waveform data, has limited the secondary use of these data for research, quality improvement, and decision support. Existing methods for collecting these data are obtrusive, require high levels of technical expertise, and are often cost-prohibitive, limiting their use and scalability for research applications. We describe here the development of an unobtrusive, open-source, scalable, and user-friendly architecture for collecting, transmitting, and storing mechanical ventilator waveform data that is generalizable to other patient care devices...
October 28, 2017: Journal of the American Medical Informatics Association: JAMIA
Patrick Wohlfahrt, Christian Möhler, Christian Richter, Steffen Greilich
PURPOSE: To determine the accuracy of particle range prediction for proton and heavier ion radiation therapy based on dual-energy computed tomography (DECT) in a realistic inhomogeneous geometry and to compare it with the state-of-the-art clinical approach. METHODS AND MATERIALS: A 3-dimensional ground-truth map of stopping-power ratios (SPRs) was created for an anthropomorphic head phantom by assigning measured SPR values to segmented structures in a high-resolution CT scan...
September 18, 2017: International Journal of Radiation Oncology, Biology, Physics
Bocheng Zhang, Heng Liu, Xiangyi Huang, Chaoqing Dong, Jicun Ren
A single-nanoparticle detection method is reported for characterizing the size distribution of noble metal nanoparticles in solution by combining resonance light scattering correlation spectroscopy (RLSCS) with the maximum entropy method (MEM). The principle of RLSCS is based on the autocorrelation analysis of the resonance light scattering (RLS) fluctuations due to Brownian motion of a single nanoparticle in a highly focused detection volume (less than 1.0 fL), which resembles fluorescence correlation spectroscopy (FCS)...
November 7, 2017: Analytical Chemistry
Chao Ye, Guang Ran, Wei Zhou, Qiang Shen, Qijie Feng, Jianxin Lin
Single crystal 6H-SiC wafers with 4° off-axis [0001] orientation were irradiated with carbon ions and then annealed at 900 °C for different time periods. The microstructure and surface morphology of these samples were investigated by grazing incidence X-ray diffraction (GIXRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Ion irradiation induced SiC amorphization, but the surface was smooth and did not have special structures. During the annealing process, the amorphous SiC was recrystallized to form columnar crystals that had a large amount of twin structures...
October 25, 2017: Materials
Jae Woong Han, Sangiliyandi Gurunathan, Yun-Jung Choi, Jin-Hoi Kim
BACKGROUND: Silver nanoparticles (AgNPs) exhibit strong antibacterial and anticancer activity owing to their large surface-to-volume ratios and crystallographic surface structure. Owing to their various applications, understanding the mechanisms of action, biological interactions, potential toxicity, and beneficial effects of AgNPs is important. Here, we investigated the toxicity and differentiation-inducing effects of AgNPs in teratocarcinoma stem cells. MATERIALS AND METHODS: AgNPs were synthesized and characterized using various analytical techniques such as UV-visible spectroscopy, X-ray diffraction, energy-dispersive X-ray spectroscopy, and transmission electron microscopy...
2017: International Journal of Nanomedicine
Zhihui Han, Hu Peng, Xiaoyan Zhao, Xun Chen, Putian Lu
Sector-scanning is a conventional scanning mode in ultrasound imaging, which can increase the area to observe. In three-dimensional (3D) ultrasound, freehand imaging system is usually used. This method uses a moving elevation focused one-dimensional (1D) transducer to construct a series of B-mode slice images, and then these B-mode slice images are combined to form a 3D volume image. When sector-scanning is used to acquire the B-mode slices, the elevation resolution is poor because of the elevation resolution of the probe and the interpolations between the slices...
October 12, 2017: Ultrasonics
Zhen Wang, Zhiyu Xiao, Chuanshou Huang, Liping Wen, Weiwen Zhang
The present article studied the effect of ultrasonic surface rolling process (USRP) on the microstructure and wear behavior of a selective laser melted Ti-6Al-4V alloy. Surface characteristics were investigated using optical microscope, nano-indentation, scanning electron microscope, transmission electron microscope and laser scanning confocal microscope. Results indicated that the thickness of pore-free surfaces increased to 100~200 μm with the increasing ultrasonic surface rolling numbers. Severe work hardening occurred in the densified layer, resulting in the formation of refined grains, dislocation walls and deformation twins...
October 19, 2017: Materials
Fujun Sun, Zhongyuan Fu, Chunhong Wang, Zhaoxiang Ding, Chao Wang, Huiping Tian
We propose and investigate an ultra-compact air-mode photonic crystal nanobeam cavity (PCNC) with an ultra-high quality factor-to-mode volume ratio (Q/V) by quadratically tapering the lattice space of the rectangular holes from the center to both ends while other parameters remain unchanged. By using the three-dimensional finite-difference time-domain method, an optimized geometry yields a Q of 7.2×10(6) and a V∼1.095(λ/nSi)(3) in simulations, resulting in an ultra-high Q/V ratio of about 6.5×10(6)(λ/nSi)(-3)...
May 20, 2017: Applied Optics
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