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Spectral polarization filtering technology is widely used in weather radar clutter suppression, but when ground clutter is mixed with precipitation, these methods will lose precipitation while filtering out clutter. To address this issue, a polarization-Doppler weather radar signal reconstruction method based on spectral continuity is proposed. This method utilizes the characteristic differences between precipitation and clutter on the range-Doppler map to achieve the preservation of precipitation and the filtering of clutter. Specifically, the spatial continuity of Doppler velocity and spectral width of precipitation is utilized to compensate for precipitation using polynomial fitting and Gaussian fitting method. The effectiveness of the proposed method is verified by the measured data of the operational weather radar. [ABSTRACT FROM AUTHOR]

Single‐unit (SU) recording in nonhuman primates (NHPs) is indispensible in the quest of how the brain works, yet electrodes currently used for the NHP brain are limited in signal longevity, stability, and spatial coverage. Using new structural materials, microfabrication, and penetration techniques, we develop a mechanically robust ultraflexible, 1 µm thin electrode array (MERF) that enables pial penetration and high‐density, large‐scale, and chronic recording of neurons along both vertical and horizontal cortical axes in the nonhuman primate brain. Recording from three monkeys yields 2,913 SUs from 1,065 functional recording channels (up to 240 days), with some SUs tracked for up to 2 months. Recording from the primary visual cortex (V1) reveals that neurons with similar orientation preferences for visual stimuli exhibited higher spike correlation. Furthermore, simultaneously recorded neurons in different cortical layers of the primary motor cortex (M1) show preferential firing for hand movements of different directions. Finally, it is shown that a linear decoder trained with neuronal spiking activity across M1 layers during monkey's hand movements can be used to achieve on‐line control of cursor movement. Thus, the MERF electrode array offers a new tool for basic neuroscience studies and brain–machine interface (BMI) applications in the primate brain. [ABSTRACT FROM AUTHOR]

Simultaneous polarimetric radars can measure the polarization scattering matrix (PSM) of moving targets within one pulse. The key point is the orthogonal waveform design to reduce the interference caused by the simultaneous transmission and reception. Meanwhile, to ensure the measurement accuracy of moving targets, the Doppler tolerance of the transmitted waveforms is also important. In this article, first, a matched filter (MF) at the receiver is considered and a unified framework with a newly proposed objective function to design Doppler resilient sequences under several constraints is described. The proposed objective function contains the widely used peak sidelobe level (PSL) and the integrated sidelobe level (ISL) as special cases. Meanwhile, a series of constraint conditions, including the unimodular constraint, the uncertainty modulus constraint, and the PAR constraint, is considered. Thereafter, a mismatched filter is considered for further improving the correlation properties and a similar framework for designing the optimal receiving filter at the expense of a controllable signal-to-noise ratio (SNR) loss is proposed. Numerical results are presented to verify the performance of the proposed methods. The designed sequence pair is also implemented on a fully polarimetric system to measure the PSM of a canonical target in the anechoic chamber, and the effectiveness of the proposed framework is verified by using the simultaneous polarimetric radar. It is predicted that the framework has the potential to be applied for other multichannel systems. [ABSTRACT FROM AUTHOR]

Radio frequency interference (RFI) has become a growing concern for weather radar, distorting radar variable estimation. By simultaneously or alternately transmitting the horizontal and vertical polarized waves, polarimetric weather radar can be referred to as SHV radar or AHV radar. The SHV radar can mimic the AHV radar by discarding either H- or V-channel measurements, which leads to an alternating scheme. In this research, the real RFI measurements from an operational C-band SHV radar are used to characterize the RFI temporal, spectral, and polarimetric features. Then, the RFI is simulated to quantify the performance of the object-orientated spectral polarimetric (OBSPol) filter in RFI mitigation. The OBSPol filter has been previously proposed by the authors to mitigate the narrowband clutter (both stationary and moving) and noise. This work extends the application of the filter to remove the RFI for SHV radar. Specifically, by taking advantage of the low copolar correlation of the RFI signal measured in AHV radar, the RFI mitigation method is designed, and its effectiveness is proven by qualitative and quantitative analyses. In particular, in the case of RFI overlapped to weather echoes in the time domain, the RFI can be mitigated, also when the duty cycle of the RFI is high. However, this work does not provide a full evaluation of the RFI mitigation performance on all radar data outputs but a proof of concept to show the effectiveness of the proposed filter for RFI mitigation. [ABSTRACT FROM AUTHOR]

