Giant X-Ray Circular Dichroism in a Time-Reversal Invariant Antiferromagnet.

X-ray circular dichroism, arising from the contrast in X-ray absorption between opposite photon helicities, serves as a spectroscopic tool to measure the magnetization of ferromagnetic materials and identify the handedness of chiral crystals. Antiferromagnets with crystallographic chirality typically lack X-ray magnetic circular dichroism because of time-reversal symmetry, yet exhibit weak X-ray natural circular dichroism. Here, the observation of giant natural circular dichroism in the Ni L3-edge X-ray absorption of Ni3TeO6 is reported, a polar and chiral antiferromagnet with effective time-reversal symmetry. To unravel this intriguing phenomenon, a phenomenological model is proposed that classifies the movement of photons in a chiral crystal within the same symmetry class as that of a magnetic field. The coupling of X-ray polarization with the induced magnetization yields giant X-ray natural circular dichroism, revealing typical ferromagnetic behaviors allowed by the symmetry in an antiferromagnet, i.e., the altermagnetism of Ni3TeO6. The findings provide evidence for the interplay between magnetism and crystal chirality in natural optical activity. Additionally, the first example of a new class of magnetic materials exhibiting circular dichroism is established with time-reversal symmetry.

Divergent neurodevelopmental profiles of very-low-birth-weight infants.

BACKGROUND: Advanced perinatal medicine has decreased the mortality rate of preterm infants. Long-term neurodevelopmental outcomes of very-low-birth-weight infants (VLBWIs) remain to be investigated. METHODS: Participants were 124 VLBWIs who had in-hospital birth from 2007 to 2015. Perinatal information, developmental or intelligence quotient (DQ/IQ), and neurological comorbidities at ages 3 and 6 years were analyzed. RESULTS: Fifty-eight (47%) VLBWIs received neurodevelopmental assessments at ages 3 and 6 years. Among them, 15 (26%) showed DQ/IQ <75 at age 6 years. From age 3 to 6 years, 21 (36%) patients showed a decrease (≤-10), while 5 (9%) showed an increase (≥+10) in DQ/IQ scores. Eight (17%) with autism spectrum disorder or attention-deficit hyperactivity disorder (ASD/ADHD) showed split courses of DQ/IQ, including two with ≤-10 and one with +31 to their scores. On the other hand, all 7 VLBWIs with cerebral palsy showed DQ ≤35 at these ages. Magnetic resonance imaging detected severe brain lesions in 7 (47%) of those with DQ <75 and 1 (18%) with ASD/ADHD. CONCLUSIONS: VLBWIs show a broad spectrum of neurodevelopmental outcomes after 6 years. These divergent profiles also indicate that different risks contribute to the development of ASD/ADHD from those of cerebral palsy and epilepsy in VLBWIs. IMPACT: Very-low-birth-weight infants (VLBWIs) show divergent neurodevelopmental outcomes from age 3 to 6 years. A deep longitudinal study depicts the dynamic change in neurodevelopmental profiles of VLBWIs from age 3 to 6 years. Perinatal brain injury is associated with developmental delay, cerebral palsy and epilepsy, but not with ASD or ADHD at age 6 years.

Outcomes of regenerative treatment for over 200 patients with tympanic membrane perforation.

