Alamouti-coded DSP algorithm with a simplified PTBC decoder for next-generation optical access networks.

The use of Alamouti-coded polarization-time block code (A-PTBC) in combination with a simple single polarization coherent receiver enables phase-diverse coherent detection without any optical polarization tracking. However, applying this technique to high-speed single-carrier systems is not straightforward, as it requires specialized digital signal processing (DSP) algorithms for data recovery, which increases DSP complexity. In this paper, we propose a novel Alamouti-coded coherent algorithm designed to significantly reduce the complexity of the receiver DSP for data recovery. The proposed algorithm achieves the comparable performance to the conventional algorithm but requires only half the number of necessary equalizers for data recovery. We validate its performance through simulations and also experimentally demonstrate a 100 Gb/s 16-quadrature amplitude modulation (QAM) single-carrier coherent system employed the single-polarization coherent receiver over 20 km of standard single-mode fiber (SMF). Through the performance verification, the coherent system with the proposed algorithm exhibits performance comparable to that of the conventional Alamouti-coded coherent system and achieves a power budget of 34 dB when the transmit launch power is set to 7 dBm at a Bit Error Rate (BER) of 1 × 10-2 for 0-20 km fiber transmission.

Exploring social activity patterns among community-dwelling older adults in South Korea: a latent class analysis.

BACKGROUND: With the trend of digitalization, social activities among the older population are becoming more diverse as they increasingly adopt technology-based alternatives. To gain a comprehensive understanding of social activities, this study aimed to identify the patterns of digital and in-person social activities among community-dwelling older adults in South Korea, examine the associated factors, and explore the difference in depressive symptoms by the identified latent social activity patterns. METHODS: Data were extracted from a nationwide survey conducted with 1,016 community-dwelling older adults (mean age 68.0 ± 6.5 years, 47.8% male). The main variables assessed were digital social activities (eight items), in-person social activities (six items), and depressive symptoms (20 items). Data were analyzed using latent class analysis, multinomial logistic regression, and multiple linear regression. RESULTS: We identified four distinct social activity patterns: "minimal in both digital and in-person" (22.0%), "moderate in both digital and in-person" (46.7%), "moderate in digital & very high in in-person" (14.5%), and "high in both digital and in-person" (16.8%). Younger age, living in multi-generational households, and higher digital literacy were associated with a higher likelihood of being in the "moderate in both digital and in-person" than the "minimal in both digital and in-person" group. Younger age, male, living in multi-generational households, residing in metropolitan areas, no dependency on IADL items, doing daily physical exercise, and higher digital literacy were associated with a higher likelihood of being in the "moderate in digital & very high in in-person" than the "minimal in both digital and in-person" group. Younger age, living in multi-generational households, no dependency on IADL items, doing daily physical exercise, and higher digital literacy were associated with a higher likelihood of being in the "high in both digital and in-person" than the "minimal in both digital and in-person" group. Depressive symptoms were significantly higher in the group with minimal engagement in both digital and in-person activities, compared to other three groups. CONCLUSIONS: This study highlights distinct patterns of social activities among Korean community-dwelling older adults. Since older adults with minimal social activity engagement can be more vulnerable to depressive symptoms, interventions that address modifiable attributes, such as supporting digital literacy and facilitating physical activity of older adults, could serve as potential strategies to enhance their social activity engagement and, consequently, their mental well-being.

Posttraumatic Growth in U.S. Military Veterans: Results from the National Health and Resilience in Veterans Study.