Modular converters such as the multilevel cascaded H-bridge (CHB) are an attractive option for multiple applications mainly because of inherent modularity and fault-tolerant operation. This article is focused on the CHB converter operating with unbalanced conditions (different dc voltages and/or modulation indexes). Under these circumstances, applying the conventional control and modulation strategies, the output voltage harmonic spectrum is degraded. In this article, a generalized variable-angle phase-shifted pulsewidth modulation (PS-PWM) technique for CHB converters with a large number of power modules (> 3) is presented. The method considers all possible cells’ combinations to form groups and assigns the role of each cell in the group. This cell role defines the identifier of the cell in the variable-angle PS-PWM technique. In the steady state, in each group of cells, the harmonic distortion of the CHB output voltage located at twice the carrier frequency ƒc is eliminated, while the distortion at 4ƒc is also diminished. Experimental results show how the proposed technique achieves superior harmonic performance without introducing any significant disadvantage. [ABSTRACT FROM AUTHOR]

High cross-polarization isolation (CPI) is crucial to the accurate polarization measurement using polarimetric phased array radar (PPAR). In this article, we propose an adaptive direction-dependent polarization state configuration (AD2PSC) method to improve the polarization isolation. Compared with the conventional fixed polarization state of radiated wave whether it is linear, circular, or elliptical polarization state, our AD2PSC approach configures the polarization state on basis of beam steering. To achieve the adaptive configuration of magnitude and phase of the dual-polarization antenna, an improved steepest descent algorithm is put forward. To facilitate the uniform representation for the polarization measurement application of PPAR, the universal expressions of intrinsic and measured backscatter matrices are derived for arbitrary polarization state. The dual-polarization dipole array is used to assess the priority of our proposed method. Compared with the conventional approaches, our approach could obtain higher CPI while being available for a larger scanning range. The configured CPI meets the specific polarization requirement for PPAR. [ABSTRACT FROM AUTHOR]

This article proposes a new control method for modular multilevel converter (MMC), which is based on a modification of the conventional nearest level control (NLC) scheme implemented by a model predictive control (MPC) technique. Applying the proposed method, the simplicity of the NLC is maintained while the current control ability in terms of both phase current and circulating current is enhanced by the MPC technique. A proper rounding function is used for each arm of the MMC instead of the conventional nearest integer function. The rounding function is determined by evaluating a cost function within the frame of MPC. To validate the proposed technique, a three-phase MMC prototype is employed. The conventional NLC-based control approach of MMC is also evaluated for comparative purposes. Results show that the proposed method exhibits excellent current-regulating ability. Compared with the conventional control scheme, the overall performance is improved without significantly increasing the computational burden or adding relevant complexity to the control system design. [ABSTRACT FROM AUTHOR]

The use of spectral polarimetric filters in the range-Doppler domain shows great promise for clutter mitigation in weather radar applications. One limitation of these filters is that they cannot deal with situations in which ground clutter and precipitation overlap. In this letter, we propose a new signal recovery technique based on kriging in the spectral domain to recover the precipitation in clutter-contaminated areas. Using synthetic radar data, we test our new method and compare its performance to that of Gaussian model adaptive processing and bilinear interpolation. Our results indicate that kriging is the most accurate and robust technique out of the three. [ABSTRACT FROM AUTHOR]

Radar micro-Doppler (m-D) signature, which reflects the micromotion dynamic and structural characteristics of radar target with micromotion, has received increasing attention. Most of the existing m-D signature-extraction methods operate in the time domain or the time-frequency domain. Different from these methods, in this paper, an m-D period estimation approach that operates in the ambiguity domain is proposed. Although the ambiguity function (AF) has been widely used in the field of radar signal processing, its application for m-D signal is introduced for the first time. It is proved that the AF of m-D signal exhibits periodicity along the lag axis and has the best concentration when the lag equals to multiples of the m-D period. Based on this, three AF concentration statistics are employed to capture the periodicity and to provide the m-D estimate. The most important property of the AF concentration statistics is that they are (or approximately) invariant to polynomial translations with terms not larger than second order even if the signal is Doppler ambiguous. Numeric simulation and real radar experiments are used to validate the effectiveness of the proposed technique. [ABSTRACT FROM AUTHOR]

