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Achieving an optimal balance between strength and ductility in advanced engineering materials has long been a challenge for researchers. In the field of material strengthening, most approaches that prevent or impede the motion of dislocations involve ductility reduction. In the present study, we propose a strengthening approach based on spinodal decomposition in which Cu and Al are introduced into a ferrous medium-entropy alloy. The matrix undergoes nanoscale periodic spinodal decomposition via a simple one-step aging procedure. Chemical fluctuations within periodic spinodal decomposed structures induce spinodal hardening, leading to a doubled strengthening effect that surpasses the conventional precipitation strengthening mechanism. Notably, the periodic spinodal decomposed structures effectively overcome strain localization issues, preserving elongation and doubling their mechanical strength. Spinodal decomposition offers high versatility because it can be implemented with minimal elemental addition, making it a promising candidate for enhancing the mechanical properties of various alloy systems.
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Point defects play a crucial role in determining the properties of atomically thin semiconductors. This work demonstrates the controlled formation of different types of defects and their comprehensive optical characterization using hyperspectral line imaging (HSLI). Distinct optical responses are observed in monolayer semiconductors grown under different stoichiometries using metal-organic chemical vapor deposition. HSLI enables the simultaneous measurement of 400 spectra, allowing for statistical analysis of optical signatures at close to a centimeter scale. The study discovers that chalcogen-rich samples exhibit remarkable optical uniformity due to reduced precursor accumulation compared to the metal-rich case. The utilization of HSLI as a facile and reliable characterization tool pushes the boundaries of potential applications for atomically thin semiconductors in future devices.
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Head and neck trauma-induced pulsatile tinnitus (PT) should be approached with caution, as it can rarely be attributed to an arteriovenous fistula (AVF). We present a 26-year-old male with a history of blunt trauma who presented delayed PT with direct AVF between the ascending pharyngeal artery (APA) and the internal jugular vein (IJV). The patient underwent occlusion of the fistula with transarterial embolization using coils and PT was completely resolved, confirming successful treatment. The delayed manifestation of PT in the APA-IJV fistula is probably due to the gradual formation of a pseudoaneurysm and subsequent AVF. This case highlights the importance of investigating PT in head trauma patients, as it can be a sign of AVF and possible complications. Overall, this case contributes to understanding delayed PT with AVF and emphasizes the importance of prompt diagnosis and treatment of AVF in patients with head and neck trauma.
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Nanosized precipitates play a critical role in increasing the strength of metallic alloys. There are many reports that the initial precipitates are metastable phases holding a different composition and crystal structure from the equilibrium precipitate. The metastable precipitate transforms to its stable phase during heat treatment. A transmission electron microscope enables researchers to study the phase transition of metastable precipitates to stable phases due to its fine resolution in identifying crystal structures and chemical compositions. This review introduces the various phase transformation mechanisms of metastable precipitates to stable phases obtained from the analysis using a transmission electron microscope. The role of dislocation movement in the phase transition is further discussed.
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Mesoscopic-scale stacking reconfigurations are investigated when van der Waals (vdW) films are stacked. A method to visualize complicated stacking structures and mechanical distortions simultaneously in stacked atom-thick films using Raman spectroscopy is developed. In the rigid limit, it is found that the distortions originate from the transfer process, which can be understood through thin film mechanics with a large elastic property mismatch. In contrast, with atomic corrugations, the in-plane strain fields are more closely correlated with the stacking configuration, highlighting the impact of atomic reconstructions on the mesoscopic scale. It is discovered that the grain boundaries do not have a significant effect while the cracks are causing inhomogeneous strain in stacked polycrystalline films. This result contributes to understanding the local variation of emerging properties from moiré structures and advancing the reliability of stacked vdW material fabrication.
