Search

The natural frequencies of structures submerged in a fluid are significantly influenced by fluid properties and adjacent structures, which can be expressed by added mass. Some finite element software can effectively determine the added mass matrix of arbitrary structures immersed in viscous fluids, provided the structure lengths are relatively long; however, the added mass specified in a second-order tensor cannot be used as is. Herein, we propose methods to calculate the coupled added mass as a single value for each structure using the MassInFlu code. When the x- and y-directional components of the coupled added mass are unequal, an effective added mass can be determined by rotating the structures or coordinate axes. Various examples considering different scenarios show that the coupled natural frequencies obtained using the coupled or effective added mass coincide with those obtained from fluid-structure interaction analyses.

Studying the function and dysfunction of complex biological systems necessitates comprehensive understanding of individual cells. Advancements in three-dimensional (3D) tissue processing and imaging modalities have enabled rapid visualization and phenotyping of cells in their spatial context. However, system-wide interrogation of individual cells within large intact tissue remains challenging, low throughput, and error-prone owing to the lack of robust labeling technologies. Here we introduce a rapid, versatile, and scalable method, eFLASH, that enables complete and uniform labeling of organ-scale tissue within one day. eFLASH dynamically modulates chemical transport and reaction kinetics to establish system-wide uniform labeling conditions throughout the day-long labeling period. This unique approach enables the same protocol to be compatible with a wide range of tissue types and probes, enabling combinatorial molecular phenotyping across different organs and species. We applied eFLASH to generate quantitative maps of various cell types in mouse brains. We also demonstrated multidimensional cell profiling in a marmoset brain block. We envision that eFLASH will spur holistic phenotyping of emerging animal models and disease models to help assess their functions and dysfunctions.

The biology of multicellular organisms is coordinated across multiple size scales, from the sub-nanoscale of molecules to the macroscale, tissue-wide interconnectivity of cell populations. Here we introduce a method for super-resolution imaging of the multiscale organization of intact tissues. The method, called magnified analysis of the proteome (MAP), linearly expands entire organs four-fold while preserving their overall architecture and three-dimensional proteome organization. MAP is based on the observation that preventing crosslinking within and between endogenous proteins during hydrogel-tissue hybridization allows for natural expansion upon protein denaturation and dissociation. The expanded tissue preserves its protein content, its fine subcellular details and its organ-scale intercellular connectivity. Off-the-shelf antibodies can be used for multiple rounds of immunolabeling and imaging of a tissue's magnified proteome, with our experiments demonstrating a success rate of 82% (100/122 antibodies tested). We show that specimen size can be reversibly modulated to image both inter-regional connections and fine synaptic architectures in the mouse brain.

Combined measurement of diverse molecular and anatomical traits that span multiple levels remains a major challenge in biology. Here, we introduce a simple method that enables proteomic imaging for scalable, integrated, high-dimensional phenotyping of both animal tissues and human clinical samples. This method, termed SWITCH, uniformly secures tissue architecture, native biomolecules, and antigenicity across an entire system by synchronizing the tissue preservation reaction. The heat- and chemical-resistant nature of the resulting framework permits multiple rounds (>20) of relabeling. We have performed 22 rounds of labeling of a single tissue with precise co-registration of multiple datasets. Furthermore, SWITCH synchronizes labeling reactions to improve probe penetration depth and uniformity of staining. With SWITCH, we performed combinatorial protein expression profiling of the human cortex and also interrogated the geometric structure of the fiber pathways in mouse brains. Such integrated high-dimensional information may accelerate our understanding of biological systems at multiple levels., Simons Foundation. Postdoctoral Fellowship, Life Sciences Research Foundation, Burroughs Wellcome Fund (Career Award at the Scientific Interface), Searle Scholars Program, Michael J. Fox Foundation for Parkinson's Research, United States. Defense Advanced Research Projects Agency, National Institutes of Health (U.S.) (1-U01-NS090473-01)

SUMMARY We propose and demonstrate an Ethernet transport system that can support hard real-time traffics with guaranteed throughput and very low jitter performance even in the presence of asynchronous traffics. The superframe structure-based Ethernet system first synchronizes all the nodes in a network by using the IEEE 1588-compliant boundary clock scheme and then reserves the traffic channels for synchronous traffics before accommodating both synchronous and asynchronous traffics in the superframe. Our experimental demonstration performed on field-programmable gate array-enabled Gigabit Ethernet test benches shows that the proposed scheme not only guarantees the throughput of the synchronous frames but also substantially reduces the jitter of the synchronous frames less than 110 ns after seven-hop transmission. Copyright © 2013 John Wiley & Sons, Ltd.