Weather radar is well recognized as an effective sensor for obtaining the microphysical and dynamical properties of precipitation at high spatial and temporal resolution. Radar calibration is one of the most important prerequisites for achieving accurate observations. In this article, a portable, cost-effective and repeatable radar calibration technique, namely, unmanned aerial vehicle (UAV)-aided radar calibration, is proposed. A UAV serves as the stable aerial platform carrying a metal sphere, flying over the radar illumination areas to complete the calibration process. The flying routine of the UAV can be pre-programmed, and thus, the antenna pattern regarding different elevation and azimuth angles can be retrieved. To obtain the position of the sphere, the real-time single-frequency precise point positioning-type global navigation satellite system solution is developed. In addition, the radar constant is calculated in the range-Doppler domain, and only the data where the metal sphere separates from clutter and other objects are selected. The S-band polarimetric Doppler transportable atmospheric radar (TARA) is used in the calibration campaign. The experiments demonstrate the following results: 1) antenna pointing calibration can be completed and 2) antenna pattern can be retrieved and weather radar constant can be accurately calculated. [ABSTRACT FROM AUTHOR]

Aiming at removing stationary and moving clutter while retaining precipitation for dual-polarization weather radar, a new clutter suppression method, named the object-orientated spectral polarimetric (OBSpol) filter, is put forward in this paper. Based on the spectral polarimetric feature and the range-Doppler continuity of precipitation, the OBSpol filter generates a filtering mask implemented on the raw range-Doppler spectrogram to mitigate the clutter and noise. The procedures are as follows. After the spectral polarimetric filtering and the mathematical morphology method, one binary mask where “1” indicates the precipitation is obtained. Then, the contiguous bins of the same value “1” in the range-Doppler domain are grouped in areas termed as objects. Whether the produced objects are precipitation or not will be further judged based on appropriate weather radar observable. Thus, combining all the filtered separate objects, a filtering mask can be obtained. In this paper, data collected by the polarimetric Doppler IRCTR drizzle radar are used to demonstrate and assess the performance of the proposed technique in the case of ground clutter, narrowband moving clutter, and noise. Two precipitation cases are examined: 1) moderate precipitation with large scale and 2) light precipitation with severe clutter contamination. In the range-Doppler spectrogram, both stationary and narrowband moving clutters are mitigated, while maintaining nonoverlapping precipitation signal. This helps to solve the problem when clutter and precipitation overlap in the time domain. In addition, the OBSpol filter is proven to be effective with different Doppler velocity resolutions. This technique can be applied in real-time due to its low computation complexity. Moreover, the spectral polarimetric filtering can be designed using the measurements of dual-polarization radar systems which do not have cross-polar measurements. Hence, the proposed clutter mitigation technique can be implemented for operational dual-polarization weather radar. [ABSTRACT FROM AUTHOR]

A novel algorithm is put forward to separate radar target and moving clutter based on a combination of the low-rank matrix optimization (LRMO) and the decision tree. Similar to the moving object detection in the field of automated video analysis, the proposed separation method, which is carried out in the range-Doppler domain, makes use of different motion variations of radar target and clutter in the spectrogram sequence. The technique is very general, but the focus of this paper is on narrowband moving clutter suppression in a weather radar. The first step in implementing this method is the generation of a range-Doppler spectrogram sequence. Then, the LRMO is applied to the obtained sequence to divide target and moving clutter into foreground and background. From the foreground sequence which is obtained by solving the LRMO, foreground frequency and spectral width are combined in a decision tree to obtain a filtering mask to mitigate the narrowband moving clutter and noise. Data collected by a polarimetric Doppler weather radar known as the IRCTR Drizzle Radar are used to validate the performance of the proposed algorithm. Moreover, its effectiveness in removing narrowband moving clutter is quantitatively assessed through comparisons with another clutter mitigation method. [ABSTRACT FROM AUTHOR]