Despite increasing recognition that positive psychological changes or posttraumatic growth (PTG) may develop after highly stressful or traumatic events, contemporary population-based data on the epidemiology of PTG in high-risk samples such as U.S. military veterans are lacking. Additionally, in light of emerging evidence suggesting an 8-factor model of posttraumatic stress disorder (PTSD) symptoms, an up-to-date characterization of how these symptom clusters relate to PTG can help inform efforts to help promote PTG. Data were analyzed from the 2019-2020 National Health and Resilience in Veterans Study (NHRVS), which surveyed a nationally representative sample of 3,847 trauma-exposed U.S. veterans. Participants completed assessments of potentially traumatic events, PTSD symptoms, and PTG, as well as a broad range of sociodemographic, military, trauma, health, personality, and psychosocial characteristics. Results revealed that 63.2% of trauma-exposed veterans and 86.4% of veterans who screened positive for PTSD endorsed moderate-or-greater PTG; these prevalences are higher than those reported in an independent U.S. veteran sample in 2011 (50.1% and 72.0%, respectively). An inverted U-shaped association was observed between PTSD symptom severity and PTG levels, with scores of 31 to 51 on the PTSD Checklist for DSM-5 associated with the highest likelihood of PTG. Intrinsic religiosity and internally- and externally-generated intrusive symptoms of PTSD were identified as the strongest correlates of PTG. Results suggest that prevention and treatment efforts to mitigate severe PTSD symptoms, and help promote intrinsic religiosity, and more deliberate and organized rumination about traumatic experiences may help foster PTG in veterans.

Realization of real-time DSP for C-band PAM-4 transmission in inter-datacenter network.

We designed and realized real-time pulse amplitude modulation-4 (PAM-4) digital signal processing (DSP) including forward error correction (FEC) for a C-band inter-datacenter network. The PAM-4 DSP is intended to compensate for chromatic dispersion and provide dispersion tolerance. A decision feedback equalizer (DFE) and maximum likelihood sequence equalizer (MLSE) were employed for the dispersion compensation. A low-density parity check (LDPC) code was used to increase coding gain. The soft-decision Viterbi algorithm (SOVA) was adopted to provide probabilistic information to the LDPC code. For implementation in a real-time field programmable gate arrays (FPGAs), we employed fully parallelized structures. In the design, three LDPC cores were operated in parallel, and the equalizers were also operated with 128 PAM-4 symbols. With the DSP, we empirically proved the feasibility of 25 km transmission without error-floor sign, corresponding to a dispersion compensation capacity of 425 ps/nm. We confirmed 35 km ∼ 85 km error-free transmission for inter-datacenter network.

Incidence and risk factors of delayed postpolypectomy bleeding: a retrospective cohort study.

BACKGROUND/AIM: Delayed bleeding is a serious complication that occurs after polypectomy. Many risk factors for delayed bleeding have been suggested, but there is little analysis of procedure-related risk factors. The purpose of this study is to identify a wide range of risk factors for delayed postpolypectomy bleeding (DPPB) and analyze the correlations of those potential DPPB risk factors. MATERIALS AND METHODS: In this retrospective cohort study, 5981 polypectomies in 3788 patients were evaluated between January 2010 and February 2012. Patient-related, polyp-related, and procedure-related factors were evaluated as potential DPPB risk factors. RESULTS: Delayed bleeding occurred in 42 patients (1.1%). Multivariate analysis revealed that polyp size >10 mm [odds ratio (OR), 2.785; 95% confidence interval (CI), 1.406-5.513; P=0.003], location in the right hemi-colon (OR, 2.289; 95% CI, 1.117-4.693; P=0.024), and endoscopist's experience (<300 total cases of colonoscopy performed; OR, 4.803; 95% CI, 2.631-8.766; P=0.001) were significant risk factors for DPPB. Especially protruded type polyps (Ip, Isp) larger than 1 cm in the right-side colon were associated with increased risk. Right-side polypectomy by a nonexpert endoscopist was a significant risk factor for DPPB, especially with procedures in the cecum area. Taking the 1.5% DPPB incidence as cutoff value, the learning curve of colonoscopic polypectomy may be estimated as 400 cases of polypectomy. CONCLUSIONS: Polyp size, endoscopist's experience, and right hemi-colon location were identified as potential risk factors for DPPB development.