Background: The C-arm fluoroscope is known as the most important equipment in pain interventions. This study was conducted to investigate the completion rate of education on radiation safety, the knowledge of radiation exposure, the use of radiation protection, and so on. Methods: Unsigned questionnaires were collected from the 27 pain physicians who applied for the final test to become an expert in pain medicine in 2011. The survey was composed of 12 questions about the position of the hospital, the kind of hospital, the use of C-arm fluoroscopy, radiation safety education, knowledge of annual permissible radiation dose, use of radiation protection, and efforts to reduce radiation exposure. Results: In this study, although most respondents (93%) had used C-arm fluoroscopy, only 33% of the physicians completed radiation safety education. Even though nine (33%) had received education on radiation safety, none of the physicians knew the annual permissible radiation dose. In comparing the radiation safety education group and the no-education group, the rate of wearing radiation-protective glasses or goggles and the use of radiation badges or dosimeters were significantly higher in the education group. However, in the use of other protective equipment, knowledge of radiation safety, and efforts to reduce radiation exposure, there were no statistical differences between the two groups. Conclusions: The respondents knew very little about radiation safety and had low interest in their radiation exposure. To make the use of fluoroscopy safer, additional education, as well as attention to and knowledge of practices of radiation safety are required for pain physicians. (Korean J Pain 2012; 25: 16-21)

Under the law of Management of Apartment Complexes, the Apartment Supplier should satisfy the demands of residents for the repair of defects found in Apartment Housing. But in the cost of defect repair, the expense of resident complaints is not included, and only the actual defect repair expense is counted. So in this study, the actual use state of defect deposits for 3 years after moving in is analyzed based on the actual use data of 39 apartment complexes. The study shows that more than 50% of defect repair deposits are spent to satisfy expenses arising from complaints by residents. This is not only caused by irrational demands of residents, but also by the adoption of a stopgap policy by Apartment Suppliers.

We propose and demonstrate a method to provide precise time synchronization in distributed control systems using a boundary clock scheme. The major drawback of the boundary clock scheme is the exponential accumulation of time synchronization error as the number of hops increases. To make the error accumulation linearly increase with the number of hops, we first separate the frequency compensation interval (FCI) and the offset and frequency compensation interval (OFCI) and then separately optimize each interval. To demonstrate the performance of this method, we implemented test benches using Ethernet-linked distributed control systems. We measured the peak-to-peak jitter performance along with the maximum time interval error to assess the short- and long-term stability after several hops in distributed control systems. Our method enables the peak-to-peak jitter to be maintained under 107 ns after seven hops. The experimental results show that the performance of time synchronization is dominated by fast jitter rather than frequency error and wander, and the proposed scheme can be used to improve the time synchronization performance in IEEE 1588-compliant control systems using boundary clock.

We report on a fiber-optic transport system for next-generation wireless-communication systems utilizing 4 times 4 multiple-input multiple-output (MIMO) orthogonal-frequency-division-multiple-access (OFDMA) technology. Our system supports time-division-duplex (TDD)-based wireless signals operating at 3.775 GHz. To accommodate the TDD-based MIMO signals over a single strand of optical fiber, we utilize nine-channel coarse wavelength-division-multiplexed optical channels: one for link delay measurement and TDD control signal transmission, four for downlink, and the others for uplink. The system first measures the propagation delay between the central base station (CBS) and the remote antenna (RA) and sends the result to delay modules to compensate for the delay added by the transmission link. This procedure makes the CBS and RA emit the downstream signals simultaneously into the air and, consequently, helps avoid the performance degradation caused by the propagation delay of the radio-over-fiber system. The system then sends the MIMO signals together with TDD control signals to the RA. Our experimental demonstration is carried out with 1-Gb/s OFDMA signals having pilot, control, and data channels. For downstream, the error vector magnitudes (EVMs) are measured to be < -30 dB after a 3.9-km transmission over conventional single-mode fiber when the antenna output power is set to be 24 dBm. For upstream, the best EVMs are measured to be < -35 dB. Both the downstream and upstream performance is limited by the shot and thermal noise of the receiver when the signal power is low, whereas nonlinear distortions of electrical amplifiers start to degrade the system performance as the signal power increases. We also measure the crosstalk between channels. It is measured to be less than -42 dB for all channels, which is found to be caused by board-to-board interference at the RA.