In this paper, a new clutter suppression method, named the moving double spectral linear depolarization ratio (MDsLDR) filter, is put forward to mitigate narrow-band clutter in weather radars. The narrow-band clutter observed in the Doppler domain includes: 1) stationary clutter such as ground clutter and 2) nonstationary clutter such as artifacts caused by the radar system itself or external sources. These artifacts are difficult to remove, because they are not confined to specific azimuth and range bins. Based on the difference of the spectral-polarization feature and the spectral continuity of precipitation and clutter, the MDsLDR filter can remove ground clutter, artifacts, and noise. The performance of the newly proposed filter is assessed by data collected by the Doppler-polarimetric IRCTR Drizzle Radar. Three precipitation cases are considered in this paper: moderate/light precipitation, convective precipitation with hook-echo signature, and light precipitation with severe artifact contamination. Furthermore, the implementation of the MDsDLR filter requires relatively low computation complexity, so that the MDsLDR filter can be operated in real time. [ABSTRACT FROM PUBLISHER]

Visual scenes can be readily decomposed into a variety of oriented components, the processing of which is vital for object segregation and recognition. In primate V1 and V2, most neurons have small spatio-temporal receptive fields responding selectively to oriented luminance contours (first order), while only a subgroup of neurons signal non-luminance defined contours (second order). So how is the orientation of second-order contours represented at the population level in macaque V1 and V2? Here we compared the population responses in macaque V1 and V2 to two types of second-order contour stimuli generated either by modulation of contrast or phase reversal with those to first-order contour stimuli. Using intrinsic signal optical imaging, we found that the orientation of second-order contour stimuli was represented invariantly in the orientation columns of both macaque V1 and V2. A physiologically constrained spatio-temporal energy model of V1 and V2 neuronal populations could reproduce all the recorded population responses. These findings suggest that, at the population level, the primate early visual system processes the orientation of second-order contours initially through a linear spatio-temporal filter mechanism. Our results of population responses to different second-order contour stimuli support the idea that the orientation maps in primate V1 and V2 can be described as a spatial-temporal energy map. [ABSTRACT FROM AUTHOR]

Summary How primates perceive objects along with their detailed features remains a mystery. This ability to make fine visual discriminations depends upon a high-acuity analysis of spatial frequency (SF) along the visual hierarchy from V1 to inferotemporal cortex. By studying the transformation of SF across macaque parafoveal V1, V2, and V4, we discovered SF-selective functional domains in V4 encoding higher SFs up to 12 cycles/°. These intermittent higher-SF-selective domains, surrounded by domains encoding lower SFs, violate the inverse relationship between SF preference and retinal eccentricity. The neural activities of higher- and lower-SF domains correspond to local and global features, respectively, of the same stimuli. Neural response latencies in high-SF domains are around 10 ms later than in low-SF domains, consistent with the coarse-to-fine nature of perception. Thus, our finding of preserved resolution from V1 into V4, separated both spatially and temporally, may serve as a connecting link for detailed object representation. [ABSTRACT FROM AUTHOR]

The perception of color is an internal label for the inferred spectral reflectance of visible surfaces. To study how spectral representation is transformed through modular subsystems of successive cortical areas, we undertook simultaneous optical imaging of intrinsic signals in macaque V1, V2, and V4, supplemented by higher-resolution electrophysiology and two-photon imaging in awake macaques. We find a progressive evolution in the scale and precision of chromotopic maps, expressed by a uniform blob-like architecture of hue responses within each area. Two-photon imaging reveals enhanced hue-specific cell clustering in V2 compared with V1. A phenomenon of endspectral (red and blue) responses that is clear in V1, recedes in V2, and is virtually absent in V4. The increase in mid- and extra-spectral hue representations through V2 and V4 reflects the nature of hierarchical processing as higher areas read out locations in chromatic space from progressive integration of signals relayed by V1. • Color-response blobs comprise a uniform architecture across V1, V2, and V4 • Blobs evolve progressively in spatial scale and separation of hue representation • Two-photon imaging shows greater hue-specific cell clustering in V2 than in V1 • Chromotopic organization achieves greater spectral uniformity from V1 to V2 to V4 How does our visual brain generate perceptual color space? Liu et al. find that within a uniform blob-like architecture of hue responses, chromotopic maps develop progressively in scale and precision along the visual hierarchy of macaque V1, V2, and V4. Such hierarchical refinement improves spectral uniformity, better reflecting color perception. [ABSTRACT FROM AUTHOR]

