Visual field asymmetries in visual word form identification.

Visual performance across the visual fields interacts with visual tasks and visual stimuli, and visual resolution decreases as a function of eccentricity, varying at isoeccentric locations. In this study, we investigated the extent of asymmetry and the rate of change in visual acuity threshold for visual word form (VWF) identification at horizontal and vertical azimuths across the fovea, and at eccentricities of 1°, 2°, 4°, 6° and 8° for 10%, 20%, 40%, and 80% contrast levels, to determine whether and how the eccentricities, meridians, and contrasts modulated the VWF identification acuity threshold. The stimuli were 16 traditional Chinese characters of similar legibility. Participants pressed a key to indicate the character presented, either monocularly or binocularly, at one of 21 randomly selected locations. A staircase procedure was used to determine the threshold, and a multiple linear regression model was used to fit the linear cortical magnification factor (CMF). We found that (1) the asymmetry was most pronounced on the vertical and superior azimuths, (2) the asymmetry between the right and left azimuths was not significant, (3) the CMF was significantly smaller on the vertical azimuth than on the horizontal azimuth, (4) the CMF was smaller on the superior vertical azimuth than on the inferior azimuth, and (5) monocular viewing and low contrast enhanced the CMF difference between azimuths. In conclusion, vertical and horizontal azimuths, location of eccentricity, contrast levels of word symbols, and monocular/binocular viewing have different effects on visual field asymmetry and cortical magnification factors.

Review of electrospun microtube array membrane (MTAM)-a novel new class of hollow fiber for encapsulated cell therapy (ECT) in clinical applications.

Encapsulated cell therapy (ECT) shows significant potential for treating neurodegenerative disorders including Alzheimer's and Parkinson's, which currently lack curative medicines and must be managed symptomatically. This novel technique encapsulates functional cells with a semi-permeable membrane, providing protection while enabling critical nutrients and therapeutic substances to pass through. Traditional ECT procedures, on the other hand, pose difficulties in terms of cell survival and retrieval. We introduce the Microtube Array Membrane (MTAM), a revolutionary technology that solves these constraints, in this comprehensive overview. Microtube Array Membrane has distinct microstructures that improve encapsulated cells' long-term viability by combining the advantages of macro and micron scales. Importantly, the MTAM platform improves biosafety by allowing the entire encapsulated unit to be retrieved in the event of an adverse reaction. Our findings show that MTAM-based ECT has a great potential in a variety of illness situations. For cancer treatment, hybridoma cells secreting anti-CEACAM 6 antibodies inhibit triple-negative breast cancer cell lines for an extended period of time. In animal brain models of Alzheimer's disease, hybridoma cells secreting anti-pTau antibodies successfully reduce pTau buildup, accompanied by improvements in memory performance. In mouse models, MTAM-encapsulated primary cardiac mesenchymal stem cells dramatically improve overall survival and heart function. These findings illustrate the efficacy and adaptability of MTAM-based ECT in addressing major issues such as immunological isolation, cell viability, and patient safety. We provide new possibilities for the treatment of neurodegenerative illnesses and other conditions by combining the potential of ECT with MTAM. Continued research and development in this subject has a lot of promise for developing cell therapy and giving hope to people suffering from chronic diseases.

Gestalt neurons and emergent properties in visual perception: A novel concept for the transformation from local to global processing.

Gestalten in visual perception are defined by emergent properties of the whole, which cannot be predicted from the sum of its parts; rather, they arise by virtue of inherent principles, the Laws of Seeing. This review attempts to assign neurophysiological correlates to select emergent properties in motion and contour perception and proposes parallels to the processing of local versus global attributes by classical versus contextual receptive fields. The aim is to identify Gestalt neurons in the visual system to account for the Laws of Seeing in causal terms and to explain "Why do things look as they do" (Koffka, 1935, p. 76).

Coarse-to-fine interaction on perceived depth in compound grating.