Significance of serum antibody test for toxocariasis in healthy healthcare examinees with eosinophilia in Seoul and Gyeongsangnam-do, Korea.

There have been numerous reports on the relationship between eosinophilia and toxocariasis. The present study investigated seropositive rates of toxocariasis among healthy people with or without eosinophilia in urban and rural areas, and assessed risk factors for positive antibody test. A total of 610 healthy people, who visited health check-up (Medicheck®, Korea Association of Health Promotion), 310 from Seoul and 300 from Gyeongsangnam-do, were subjected for this study. Their serum samples were tested by ELISA with the crude antigen of Toxocara canis larvae. Cross-reactions with other tissue invading helminth antigens were also investigated. Total antibody positive rate of toxocariasis was 8.7% of the 610 subjects. When the subjects were grouped into 3 by their eosinophil counts, the antibody positive rates significantly differed by the groups; 5.9% (18/306) in the group<350/µL, 10.0% (11/110) in the group 350-500/µL, and 12.4% (24/194) in the group>500/µL (P=0.028). A total of 22 serum samples cross-reacted with other tissue-invading helminth antigens. A questionnaire analysis recognized drinking alcohol and smoking as significant risk factors of toxocariasis. In conclusion, toxocariasis antibody positive rate is correlated with eosinophil counts. It is recommended that healthy subjects with eosinophilia by routine health examination and risk factors undergo Toxocara serology by multiantigen ELISA to investigate etiology.

Intramedullary Impaction of the Basicervical Component Is Determinant of Fixation Failure in a Simple Two-Part Pertrochanteric Fracture.

OBJECTIVES: To evaluate initial fracture morphology influences on outcomes in simple 2-part pertrochanteric fracture, with a focus on the basicervical component and its initial impaction. DESIGN: A retrospective cohort series. SETTING: Single Level I Trauma Center. PATIENTS SELECTION CRITERIA: Patients older than 60 years with intertrochanteric fractures between 2011 and 2022 were retrospectively reviewed. Inclusion criteria comprised simple 2-part pertrochanteric fractures (Orthopaedic Trauma Association [OTA]/Arbetisgemeinschaftfur Osteosynthesefragen [AO] 31-A1.2) with a basicervical component who underwent cephalomedullary nailing and had a minimum follow-up of 6 months. Patients were divided whether the basicervical component was impacted into the medullary canal (intramedullary impaction [II] group) or displaced beyond the medullary canal (extramedullary [E] group). Exclusion criteria encompassed pathologic fractures, nondisplaced fractures, and basicervical neck fractures (OTA/AO 31-B3). OUTCOME MEASUREMENTS AND COMPARISONS: Reduction status was assessed as unacceptable if the head and neck (proximal) fragment was positioned intramedullary with respect to the distal fragment in either the anterior posterior or cross-lateral x-ray and acceptable otherwise. In addition, the degree of impaction on x-ray and CT scans (coronal, sagittal, axial) at injury was analyzed as a risk factor for failure. Revision rates and lag screw sliding over 15 mm were compared between the II and E groups. RESULTS: Hundred fifteen patients (95 female, average age 80 years) were included. The II group (n = 58) compared with E group (n = 57) showed more acceptable postoperative reductions (57% vs. 81%, P = 0.001), but significantly higher fixation failure (16% vs. 3.5%, P = 0.048) and fracture collapse (28% vs. 7%, P = 0.01). II was identified as a significant independent predictor for failure (odds ratio 5.64, 95% confidence interval, 2.14-16.9, P < 0.001) with more than 19.5-mm impaction in sagittal CT scan as the threshold linked to increased failure risk. CONCLUSIONS: This study highlights the significance of specific intertrochanteric fracture patterns, particularly II of a basicervical component and impaction severity (≥19.5 mm), as drivers of fixation failure. LEVEL OF EVIDENCE: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Helping the Helpers: Mental Health Challenges of Psychosocial Support Workers During the Russian-Ukrainian War.