Fault diagnosis technologies for ocean-going marine diesel engines play an important role in the safety and reliability of ship navigation. Although many fault diagnosis technologies have achieved acceptable results for single fault of diesel engines, the diagnosis of multiple faults is rarely involved. Due to the strong correlation, non-linearity and randomness of multiple faults, it is extremely difficult to make an accurate diagnosis. In this study, diagnosis methods based on thermal parametric analysis combined with different neural network algorithms were established and used for the diagnosis of multiple faults in the ocean-going marine diesel engine. The results show that the Levenberg Marquardt back propagation neural network has the highest diagnostic accuracy rate of 88.89% and 100% for multiple faults and single faults, respectively, and its diagnostic time is also relatively short, 0.78 s. The Bayesian regularization back propagation neural network can give a diagnostic accuracy rate of 100% for single faults, but for multiple faults, the diagnostic accuracy rate is only 55.56%, and the diagnosis time for the entire sample is the longest. As for the probabilistic neural network, although it has the fastest diagnosis speed, it has the lowest diagnostic accuracy rate for both single faults and multiple faults. The results may provide references for the online diagnosis of single faults and multiple faults in ocean-going marine diesel engines., Competing Interests: Declaration of conflicting interestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Studying the mismatch between perception and reality helps us better understand the constructive nature of the visual brain. The Pinna-Brelstaff motion illusion is a compelling example illustrating how a complex moving pattern can generate an illusory motion perception. When an observer moves toward (expansion) or away (contraction) from the Pinna-Brelstaff figure, the figure appears to rotate. The neural mechanisms underlying the illusory complex-flow motion of rotation, expansion, and contraction remain unknown. We studied this question at both perceptual and neuronal levels in behaving male macaques by using carefully parametrized Pinna-Brelstaff figures that induce the above motion illusions. We first demonstrate that macaques perceive illusory motion in a manner similar to that of human observers. Neurophysiological recordings were subsequently performed in the middle temporal area (MT) and the dorsal portion of the medial superior temporal area (MSTd). We find that subgroups of MSTd neurons encoding a particular global pattern of real complex-flow motion (rotation, expansion, contraction) also represent illusory motion patterns of the same class. They require an extra 15 ms to reliably discriminate the illusion. In contrast, MT neurons encode both real and illusory local motions with similar temporal delays. These findings reveal that illusory complex-flow motion is first represented in MSTd by the same neurons that normally encode real complex-flow motion. However, the extraction of global illusory motion in MSTd from other classes of real complex-flow motion requires extra processing time. Our study illustrates a cascaded integration mechanism from MT to MSTd underlying the transformation from external physical to internal nonveridical flow-motion perception. SIGNIFICANCE STATEMENT The neural basis of the transformation from objective reality to illusory percepts of rotation, expansion, and contraction remains unknown. We demonstrate psychophysically that macaques perceive these illusory complex-flow motions in a manner similar to that of human observers. At the neural level, we show that medial superior temporal (MSTd) neurons represent illusory flow motions as if they were real by globally integrating middle temporal area (MT) local motion signals. Furthermore, while MT neurons reliably encode real and illusory local motions with similar temporal delays, MSTd neurons take a significantly longer time to process the signals associated with illusory percepts. Our work extends previous complex-flow motion studies by providing the first detailed analysis of the neuron-specific mechanisms underlying complex forms of illusory motion integration from MT to MSTd., (Copyright © 2019 the authors.)

To explore a new surgical approach for chin augmentation using a prosthesis with 3 intraoral vertical incisions whereby placement of the prosthesis is more convenient and accurate, with fewer postoperative complications. Following the anatomic characteristics of the chin, a bilateral mucosal vertical incision and a median observation incision are made. The V-shaped mark on the upper side of the prosthesis can be seen through the observation incision after it is placed from the lateral incision into the predesigned compartment. The incision can be sutured if there is no bleeding in the operation area. Surgery performed in all 19 patients with mild microgenia with 6 to 12 months of follow-up resulted in satisfactory chin and face shape without any complications. The application of this novel method can correct McCarthy type I microgenia with more accurate positioning, less possibility of bilateral sideways and/or up/down movement, and fewer complications.

