Millimeter-Wave Band Electro-Optical Imaging System Using Polarization CMOS Image Sensor and Amplified Optical Local Oscillator Source.

In this study, we developed and demonstrated a millimeter-wave electric field imaging system using an electro-optic crystal and a highly sensitive polarization measurement technique using a polarization image sensor, which was fabricated using a 0.35-µm standard CMOS process. The polarization image sensor was equipped with differential amplifiers that amplified the difference between the 0° and 90° pixels. With the amplifier, the signal-to-noise ratio at low incident light levels was improved. Also, an optical modulator and a semiconductor optical amplifier were used to generate an optical local oscillator (LO) signal with a high modulation accuracy and sufficient optical intensity. By combining the amplified LO signal and a highly sensitive polarization imaging system, we successfully performed millimeter-wave electric field imaging with a spatial resolution of 30×60 µm at a rate of 1 FPS, corresponding to 2400 pixels/s.

Brain-implantable needle-type CMOS imaging device enables multi-layer dissection of seizure calcium dynamics in the hippocampus.

Objective: Current neuronal imaging methods mostly use bulky lenses that either impede animal behavior or prohibit multi-depth imaging. To overcome these limitations, we developed a lightweight lensless biophotonic system for neuronal imaging, enabling compact and simultaneous visualization of multiple brain layers.Approach: Our developed 'CIS-NAIST' device integrates a micro-CMOS image sensor, thin-film fluorescence filter, micro-LEDs, and a needle-shaped flexible printed circuit. With this device, we monitored neuronal calcium dynamics during seizures across the different layers of the hippocampus and employed machine learning techniques for seizure classification and prediction.Main results: The CIS-NAIST device revealed distinct calcium activity patterns across the CA1, molecular interlayer, and dentate gyrus. Our findings indicated an elevated calcium amplitude activity specifically in the dentate gyrus compared to other layers. Then, leveraging the multi-layer data obtained from the device, we successfully classified seizure calcium activity and predicted seizure behavior using Long Short-Term Memory and Hidden Markov models.Significance: Taken together, our 'CIS-NAIST' device offers an effective and minimally invasive method of seizure monitoring that can help elucidate the mechanisms of temporal lobe epilepsy.

Reduced graphene oxide/zinc oxide composite as an electrochemical sensor for acetylcholine detection.

Acetylcholine (ACh) plays a pivotal role as a neurotransmitter, influencing nerve cell communication and overall nervous system health. Imbalances in ACh levels are linked to neurodegenerative diseases, such as Alzheimer's and Parkinson's. This study focused on developing electrochemical sensors for ACh detection, utilizing graphene oxide (GO) and a composite of reduced graphene oxide and zinc oxide (rGO/ZnO). The synthesis involved modified Hummers' and hydrothermal methods, unveiling the formation of rGO through deoxygenation and the integration of nano-sized ZnO particles onto rGO, as demonstrated by XPS and TEM. EIS analysis also revealed the enhancement of electron transfer efficiency in rGO/ZnO. Cyclic voltammograms of the electrode, comprising the rGO/ZnO composite in ACh solutions, demonstrated prominent oxidation and reduction reactions. Notably, the composite exhibited promise for ACh detection due to its sensitivity, low detection threshold, reusability, and selectivity against interfering compounds, specifically glutamate and gamma-aminobutyric acid. The unique properties of rGO, such as high specific surface area and electron mobility, coupled with ZnO's stability and catalytic efficiency, contributed to the composite's potential in electrochemical sensor applications. This research, emphasizing the synthesis, fabrication, and characterization of the rGO/ZnO composite, established itself as a reliable platform for detecting the acetylcholine neurotransmitter.

Real-time monitoring of cortical brain activity in response to acute pain using wide-area Ca2+ imaging.

Previous human and rodent studies indicated that nociceptive stimuli activate many brain regions that is involved in the somatosensory and emotional sensation. Although these studies have identified several important brain regions involved in pain perception, it has been a challenge to observe neural activity directly and simultaneously in these multiple brain regions during pain perception. Using a transgenic mouse expressing G-CaMP7 in majority of astrocytes and a subpopulation of excitatory neurons, we recorded the brain activity in the mouse cerebral cortex during acute pain stimulation. Both of hind paw pinch and intraplantar administration of formalin caused strong transient increase of the fluorescence in several cortical regions, including primary somatosensory, motor and retrosplenial cortex. This increase of the fluorescence intensity was attenuated by the pretreatment with morphine. The present study provides important insight into the cortico-cortical network during pain perception.