To encode binocular disparity, the visual system uses a pair of left eye and right eye bandpass filters with either a position or a phase offset between them. Such pairs are considered to exit at multiple scales to encode a wide range of disparity. However, local disparity measurements by bandpass mechanisms can be ambiguous, particularly when the actual disparity is larger than a half-cycle of the preferred spatial frequency of the filter, which often occurs in fine scales. In this study, we investigated whether the visual system uses a coarse-to-fine interaction to resolve this ambiguity at finer scales for depth estimation from disparity. The stimuli were stereo grating patches composed of a target and comparison patterns. The target patterns contained spatial frequencies of 1 and 4 cycles per degree (cpd). The phase disparity of the low-frequency component was 0° (at the horopter), -90° (uncrossed), or 90° (crossed), and that of the high-frequency components was changed independent of the low-frequency disparity, in the range between -90° (uncrossed) and 90° (crossed). The observers' task was to indicate whether the target appeared closer to the comparison pattern, which always shared the disparity with the low-frequency component of the target. Regardless of whether the comparison pattern was a 1-cpd + 4-cpd compound or a 1-cpd simple grating, the perceived depth order of the target and the comparison varied in accordance with the phase disparity of the high-frequency component of the target. This effect occurred not only when the low-frequency component was at the horopter, but also when it contained a large disparity corresponding to one cycle of the high-frequency component (±90°). Our findings suggest a coarse-to-fine interaction in multiscale disparity processing, in which the depth interpretation of the high-frequency changes based on the disparity of the low-frequency component.

Suprathreshold length summation.

To investigate the mechanisms underlying elongated spatial summation with a pattern-masking paradigm, we measured the contrast detection thresholds for elongated Gabor targets situated at 3° eccentricity to either the left or right of the fixation and elongated along an arc of the same radius to access homogeneous retinal sensitivity. The mask was a ring with a Gabor envelope of the same 3° center radius containing either a concentric (iso-orientation mask) or a radial (orthogonal mask) modulation. The task of the observer was to indicate whether the target in each trial was on the left or the right of the fixation. With orthogonal or low contrast iso-orientation masks, target thresholds first decreased with size with slope -1 on log-log coordinates until the target length reached 45' (specified as the half-height full-width of the Gabor envelope) and then further decreased according to a slope of -1/2, the latter being the signature of an ideal summation process. When the contrast of the iso-orientation mask was sufficiently high, however, the target thresholds, while still showing a -1 slope up to ∼10', asymptoted up to about 50' length, suggesting that the presence of the mask eliminated the ideal summation regime. Beyond about 50', the data approximated another -1 slope decrease in threshold, suggesting the existence of an extra-long channel that is not revealed by the conventional spatial summation paradigm. The full results could be explained by a divisive inhibition model, in which second-order filters sum responses across local oriented channels, combined with a single extra-long filter at least 300' in extent. In this model, the local filter response is given by the linear excitation of the local channels raised to a power, and scaled by divisive inhibition from all channels in the neighborhood. With the high-contrast iso-orientation masks, such divisive inhibition swamps the response to eliminate the ideal summation regime until the stimulus is long enough to activate the extra-long filter.

Unveiling the Power of Anticancer Drug Screening: A Clinical Case Study Comparing the Effectiveness of Hollow Fiber Assay Microtube Array Membrane (MTAM-HFA) in Breast Cancer Patients.

Breast cancer is a severe public health problem, and early treatment with powerful anticancer drugs is critical for success. The researchers investigated the clinical results of a novel screening tool termed Microtube Array Membrane Hollow Fiber Assay (MTAM-HFA) in breast cancer patients in this clinical investigation. In all trial participants, the MTAM-HFA was utilized to identify active medicines for the treatment of breast cancer. The MTAM-HFA was shown to be extremely useful in predicting patient response to anticancer medication therapy in this study. Furthermore, the substantial association between the MTAM-HFA screening outcome and the clinical outcome of the respective patients emphasizes the promise of this unique screening technology in discovering effective anticancer medication combinations for the treatment of breast cancer. These findings indicate that the MTAM-HFA has clinical significance and might be a valuable tool in the development of tailored therapy for cancer care. This study provides helpful information for physicians and scientists working on breast cancer therapy research. The potential benefits of employing MTAM-HFA to find accurate therapies for breast cancer patients might lead to enhanced personalized medicine approaches to cancer care, resulting in better patient outcomes. Overall, the MTAM-HFA screening approach has the potential to revolutionize customized cancer therapy, providing hope to both patients and physicians.

Seismic Performance and Nonlinear Strain Analysis of Mechanical Splices for High-Strength Reinforcement in Concrete Structures.