OBJECTIVE: The ongoing Russian-Ukrainian war has been linked to mental health problems in the Ukrainian general population. To date, however, scarce research has examined the mental health of psychosocial support workers (PSWs) in Ukraine who have a burdensome workload in the context of ongoing conflict. This study aimed to examine the prevalence and correlates of burnout, posttraumatic stress disorder (PTSD), and suicidal ideation (SI) in PSWs in Ukraine during the Russian-Ukrainian war. METHODS: One hundred seventy-eight PSWs in Ukraine completed a survey assessing war exposure, mental health, and psychosocial characteristics. RESULTS: A total 59.6% of PSWs screened positive for burnout, 38.2% for PTSD, and 10.7% for current SI. Lower optimism was associated with greater odds of burnout. Greater distress from witnessing war-related destruction, lower optimism, lower presence of meaning in life, and lower levels of close social relationships were associated with greater odds of burnout. Lower presence of meaning in life was associated with greater odds of SI. CONCLUSIONS: Results of this study highlight the mental health challenges faced by PSWs in Ukraine during the ongoing Russian-Ukrainian war. They further suggest that interventions to foster meaning in life and promote social connectedness may "help the helpers" during this ongoing conflict.

Functional significance of posttraumatic growth in U.S. military veterans.

BACKGROUND: Although many studies indicate that individuals who have experienced a traumatic event can experience posttraumatic growth (PTG), some researchers have questioned the significance of PTG in associations with functioning. The role of PTG in functioning following trauma may be better elucidated by accounting for its joint effects with posttraumatic stress disorder (PTSD) symptoms. METHODS: Data were analyzed from the National Health and Resilience in Veterans Study, which surveyed a nationally representative sample of 3847 trauma-exposed U.S. veterans. Participants completed assessments of potentially traumatic events, PTSD symptoms, and PTG, as well as a broad range of sociodemographic, military, trauma, health, personality, and psychosocial characteristics. RESULTS: PTG was independently and moderately associated with higher mental, cognitive, and psychosocial functioning, but not physical functioning. Results showed a similar pattern of findings when examining relations between subdomains of PTG and these aspects of functioning. Additionally, among veterans who screened positive for PTSD, those who endorsed PTG reported higher levels of mental, cognitive, and/or psychosocial functioning than those who did not endorse PTG. LIMITATIONS: Findings may be limited by the use of a cross-sectional design, retrospective self-reports of PTG, and a predominantly older white male veteran sample. CONCLUSION: Results provide support for the functional significance of PTG and highlight the importance of considering PTSD symptoms to better understand the role of PTG in functioning. Clinical interventions to foster PTG may help promote post-trauma functioning.

The successful endoscopic hemostasis factors in bleeding from advanced gastric cancer.

BACKGROUND: When patients with advanced gastric cancer experience active bleeding, gastroenterologists normally choose between two treatment modalities, endoscopic hemostasis and transarterial embolization (TAE). In patients with advanced gastric cancer with bleeding, the predictive factors for endoscopic hemostatic failure are still unknown. Thus, the purpose of this study was to evaluate predictive factors for endoscopic hemostasis failure and to differentiate which hemostasis procedure is more effective for advanced gastric cancer with bleeding. METHODS: We reviewed the medical records of patients who were diagnosed with advanced gastric cancer and acute non-variceal gastric bleeding from January 2006 to August 2011. Forty-five patients were enrolled in this study and they were divided into a group of 14 patients who had experienced successful endoscopic hemostasis and a group of 31 patients who had had unsuccessful hemostasis with the first endoscopy and then underwent TAE. RESULTS: Lesion size and bleeding condition of Forrest class 1a or 1b were statistically significant predictive factors for endoscopic hemostatic failure (P = 0.023 and P = 0.017, respectively). On multivariate logistic regression analysis, size (lesion >2 cm) was a significant predictive factor for endoscopic hemostatic failure [adjusted odds ratio (aOR) 8.056; 95% confidence interval (CI) 1.329-48.846]. CONCLUSIONS: We determined that small bleeding lesions (<2 cm) and exposed vessels in the bleeding site with gastric cancer indicated that endoscopic hemostasis would be an effective hemostatic modality to choose. Particularly, in the opposite condition, the presence of large bleeding lesions (>2 cm) and non-exposed vessel bleeding with a tumor, endoscopic hemostasis failure is predicted and TAE could be recommended.

