305 research outputs found
Percolation properties of growing networks under an Achlioptas process
We study the percolation transition in growing networks under an Achlioptas
process (AP). At each time step, a node is added in the network and, with the
probability , a link is formed between two nodes chosen by an AP. We
find that there occurs the percolation transition with varying and the
critical point is determined from the power-law behavior
of order parameter and the crossing of the fourth-order cumulant at the
critical point, also confirmed by the movement of the peak positions of the
second largest cluster size to the . Using the finite-size scaling
analysis, we get and , which
implies and . The Fisher exponent
for the cluster size distribution is obtained and shown to
satisfy the hyperscaling relation.Comment: 4 pages, 5 figures, 1 table, journal submitte
Biomechanics Differ for Individuals With Similar Self-Reported Characteristics of Patellofemoral Pain During a High-Demand Multiplanar Movement Task
Context: Patellofemoral pain (PFP) is often categorized by researchers and clinicians using subjective self-reported PFP characteristics; however, this practice might mask important differences in movement biomechanics between PFP patients. Objective: To determine whether biomechanical differences exist during a high-demand multiplanar movement task for PFP patients with similar self-reported PFP characteristics but different quadriceps activation levels. Design: Cross-sectional design. Setting: Biomechanics laboratory. Participants: A total of 15 quadriceps deficient and 15 quadriceps functional (QF) PFP patients with similar self-reported PFP characteristics. Intervention: In total, 5 trials of a high-demand multiplanar land, cut, and jump movement task were performed. Main Outcome Measures: Biomechanics were compared at each percentile of the ground contact phase of the movement task (alpha =.05) between the quadriceps deficient and QF groups. Biomechanical variables included (1) whole-body center of mass, trunk, hip, knee, and ankle kinematics; (2) hip, knee, and ankle kinetics; and (3) ground reaction forces. Results: The QF patients exhibited increased ground reaction force, joint torque, and movement, relative to the quadriceps deficient patients. The QF patients exhibited: (1) up to 90, 60, and 35Nmore vertical, posterior, and medial ground reaction force at various times of the ground contact phase; (2) up to 4 degrees more knee flexion during ground contact and up to 4 degrees more plantarflexion and hip extension during the latter parts of ground contact; and (3) up to 26, 21, and 48 N.m more plantarflexion, knee extension, and hip extension torque, respectively, at various times of ground contact. Conclusions: PFP patients with similar self-reported PFP characteristics exhibit different movement biomechanics, and these differences depend upon quadriceps activation levels. These differences are important because movement biomechanics affect injury risk and athletic performance. In addition, these biomechanical differences indicate that different therapeutic interventions may be needed for PFP patients with similar self-reported PFP characteristics
The role of infectious disease consultations in the management of patients with fever in a long-term care facility.
BackgroundInfectious disease (ID) clinicians can provide essential services for febrile patients in tertiary hospitals. The aim of this study was to evaluate the role of ID consultations (IDC) in managing hospitalized patients with infections in an oriental medical hospital (OMH), which serves as a long-term care facility. To our knowledge, this is the first study on the role of IDCs in managing patients in an OMH.MethodsThis retrospective study was conducted in an OMH in Seoul, Korea, from June 2006 to June 2013.ResultsAmong the 465 cases of hospital-acquired fever, 141 (30.3%) were referred for ID. The most common cause of fever was infection in both groups. The peak body temperature of the patient was higher in IDC group (38.8±0.6°C vs. 38.6±0.5°C, pConclusionInfection was the most common cause of fever in patients hospitalized for OMH. Infection as the focus of fever, underlying cancer, and MODS was associated with increased 30-day mortality in patients with nosocomial fever. Appropriate antibiotic therapy was associated with decreased infection-attributable mortality in patients with infectious fever
Unusual Primary Peritonitis due to Streptococcus pyogenes in a Young Healthy Woman