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Objective: Anxiety and depression are psychiatric comorbidities potentially associated with dizziness and migraine, which can influence disease state, prognosis, and clinical outcomes. Vestibular migraine (VM) is a disease that causes repeated vestibular symptoms in people with a history of migraines. We investigated the prevalence and contributing factors of anxiety and depression in patients with VM. Methods: A total of 74 patients with VM were enrolled in this study. All patients underwent pure-tone audiometry, the examination of spontaneous nystagmus, Dix-Hallpike maneuver or supine-roll test, video head impulse test, and caloric testing on the day of the visit. We used the Hospital Anxiety and Depression Scale (HADS) to assess the symptoms of anxiety and depression. Dizziness Handicap Inventory was used to measure the intensity of vestibular symptoms. The participants were divided into normal and abnormal groups based on their HADS anxiety and depression scores, and demographic and clinical factors were analyzed. To identify factors associated with anxiety and depression, multivariate logistic regression analyses were performed. Results: A total of 36 (48.6%) patients demonstrated clinically relevant anxiety levels, and 24 (32.4%) demonstrated depression. Twenty-five (33.8%) patients were diagnosed with peripheral vestibular dysfunction. In the multivariable analyses, peripheral vestibular dysfunction and severe intensity vestibular symptoms were significantly associated with anxiety and depression. None of migraine features were significantly associated with anxiety and depression. Conclusion: The prevalence of anxiety in patients with VM is considerably higher than in the depression. VM patients with peripheral vestibular dysfunction are particularly susceptible to anxiety and depression. Therefore, timely screening for vestibular function and psychiatric disorders in VM patients should be considered.
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BACKGROUND: Acute appendicitis is the most common cause of non-obstetric surgical disease in pregnant women. The diagnosis and treatment of appendicitis during pregnancy are very important because it can cause life-threatening morbidity to the fetus and mother. We evaluated the clinical characteristics of acute appendicitis in pregnant women. METHODS: We retrospectively reviewed a medical database that included patients who underwent surgery for acute appendicitis at our hospital from January 2013 through December 2022. We compared non-pregnant women of reproductive age with pregnant women. We classified the pregnant women according to gestational age. RESULT: A total of 828 patients were reproductive-aged women between 15 and 44 years old. There were 759 non-pregnant patients and 69 pregnant patients. ASA (American Society of Anesthesiologists) physical status classes were significantly higher and hospital stays were significantly longer in the pregnant group. There was no significant intergroup difference in terms of the proportions of complicated appendicitis, extended surgery, or complications. When the enrolled pregnant women were divided into three subgroups according to gestational age, the mean operation time was longest in the third-trimester subgroup. There were no differences among the subgroups in terms of the proportions of complicated appendicitis, extended surgery, or complications, nor were there differences among the subgroups in terms of laboratory findings. Preterm labor and stillbirth occurred in two pregnant women with complicated appendicitis in the second trimester. CONCLUSION: Immediate surgical treatment should be strongly considered in pregnant women with appendicitis. Efforts for more accurate diagnosis are needed for pregnant women with appendicitis.
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Background and Objectives: Inguinal hernia is a common surgical disease. Traditional open herniorrhaphy has been replaced by laparoscopic herniorrhaphy. Nowadays, many attempts at robotic herniorrhaphy have been reported in western countries, but there have been no reports in South Korea. The purpose of this study is to report our initial experience with robotic inguinal hernia surgery, compared to laparoscopic inguinal hernia surgery. Materials and Methods: We analyzed the clinical data from 100 patients who received inguinal hernia surgery in our hospital from November 2020 to June 2022. Fifty patients underwent laparoscopic surgery, and 50 patients underwent robotic surgery using the da Vinci Xi system. All hernia surgeries were performed by a single surgeon using the transabdominal preperitoneal (TAPP) method. Results: The mean operation time and hospital stay were not statistically different. On the first postoperative day, the visual analog scale (VAS) pain score was significantly lower in the robotic surgery group (2.9 ± 0.5 versus 2.5 ± 0.7, p = 0.015). Cumulative sum analysis revealed an approximately 12-case learning curve for robotic-assisted TAPP hernia surgery. Conclusions: Robotic-assisted TAPP inguinal hernia surgery is technically acceptable to surgeons who have performed laparoscopic inguinal hernia surgery, and the learning curve is relatively short. It is thought to be a good step toward learning other robot-assisted operations.