Digital literacy among Korean older adults: A scoping review of quantitative studies.

Background: While digital literacy has become an essential competency for individuals across generations and sectors of society, supporting digital literacy in older adults is particularly challenging. South Korea is among the many countries undergoing rapid digitalization and population aging. Therefore, it is timely to identify the current understanding of digital literacy among older adults in South Korea. Aim: To identify prior studies that quantitatively measure digital literacy among older adults in South Korea and to identify and evaluate how digital literacy was measured in the reviewed studies. Methods: The study followed Arksey and O'Malley's scoping review framework, searching through four international (PubMed, CINAHL, Embase, and Cochrane Library) and four Korean (RISS, KISS, KCI, and KMBase) databases. Results: Among 42 studies included in the final analysis, 38 were cross-sectional studies, and 21 employed primary data. Digital literacy was assessed in various scopes, including digital literacy, e-health literacy, Internet use, and smartphone use. Of the 25 identified measures, three were validated; the rest varied greatly, from using a few items from large surveys to employing investigator-developed measures. Based on the European Commission's Digital Competence Framework, the most commonly addressed components were "information and data literacy" and "communication and collaboration." Conclusions: In recent years, attention toward digital literacy among South Korean older adults has grown rapidly. However, the level of digital literacy among older adults in South Korea remains inconclusive given measurement heterogeneity. Developing and validating more robust measures are warranted to evaluate digital literacy among older adults with diverse functions and circumstances.

Pandemic-related posttraumatic psychological growth in U.S. military veterans: A 3-year, nationally representative, longitudinal study.

Little is known about the positive psychological changes or posttraumatic growth (PTG) in response to the pandemic as the COVID-19 vaccines has become widely available. This longitudinal study aimed to characterize changes in the prevalence of pandemic-related PTG, and to identify and quantify the relative importance of PTG correlates pre-pandemic, 1- year peri­pandemic, and 2-years post-pandemic onset. A total of 2,441 U.S. military veterans completed Wave 3 assessment of the National Health and Resilience in Veterans Study. In the full sample, a significant decrease from peri­pandemic to 2-years post-pandemic onset was observed in overall pandemic-related PTG (41.5% to 32.2%) and four domains of PTG (appreciation of life, relating to others, personal strength, spiritual changes). Among veterans who screened positive for pandemic-related posttraumatic stress symptoms, the prevalence of pandemic-related PTG was markedly higher and did not change from peri­pandemic to 2-years post-pandemic onset (78.4% to 73.4%). Greater pre-pandemic PTG (personal strength and new possibilities) and greater worries about the effect of pandemic on one's mental health were the strongest correlates of pandemic-related PTG 2-years post-pandemic onset. Results suggest that psychosocial interventions to bolster PTG in relation to early life traumas may help facilitate PTG in response to the pandemic and related crises.

Ferromagnetically coupled magnetic impurities in a quantum point contact.

We investigate the ground and excited states of interacting electrons in a quantum point contact using an exact diagonalization method. We find that strongly localized states in the point contact appear when a new transverse conductance channel opens and longitudinal resonant level is formed due to momentum mismatch. These localized states form magnetic impurity states which are stable in a finite regime of chemical potential and excitation energy. Interestingly, these magnetic impurities have ferromagnetic coupling, which sheds light on the experimentally observed puzzling coexistence of Kondo correlation and spin filtering in a quantum point contact.