This study investigates the strain development in reinforcing bars within the plastic hinge regions of beams and columns, with the main objective of modifying the current acceptance criteria for mechanical bar splices to accommodate high-strength reinforcement. The investigation utilizes numerical analysis based on moment-curvature and deformation analysis of typical beam and column sections in a special moment frame. The results indicate that the use of higher grade reinforcement, such as Grade 550 or 690, results in lower strain demands in the plastic hinge regions compared to Grade 420 reinforcement. To validate the modified seismic loading protocol, over 100 samples of mechanical coupling systems were tested in Taiwan. The test results demonstrate that the majority of these systems can successfully complete the modified seismic loading protocol and are suitable for use in critical plastic hinge regions of special moment frames. However, caution is advised for slender mortar-grouted coupling sleeves, as they were unable to fulfill the seismic loading protocols. These sleeves may be conditionally used in plastic hinge regions of precast columns, provided they meet specific conditions and demonstrate seismic performance through structural testing. The findings of this study offer valuable insight into the design and application of mechanical splices in high-strength reinforcement scenarios.

Achromatic and chromatic contrast discrimination in patients with type 2 diabetes.

Effects of type 2 diabetes on achromatic and chromatic contrast sensitivity (CS) are still controversial. In this study, we aimed to investigate CS in patients without diabetic retinopathy (no-DR) and in those with non-proliferative DR (NPDR) and proliferative DR (PDR) using psychophysical methods with transient and sustained achromatic stimuli and color patches. Achromatic CS was measured with the pulsed pedestal (PP) paradigm (7, 12, and 19 cd/m2) and pedestal-△-pedestal (P-△-P) paradigm (11.4, 18, and 28.5 cd/m2). A chromatic discrimination paradigm that assesses protan, deutan, and tritan color vision was adopted. Forty-two patients (no-DR n = 24, NPDR n = 12, PDR = 6; male n = 22, mean age = 58.1 y/o) and 38 controls (male n = 18, mean age = 53.4 y/o) participated. In patients, mean thresholds were higher than in controls and linear trends were significant in most conditions. For the PP paradigm, differences were significant in the PDR and NPDR groups in the 7 and 12 cd/m2 condition. For the P-△-P paradigm, differences were only significant in the PDR group in the 11 cd/m2 condition. Chromatic contrast loss was significant in the PDR group along the protan, deutan and tritan axes. The results suggest independent involvements of achromatic and chromatic CS in diabetic patients.

A One-Size-Fits-All Approach to Pressure Ulcers: Whole-Buttock Fasciocutaneous Advancement Flap.

BACKGROUND: Buttock pressure injuries can be difficult to treat. There are many choices of flaps to reconstruct these wounds, but few are large, technically simple, and easily recycled. AIM AND OBJECTIVE: We are presenting our experience on surgical reconstruction of buttock pressure injuries using large whole-buttock fasciocutaneous flaps that are easily designed for ulcers regardless of location and size and are easily recycled for treatment of recurrences. MATERIAL AND METHODS: We conducted a retrospective review of all patients who received reconstruction with fasciocutaneous rotational flaps for buttock region pressure injuries from January 2013 to December 2018. The key steps of this one-size-fits-all flap include elevation of a large, oversized flap to achieve tension-free closure, avoiding fascial incisions over bony prominences, placing the V-Y type closure wound in the posteromedial thigh, and the use of closed incisional negative wound therapy postoperatively. RESULTS: Fifty patients underwent 54 flaps reconstruction for coverage of stage 4 gluteal pressure injuries between January 2013 and December 2018. Seventy-four percent healed without the need for further operation. The average size of the defect was 90 cm2 (maximum = 300 cm2). The average follow-up period was 31 months. Four of the 54 flaps were "recycled" flaps, 3 were performed for the coverage of recurrent ulcers and 1 flap was performed for treatment of a postoperative wound dehiscence. CONCLUSIONS: We recommend this simple, one-size-fits-all approach, whole-buttock fasciocutaneous flap when surgically treating gluteal pressure injuries for selected patients.

Reliability analysis of a novel measurement system for quantifying human skin color.