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Hernia Inguinal , Laparoscopía , Robótica , Cirujanos , Humanos , Hernia Inguinal/cirugía , Laparoscopía/métodos , República de Corea , Resultado del TratamientoRESUMEN
An electron probe X-ray microanalyzer (EPMA) is an essential tool for studying chemical composition distribution in the microstructure. Quantifying chemical composition using standard specimens is commonly used to determine the composition of individual phases. However, the local difference in chemical composition in the standard specimens brings the deviation of the quantified composition from the actual one. This study introduces how to overcome the error of quantification in EPMA in the practical aspect. The obtained results are applied to evaluate the chemical composition of retained austenite in multi-phase steel. Film-type austenite shows higher carbon content than blocky-type one. The measured carbon contents of the retained austenite show good coherency with the calculated value from the X-ray diffraction.
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Chemical short-range order in disordered solid solutions often emerges with specific heat treatments. Unlike thermally activated ordering, mechanically derived short-range order (MSRO) in a multi-principal-element Fe40Mn40Cr10Co10 (at%) alloy originates from tensile deformation at 77 K, and its degree/extent can be tailored by adjusting the loading rates under quasistatic conditions. The mechanical response and multi-length-scale characterisation pointed to the minor contribution of MSRO formation to yield strength, mechanical twinning, and deformation-induced displacive transformation. Scanning and high-resolution transmission electron microscopy and the anlaysis of electron diffraction patterns revealed the microstructural features responsible for MSRO and the dependence of the ordering degree/extent on the applied strain rates. Here, we show that underpinned by molecular dynamics, MSRO in the alloys with low stacking-fault energies forms when loaded at 77 K, and these systems that offer different perspectives on the process of strain-induced ordering transition are driven by crystalline lattice defects (dislocations and stacking faults).
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Background and Objectives: Gallbladder (GB) stones, a major cause of symptomatic cholecystitis, are more likely to develop in post gastrectomy people. Our purpose is to evaluate characteristics of symptomatic cholecystitis after gastrectomy. Materials and Method: In January 2011−December 2021, total 1587 patients underwent operations for symptomatic cholecystitis at our hospital. We reviewed the patients' general characteristics, operation results, pathologic results, and postoperative complications. We classified the patients into non-gastrectomy and gastrectomy groups, further divided into subtotal gastrectomy and total gastrectomy groups. Result: The patients' ages, male proportion, and the open surgery rate were significantly higher (127/1543 (8.2%) vs. 17/44 (38.6%); p < 0.001), and the operation time was longer (102.51 ± 52.43 vs. 167.39 ± 82.95; p < 0.001) in the gastrectomy group. Extended surgery rates were significantly higher in the gastrectomy group (56/1543 (3.6%) vs. 12/44 (27.3%); p < 0.001). The period from gastrectomy to symptomatic cholecystitis was significantly shorter in the total gastrectomy group (12.72 ± 10.50 vs. 7.25 ± 4.80; p = 0.040). Conclusion: GB stones were more likely to develop in post-gastrectomy patients and extended surgery rates were higher. The period to cholecystitis was shorter in total gastrectomy. Efforts to prevent GB stones are considered in post-gastrectomy patients.
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Colecistectomía Laparoscópica , Colecistitis , Cálculos Biliares , Humanos , Masculino , Colecistitis/complicaciones , Colecistitis/cirugía , Gastrectomía/efectos adversos , Gastrectomía/métodos , Cálculos Biliares/cirugía , Cálculos Biliares/complicaciones , Colecistectomía/métodos , Colecistectomía Laparoscópica/métodos , Estudios RetrospectivosRESUMEN
This study investigated the antidiabetic outcomes after gastrectomy with long-limb RY reconstruction (LRYR) and the prognostic factors for remission after 1 year in patients with type 2 diabetes (T2DM) and gastric cancer. In 25 Koreans with T2DM and gastric cancer, plasma glucose and insulin levels were measured during a 75 g oral glucose tolerance test, before and 1 week after gastrectomy with LRYR. Patients were examined after 1 year and we defined glycemic control as "remission" when the HbA1c level after 1 year was <6.0% without medication. One year after surgery, 12 patients achieved HbA1c < 6.0% without medication. Among the preoperative indices, the duration of diabetes was shorter in the remission group than that in the non-remission group (median 2.0 [0-6.5] years vs 7.0 [4.5-10.0] years, P = .023). At 1 week after surgery, significant improvements in fasting, 30 minutes, 60 minutes, 90 minutes stimulated glucose levels and insulin resistance (HOMA-IR and Matsuda index) were found only in the remission group. The multivariable logistic regression analysis results showed that higher 30 minutes stimulated glucose level and HOMA-IR index at 1 week after surgery were independent factors for lower odds of 1-year diabetes remission. Shorter duration of diabetes and early postoperative improvements in 30 minutes stimulated glucose level and HOMA-IR were important determinants of long-term antidiabetic outcomes after gastrectomy with LRYR in patients with T2DM and gastric cancer.