OBJECTIVE: To evaluate outcomes of a regenerative treatment (RT) for over 200 patients with tympanic membrane perforation (TMP). The RT-TMP method involves a gelatin sponge, basic fibroblast growth factor (bFGF) and fibrin glue. METHODS: The study population included 216 patients and 234 ears (male: female =100:116; age 1-93 years). All enrolled patients were treated with RT-TMP in which TMP edges were disrupted mechanically and a gelatin sponge immersed in bFGF was inserted into the perforation. Fibrin glue was then dripped over the sponge. Patient outcomes including TMP closure rates, change in hearing level, and complications were obtained from retrospective medical chart reviews. The TMP was examined three or more weeks after surgery. The treatment was repeated up to 4 times until complete TMP closure was achieved. RESULTS: After mechanical disruption, the perforation size was Grade I, ≤1/3 of entire TM area in 22 ears (9.4 %), Grade II, 1/3-2/3 of entire TM in 77 ears (32.9 %) and Grade III, ≥2/3 of entire TM area in 135 ears (57.7 %). The overall TMP closure rates were 97.0 % (227/234). Complete TMP closure was achieved in 68.8 % (161/234), 22.6 % (53/234), 4.7 % (11/234) and 0.9 % (2/234) of ears after 1, 2, 3 and 4 treatments, respectively. In 7 of 234 ears (3.0 %), the TMPs were not closed completely after 4 treatments. There was no correlation between TMP size after mechanical disruption and number of treatments required to achieve complete closure (Fisher's exact test p = 0.70). The mean air-conduction hearing threshold at low frequency improved from 57.3 ± 16.7 dB before treatment to 37.3 ± 16.0 dB (p < 0.0001) after closure of TMPs. For middle and high frequencies, the improvement was 49.0 ± 19.3 dB to 36.9 ± 17.9 dB (p < 0.0001) and 57.7 ± 22.9 dB to 49.2 ± 23.3 dB (p < 0.0001), respectively. The mean air-bone gaps also improved significantly, and were within 10 dB at 250 Hz, 500 Hz and 1 kHz, and 11 dB at 2 kHz. One or more complications occurred in 32 patients (32/216; 14.8 %). The most common complication was formation of an epithelial pearl (16 ears; 6.8 %), followed by severe TM retraction (9 ears; 3.8 %) and otitis media with effusion (6 ears; 2.6 %). There were no serious complications that caused deterioration of the patient's general condition. CONCLUSION: Our results showed that RT-TMP had high success rates for TMP closure and good hearing improvement and produced no severe complications that could affect general health status. This novel therapy is simple, safe and minimally invasive, and could help improve the quality of life in patients with TMP.

Radiomics model of diffusion-weighted whole-body imaging with background signal suppression (DWIBS) for predicting axillary lymph node status in breast cancer.

BACKGROUND: In breast cancer diagnosis and treatment, non-invasive prediction of axillary lymph node (ALN) metastasis can help avoid complications related to sentinel lymph node biopsy. OBJECTIVE: This study aims to develop and evaluate machine learning models using radiomics features extracted from diffusion-weighted whole-body imaging with background signal suppression (DWIBS) examination for predicting the ALN status. METHODS: A total of 100 patients with histologically proven, invasive, clinically N0 breast cancer who underwent DWIBS examination consisting of short tau inversion recovery (STIR) and DWIBS sequences before surgery were enrolled. Radiomic features were calculated using segmented primary lesions in DWIBS and STIR sequences and were divided into training (n = 75) and test (n = 25) datasets based on the examination date. Using the training dataset, optimal feature selection was performed using the least absolute shrinkage and selection operator algorithm, and the logistic regression model and support vector machine (SVM) classifier model were constructed with DWIBS, STIR, or a combination of DWIBS and STIR sequences to predict ALN status. Receiver operating characteristic curves were used to assess the prediction performance of radiomics models. RESULTS: For the test dataset, the logistic regression model using DWIBS, STIR, and a combination of both sequences yielded an area under the curve (AUC) of 0.765 (95% confidence interval: 0.548-0.982), 0.801 (0.597-1.000), and 0.779 (0.567-0.992), respectively, whereas the SVM classifier model using DWIBS, STIR, and a combination of both sequences yielded an AUC of 0.765 (0.548-0.982), 0.757 (0.538-0.977), and 0.779 (0.567-0.992), respectively. CONCLUSIONS: Use of machine learning models incorporating with the quantitative radiomic features derived from the DWIBS and STIR sequences can potentially predict ALN status.

Construction of brain area risk map for decision making using surgical navigation and motor evoked potential monitoring information.

PURPOSE: Surgical devices or systems typically operate in a stand-alone manner, making it difficult to perform integration analysis of both intraoperative anatomical and functional information. To address this issue, the intraoperative information integration system OPeLiNK® was developed. The objective of this study is to generate information for decision making using surgical navigation and intraoperative monitoring information accumulated in the OPeLiNK® database and to analyze its utility. METHODS: We accumulated intraoperative information from 27 brain tumor patients who underwent resection surgery. First, the risk rank for postoperative paralysis was set according to the attenuation rate and amplitude width of the motor evoked potential (MEP). Then, the MEP and navigation log data were combined and plotted on an intraoperative magnetic resonance image of the individual brain. Finally, statistical parametric mapping (SPM) transformation was performed to generate a standard brain risk map of postoperative paralysis. Additionally, we determined the anatomical high-risk areas using atlases and analyzed the relationship with each set risk rank. RESULTS: The average distance between the navigation log corresponding to each MEP risk rank and the anatomical high-risk area differed significantly between the with postoperatively paralyzed and without postoperatively paralyzed groups, except for "safe." Furthermore, no excessive deformation was observed resulting from SPM conversion to create the standard brain risk map. There were cases in which no postoperative paralysis occurred even when MEP decreased intraoperatively, and vice versa. CONCLUSION: The time synchronization reliability of the study data is very high. Therefore, our created risk map can be reported as being functional at indicating the risk areas. Our results suggest that the statistical risks of postoperative complications can be presented for each area where brain surgery is to be performed. In the future, it will be possible to provide surgical navigation with intraoperative support that reflects the risk maps created.