Background: Precision is crucial in determining the appropriate procedure for implementing further trials. We conducted a study to explore the reliability of a novel measuring system for human skin color. Methods: The novel skin color measuring system was used to capture the skin color of four volunteers (2 males and 2 females) from the same location on each subject by the same operator. The measurement was repeated for different poses and instrument factors (camera and shooting protocol) in the red, green, and blue (RGB) system. The average color depth in each image was calculated and converted from 0 to 255. The spread of measures and the Bland-Altman plot was displayed to determine each variance source's random error, with the interclass correlation coefficients applied to reflect the reliability. Result: The RGB color depth in the experiment ranged from 190, 152, and 122 to 208, 170, and 142. The 95% confidential interval of the differences from the means in RGB colors for the different protocols were ±2.8, ±2.6, and ±2.1, respectively. The largest variation in the replicate trials was observed when subjects were in a supine position (standard deviation: 2). The interclass correlation coefficients were greater than 90%, suggesting that the developed system is highly precise. Conclusion: This study demonstrated that the developed device could stably and reliably detect human skin color across different common sources of variation, and thus could be applied clinically to explore relationships between health/disease and skin color changes.

Degradable Biocompatible Porous Microtube Scaffold for Extended Donor Cell Survival and Activity.

Cell therapy has significant therapeutic potential but is often limited by poor donor cell retention and viability at the host implantation site. Biomaterials can improve cell retention by providing cells with increased cell-cell and cell-matrix contacts and materials that allow three-dimensional cell culture to better recapitulate native cell morphology and function. In this study, we engineered a scaffold that allows for cell encapsulation and sustained three-dimensional cell culture. Since cell therapy is largely driven by paracrine secretions, the material was fabricated by electrospinning to have a large internal surface area, micrometer-thin walls, and nanoscale surface pores to allow for nutrient exchange without early cell permeation. The material is degradable, which allows for less invasive removal of the implant. Here, a biodegradable poly(lactic-co-glycolic acid) (PLGA) microtube array membrane was fabricated. In vitro testing showed that the material supported the culture of human dermal fibroblasts for at least 21 days, with paracrine secretion of pro-angiogenic FGF2. In vivo xenotransplantation of human cells in an immunocompetent mouse showed that donor cells could be maintained for more than one month and the material showed no obvious toxicity. Analysis of gene expression and tissue histology surrounding the implant showed that the material produced muted inflammatory and immune responses compared to a permanent implant and increased markers of angiogenesis.

Porous scaffold for mesenchymal cell encapsulation and exosome-based therapy of ischemic diseases.

Ischemic diseases including myocardial infarction (MI) and limb ischemia are some of the greatest causes of morbidity and mortality worldwide. Cell therapy is a potential treatment but is usually limited by poor survival and retention of donor cells injected at the target site. Since much of the therapeutic effects occur via cell-secreted paracrine factors, including extracellular vesicles (EVs), we developed a porous material for cell encapsulation which would improve donor cell retention and survival, while allowing EV secretion. Human donor cardiac mesenchymal cells were used as a model therapeutic cell and the encapsulation system could sustain three-dimensional cell growth and secretion of therapeutic factors. Secretion of EVs and protective growth factors were increased by encapsulation, and secreted EVs had hypoxia-protective, pro-angiogenic activities in in vitro assays. In a mouse model of limb ischemia the implant improved angiogenesis and blood flow, and in an MI model the system preserved ejection fraction %. In both instances, the encapsulation system greatly extended donor cell retention and survival compared to directly injected cells. This system represents a promising therapy for ischemic diseases and could be adapted for treatment of other diseases in the future.

Neural correlates of lateral modulation and perceptual filling-in in center-surround radial sinusoidal gratings: an fMRI study.

We investigated lateral modulation effects with functional magnetic resonance imaging. We presented radial sinusoidal gratings in random sequence: a scotoma grating with two arc-shaped blank regions (scotomata) in the periphery, one in the left and one in the right visual field, a center grating containing pattern only in the scotoma regions, and a full-field grating where the pattern occupied the whole screen. On each trial, one of the three gratings flickered in counterphase for 10 s, followed by a blank period. Observers were instructed to perform a fixation task and report whether filling-in was experienced during the scotoma condition. The results showed that the blood-oxygen-level-dependent signal was reduced in areas corresponding to the scotoma regions in the full-field compared to the center condition in V1 to V3 areas, indicating a lateral inhibition effect when the surround was added to the center pattern. The univariate analysis results showed no difference between the filling-in and no-filling-in trials. However, multivariate pattern analysis results showed that classifiers trained on activation pattern in V1 to V3 could differentiate between filling-in and no-filling-in trials, suggesting that the neural activation pattern in visual cortex correlated with the subjective percept.