Exposure Time Control Method for Higher Intermediate Frequency in Optical Heterodyne Imaging and Its Application to Electric-Field Imaging Based on Electro-Optic Effect.

We propose and demonstrate a method for equivalent time sampling using image sensors to selectively detect only the target frequency. Shortening the exposure time of the image sensor and using equivalent time sampling allows for the detection of frequency components that are higher than the frame rate. However, the imaging system in our previous work was also sensitive to the frequency component at 1/4 of the frame rate. In this study, we control the phase relationship between the exposure time and observed signal by inserting an additional interval once every four frames to detect the target frequency selectively. With this technique, we conducted electric field imaging based on the electro-optic effect under high noise conditions in the low-frequency band to which the conventional method is sensitive. The results demonstrated that the proposed method improved the signal-to-noise ratio.

Goreisan regulates cerebral blood flow according to barometric pressure fluctuations in female C57BL/6J mice.

Goreisan is a Kampo medicine used to treat headaches associated with climate change. Here, by using an implantable complementary metal-oxide-semiconductor (CMOS) device, we evaluated the effects of Goreisan and loxoprofen on cerebral blood flow (CBF) dynamics associated with barometric pressure fluctuations in freely moving mice. In the vehicle group, decreasing barometric pressure increased CBF that was prevented by Goreisan and loxoprofen. Notably, Goreisan, but not loxoprofen, reduced CBF after returning to atmospheric pressure. These results indicate that, unlike the mechanism of action of antipyretic analgesics, Goreisan normalizes CBF abnormalities associated with barometric pressure fluctuations by actively reducing CBF increase.

Balancing risk-return decisions by manipulating the mesofrontal circuits in primates.

Decision-making is always coupled with some level of risk, with more pathological forms of risk-taking decisions manifesting as gambling disorders. In macaque monkeys trained in a high risk-high return (HH) versus low risk-low return (LL) choice task, we found that the reversible pharmacological inactivation of ventral Brodmann area 6 (area 6V) impaired the risk dependency of decision-making. Selective optogenetic activation of the mesofrontal pathway from the ventral tegmental area (VTA) to the ventral aspect of 6V resulted in stronger preference for HH, whereas activation of the pathway from the VTA to the dorsal aspect of 6V led to LL preference. Finally, computational decoding captured the modulations of behavioral preference. Our results suggest that VTA inputs to area 6V determine the decision balance between HH and LL.

Postoperative Swallowing Function in Patients with Deep Neck Infection.

Introduction: Early detection of dysphagia risk, initiating rehabilitation, and resumption of appropriate diet based on swallowing function is important during deep neck infection (DNI) control. This study aimed to evaluate the extent of cervical abscess development, particularly in the deep neck space, and its relationship to postoperative swallowing function. Methods: A retrospective chart review was performed for all DNI cases treated between April 2015 and April 2021. Deep neck spaces were divided into categories based on computed tomography findings. Functional Oral Intake Scale (FOIS) scores of 4 or higher was defined as normal or slight swallowing disorder and 3 or lower as dysphagia. Results: Seventeen cases were included in the analysis. Based on FOIS, 14 cases were classified into the dysphagia group at 2 weeks after surgery, 11 cases at 4 weeks, and 8 cases at 8 weeks. There was no significant difference between the location of the abscess and dysphagia at 2 weeks after surgery. Patients with anterior cervical space abscess significantly increased dysphagia 4 weeks (p = 0.018) and 8 weeks (p = 0.036) after surgery. Conclusion: Abscess formation in the anterior cervical space may be associated with prolonged dysphagia after treatment due to inflammation and scarring of the muscles associated with swallowing.

Investigating the Influence of Morphine and Cocaine on the Mesolimbic Pathway Using a Novel Microimaging Platform.

Dopamine (DA)'s relationship with addiction is complex, and the related pathways in the mesocorticolimbic system are used to deliver DA, regulating both behavioral and perceptual actions. Specifically, the mesolimbic pathway connecting the ventral tegmental area (VTA) and the nucleus accumbens (NAc) is crucial in regulating memory, emotion, motivation, and behavior due to its responsibility to modulate dopamine. To better investigate the relationship between DA and addiction, more advanced mapping methods are necessary to monitor its production and propagation accurately and efficiently. In this study, we incorporate dLight1.2 adeno-associated virus (AAV) into our latest CMOS (complementary metal-oxide semiconductor) imaging platform to investigate the effects of two pharmacological substances, morphine and cocaine, in the NAc using adult mice. By implanting our self-fabricated CMOS imaging device into the deep brain, fluorescence imaging of the NAc using the dLight1.2 AAV allows for the visualization of DA molecules delivered from the VTA in real time. Our results suggest that changes in extracellular DA can be observed with this adapted system, showing potential for new applications and methods for approaching addiction studies. Additionally, we can identify the unique characteristic trend of DA release for both morphine and cocaine, further validating the underlying biochemical mechanisms used to modulate dopaminergic activation.