Analyzing the Local Electronic Structure of Co3O4 Using 2p3d Resonant Inelastic X-ray Scattering.

We present the cobalt 2p3d resonant inelastic X-ray scattering (RIXS) spectra of Co3O4. Guided by multiplet simulation, the excited states at 0.5 and 1.3 eV can be identified as the 4 T 2 excited state of the tetrahedral Co2+ and the 3 T 2g excited state of the octahedral Co3+, respectively. The ground states of Co2+ and Co3+ sites are determined to be high-spin 4 A 2(T d ) and low-spin 1 A 1g (Oh ), respectively. It indicates that the high-spin Co2+ is the magnetically active site in Co3O4. Additionally, the ligand-to-metal charge transfer analysis shows strong orbital hybridization between the cobalt and oxygen ions at the Co3+ site, while the hybridization is weak at the Co2+ site.

Current Landscape of Sonodynamic Therapy for Treating Cancer.

Recent advancements have tangibly changed the cancer treatment landscape. However, curative therapy for this dreadful disease remains an unmet need. Sonodynamic therapy (SDT) is a minimally invasive anti-cancer therapy involving a chemical sonosensitizer and focused ultrasound. A high-intensity focused ultrasound (HIFU) beam is used to destroy or denature targeted cancer tissues. Some SDTs are based on unfocused ultrasound (US). In some SDTs, HIFU is combined with a drug, known as a chemical sonosensitizer, to amplify the drug's ability to damage cancer cells preferentially. The mechanism by which US interferes with cancer cell function is further amplified by applying acoustic sensitizers. Combining multiple chemical sonosensitizers with US creates a substantial synergistic effect that could effectively disrupt tumorigenic growth, induce cell death, and elicit an immune response. Therefore, the minimally invasive SDT treatment is currently attracting attention. It can be combined with targeted therapy (double-targeting cancer therapy) and immunotherapy in the future and is expected to be a boon for treating previously incurable cancers. In this paper, we will consider the current state of this therapy and discuss parts of our research.

Combined effect of pulmonary rehabilitation and music therapy in patients with chronic obstructive pulmonary disease.

[Purpose] We aimed to analyze parameters of pulmonary function and physiological, psychological, and physical factors in patients with chronic obstructive pulmonary disease (COPD) receiving pulmonary rehabilitation (PR) and music therapy (MT). [Participants and Methods] This randomized crossover comparative study included in-patients diagnosed with COPD and a ratio of forced expiratory volume measured at the first second and forced vital capacity (FEV1/FVC) of <70% after administration of a bronchodilator. Patients were randomly divided into two groups that received either PR only or MT and PR (n=13 each). The PR program included conditioning, respiratory muscle training, and endurance training, whereas the MT program included vocal, singing, and breathing exercises using a keyboard harmonica. The programs lasted 8 weeks, in which pre- and post-intervention data were compared every 4 weeks. [Results] The FEV1/FVC in the MT group improved after the intervention. Expiratory volume control was obtained better with feedback by sound than with expiration practice. In the MT and PR program, it was easier to adjust the timing and volume of breathing, obtain expiratory volume control, and, thus, improve FEV1/FVC than in conventional practice. [Conclusion] Combining MT with PR improves parameters of pulmonary function in patients with COPD. Music therapy is a novel approach that, in combination with PR, may be used in COPD management.

The characteristics and clinical course of patients with COVID-19 who received invasive mechanical ventilation in Osaka, Japan.

