31 research outputs found
A Dynamic Resource Manager with Effective Resource Isolation Based on Workload Types in Virtualized Cloud Computing Environments
To use computing resources for processing parallel algorithms on demand, cloud computing has been widely used since it is able to scale in response to load increases and decreases. Typically, cloud computing providers offer virtual machines to cloud users with static configurations, and these configurations are not changed until virtual machines are shutting down. To accelerate parallel processing computations in cloud computing environments, we design and implement a dynamic resource manager by isolating resources based on workload types. To avoid unnecessary context switching and increase CPUs affinity, our dynamic resource manager determines whether vCPU to physical CPU core pinning is required. If so, the VM’s vCPUs are pinned by our dynamic resource manager, which can guarantee the resource and performance isolation. With our proposed resource manager for virtual machines, we can achieve a performance boost and load balancing at the same time. Performance results show that our proposed method outperforms the default scheduler of Xen about 36.2% by reducing the number of context switching for VMs
Edge-functionalized graphene-like platelets as a co-curing agent and a nanoscale additive to epoxy resin
A newly developed method for the edge-selective functionalization of "pristine" graphite with 4-aminobenzoic acid was applied for the synthesis of 4-aminobenzoyl-functionalized graphite (AB-graphite) through a "direct" Friedel-Crafts acylation in a polyphosphoric acid (PPA)/phosphorus pentoxide medium (P(2)O(5)). The AB moiety at the edge of the AB-graphite played the role of a molecular wedge to exfoliate the AB-graphite into individual graphene and graphene-like platelets upon dispersion in polar solvents. These were used as a co-curing agent and a nanoscale additive to epoxy resin. The physical properties of the resulting epoxy/AB-graphite composites were improved because of the efficient load transfer between the additive and epoxy matrix through covalent links.close191
Small Bowel Metastatic Cancer Observed With Double Balloon Enteroscopy in a Patient With a Past History of Multiple Cancers
Small bowel tumors are very rare and generally malignant. As a result of the anatomical location and nonspecific manifestations of small bowel tumors, they are very difficult to diagnose. Balloon-assisted enteroscopy is a relatively noninvasive method compared to surgical resection, and allows for real-time observation, tissue confirmation with biopsy, and interventional procedures. Here, we report the case of a 69-year-old woman with a small bowel metastatic carcinoma observed with double balloon enteroscopy (DBE). She had a history of multiple cancers including ovarian cancer, bladder cancer, and breast cancer. The antegrade DBE procedure was performed before surgery for biopsy tissue confirmation. The patient underwent small bowel resection, and the final diagnosis was the same as that determined by preoperative biopsy. The final diagnosis was metastatic small bowel cancer originating from a cancer of the breast. This is the first detailed report of the preoperative diagnosis of small intestinal metastatic breast cancer by DBE
Active pulmonary tuberculosis and latent tuberculosis infection among homeless people in Seoul, South Korea: a cross-sectional study
Background : The aim of this study was to determine the prevalence rate of latent TB infection (LTBI) and active TB among homeless in Seoul metropolitan city, South Korea, and to compare the TB burden among homeless people with that of a control group.
Methods : The homeless participants were recruited from five sites between October 30, 2009 and April 12, 2010. LTBI was diagnosed through the QuantiFERON(R) TB Gold In-Tube(QFT-GIT) assay and a tuberculin skin test(TST) and, and active PTB was diagnosed based on chest radiography. Results : Among 313 participants, the prevalence of LTBI was 75.9% (95% CI, 71.1-80.8%) and 79.8% (95% CI, 74.9-84.7%) based on a QFT-GIT assay and the TST, respectively, and that of active PTB was 5.8% (95% CI, 3.2-8.3%). The prevalence of LTBI among homeless participants was about five times higher than controls. Also, the age-specific prevalence rate ratio of active PTB was as high as 24.86. Conclusions : The prevalence rate of LTBI as well as active PTB among homeless people was much higher than that of the general population in South Korea. Thus, adequate strategies to reduce the TB burden among homeless people are needed.Peer Reviewe
Independent effect of body mass index variation on amyloid-β positivity
ObjectivesThe relationship of body mass index (BMI) changes and variability with amyloid-β (Aβ) deposition remained unclear, although there were growing evidence that BMI is associated with the risk of developing cognitive impairment or AD dementia. To determine whether BMI changes and BMI variability affected Aβ positivity, we investigated the association of BMI changes and BMI variability with Aβ positivity, as assessed by PET in a non-demented population.MethodsWe retrospectively recruited 1,035 non-demented participants ≥50 years of age who underwent Aβ PET and had at least three BMI measurements in the memory clinic at Samsung Medical Center. To investigate the association between BMI change and variability with Aβ deposition, we performed multivariable logistic regression. Further distinctive underlying features of BMI subgroups were examined by employing a cluster analysis model.ResultsDecreased (odds ratio [OR] = 1.68, 95% confidence interval [CI] 1.16–2.42) or increased BMI (OR = 1.60, 95% CI 1.11–2.32) was associated with a greater risk of Aβ positivity after controlling for age, sex, APOE e4 genotype, years of education, hypertension, diabetes, baseline BMI, and BMI variability. A greater BMI variability (OR = 1.73, 95% CI 1.07–2.80) was associated with a greater risk of Aβ positivity after controlling for age, sex, APOE e4 genotype, years of education, hypertension, diabetes, baseline BMI, and BMI change. We also identified BMI subgroups showing a greater risk of Aβ positivity.ConclusionOur findings suggest that participants with BMI change, especially those with greater BMI variability, are more vulnerable to Aβ deposition regardless of baseline BMI. Furthermore, our results may contribute to the design of strategies to prevent Aβ deposition with respect to weight control