Trans-sutural distraction osteogenesis (TSDO) has been successfully used to correct midfacial hypoplasia in growing patients for years. The effects of TSDO, however, remain difficult to predict in adult patients. The aim of this study was to determine the biologic basis for the age-related increase in difficulty of performing TSDO. A total of 45 male Sprague Dawley (SD) rats were obtained in 3 age groups: 4 weeks old (4W, N = 15), 3 months old (3M, N = 15), and 13 months old (13M, N = 15). The zygomaticomaxillary sutures (ZMS) were dissected, and their morphology was evaluated by histology and micro-computed tomography (micro-CT). Quantitative real-time polymerase chain reaction of the ZMS and blood samples taken from the abdominal aorta were also used to assess the effects of age at the molecular level. Compared with the 4W rats, the number of fibroblasts in the ZMS was decreased, the bone plate adjacent to the ZMS was thicker, and the texture was denser in the 13M rats. Micro-computed tomography analysis showed the density of the ZMS was significantly increased in the 13M group (P < 0.05). The density ratio of the ZMS to the adjacent bone was increased from 0.14:1 in the 4M group to 0.54:1 in the 13M group. The gene expression of osteocalcin (OC) was significantly lower at 13M than at 3M (P < 0.05). The OC and alkaline phosphatase (ALP) serum levels were significantly lower at 13M than at 4W (P < 0.05). During aging, the decreased osteogenesis activity both systemically and locally may be the biologic effect that limits the application of TSDO in older patients.

Background: Although maxillary distraction osteogenesis has been used for early treatment of midfacial hypoplasia, the inevitable osteotomies are still a complicated and invasive procedure for growing patients. Based on the bone-borne trans-sutural distraction osteogenesis, novel improvements to the approach were made to treat midfacial hypoplasia, and the clinical outcomes and skeletal changes were analyzed., Methods: Seventy consecutive growing cleft lip and palate patients with midfacial hypoplasia were treated with trans-sutural distraction osteogenesis. The distraction system consists of a rigid external distractor, nickel-titanium shape memory alloy spring, and bone-borne traction hooks. The whole distraction process was recorded in detail clinically. Lateral cephalographs and computed tomographic scans were taken and analyzed by cephalometric measurement and color-map analysis to assess the skeletal changes., Results: All of the patients except one achieved satisfactory appearance and occlusal relationship. The unilateral maximum traction force presented an increased trend with age, but this relationship was not absolute. The whole trans-sutural distraction osteogenesis process was divided into three clinical stages: the startup period, the rapid movement period, and the consolidation period. Cephalometric analysis showed a great increase in SNA, ANB and horizontal movement of the maxillae after distraction, but with marginal relapse at 6 to 18 months postoperatively. Visualized changes of the midfacial skeleton were observed by three-dimensional color mapping. The results showed an unequal advancement in different regions., Conclusion: Trans-sutural distraction osteogenesis process with adaptations offers an alternative method for the early treatment of midfacial hypoplasia in growing patients with cleft lip and palate., Clinical Question/level of Evidence: Therapeutic, IV.

Objective: To evaluate the influence of polymorphisms in nucleotide excision repair (NER) and homologous recombination repair (HRR) pathways on the development of osteosarcoma patients., Methods: Genotypes of ERCC1 rs11615 and rs3212986, ERCC2 rs1799793 and rs13181, NBN rs709816 and rs1805794, RAD51 rs1801320, rs1801321 and rs12593359, and XRCC3 rs861539 were conducted by Polymerase Chain Reaction Restriction Fragment Length Polymorphism (PCR-RFLP) assay., Results: Total 148 osteosarcoma patients and 296 control subjects were collected from Taizhou First People's Hospital. Conditional logistic regression analyses found that individuals carrying with GA+AA genotype of ERCC2 rs1799793 and GC+CC genotype of NBN rs1805794 were significantly associated with increased risk of osteosarcoma, and the ORs(95%CI) were 1.58(1.03-2.41) and 2.66(1.73-4.08), respectively. We found that GA+AA genotype of ERCC2 rs1799793 or GC+CC genotype of NBN rs1805794 were associated with an increased risk of osteosarcoma in females, with ORs(95%CI) of 2.42(1.20-4.87) and 2.01(1.07-4.23), respectively., Conclusion: Our results suggest that ERCC2 rs1799793 and NBN rs1805794 polymorphisms were associated with an increased risk for osteosarcoma, which suggests that NER and HRR pathways modulate the risk of developing osteosarcoma.