Design of Waveguide Polarization Convertor Based on Asymmetric 1D Photonic Crystals.

Photonic crystals possess metastructures with a unique dispersion relation. An integrated optical circuit plays a crucial role in quantum computing, for which miniaturized optical components can be designed according to the characteristics of photonic crystals. Because the stable light transmission mode for a square waveguide is transverse electric or transverse magnetic polarization, we designed a half-waveplate element with a photonic crystal that can rotate the polarization direction of the light incident on a waveguide by 90°. Using the dispersion relation of photonic crystals, the polarization rotation length and the optical axis's angle of deviation from the electric field in the eigenmode can be effectively calculated. Polarization rotators designed on the basis of photonic crystal structures can effectively reduce the insertion loss of components and exhibit favorable polarization rotation performance.

Microtube Array Membrane Encapsulated Cell Therapy: A Novel Platform Technology Solution for Treatment of Alzheimer's Disease.

Alzheimer's disease is the most frequent form of dementia in aging population and is presently the world's sixth largest cause of mortality. With the advancement of therapies, several solutions have been developed such as passive immunotherapy against these misfolded proteins, thereby resulting in the clearance. Within this segment, encapsulated cell therapy (ECT) solutions that utilize antibody releasing cells have been proposed with a multitude of techniques under development. Hence, in this study, we utilized our novel and patented Microtube Array Membranes (MTAMs) as an encapsulating platform system with anti-pTau antibody-secreting hybridoma cells to study the impact of it on Alzheimer's disease. In vivo results revealed that in the water maze, the mice implanted with hybridoma cell MTAMs intracranially (IN) and subcutaneously (SC) showed improvement in the time spent the goal quadrant and escape latency. In passive avoidance, hybridoma cell loaded MTAMs (IN and SC) performed significantly well in step-through latency. At the end of treatment, animals with hybridoma cell loaded MTAMs had lower phosphorylated tau (pTau) expression than empty MTAMs had. Combining both experimental results unveiled that the clearance of phosphorylated tau might rescue the cognitive impairment associated with AD.

The role of color contrast gain control in global form perception.

A Glass pattern consists of randomly distributed dot pairs, or dipoles, whose orientation is determined by a geometric transform, which defines the global percept perceived by an observer. The perception of Glass patterns involves a local process that associates dot pairs into dipoles and a global process that groups the dipoles into a global structure. In the present study, we used a variant of Glass patterns, which was composed of randomly distributed tripoles instead of dipoles, to estimate the influence of color contrast on perceptual grouping. Each tripole contained an anchor dot and two context dots. Grouping the anchor dot with one of the context dots resulted in a global percept of a clockwise spiral, while grouping with the other dot, a counter-clockwise spiral. All dots in each pattern were modulated in the same color direction but different contrasts. Four colors were involved, namely, red, green, blue, and yellow. The observers were to determine whether the spiral in each trial was clockwise or counter-clockwise. The probability of a context dot being grouped with the anchoring dot increased with its color contrast to a certain level, then decreased when the contrast continued to increase. Such probability decreased as the contrast of the other context dot increased. Our result cannot be explained by existing models in the literature, but with a divisive inhibition model. The equiluminance contrast result observed here is similar to the inverted U-shaped function for luminance contrast result previously reported by us, except that the color contrast model comprises a weaker self-inhibition component.

Microtube Array Membrane Hollow Fiber Assay (MTAM-HFA)-An Accurate and Rapid Potential Companion Diagnostic and Pharmacological Interrogation Solution for Cancer Immunotherapy (PD-1/PD-L1).