The Transition of Pediatric Tracheobronchial Foreign Body Cases in the Past 36 Years: A Retrospective Single-Center Study in Japan.

Tracheobronchial foreign bodies (TFBs) are pediatric airway emergencies frequently seen. We aimed to examine the changes in the clinical characteristics of pediatric TFB patients in a single institution within the past 36 years. We retrospectively reviewed the data of 85 patients aged 0-10 years with TFBs lodged in the trachea or bronchus admitted at the Department of Otolaryngology-Head and Neck Surgery at Tohoku University Hospital between 1986 and 2021. We also compared the characteristics, diagnostic methods, and treatments of the previous 64 cases (1986-2005) with those of the recent 21 cases (2006-2021). The number of TFB patients decreased later in this study (3.2 vs. 1.3 patients per year). The proportion of TFB patients aged > 3 years was significantly higher in the later period (6.3% vs. 23.8%, p = 0.038). Peanut was the most common cause of TFBs in both periods, and the overall incidence of peanut aspiration significantly decreased in the later period (68.8% vs. 38.1%, p = 0.019). No patient had an undetected TFB for more than 1 month after the onset of symptoms in the later period. Foreign body extraction using rigid bronchoscopy was performed in all patients earlier, whereas flexible bronchoscopy was used in 14.3% later. Our study revealed a recent trend in the clinical characteristics of pediatric TFB patients in a single institution in Northeast Japan. The prevention and treatment of pediatric TFBs should be considered following the recent trends.

Study on the Mechanism of the Pink Tooth Phenomenon Using Bovine Teeth: A Pilot Study.

The pink teeth phenomenon has occasionally been observed in forensic autopsies. This study aimed to establish an experimental pink tooth model and an objective color tone evaluation method in order to clarify changes in the color tone of teeth and the relationship with hemoglobin monoxide and its decomposition products and with red pigment-producing bacteria, under various external environmental factors. It was confirmed that the color tone evaluation with ΔE and the L*C*h color space was useful. The results of various examinations using this model showed that color development was suppressed under aerobic conditions, faded early under light, became bright red under a low temperature and showed a tendency to be reddish at 3 days under high humidity and in the presence of soft tissue. The biochemical analysis revealed a significant increase in carboxyhemoglobin at 7 days and a tendency toward increasing the total heme pigment and bilirubin levels over time. The bacteriological analysis revealed that red pigment-producing bacteria increased over time but that the color faded after 7 days. These results suggest that putrefaction greatly affects the pink teeth phenomenon, whereas red pigment-producing bacteria have little effect on the occurrence of pink teeth. However, further studies are needed to clarify bacteriological involvement.

Estimating the way of deposition of saliva stains using quantitative analysis of forensic salivary biomarkers.

Analyzing the way of deposition of saliva stains contributes to appropriate interpretation of saliva as evidence in court, particularly in sexual assault cases. In this proof-of-concept study, we aimed to confirm the difference between drooling-derived (non-contact) saliva and licking-derived (contact) saliva and clarify whether objectively distinguishing between the two saliva is possible. To allow discrimination between these two samples, an indicator was devised where the relative Streptococcus salivarius DNA quantity was calculated by dividing the S. salivarius DNA copies by the amount of stained saliva from the same saliva sample using quantitative polymerase chain reaction and salivary α-amylase activity assays. The study findings reveal that the value of the proposed indicator of licking-derived saliva was 100-fold significantly greater than that of drooling-derived saliva (P < 0.05, Welch's t-test). However, theoretical and technical challenges preclude the application of this indicator as a practical method. We believe that this saliva-specific bacterial DNA-based approach could allow estimation of the saliva stain deposition method.

Thin and Scalable Hybrid Emission Filter via Plasma Etching for Low-Invasive Fluorescence Detection.

Hybrid emission filters, comprising an interference filter and an absorption filter, exhibit high excitation light rejection performance and can act as lensless fluorescent devices. However, it has been challenging to produce them in large batches over a large area. In this study, we propose and demonstrate a method for transferring a Si substrate, on which the hybrid filter is deposited, onto an image sensor by attaching it to the sensor and removing the substrate via plasma etching. Through this method, we can transfer uniform filters onto fine micrometer-sized needle devices and millimeter-sized multisensor chips. Optical evaluation reveals that the hybrid filter emits light in the 500 to 560 nm range, close to the emission region of green fluorescent protein (GFP). Furthermore, by observing the fluorescence emission from the microbeads, a spatial resolution of 12.11 µm is calculated. In vitro experiments confirm that the fabricated device is able to discriminate GFP emission patterns from brain slices.