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Diabetes Mellitus Tipo 2 , Neoplasias Gástricas , Diabetes Mellitus Tipo 2/complicaciones , Diabetes Mellitus Tipo 2/cirugía , Gastrectomía/métodos , Glucosa/uso terapéutico , Hemoglobina Glucada/análisis , Humanos , Hipoglucemiantes/uso terapéutico , Neoplasias Gástricas/tratamiento farmacológico , Neoplasias Gástricas/cirugíaRESUMEN
Background and Objectives: The COVID-19 pandemic has brought serious changes in healthcare systems worldwide, some of which have affected patients who need emergency surgery. Acute appendicitis is the most common surgical disease requiring emergency surgery. This study was performed to determine how the COVID-19 pandemic has changed the treatment of patients with acute appendicitis in South Korea. Materials and Methods: We retrospectively reviewed a medical database that included patients who underwent surgery for acute appendicitis in our hospital from January 2019 to May 2021. We classified the patients into two groups according to whether they were treated before or after the COVID pandemic and 10 March 2020 was used as the cutoff date, which is when the World Health Organization declared the COVID pandemic. Results: A total of 444 patients were included in the "Pre-COVID-19" group and 393 patients were included in the "COVID-19" group. In the "COVID-19" group, the proportion of patients with severe morbidity was significantly lower. The time that the patients spent in the emergency room before surgery was significantly longer in the "COVID-19" group (519.11 ± 486.57 min vs. 705.27 ± 512.59 min; p-value < 0.001). There was no difference observed in the severity of appendicitis or in the extent of surgery between the two groups. Conclusions: During the COVID-19 pandemic, a statistically significant time delay (186.16 min) was needed to confirm COVID-19 infection status. However, there was no clinical difference in the severity of appendicitis or in the extent of surgery. To ensure the safety of patients and medical staff, a COVID-19 PCR test should be performed.
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Apendicitis , COVID-19 , Enfermedad Aguda , Apendicectomía/efectos adversos , Apendicitis/epidemiología , Apendicitis/cirugía , Humanos , Pandemias , Estudios RetrospectivosRESUMEN
BACKGROUND: The method by which mental health screening result reports are given affects the user's health behavior. Lists with the distribution of scores in various mental health areas is difficult for users to understand, and if the results are negative, they may feel more embarrassed than necessary. Therefore, we propose using group-tailored feedback, grouping people of similar mental health types by cluster analysis for comprehensive explanations of multidimensional mental health. METHODS: This cross-sectional, observational study was conducted using a qualitative approach based on cluster analysis. Data were collected via a developed mental screening website, with depression, anxiety, sleep problems, perfectionism, procrastination, and attention assessed for 2 weeks in January 2020 in Korea. Participants were randomly recruited, and sample size was 174. Total was divided into 25 with severe depression/anxiety (SDA+) and 149 without severe depression/anxiety (SDA-) according to the PHQ-9 and GAD-7 criteria. Cluster analysis was conducted in each group, and an ANOVA was performed to find significant clusters. Thereafter, structured discussion was performed with mental health professionals to define the features of the clusters and construct the feedback content initially. Thirteen expert counselors were interviewed to reconstruct the content and validate the effectiveness of the developed feedback. RESULTS: SDA- was divided into 3 using the k-means algorithm, which showed the best performance (silhouette score = 0.32, CH score = 91.67) among the clustering methods. Perfectionism and procrastination were significant factors in discretizing the groups. SDA+ subgroups were integrated because only 25 people belonged to this group, and they need professional help rather than self-care. Mental status and treatment recommendations were determined for each group, and group names were assigned to represent their features. The developed feedback was assessed to improve mental health literacy (MHL) through integrative and understandable explanations of multidimensional mental health. Moreover, it appeared that a sense of belonging was induced to reduce reluctance to face the feedback. CONCLUSIONS: This study suggests group-tailored feedback using cluster analysis, which identifies groups of university students by integrating multidimensions of mental health. These methods can help students increase their interest in mental health and improve MHL to enable timely help.