Immunotherapy is one of the most promising forms of cancer treatment. In particular, immune checkpoint blockers (ICBs) represent some of the leading candidates which many drug developers have heavily invested in. During pre-clinical development and prior to human clinical trials, animal tests are a critical component for determining the safety and efficacy of newly developed ICBs for cancer treatment. In this study, we strive to demonstrate the feasibility of using hollow fiber assay microtube array membrane (MTAM-HFA) in the screening of anti-cancer ICBs. The MTAM-HFA process was carried out by encapsulating peripheral blood mononuclear cells (PBMCs) and the target cancer cells (cell lines or primary cells) and subcutaneously implanting them into Balb/C mice. At predetermined time points combination regimens of PD-1/PD-L1+ were administered accordingly and at a predetermined time point, the MTAMs were retrieved, and cell viability assays were carried out. The outcomes of the MTAM-HFA were compared against the clinical outcome of patients. Clinical comparison demonstrated excellent correlation between the screening outcome of MTAM-HFA of PD-1/PD-L1+ combination therapy and the clinical outcome of the lung cancer patients. Basic cell studies revealed that the utilization of MTAM-HFA in PD-1/PD-L1+ combination therapy revealed enhanced T-cell activity upon the administration of the PD-1/PD-L1 drug; thereby resulting in the reduction of tumor cell viability by up to 70%, and the cytotoxic effects by 82%. The outcome was echoed in the in vivo cell studies. This suggested that the MTAM-HFA system is suitable for use in PD-1/PD-L1+ screening and the accuracy, rapidity and cost effectiveness made it extremely suitable for application as a companion diagnostic system in both personalized medicine for cancer treatment and could potentially be applied to screen for candidate compounds in the development of next generation PD-1/PD-L1+ combination therapies.

The effect of textured background and perceived distance on perceived size.

The perceived size of an object depends on its spatial context, in addition to its projected image on the retina and perceived distance. However, how these factors interact with each other to affect perceived object size is still not clear. In this study, we manipulated the binocular disparity of images to assess the effect of perceived distance on perceived object size, as well as background element size to assess the effect of context. The perceived target size under different combinations of perceived distance and context was measured with a two-interval forced-choice paradigm, in which one interval contained a standard disk with a textured background while the other contained a comparison disk on a blank background in each trial. The observers were instructed to indicate which interval contained a larger disk. A staircase procedure was used to measure the point of subjective equality for the perceived target size. Our results showed that the perceived target size increased with the perceived distance while decreased with background element size. In addition, context modulated the relationship between the perceived target size and perceived distance. The data can be explained by a computational model that incorporates several size selective channels whose size sensitivity to a stimulus can be modulated by its disparity. The target response of each channel is subjected to the divisive inhibition signal from the size information in the context. The perceived size is determined by the weighted average of the responses of these size channels. This model can explain more than 91% of variability in the averaged data. Thus, while both perceived distance and context can affect the perceived size of an object, they exert the effect through different mechanisms.

Repairing Facial Fractures with Interrupted Maxillary-mandibular Arches by Computer-assisted Reverse Planning Model Surgery.

BACKGROUND: Management of comminuted facial fractures with maxillary-mandibular arch interruption is difficult, resulting in inadequate bone reduction and malocclusion. Traditionally, a good quality dental splint is helpful, but difficult to obtain in acute trauma. We apply a computer-assisted design and three-dimensional printing technology to improve splint fabrication and utilization, thus facilitating restoration of dental occlusion and facial fracture. METHODS: We retrospectively reviewed patients who suffered from facial fractures with interruption of the maxillary-mandibular arches. We developed the "computer-assisted reverse planning and three-dimensional printing model surgery" algorithm and applied it in selected patients. An occlusal splint was created as a surgical guide to enhance the maxilla-mandibular unit repair by taking care of the bone reduction and occlusion. All included patients were followed up to assess the functional outcome and patients suitable for this method. RESULTS: From Jan 2015 to Aug 2020, 10 patients (eight men and two women) with comminuted facial fractures were included. The average time of surgery was 9.2 days. The average follow-up time was 8.6 months. There was no patient who needed major revision to correct malocclusion or facial asymmetry. CONCLUSIONS: A computer-assisted design splint decreases intraoperative inaccuracies and difficulty in comminuted maxillo-mandibular fractures. It is a useful and reliable alternative. Collaboration with an experienced engineer and patient selection are indispensable in delivering successful outcomes. Patients who have more than three bone fragments in a single dental arch or more than four bone fragments in the entire maxillary-mandibular unit appear to be excellent candidates for this method.