We describe the first case of primary peritonitis in Korea of a healthy person due to Streptococcus pyogenes. In the absence of comorbid conditions, such as liver cirrhosis, immunosuppression, or nephrotic syndrome, primary peritonitis is uncommon in a young healthy woman. Abdomen computed tomography revealed ascites in the lower abdomen and peritoneal enhancement suggesting peritonitis. In diagnostic laparoscopy, purulent ascites was found in the pelvic cavity but both ovaries and fallopian tubes were intact. There were no intra-abdominal abnormalities such as bowel perforation, appendicitis, or necrosis. The reports of blood culture, ascites culture, and cervical swab culture confirmed S. pyogenes. After use of antibiotics, the patient was cured and discharged without sequelae
Metastatic Gastric Adenocarcinoma Presenting as a Solitary Plaque on the Palm
Cutaneous metastases from gastric adenocarcinoma are extremely rare. When present, metastasis typically signifies disseminated disease with a poor prognosis. We report a case of an 80-year-old male with gastric cancer who presented with a single, erythematous plaque on the left palm, a very rare site for skin metastasis. Results of a skin biopsy demonstrated that the cutaneous metastasis originated from the stomach. This report emphasized the need for appropriate investigation into newly appearing, unusual, or persistent skin lesions
Thyroid Transcription Factor-1 Facilitates Cerebrospinal Fluid Formation by Regulating Aquaporin-1 Synthesis in the Brain
In the brain, aquaporin-1 (AQP-1), a water channel for high osmotic water permeability, is mainly expressed in the apical membrane of the ventricular choroid plexus and regulates formation of cerebrospinal fluid (CSF). Although the physiology of AQP-1 has been the subject of several publications, much less is known about the trans-acting factors involved in the control of AQP-1 gene expression. Here we report that TTF-1, a homeodomain-containing transcriptional regulator, is coexpressed with AQP-1 in the rat brain choroid plexus and enhances AQP-1 gene transcription by binding to conserved core TTF-1-binding motifs in the 5'-flanking region of the AQP-1 gene. Intracerebroventricular administration of an antisense TTF-1 oligodeoxynucleotide significantly decreased AQP-1 synthesis and reduced CSF formation. In addition, blockade of TTF-1 synthesis increased survival of the animals following acute water intoxication-induced brain edema. These results suggest that TTF-1 is physiologically involved in the transcriptional control of AQP-1, which is required for CSF formation
Fatal Necrotizing Fasciitis Due to Streptococcus pneumoniae: A Case Report
Necrotizing fasciitis is known to be a highly lethal infection of deep-seated subcutaneous tissue and superficial fascia. Reports of necrotizing fasciitis due to Streptococcus pneumoniae are exceedingly rare. We report a case of necrotizing fasciitis in a 62-yr-old man with liver cirrhosis and diabetes mellitus. He presented with painful swelling of left leg and right hand. On the day of admission, compartment syndrome was aggravated and the patient underwent surgical exploration. Intra-operative findings revealed necrotizing fasciitis and cultures of two blood samples and wound aspirates showed S. pneumoniae. The patient died despite debridement and proper antimicrobial treatment. To the best of our knowledge, this is the first case of fatal necrotizing fasciitis with meningitis reported in Korea. We also review and discuss the literature on pneumococcal necrotizing fasciitis
Hepatocellular carcinoma incidence is decreasing in Korea but increasing in the very elderly
Background/Aims A comprehensive analysis of trends in the incidence of hepatocellular carcinoma (HCC) is important for planning public health initiatives. We aimed to analyze the trends in HCC incidence in South Korea over 10 years and to predict the incidence for the year 2028. Methods Data from patients with newly diagnosed HCC between 2008 and 2018 were obtained from Korean National Health Insurance Service database. Age-standardized incidence rates (ASRs) were calculated to compare HCC incidence. A poisson regression model was used to predict the future incidence of HCC. Results The average crude incidence rate (CR) was 22.4 per 100,000 person-years, and the average ASR was 17.6 per 100,000 person-years between 2008 and 2018. The CR (from 23.9 to 21.2 per 100,000 person-years) and ASR (from 21.9 to 14.3 per 100,000 person-years) of HCC incidence decreased during the past ten years in all age groups, except in the elderly. The ASR of patients aged ≥80 years increased significantly (from 70.0 to 160.2/100,000 person-years; average annual percent change, +9.00%; P<0.001). The estimated CR (17.9 per 100,000 person-years) and ASR (9.7 per 100,000 person-years) of HCC incidence in 2028 was declined, but the number of HCC patients aged ≥80 years in 2028 will be quadruple greater than the number of HCC patients in 2008 (from 521 to 2,055), comprising 21.3% of all HCC patients in 2028. Conclusions The ASRs of HCC in Korea have gradually declined over the past 10 years, but the number, CR, and ASR are increasing in patients aged ≥80 years