Fast frequency discrimination and phoneme recognition using a biomimetic membrane coupled to a neural network.

In the human ear, the basilar membrane plays a central role in sound recognition. When excited by sound, this membrane responds with a frequency-dependent displacement pattern that is detected and identified by the auditory hair cells combined with the human neural system. Inspired by this structure, we designed and fabricated an artificial membrane that produces a spatial displacement pattern in response to an audible signal, which we used to train a convolutional neural network. When trained with single frequency tones, this system can unambiguously distinguish tones closely spaced in frequency. When instead trained to recognize spoken vowels, this system outperforms existing methods for phoneme recognition, including the discrete Fourier transform, zoom FFT and chirp z-transform, especially when tested in short time windows. This sound recognition scheme therefore promises significant benefits in fast and accurate sound identification compared to existing methods.

Effect of Au Nanoparticles and Scattering Layer in Dye-Sensitized Solar Cells Based on Freestanding TiO2 Nanotube Arrays.

The development of high efficiency dye-sensitized solar cells (DSSCs) has received tremendous attention. Many researchers have introduced new materials for use in DSSCs to achieve high efficiency. In this study, the change in power conversion efficiency (PCE) of DSSCs was investigated by introducing two types of materials-Au nanoparticles (Au NPs) and a scattering layer. A DSSC fabricated without neither Au NPs nor a scattering layer achieved a PCE of 5.85%. The PCE of a DSSC based on freestanding TiO2 nanotube arrays (f-TNTAs) with Au NPs was 6.50% due to better electron generation because the plasmonic absorption band of Au NPs is 530 nm, which matches the dye absorbance. Thus, more electrons were generated at 530 nm, which affected the PCE of the DSSC. The PCE of DSSCs based on f-TNTAs with a scattering layer was 6.61% due to better light harvesting by scattering. The scattering layer reflects all wavelengths of light that improve the light harvesting in the active layer in DSSCs. Finally, the PCE of DSSCs based on the f-TNTAs with Au NPs and a scattering layer was 7.12% due to the synergy of better electron generation and light harvesting by plasmonics and scattering. The application of Au NPs and a scattering layer is a promising research area for DSSCs as they can increase the electron generation and light harvesting ability.

The bZIP transcription factor OsABF1 is an ABA responsive element binding factor that enhances abiotic stress signaling in rice.

A number of basic leucine zipper (bZIP) transcription factors are known to function in stress signaling in plants but few have thus far been functionally characterized in rice. In our current study in rice, we have newly isolated and characterized the OsABF1 (Oryza sativa ABA responsive element binding factor 1) gene that encodes a bZIP transcription factor. Its expression in seedling shoots and roots was found to be induced by various abiotic stress treatments such as anoxia, salinity, drought, oxidative stress, cold and abscisic acid (ABA). Subcellular localization analysis in maize protoplasts using GFP fusion vectors indicated that OsABF1 is a nuclear protein. In a yeast experiment, OsABF1 was shown to bind to ABA responsive elements (ABREs) and its N-terminal region was necessary to transactivate the downstream reporter gene. The homozygous T-DNA insertional mutants Osabf1-1 and Osabf1-2 were more sensitive in response to drought and salinity treatments than wild type plants. Furthermore, the upregulated expression of some ABA/stress-regulated genes in response to ABA treatment was suppressed in these Osabf1 mutants. Our current results thus suggest that OsABF1 is involved in abiotic stress responses and ABA signaling in rice.

Au-Embedded and Carbon-Doped Freestanding TiO2 Nanotube Arrays in Dye-Sensitized Solar Cells for Better Energy Conversion Efficiency.