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Salud Mental , Estudiantes , Análisis por Conglomerados , Estudios Transversales , Retroalimentación , Humanos , UniversidadesRESUMEN
OBJECTIVE: According to reported spawning characteristics of Japanese eel, Anguilla japonica, which exhibit spawning and migration patterns that are synchronized with lunar cycles and photoperiod, we hypothesized that a close association exists between specific photic signals (daylight, daylength, and moonlight) and endocrinological regulation. Given the photic control in melatonin secretion, this hypothesis was tested by investigating whether melatonin signals act as mediators relaying photic signals during testis development in the eel. METHODS: We examined changes in melatonin-secretion patterns using time-resolved fluorescence immunoassays in sexually immature and mature male Japanese eels under the condition of a new moon (NM) and a full moon (FM). RESULTS: The eye and plasma melatonin levels exhibited a nocturnal pattern under a 12-h light: dark cycle (12L12D) or under constant darkness (DD), but not with constant light (LL). Eye melatonin levels were similar under the 12L12D and short-day (9L15D) conditions. In the long-day condition (15L9D), secreted plasma melatonin levels were stable, whereas short-day melatonin secretion began when darkness commenced. Sexual maturation began at 8 weeks following intraperitoneal injection of human chorionic gonadotropin (hCG), and NM exposure led to significantly higher eye and plasma melatonin levels compared with those detected under FM exposure.
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As the physical properties of ABX3 perovskite-based oxides strongly depend on the geometry of oxygen octahedra containing transition-metal cations, precise identification of the distortion, tilt, and rotation of the octahedra is an essential step toward understanding the structure-property correlation. Here we discover an important electrostatic origin responsible for remarkable Jahn-Teller-type tetragonal distortion of oxygen octahedra during atomic-level direct observation of two-dimensional [AX] interleaved shear faults in five different perovskite-type materials, SrTiO3, BaCeO3, LaCoO3, LaNiO3, and CsPbBr3. When the [AX] sublayer has a net charge, for example [LaO]+ in LaCoO3 and LaNiO3, substantial tetragonal elongation of oxygen octahedra at the fault plane is observed and this screens the strong repulsion between the consecutive [LaO]+ layers. Moreover, our findings on the distortion induced by local charge are identified to be a general structural feature in lanthanide-based An + 1BnX3n + 1-type Ruddlesden-Popper (RP) oxides with charged [LnO]+ (Ln = La, Pr, Nd, Eu, and Gd) sublayers, among more than 80 RP oxides and halides with high symmetry. The present study thus demonstrates that the local uneven electrostatics is a crucial factor significantly affecting the crystal structure of complex oxides.
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The development of COVID-19 vaccines is critical in controlling global health issues under the COVID-19 pandemic. The subunit vaccines are the safest and most widely used vaccine platform and highly effective against a multitude of infectious diseases. An adjuvant is essential for subunit vaccines to enhance the magnitude and durability of immune responses. In this study, we determined whether a combination of toll-like receptor (TLR)1/2 and TLR3 agonists (L-pampo) can be a potent adjuvant for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) subunit vaccine. We measured a neutralizing antibody (nAb) and an angiotensin-converting enzyme 2 (ACE2) receptor-blocking antibody against SARS-CoV-2 receptor-binding domain (RBD). We also detected interferon-gamma (IFN-γ) production by using ELISPOT and ELISA assays. By employing a ferret model, we detected nAbs and IFN-γ producing cells and measured viral load in nasal wash after the challenge of SARS-CoV-2. We found that SARS-CoV-2 antigens with L-pampo stimulated robust humoral and cellular immune responses. The efficacy of L-pampo was higher than the other adjuvants. Furthermore, in the ferret model, SARS-CoV-2 antigens with L-pampo elicited nAb response and antigen-specific cellular immune response against SARS-CoV-2, resulting in substantially decreased viral load in their nasal wash. Our study suggests that SARS-CoV-2 antigens formulated with TLR agonists, L-pampo, can be a potent subunit vaccine to promote sufficient protective immunity against SARS-CoV-2.