Upregulation of P21-Activated Kinase 1 (PAK1)/CREB Axis in Squamous Non-Small Cell Lung Carcinoma
Background/Aims: p21-activated Ser/Thr kinase 1 (PAK1) is essential for the genesis and development of many cancers. The purpose of this study was to investigate the role of the PAK1–cyclic AMP response element-binding (CREB) axis in non-small cell lung cancer (NSCLC) tumorigenesis and its related mechanisms. Methods: Western blot assay and immunohistochemical staining were employed to investigate the PAK1 and CREB expression in the tissue microarray of human squamous NSCLC. Co-immunoprecipitation and immunofluorescence confocal assays were performed to determine the link between PAK1 and CREB. NSCLC xenograft models were used to study oncogenic function of PAK1 in vivo. Results: We observed that PAK1 and CREB expression levels were significantly elevated in human squamous NSCLC-tissue specimens, compared with those in adjacent normal bronchial or bronchiolar epithelial-tissue specimens, as well as their phosphorylated forms, based on western blotting. We showed in vitro that PAK1 knockdown by small-interfering RNA (siRNA) blocked CREB phosphorylation, whereas plasmid-based PAK1 overexpression resulted in CREB phosphorylation at Ser133, based on western blotting. In addition, PAK1 interacted with CREB in co-immunoprecipitation assays. Additionally, our in vitro findings detected by flow cytometry revealed that PAK1 silencing attenuated cell cycle progression, inducing apoptosis. Inhibition of PAK1 expression reduced tumor sizes and masses by modulating CREB expression and activation in xenograft models. Conclusion: These results suggest a novel mechanism whereby the PAK1–CREB axis drives carcinogenesis of squamous-cell carcinomas, and have important implications in the development of targeted therapeutics for squamous-cell lung cancer
Differential spatial expression of peripheral olfactory neuron-derived BACE1 induces olfactory impairment by region-specific accumulation of beta-amyloid oligomer
Olfactory dysfunction is a common symptom associated with neurodegenerative diseases including Alzheimer's disease (AD). Although evidence exists to suggest that peripheral olfactory organs are involved in the olfactory dysfunction that accompanies AD pathology, the underlying mechanisms are not fully understood. As confirmed using behavioral tests, transgenic mice overexpressing a Swedish mutant form of human amyloid precursor proteins exhibited olfactory impairments prior to evidence of cognitive impairment. By measuring the expression of tyrosine hydroxylase, we observed that specific regions of the olfactory bulb (OB) in Tg2576 mice, specifically the ventral portion exhibited significant decreases in the number of dopaminergic neurons in the periglomerular regions from the early stage of AD. To confirm the direct linkage between these olfactory impairments and AD-related pathology, beta-site amyloid precursor protein cleaving enzyme 1 (BACE1)-the initiating enzyme in A beta genesis-and beta-amyloid peptide (A beta), hallmarks of AD were analyzed. We found that an increase in BACE1 expression coincided with an elevation of amyloid-beta (A beta) oligomers in the ventral region of OB. Moreover, olfactory epithelium (OE), in particular the ectoturbinate in which axons of olfactory sensory neurons (OSNs) have direct connections with the dendrites of mitral/tufted cells in the ventral part of OB, exhibited significant decreases in both thickness and cell number even at early stages. This result suggests that A beta oligomer toxicity in the OE may have induced a decline in the number of OSNs and functional impairment of the olfactory system. We first demonstrated that disproportionate levels of regional damage in the peripheral olfactory system may be a specific symptom of AD with A beta oligomer accumulation occurring prior to damage within the CNS. This regional damage in the olfactory system early in the progression of AD may be closely related to AD-related pathological abnormality and olfactory dysfunction found in AD patients.1
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