OBJECTIVE: To describe the detailed clinical course of patients with coronavirus disease 2019 (COVID-19) who received invasive mechanical ventilation. METHODS: We conducted a case series of patients with COVID-19 who received invasive mechanical ventilation in Osaka, Japan, between January 29 and May 28, 2020. We describe the patient characteristics and clinical course from onset. Additionally, we fitted logistic regression models to investigate the associations between patient characteristics and the 30-day mortality rate. RESULTS: A total of 125 patients who received invasive mechanical ventilation (median age [interquartile range], 68 [57-73] years; male, 77.6%) were enrolled. Overall, the 30-day mortality was 24.0%, and the median (interquartile range) length of ICU stay and length of invasive mechanical ventilation use were 16 (12-29) days and 13 (9-26) days, respectively. From clinical onset, 121 patients (96.8%) were intubated within 14 days. In multivariable logistic regression analysis, age of 65 years or older (odds ratio, 3.56; 95% confidence interval, 1.21-10.49; P = 0.02) and male sex (odds ratio, 3.75; 95% confidence interval, 1.00-11.24, P = 0.04) were significantly associated with a higher 30-day mortality rate. CONCLUSIONS: In this case series of patients with COVID-19 who received invasive mechanical ventilation in Japan, the 30-day mortality rate was 24.0%, and age 65 years or older and male sex were associated with higher 30-day mortality rate.

Robotic Technology in Operating Rooms: a Review.

Purpose of Review: With the rapid growth and development of robotic technology, its implementation in medical fields has also been significantly increasing, with the transition from the period of mainly using surgical robots to the era with combinations of multiple types of robots. Therefore, this paper introduces the newest robotic systems and technology applied in operating rooms as well as their architectures for integration. Recent Findings: Besides surgical robots, other types of robotic devices and machines such as diagnostic and treatment devices with robotic operating tables, robotic microscopes, and assistant robots for surgeons emerge one after another, improving the quality of surgery from different aspects. With the increasing number and type of robots, their integration platforms are also proposed and being spread. Summary: This review paper presents state-of-the-art robot-related technology in the operating room. Robotic platforms and robot components which appeared in the last decade are described. In addition, system architectures for the integration of robots as well as other devices in operating rooms are also introduced and compared.

Two new records of powdery mildews (Erysiphaceae) from Japan: Erysiphe actinidiicola sp. nov. and Erysiphe sp. on Limonium tetragonum.

Erysiphe actinidiicola on Actinidia polygama is described based on morphological and molecular data. Erysiphe actinidiicola is distinguished from E. actinidiae var. actinidiae by having irregularly to dichotomously branched chasmothecial appendages, larger chasmothecia sizes and numbers of asci per chasmothecium. Molecular analyses indicated that this species forms a clade separated from E. actinidiae var. actinidiae. An epitype is proposed for E. actinidiae var. actinidiae with ex-epitype sequences. A powdery mildew found on Limonium tetragonum is tentatively described as Erysiphe sp. This species is distinguished from E. limonii, a powdery mildew on Limonium spp., based on the DNA sequence differences in the 28S rDNA and internal transcribed spacer region as well as the morphological differences in the length of the conidiophores. This is the first record of powdery mildew on L. tetragonum in the world.

Video-based neonatal state assessment method for timing of procedures.

BACKGROUND: Procedures should be performed when an infant is most receptive to disruptions in order to reduce the stress on the infant. However, frequent direct observations place a heavy burden on medical staff. There is therefore a need for a method for quantitatively and automatically evaluating the neonatal state. METHODS: Ten infants in our hospital were enrolled in this study. The states of the infants were assessed by medical staff using the Brazelton Neonatal Behavioral Assessment Scale and were recorded on video at the same time. The recorded states were reclassified as activity levels, a new state classification method that includes middle activity, which is the appropriate time for a procedure. Using image analysis, motions of the infant were quantified as two indices: activity and pause time. Activity and pause time were compared for each activity level. The cutoff values of the indices were calculated, and the sensitivity and specificity of the middle activity were calculated. RESULTS: There was a significant difference between all groups of activity level (P < 0.01). The maximum sensitivity and specificity of middle activity were 71.7% and 51.2%, respectively. CONCLUSIONS: The neonatal state of infants can be quantitatively and automatically evaluated using video cameras, and the activity level can be used to determine an appropriate time for procedures in infants. This will reduce the burden on medical staff and lead to less stressful procedures for infants.

The iArmS Robotic Armrest Prolongs Endoscope Lens-Wiping Intervals in Endoscopic Sinus Surgery.