Multi-Region Microdialysis Imaging Platform Revealed Dorsal Raphe Nucleus Calcium Signaling and Serotonin Dynamics during Nociceptive Pain.

In this research, we combined our ultralight micro-imaging device for calcium imaging with microdialysis to simultaneously visualize neural activity in the dorsal raphe nucleus (DRN) and measure serotonin release in the central nucleus of the amygdala (CeA) and the anterior cingulate cortex (ACC). Using this platform, we observed brain activity following nociception induced by formalin injection in the mouse's hind paw. Our device showed that DRN fluorescence intensity increased after formalin injection, and the increase was highly correlated with the elevation in serotonin release in both the CeA and ACC. The increase in calcium fluorescence intensity occurred during the acute and inflammatory phases, which suggests the biphasic response of nociceptive pain. Furthermore, we found that the increase in fluorescence intensity was positively correlated with mouse licking behavior. Lastly, we compared the laterality of pain stimulation and found that DRN fluorescence activity was higher for contralateral stimulation. Microdialysis showed that CeA serotonin concentration increased only after contralateral stimulation, while ACC serotonin release responded bilaterally. In conclusion, our study not only revealed the inter-regional serotonergic connection among the DRN, the CeA, and the ACC, but also demonstrated that our device is feasible for multi-site implantation in conjunction with a microdialysis system, allowing the simultaneous multi-modal observation of different regions in the brain.

Investigating the Modulation of the VTA Neurons in Nicotine-Exposed Pups during Early Maturation Using Optogenetics.

Advancing the understanding of the relationship between perinatal nicotine addiction and the reward mechanism of the brain is crucial for uncovering and implementing new treatments for addiction control and prevention. The mesolimbic pathway of the brain, also known as the reward pathway, consists of two main areas that regulate dopamine (DA) and addiction-related behaviors. The ventral tegmental area (VTA) releases DA when stimulated, causing the propagation of neuronal firing along the pathway. This ends in the release of DA into the extracellular space of the nucleus accumbens (NAc), which is directly modulated by the uptake of DA. Much research has been conducted on the effects of nicotine addiction, but little research has been conducted concerning nicotine addiction and the mesolimbic pathway regarding maturation due to the small brain size. In this study, we apply our novel microstimulation experimental system to rat pups that have been perinatally exposed to nicotine. By using our self-fabricated photo-stimulation (PS) device, we can stimulate the VTA and collect dialysate, which is then used to estimate DA released into the NAc. The proposed platform has demonstrated the potential to monitor neural pathways as the pups mature.

Comparison of racemization rates between vital and endodontically treated teeth for age estimation.

Amino acid racemization of dentin (AAR) is among the most precise methods for age estimation in unidentified adult cadavers. Although vital teeth are generally used for this technique, cases often have endodontically treated (Endo) teeth only. Therefore, the aim of this preliminary pilot study was to determine the applicability of Endo teeth by comparing AAR rates between vital and Endo teeth. Thirty-six dentin samples from vital teeth and 18 dentin samples from Endo teeth were analyzed, including the maxillary first premolar, maxillary second molar, and mandibular second premolar. Standard calibration curves for the mandibular second premolar and maxillary second molar were compared among vital teeth, Endo teeth, and mixed vital/Endo teeth. Discrepancies between estimated and actual ages were assessed by analyzing the AAR rates for the maxillary first premolar between vital and Endo teeth. The AAR rates for Endo teeth were higher than those for vital teeth in both the mandibular second premolar and maxillary second molar, and the correlation of the standard calibration curve for vital teeth only was highest (r = 0.982836; r = 0.92011467), followed by mixed (r = 0.949579; r = 0.76158) and Endo teeth only (r = 0.896082; r = 0.744991). In the maxillary first premolar, discrepancies were more than 10 years for all 5 Endo teeth, based on the standard calibration curve of vital teeth. The present study suggests that the AAR rates for Endo teeth might be affected by variation in dentin structure between vital and Endo teeth.

Videofluoroscopic Dysphagia Scale as an Additional Indicator of Gastrostomy in Patients with Amyotrophic Lateral Sclerosis with Dysphagia.