Nondestructive chemical processing of porous samples such as fixed biological tissues typically relies on molecular diffusion. Diffusion into a porous structure is a slow process that significantly delays completion of chemical processing. Here, we present a novel electrokinetic method termed stochastic electrotransport for rapid nondestructive processing of porous samples. This method uses a rotational electric field to selectively disperse highly electromobile molecules throughout a porous sample without displacing the low-electromobility molecules that constitute the sample. Using computational models, we show that stochastic electrotransport can rapidly disperse electromobile molecules in a porous medium. We apply this method to completely clear mouse organs within 1-3 days and to stain them with nuclear dyes, proteins, and antibodies within 1 day. Our results demonstrate the potential of stochastic electrotransport to process large and dense tissue samples that were previously infeasible in time when relying on diffusion.

Background: Although many clinicians know about the reducing effects of the pulsed and low-dose modes for fluoroscopic radiation when performing interventional procedures, few studies have quantified the reduction of radiation-absorbed doses (RADs). The aim of this study is to compare how much the RADs from a fluoroscopy are reduced according to the C-arm fluoroscopic modes used. Methods: We measured the RADs in the C-arm fluoroscopic modes including ‘conventional mode’, ‘pulsed mode’, ‘low-dose mode’, and ‘pulsed ＋ low-dose mode’. Clinical imaging conditions were simulated using a lead apron instead of a patient. According to each mode, one experimenter radiographed the lead apron, which was on the table, consecutively 5 times on the AP views. We regarded this as one set and a total of 10 sets were done according to each mode. Cumulative exposure time, RADs, peak X-ray energy, and current, which were viewed on the monitor, were recorded. Results: Pulsed, low-dose, and pulsed ＋ low-dose modes showed significantly decreased RADs by 32%, 57%, and 83% compared to the conventional mode. The mean cumulative exposure time was significantly lower in the pulsed and pulsed ＋ low-dose modes than in the conventional mode. All modes had pretty much the same peak X-ray energy. The mean current was significantly lower in the low-dose and pulsed ＋ low-dose modes than in the conventional mode. Conclusions: The use of the pulsed and low-dose modes together significantly reduced the RADs compared to the conventional mode. Therefore, the proper use of the fluoroscopy and its C-arm modes will reduce the radiation exposure of patients and clinicians. (Korean J Pain 2011; 24: 199-204)

We demonstrate a fiber-optic transport system for next generation wireless communication systems utilizing time division duplex-based 4times4 multiple-input multiple-output orthogonal frequency division multiple access technologies.

Premature infants with respiratory distress syndrome may have clinically significant shunting through a patent ductus arteriosus (PDA). Left-to-right shunting through the PDA may lead to left ventricular volume overload and pulmonary edema. We present a case of perioperative management for severe respiratory distress syndrome in a premature infant who underwent surgical closure of PDA. Under general anesthesia, the infant was successfully managed by inhaled nitric oxide, high frequency oscillation ventilation with intermittent mandatory ventilation despite intermittent hypoxia. The operation was performed safely in the neonatal intensive care unit.

A probabilistic atlas of the human brain (Statistical Probabilistic Anatomical Maps: SPAM) was developed by the international consortium for brain mapping (ICBM). It is a good frame for calculating volume of interest (VOI) in many fields of brain images. After calculating the counts in VOI using the product of probability of SPAM images and counts in FDG images, asymmetric indices (AI) were calculated and used for finding epileptogenic zones in mesial temporal lobe epilepsy (mTLE). FDG PET images from 18 surgically confirmed mTLE patients and 22 age-matched controls were spatially normalized to the average brain MRI template of ICBM. Counts from normalized PET images were multiplied with the probability of 12 VOIs from SPAM images in both temporal lobes. Finally AI were calculated on each pair of VOIs, and compared with visual assessment. If AI of mTLE patients were not within 2.9 standard deviation from those of normal control group (P0.008; Bonferroni correction for P0.05), epileptogenic zones were considered to be found successfully. The counts of VOIs in the normal control group were symmetric (AI4.3%, paired t test P0.05) except for those of the inferior temporal gyrus (P0.001). By AIs in six pairs of VOIs, PET in mTLE had deficit on one side (P0.05). Lateralization was correct in only 14/18 of patients by AI, but 17/18 were consistent with visual inspection. In three patients with normal AI, PET images were symmetric on visual inspection. The asymmetric indices obtained by taking the product of the statistical probability anatomical map and FDG PET, correlated well with visual assessment in mTLE patients. SPAM is useful for the quantification of VOIs in functional images.