Objective. Fouling of the endoscope lens is a major problem in endoscopic sinus surgery (ESS). We examined whether the use of the intelligent arm support system (iArmS), a robotic armrest, could prolong endoscope lens-wiping intervals in ESS and thus allow for continuously clear endoscopic images. Study Design. This study is a prospective, nonrandomized crossover study. Methods. Three surgeons who performed ESS at 2 centers each conducted 3 operations with the iArmS and 3 operations without the iArmS; thus, 18 operations were assessed. To blind the assessments, we performed them prospectively without informing subjects of the endpoints. We recorded the operations and observed the recordings at a later date; endoscope lens-wiping times were noted in seconds to determine the endoscope lens-wiping intervals. Our examination was based on the null hypothesis that endoscope lens-wiping intervals would not differ according to the use or nonuse of the iArmS. Results. The median endoscope lens-wiping intervals with and without using the iArmS were 361 seconds and 135 seconds, respectively. Based on the Wilcoxon rank-sum test, this difference was significant (P = 0.001); thus, the null hypothesis was rejected. This result indicated that endoscope lens-wiping intervals are greatly prolonged by the use of the iArmS. Conclusion. The iArmS robotic armrest is suitable for ESS, prolongs endoscope lens-wiping intervals, and facilitates obtaining continuous clear endoscopic images.

Saturation and self-absorption effects in the angle-dependent 2p3d resonant inelastic X-ray scattering spectra of Co3.

Angle-dependent 2p3d resonant inelastic X-ray scattering spectra of a LaCoO3 single crystal and a 55 nm LaCoO3 film on a SrTiO3 substrate are presented. Theoretical calculation shows that, with ∼20 meV resolved Co 2p3d resonant inelastic X-ray scattering (RIXS), the excited states of the isotropic 1A1g(Oh) ground state are split by 3d spin-orbit coupling, which can be distinguished via their angular dependence. However, strong self-absorption and saturation effects distort the spectra of the LaCoO3 single crystal and limit the observation of small angular dependence. In contrast, the RIXS on 55 nm LaCoO3 shows less self-absorption effects and preserves the angular dependence of the excited states.

GATOR: connecting integrated operating room solutions based on the IEEE 11073 SDC and ORiN standards.

PURPOSE: Medical device interoperability in operating rooms (OR) provides advantages for both, patients and physicians. Several approaches were made to provide standards for successful device integration. However, with high heterogeneity of standards in the market, device vendors may reject these approaches. The aim of this work is therefore to provide a proof of concept for the connection of two promising integration solutions OR.NET and SCOT to increase vendor interest. METHODS: The connection of devices between both domains is targeted by implementing an application to map device capabilities between the IEEE 11073 SDC and ORiN standards. Potential properties of the respective architectures are defined. The connection was evaluated by latency measurements in a demonstrator setup utilizing an OR light as an exemplary device. RESULTS: The latency measurements resulted in a similar transmission speed of the GATOR (53.0 ms) and direct SDC-to-SDC (38.0 ms) communication. Direct proprietary ORiN-to-ORiN communication was faster in any case (8.0 ms). CONCLUSION: A connection between both standards was successfully achieved via the GATOR application. The results show comparable magnitudes of the communication between the standards compared to the direct standard-internal communication.

Sonodynamic Therapy With Anticancer Micelles and High-Intensity Focused Ultrasound in Treatment of Canine Cancer.

Sonodynamic therapy (SDT) is a minimally invasive anticancer therapy involving a chemical sonosensitizer and high-intensity focused ultrasound (HIFU). SDT enables the reduction of drug dose and HIFU irradiation power compared to those of conventional monotherapies. In our previous study, mouse models of colon and pancreatic cancer were used to confirm the effectiveness of SDT vs. drug-only or HIFU-only therapy. To validate its usefulness, we performed a clinical trial of SDT using an anticancer micelle (NC-6300) and our HIFU system in four pet dogs with spontaneous tumors, including chondrosarcoma, osteosarcoma, hepatocellular cancer, and prostate cancer. The fact that no adverse events were observed, suggests the usefulness of SDT.

Function of Epirubicin-Conjugated Polymeric Micelles in Sonodynamic Therapy.