Dye-sensitized solar cells (DSSCs) are fabricated with freestanding TiO2 nanotube arrays (TNTAs) which are incorporated with Au nanoparticles (NPs) and carbon materials via electrodeposition and chemical vapor deposition (CVD) method to create a plasmonic effect and better electron transport that will enhance their energy conversion efficiency (ECE). The ECE of DSSCs based on the freestanding TNTAs is 5.87%. The ECE of DSSCs, based on the freestanding TNTAs with Au NPs or carbon materials, is 6.57% or 6.59%, respectively, and the final results of DSSCs according to the freestanding TNTAs with Au NPs and carbon materials is increased from 5.87% to 7.24%, which is an enhancement of 23.34% owing to plasmonic effect and better electron transport. Au NPs are incorporated into the channel of freestanding TNTAs and are characterized by CS-corrected-field emission transmission electron microscope (Cs-FE-TEM) and elemental mapping. Carbon materials are also well-incorporated in the channel of freestanding TNTAs and are analyzed by Raman spectroscopy.

Sonographic estimation of needle depth for cervical epidural blocks.

BACKGROUND: Cervical epidural steroid injections are often used to treat acute and chronic pain syndromes involving the face, neck, and upper extremities. Ultrasound has evolved as a valuable tool for performing neuraxial blocks, providing useful prepuncture information on the structure. Our goal was to evaluate the accuracy and precision of ultrasound by comparing skin to dura distance from ultrasound with the actual skin to epidural depth. METHODS: We enrolled 50 patients undergoing cervical epidural blocks at the pain clinic. Ultrasound images with transverse and longitudinal median views of the C6/7 area were taken. The epidural needle was inserted, reproducing the direction of the ultrasound beam on the longitudinal median view. Measured distances from skin to dura on each ultrasound view were compared with the actual needle depth. Additionally, we examined ultrasound visibility, the number of puncture attempts, and any complications related to the procedure. RESULTS: Concordance correlation coefficients between the measured distances on ultrasound and actual needle depth were 0.9272 and 0.9268 on transverse and longitudinal median view, respectively. The cervical epidural block was successfully performed on 48 patients (96%). There were two incidents (4%) of dural puncture. No bloody taps, postprocedure complications, or hemodynamic instability related to cervical epidural blocks occurred. CONCLUSIONS: Ultrasound provides very accurate information on the skin to dura distance for epidural blocks in the cervical spine. Knowledge of skin to dura distance and a preview of spinal anatomy before puncture can more safely identify the epidural space.

The effect of isoflurane, halothane and pentobarbital on noise-induced hearing loss in mice.

BACKGROUND: Ear surgery using mastoid drills can lead to noise-induced hearing loss (NIHL). We investigated whether inhaled anesthetics or pentobarbital could have protective effects on NIHL in mice. METHODS: Mice were exposed to broad band white noise for 3 h per day for 3 consecutive days, with or without anesthesia, using halothane, isoflurane, or pentobarbital. The hearing level of each mouse was analyzed before exposure, and 1 day, 1, 2, and 3 Wk, and 1 mo after noise exposure by measuring auditory brainstem response thresholds. At 1 Wk after noise exposure, the organ of Corti was stained with a fluorescent isothiocyanate-conjugated phalloidin probe and a TUNEL kit. RESULTS: In the unanesthetized control group, the hearing threshold increased to 77.5 +/- 8.0 dB hearing level (HL) after noise stimulation. In the pentobarbital, isoflurane, and halothane groups, hearing threshold increased to 62.5 +/- 6.3 dB HL, 45.5 +/- 9.8 dB HL, and 39.3 +/- 6.2 dB HL, respectively, with all anesthetized groups of mice showing significantly preserved hearing compared with the control group (P < 0.05). But, in mice anesthetized with pentobarbital, hearing loss was more severe than in those treated with the inhaled anesthetics (P < 0.05). Hair cell survival was reduced in unanesthetized control mice and somewhat reduced in pentobarbital-treated mice, but largely unaffected in mice treated with inhaled anesthetics. CONCLUSIONS: These findings indicate that, while halothane, isoflurane and pentobarbital could protect mice against NIHL and hair cell damage, inhaled anesthetics were more effective.