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BACKGROUND: Perforated peptic ulcer (PPU) is a disease whose incidence is decreasing. However, PPU still requires emergency surgery. The aim of this study was to review the clinical characteristics of patients who received primary repair for PPU and identify the predisposing factors associated with severe complications. METHOD: From January 2011 to December 2020, a total of 75 patients underwent primary repair for PPU in our hospital. We reviewed the patients' data, including general characteristics and perioperative complications. Surgical complications were evaluated using the Clavien-Dindo Classification (CDC) system, with which we classified patients into the mild complication (CDC 0-III, n = 61) and severe complication (CDC IV-V, n = 14) groups. RESULT: Fifty patients had gastric perforation, and twenty-five patients had duodenal perforation. Among surgical complications, leakage or fistula were the most common (5/75, 6.7%), followed by wound problems (4/75, 5.3%). Of the medical complications, infection (9/75, 12%) and pulmonary disorder (7/75, 9.3%) were common. Eight patients died within thirty days after surgery (8/75, 10.7%). Liver cirrhosis was the most significant predisposing factor for severe complications (HR = 44.392, p = 0.003). CONCLUSION: PPU is still a surgically important disease that has significant mortality, above 10%. Liver cirrhosis is the most important underlying disease associated with severe complications.
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Although numerous studies on oxide catalysts for an efficient oxygen evolution reaction have been carried out to compare their catalytic performance and suggest new compositions, two significant constraints have been overlooked. One is the difference in electronic conduction behavior between catalysts (metallic versus insulating) and the other is the strong crystallographic surface orientation dependence of the catalysis in a crystal. Consequently, unless a comprehensive comparison of the oxygen-evolution catalytic activity between samples is made on a crystallographically identical surface with sufficient electron conduction, misleading interpretations on the catalytic performance and mechanism may be unavoidable. To overcome these limitations, we utilize both metallic (001) LaNiO3 epitaxial thin films together with metal dopants and semiconducting (001) LaCoO3 epitaxial thin films supported with a conductive interlayer. We identify that Fe, Cr, and Al are beneficial to enhance the catalysis in LaNiO3 although their perovskite counterparts, LaFeO3, LaCrO3, and LaAlO3, with a large bandgap are inactive. Furthermore, semiconducting LaCoO3 is found to have more than one order higher activity than metallic LaNiO3, in contrast to previous reports. Showing the importance of facilitating electron conduction, our work highlights the impact of the near-Fermi-level d-orbital states on the oxygen-evolution catalysis performance in perovskite oxides.
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Outbreaks of infectious disease in shrimp pose a serious threat to shrimp agriculture worldwide. Shrimp lack adaptive immunity and depend only on innate immunity as a defense system against infectious disease. Toll-like receptors (TLR) are reported to play a critical role in the innate immune system. In this study, we identified a Toll-like receptor gene of a species of freshwater shrimp, Macrobrachium nipponense, designated MnToll, for the first time. The sequence of MnToll encoded 935 residues arranged as 10 leucine-rich repeat (LRR) domains, a leucine-rich repeat C-terminal (LRR CT) domain and a Toll/interleukin-1 receptor (TIR) domain and displayed 90% amino acid similarity to previously identified TLRs (Toll 1 and 2) of Macrobrachium rosenbergii. We additionally evaluated mRNA expression of MnToll in various tissues, including heart, gills, stomach, digestive gland, ventral nerve cord, antennal gland and muscle. Following infection with a viral pathogen, white spot syndrome virus (WSSV), MnToll expression was significantly upregulated between 12 and 72 h. Our data collectively suggest that the newly identified MnToll gene belongs to the TLR family in shrimp and is potentially involved in innate host defense, especially against WSSV.