Effects of noise on a model of oscillatory chemical reaction

A simple oscillating reaction model subject to additive Gaussian white noise is investigated as the model is located in the dynamic region of oscillations. The model is composed of three ordinary differential equations representing the time evolutions of X, Y, and Z, respectively. Initially, a uniform random noise is separately added to the three equations to study the effect of noise on the oscillatory cycle of X, Y, and Z. For a given value of noise intensity, the amplitude of oscillation increases monotonically with time. Furthermore, the noise is added to any one of the three equations to study the impact of noise on one species on the bifurcation behavior of the other

Isolated pulmonary cryptococcosis in an immunocompetent boy

Pulmonary cryptococcosis is rare in immunocompetent subjects. Here, we present the case of a 16-year-old boy who was referred to our pediatric department for the management of multiple consolidations detected on chest radiography, which was routinely performed when the patient was being evaluated for an ankle fracture. Fine needle aspiration biopsy was performed, and the definitive diagnosis was established as cryptococcal pneumonia. After 8 weeks of antifungal treatment, the pulmonary nodules on the chest radiographs disappeared

Catatonia associated with prolonged stupor after general anesthesia in a patient with multiple neuropsychiatric disorders -a case report-

Background Delayed emergence after general anesthesia may significantly affect a patient’s condition. We present the case of a patient who experienced prolonged delayed recovery of consciousness, language, and motor response due to catatonia after eight hours of total elbow arthroplasty under general anesthesia. Case A 68-year-old woman with neuropsychiatric disorders and Parkinson’s disease did not respond adequately during recovery after more than eight hours of general anesthesia. Following the operation, the patient was semi-comatose and appeared to have nonconvulsive status epilepticus upon awakening from anesthesia. However, subsequent examinations did not reveal any organic causes. The patient was subsequently diagnosed with catatonia, treated, and discharged following gradual improvement. Conclusions Although rare, patients taking psychiatric drugs for an extended period may experience delayed emergence after prolonged general anesthesia without identifiable causes. Catatonia should be considered in the differential diagnoses of these patients

Anesthetic management of an elderly COVID-19 patient with pulmonary thromboembolism for hip surgery - A case report -

Background COVID-19 and delayed hip surgery are well-known risk factors for thromboembolism in elderly patients. Case We report the case of an 88-year-old female patient with COVID-19 and pulmonary thromboembolism (PTE) who underwent delayed hip surgery 21 days after the injury. Heparinization and inferior vena cava filters were used to treat and prevent PTE. Transesophageal echocardiography and extracorporeal membrane oxygenation sheaths were inserted as a precaution in case of emergencies during surgery; the procedure was performed without any specific event. Conclusions COVID-19-infected patients suffering from a hip fracture have a high risk of thromboembolism, and therefore, require utmost attention for appropriate evaluation and prevention

Direct Synthesis of Molybdenum Phosphide Nanorods on Silicon Using Graphene at the Heterointerface for Efficient Photoelectrochemical Water Reduction

MoP nanorod-array catalysts were directly synthesized on graphene passivated silicon photocathodes without secondary phase. Mo-O-C covalent bondings and energy band bending at heterointerfaces facilitate the electron transfer to the reaction sites. Numerous catalytic sites and drastically enhanced anti-reflectance of MoP nanorods contribute to the high solar energy conversion efficiency. Abstract Transition metal phosphides (TMPs) and transition metal dichalcogenides (TMDs) have been widely investigated as photoelectrochemical (PEC) catalysts for hydrogen evolution reaction (HER). Using high-temperature processes to get crystallized compounds with large-area uniformity, it is still challenging to directly synthesize these catalysts on silicon photocathodes due to chemical incompatibility at the heterointerface. Here, a graphene interlayer is applied between p-Si and MoP nanorods to enable fully engineered interfaces without forming a metallic secondary compound that absorbs a parasitic light and provides an inefficient electron path for hydrogen evolution. Furthermore, the graphene facilitates the photogenerated electrons to rapidly transfer by creating Mo-O-C covalent bondings and energetically favorable band bending. With a bridging role of graphene, numerous active sites and anti-reflectance of MoP nanorods lead to significantly improved PEC-HER performance with a high photocurrent density of 21.8 mA cm−2 at 0 V versus RHE and high stability. Besides, low dependence on pH and temperature is observed with MoP nanorods incorporated photocathodes, which is desirable for practical use as a part of PEC cells. These results indicate that the direct synthesis of TMPs and TMDs enabled by graphene interlayer is a new promising way to fabricate Si-based photocathodes with high-quality interfaces and superior HER performance. Graphic Abstrac

Severe pulmonary edema occurred during endobronchial ultrasound under monitored anesthesia care - A case report -

Background Endobronchial ultrasound (EBUS) is widely used to diagnose lung cancer. Monitored anesthesia care (MAC) can enhance patient comfort and procedural conditions during EBUS. EBUS under MAC is usually safe but can lead to various complications. Case A 34-year-old male who had increased sputum for two months showed an enlarged paratracheal lymph node and planned for lymph node biopsy by EBUS. During EBUS under MAC, an unexpected oxygen saturation decline required intervention. After intubation, copious frothy fluid was suctioned from the bronchi, and oxygenation was recovered. A narrowed trachea and the EBUS bronchoscope might have resulted in upper airway obstruction, and suction performed under these conditions might have caused pulmonary edema. The patient received non-invasive ventilation and high-flow nasal cannula and recovered without complications. Conclusions When there is an expected risk of upper airway obstruction during EBUS, careful preoperative evaluation and preparation are essential to prevent negative pressure pulmonary edema