Pseudobulbar palsy and bulbar palsy cause dysphagia in patients with amyotrophic lateral sclerosis (ALS). Dysphagia in patients with ALS not only increases the risk of aspiration and pneumonia but also leads to malnutrition and weight loss, which are poor prognostic factors. Gastrostomy is the preferred route of feeding and nutritional support in patients with dysphagia. However, there are no established standards to determine the ideal timing of gastrostomy for patients with ALS. Therefore, we used the videofluoroscopic dysphagia scale (VDS), which objectively quantifies swallowing function, in videofluoroscopic swallowing study (VFSS) to investigate whether this scale at diagnosis can be a useful predictor for the timing of gastrostomy. We retrospectively evaluated 22 patients with ALS who were diagnosed at our hospital. We assessed the VDS scores in all patients within 3 months of diagnosis. A decline in the ALS functional rating scale revised (ALSFRS-R) scores was used as an indicator of disease progression. As a result, we found that the VDS score of the pharyngeal phase and the total VDS score were significantly correlated with the ΔALSFRS-R scores. These scores were also associated with the existing indicators for the timing of gastrostomy, i.e., decreased body weight and percent-predicted forced vital capacity. We demonstrated the noninferiority of the VDS scores relative to the existing indicators. In addition, the VDS score of the pharyngeal phase was significantly correlated with the time from diagnosis to gastrostomy. The VDS score could estimate the timing of gastrostomy in patients with ALS with dysphagia at diagnosis.

Bedside evaluation of swallowing function to predict aspiration pneumonia in Duchenne muscular dystrophy.

OBJECTIVE: Aspiration pneumonia is one of the leading causes of death in patients with muscular dystrophy; therefore, it is important to predict its occurrence in the clincal setting. We aimed to examine the usefulness of repeated saliva swallowing test (RSST), modified water swallowing test (MWST), and flexible endoscopic evaluation of swallowing (FEES) for evaluating the Hyodo score at the bedside, to predict the risk of aspiration pneumonia in patients with Duchenne muscular dystrophy (DMD). METHODS: In this retrospective cohort study involving 43 patients, we evaluated the swallowing function using the RSST, MWST, and FEES, and predicted the likelihood of aspiration pneumonia within 2 years after the assessment. The Hyodo score, a scoring system for evaluating the swallowing function determined by the FEES, was used. RESULTS: Pneumonia was observed in 14 patients (32.6%). The RSST was not significantly useful for predicting the onset of pneumonia. The MWST was reported to have a cutoff value of < 4 points. Significantly more patients in the pneumonia group had an MWST score of < 4 points. The results revealed that the occurrence of pneumonia could be predicted based on a Hyodo cutoff score of ≥ 6. Significantly more patients in the pneumonia group had an MWST score of < 4 or a Hyodo score of ≥ 6. CONCLUSIONS: Combining MWST and FEES is useful for evaluating the bedside swallowing function and predicting the onset of pneumonia.

Forensic Characteristics of Physical Elder Abuse and Current Status and Issues of Collaboration between Forensic Medicine Departments and Related Institutions in Japan.

This study sought to clarify the characteristics and trends of physical elder abuse and the status of collaboration between forensic medicine departments and related institutions in Japan. Questionnaires were sent to 82 forensic medicine departments and 2857 institutions randomly selected from hospitals, municipalities and public community general support centers. The survey period was February to June 2021, including an extension period for collection. Responses from 675 facilities were analyzed. The most common finding in cases of physical elder abuse at forensic medicine departments was subcutaneous hemorrhage on the head (85.7%), with mixed old and new injuries most commonly observed in the lower limbs (70%). There were few cases in which there was collaboration between forensic medicine departments and other institutions. Among the issues identified, there is a need to provide related institutions with information obtained in forensic medicine departments. A new collaboration system is needed to achieve this.

Development of Compact Readout Device for Neural Observation System using Fluorescence Imaging and Fast-scan Cyclic Voltammetry.

A readout device for a dual-functional neural observation system is presented. The authors separately developed the reading operation of an implantable CMOS image sensor and a setup for fast-scan cyclic voltammetry and implemented them together in a microcontroller-based device. The developed imaging readout device with a size of [Formula: see text] can reach the highest reading rate of 160 fps with a 120×268 pixel image sensor. The voltammetry function was verified through an experiment using commercial carbon fiber electrodes in phosphate-buffered saline. When the imaging is sequentially operated with 400 V/s-scan rate voltammetry from -0.4 to 1.3 V, the system can operate at up to 60 fps. With this system, calcium imaging and dopamine recording in a freely behaving mouse can be achieved together in a simpler manner. This study aims to be the basis for the development of an implantable multi-functional sensor.