The combinatory use of high-intensity focused ultrasound (HIFU) and epirubicin (EPI)-conjugated polymeric micellar nanoparticles (NC-6300) is thought to be a less invasive and more efficient method of cancer therapy. To investigate the mechanism underlying the combination effect, we examined the effect of trigger-pulsed HIFU (TP-HIFU) and NC-6300 from the perspective of reactive oxygen species (ROS) generation, which is considered the primary function of sonodynamic therapy (SDT), and changes in drug characteristics. TP-HIFU is an effective sequence for generating hydroxyl radicals to kill cancer cells. EPI was susceptible to degradation by TP-HIFU through the production of hydroxyl radicals. In contrast, EPI degradation of NC-6300 was suppressed by the hydrophilic shell of the micelles. NC-6300 also exhibited a sonosensitizer function, which promoted the generation of superoxide anions by TP-HIFU irradiation. The amount of ROS produced by TP-HIFU reached a level that caused structural changes to the cellular membrane. In conclusion, drug-conjugated micellar nanoparticles are more desirable for SDT because of accelerated ROS production and drug protection from ROS. Furthermore, a combination of NC-6300 and TP-HIFU is useful for minimally invasive cancer therapy with cooperative effects of HIFU-derived features, antitumor activity of EPI, and increased ROS generation to cause damage to cancer cells.

Profile of the ORION (Osaka emergency information Research Intelligent Operation Network system) between 2015 and 2016 in Osaka, Japan: a population-based registry of emergency patients with both ambulance and in-hospital records.

AIM: To describe the registry design of the Osaka Emergency Information Research Intelligent Operation Network system (ORION) and its profile of hospital information, patient and emergency medical service characteristics, and in-hospital outcomes among all patients transported to critical care centers and emergency hospitals in Osaka Prefecture, Japan. METHODS: The Osaka Prefecture Government has developed and introduced an information system for emergency patients (the ORION system) that uses a smartphone application (app) for hospital selection by on-scene emergency medical service personnel and has been accumulating all ambulance records. Since January 2015, medical institutions have obtained information on the diagnosis and outcome of patients transported to medical institutions, and the ORION system merged these data with ambulance records including smartphone app data. RESULTS: From January 2015 to December 2016, 753,301 eligible patients were registered. The mean age was 58.7 years, and 51.5% of patients were male. After hospital arrival, 39.7% were hospitalized, 58.2% were discharged from hospital, 1.1% changed hospital, and 1.0% died. The most common diagnoses were injury, poisoning, and certain other consequences of external causes. Among the hospitalized patients, 29.2% were continuously hospitalized, 59.0% discharged, 5.2% changed hospital, and 5.8% were dead at 21 days after hospitalization. The most common confirmed diagnosis was diseases of the circulatory system. CONCLUSION: Using the ORION system developed and operated by Osaka Prefecture since January 2015, we described the epidemiological data of all emergency patients transported to emergency hospitals. Analysis using the ORION database in the future could lead to improvements in the emergency transport system and patient outcomes.

Usefulness of a Newly Developed Ultrasonic Microdissector in Neurosurgery: A Preliminary Experimental Study.

BACKGROUND: Dissection and division of tissues are widely performed in microscopic neurosurgery, especially in brain tumor resection. Dissection maneuvers can be divided into two types: sharp dissection with microscissors and blunt dissection using a dissector. It is essential to use the appropriate method according to the intraoperative situation and conditions. Therefore, specific tools for each type of dissection maneuver are required. We developed an ultrasonic microdissector, a newly designed tool that functions as both microscissors and dissector to further advance brain tumor surgery. This preliminary experimental study was performed to evaluate the usefulness of this new device. METHODS: Solfy F (J. Morita Mfg. Corp., Kyoto, Japan), a dental ultrasonic instrument, was used to provide power in this study. Two experiments were performed. The first one involved touching the brain parenchyma of a pig cadaver with the tip of the ultrasonic microdissector under various conditions to investigate its side effects. In the second experiment, the rat femoral artery, vein, and nerve were dissected from surrounding structures using a prototype of the ultrasonic microdissector. The effects of this device were then investigated histologically. RESULTS: The amount of tissue damage was greater with the higher ultrasonic power. No irrigation and a long manipulation time also affected tissue degeneration. Dissection using the ultrasonic microdissector was superior to conventional dissection methods in terms of time (p < 0.05) and safety without any additional histologic damages. CONCLUSIONS: The newly developed ultrasonic microdissector can dissect soft tissue without damage to the surrounding tissue. Further studies are required to determine the optimal intensity for its clinical use.