A contact investigation after exposure to a child with disseminated tuberculosis mimicking inflammatory bowel disease

Purpose Tuberculosis (TB) is one of the most important diseases that cause significant mortality and morbidity in young children. Data on TB transmission from an infected child are limited. Herein, we report a case of disseminated TB in a child and conducted a contact investigation among exposed individuals. Methods A 4-year-old child without Bacille Calmette-Guérin vaccination was diagnosed as having culture-proven disseminated TB. The child initially presented with symptoms of inflammatory bowel disease, and nosocomial and kindergarten exposures were reported. The exposed individuals to the index case were divided into 3 groups, namely household, nosocomial, or kindergarten contacts. Evaluation was performed following the Korean guidelines for TB. Kindergarten contacts were further divided into close or casual contacts. Chest radiography and tuberculin skin test or interferon-gamma-releasing assay were performed for the contacts. Results We examined 327 individuals (3 household, 10 nosocomial, and 314 kindergarten contacts), of whom 18 (5.5%), the brother of the index patient, and 17 kindergarten children were diagnosed as having latent TB infection (LTBI). LTBI diagnosis was more frequent in the children who had close kindergarten contact with the index case (17.1% vs. 4.4%, P=0.007). None of the cases had active TB. Conclusion This is the first reported case of TB transmission among young children from a pediatric patient with disseminated TB in Korea. TB should be emphasized as a possible cause of chronic diarrhea and failure to thrive in children. A national TB control policy has been actively applied to identify Korean children with LTBI

Neurotrophic interactions between neurons and astrocytes following AAV1-Rheb(S16H) transduction in the hippocampus in vivo

Background and Purpose: We recently reported that AAV1-Rheb(S16H) transduction could protect hippocampal neurons through the induction of brain-derived neurotrophic factor (BDNF) in the rat hippocampus in vivo. It is still unclear how neuronal BDNF produced by AAV1-Rheb(S16H) transduction induces neuroprotective effects in the hippocampus and whether its up-regulation contributes to the enhance of a neuroprotective system in the adult brain. Experimental Approach: To determine the presence of a neuroprotective system in the hippocampus of patients with Alzheimer's disease (AD), we examined the levels of glial fibrillary acidic protein, BDNF and ciliary neurotrophic factor (CNTF) and their receptors, tropomyocin receptor kinase B (TrkB) and CNTF receptor α(CNTFRα), in the hippocampus of AD patients. We also determined whether AAV1-Rheb(S16H) transduction stimulates astroglial activation and whether reactive astrocytes contribute to neuroprotection in models of hippocampal neurotoxicity in vivo and in vitro. Key Results: AD patients may have a potential neuroprotective system, demonstrated by increased levels of full-length TrkB and CNTFRα in the hippocampus. Further AAV1-Rheb(S16H) transduction induced sustained increases in the levels of full-length TrkB and CNTFRα in reactive astrocytes and hippocampal neurons. Moreover, neuronal BDNF produced by Rheb(S16H) transduction of hippocampal neurons induced reactive astrocytes, resulting in CNTF production through the activation of astrocytic TrkB and the up-regulation of neuronal BDNF and astrocytic CNTF which had synergistic effects on the survival of hippocampal neurons in vivo. Conclusions and Implications: The results demonstrated that Rheb(S16H) transduction of hippocampal neurons could strengthen the neuroprotective system and this intensified system may have a therapeutic value against neurodegeneration in the adult brain. © 2019 The Authors. British Journal of Pharmacology published by John Wiley & Sons Ltd on behalf of British Pharmacological Society1

Clinical features and outcomes of gastric variceal bleeding: retrospective Korean multicenter data

Background/AimsWhile gastric variceal bleeding (GVB) is not as prevalent as esophageal variceal bleeding, it is reportedly more serious, with high failure rates of the initial hemostasis (>30%), and has a worse prognosis than esophageal variceal bleeding. However, there is limited information regarding hemostasis and the prognosis for GVB. The aim of this study was to determine retrospectively the clinical outcomes of GVB in a multicenter study in Korea.MethodsThe data of 1,308 episodes of GVB (males:females=1062:246, age=55.0±11.0 years, mean±SD) were collected from 24 referral hospital centers in South Korea between March 2003 and December 2008. The rates of initial hemostasis failure, rebleeding, and mortality within 5 days and 6 weeks of the index bleed were evaluated.ResultsThe initial hemostasis failed in 6.1% of the patients, and this was associated with the Child-Pugh score [odds ratio (OR)=1.619; P<0.001] and the treatment modality: endoscopic variceal ligation, endoscopic variceal obturation, and balloon-occluded retrograde transvenous obliteration vs. endoscopic sclerotherapy, transjugular intrahepatic portosystemic shunt, and balloon tamponade (OR=0.221, P<0.001). Rebleeding developed in 11.5% of the patients, and was significantly associated with Child-Pugh score (OR=1.159, P<0.001) and treatment modality (OR=0.619, P=0.026). The GVB-associated mortality was 10.3%; mortality in these cases was associated with Child-Pugh score (OR=1.795, P<0.001) and the treatment modality for the initial hemostasis (OR=0.467, P=0.001).ConclusionsThe clinical outcome for GVB was better for the present cohort than in previous reports. Initial hemostasis failure, rebleeding, and mortality due to GVB were universally associated with the severity of liver cirrhosis