Background: The purposes of this study were to evaluate the effects of transsutural distraction osteogenesis applied to the maxillary complex with a new internalized distraction device and to analyze the long-term osteogenesis outcome., Materials and Methods: Three-month-old beagle dogs were treated with a self-designed internalized distractor. The feasibility was evaluated, and the effects of the maxillary growth were measured using radiography and computed tomography (CT). The regenerated bone was examined with micro-CT, biomechanical testing, and histology 1 year after the distraction., Results: The experimental group showed significantly larger forward displacement of maxillary during the distraction. One year after the distraction, the micro-CT showed more incompact structure and bone volume/total volume was significantly less in the experimental group. Biomechanical testing also showed a significantly lower yield but with no difference in stiffness. Histologic staining found osteoclasts deposited in the region of the suture and osteoblasts on the bone surface. The immunohistochemical staining of osteoprotegrin and receptor activator of nuclear factor-κ B ligand showed evidence of expression in suture area components and osteocytes with no difference between the groups., Conclusions: Transsutural distraction osteogenesis using an internalized distractor with skull anchorage demonstrated feasibility. It is expected that this device may provide new thoughts in developing an appropriate appliance for clinical use in young patients with midfacial hypoplasia. Moreover, the long-term osteogenesis analysis findings suggest that the metabolism of sutural area still remained active, which enhanced our understanding of bone remodeling in the sutural area to manage maxillary relapse after transsutural distraction osteogenesis.

Background: Maxillary anterior segmental distraction osteogenesis (MASDO) is a recently used method for correction of severe maxillary retrusion in cleft lip and palate (CLP) patients. In this article, we evaluated the feasibility of MASDO using rigid external distraction (RED) and rapid orthodontic tooth movement to correct severe maxillary retrusion in CLP patients., Methods: Fourteen male and five female complete CLP patients between the ages of 18 and 22 years (mean age 19.7 years) at the time of distraction, with severe maxillary retrusion, were treated with the rigid external distraction (RED) device after maxillary anterior osteotomy. Rapid orthodontic tooth movement was started one week after the MASDO. Standard profile photographic, cephalometric films were obtained preoperatively and after therapy. Sella-nasion-point A (SNA) and Sella-nasion-point B (SNB) angles were measured to reflect changes in maxillary and mandibular position, and the distance between anterior nasal spine and posterior nasal spine (ANS-PNS) was measured to represent the maxillary dental arch length., Results: The SNA angle increased from an average of 74.6° (range 73.0°-78.0°), preoperatively, to 83.4° (range 78.6°-88.0°) after the RED was removed (P < 0.01). All cases of severe maxillary retrusion were improved. Nine patients' profiles became harmonious after therapy. One patient had a bimaxillary protrusion deformity and needed further surgery. The regenerate alveolar crest and edentulous space on both segments was almost completely eliminated after rapid orthodontic tooth movement., Conclusion: MASDO with the RED system and rapid orthodontic tooth movement is a successful way of correcting severe maxillary retrusion in CLP patients.

The cortical processing of illusory contours provides a unique window for exploring the brain mechanisms underlying visual perception. Previous electrophysiological single-cell recordings demonstrate that a subgroup of cells in macaque V1 and V2 signal the presence of illusory contours, whereas recent human brain imaging studies reveal higher-order visual cortices playing a central role in illusory figure processing. It seems that the processing of illusory contours/figures may engage multiple cortical interactions between hierarchically organized processing stages in the ventral visual pathway of primates. However, it is not yet known in which brain areas illusory contours are represented in the same manner as real contours at both the population and single-cell levels. Here, by combining intrinsic optical imaging in anesthetized rhesus macaques with single-cell recordings in awake ones, we found a complete overlap of orientation domains in visual cortical area V4 for processing real and illusory contours. In contrast, the orientation domains mapped in early visual areas V1 and V2 mainly encoded the local physical stimulus features inducing the subjective perception of global illusory contours. Our results indicate that real and illusory contours are encoded equivalently by the same functional domains in V4, suggesting that V4 is a key cortical locus for integration of local features into global contours.