Active pulmonary tuberculosis and latent tuberculosis infection among homeless people in Seoul, South Korea: a cross-sectional study
BACKGROUND: The aim of this study was to determine the prevalence rate of latent TB infection (LTBI) and active TB among homeless in Seoul metropolitan city, South Korea, and to compare the TB burden among homeless people with that of a control group. METHODS: The homeless participants were recruited from five sites between October 30, 2009 and April 12, 2010. LTBI was diagnosed through the QuantiFERON(R) TB Gold In-Tube(QFT-GIT) assay and a tuberculin skin test(TST) and, and active PTB was diagnosed based on chest radiography. RESULTS: Among 313 participants, the prevalence of LTBI was 75.9% (95% CI, 71.1-80.8%) and 79.8% (95% CI, 74.9-84.7%) based on a QFT-GIT assay and the TST, respectively, and that of active PTB was 5.8% (95% CI, 3.2-8.3%). The prevalence of LTBI among homeless participants was about five times higher than controls. Also, the age-specific prevalence rate ratio of active PTB was as high as 24.86. CONCLUSIONS: The prevalence rate of LTBI as well as active PTB among homeless people was much higher than that of the general population in South Korea. Thus, adequate strategies to reduce the TB burden among homeless people are needed
The Efficacy of Utilizing Platelet-Rich Fibrin for Managing Periodontal Intrabony Defects in Conjunction with Graft Material: A Systematic Review and Meta-Analysis
Platelet-rich fibrin has become increasingly popular in recent years due to its remarkable capacity to accelerate the post-surgery wound healing process, reduce inflammation, and promote tissue repair. This study aimed to perform a meta-analysis to evaluate the effect of platelet-rich fibrin in mixture form with bone substitute, as a membrane, or in combination. A comprehensive search using a combination of controlled vocabulary (MeSH) and free-text terms was undertaken by two reviewers to identify published randomized clinical trials. Three major electronic databases (Medline via PubMed, Cochrane database, and Embase) and the clinical trials registry (clinicaltrials.gov) were searched up to 9 July 2023. The results of the meta-analysis showed that the pooled standardized mean difference of probing depth for platelet-rich fibrin was 0.61 (95% CI, 0.33 to 0.88). The results of the meta-analysis showed that the mean difference in clinical attachment level for platelet-rich fibrin was 0.68 (95% CI, 0.35 to 1.01). The results of the meta-analysis showed that the mean difference in bone fill for platelet-rich fibrin was 0.50 (95% CI, 0.23 to 0.78). In conclusion, the study found that platelet-rich fibrin was effective as adjunct to periodontal regeneration
Evaluation of the Differences in the Stability of Alveolar Bone around Dental Implant and Implant Failure between Platform Matching and Platform Switching: A Systematic Review and Meta-Analysis
Background: This research was designed to carry out a meta-analysis in order to evaluate the dissimilarities in the stability of alveolar bone round dental implants and implant failure between platform switching (PS) and platform mating (PM). Methods: The investigation utilized a comprehensive search strategy that incorporated controlled vocabulary (MeSH) and free-text terms. This search was performed by two reviewers to identify published systematic reviews. Three major electronic databases, including Medline via PubMed, the Cochrane database, and Embase, were searched up to November 2023. Results: Initially, 466 articles were identified, but only twelve studies met the criteria for inclusion in the meta-analysis. The results showed that the pooled mean difference for reducing marginal bone loss (MBL) was −0.60 (95% confidence interval (CI), −0.91 to −0.28; p p p < 0.01), and it revealed that there were significant differences between subgroups. However, the meta-analysis on implant failure did not show a significant difference between PS and PM implants. Conclusions: In conclusion, the study found that PS implants are more effective in reducing MBL compared to PM implants. Nevertheless, no significant difference was observed in the long-term effectiveness of reducing MBL and implant failure rate
Anti-Helicobacter pylori activity of crude N-acetylneuraminic acid isolated from glycomacropeptide of whey
Helicobacter pylori colonizes the gastric mucosa of about half of the world’s population, causing chronic gastritis and gastric cancer. An increasing emergence of antibiotic-resistant H. pylori arouses demand on alternative non-antibiotic-based therapies. In this study, we freshly prepared crude N-acetylneuraminic acid obtained from glycomacropeptide (G-NANA) of whey through a neuraminidase-mediated reaction and evaluated its antibacterial ability against H. pylori and H. felis. Overnight cultures of the H. pylori were diluted with fresh media and different concentrations (1-150 mg/mL) of crude G-NANA were added directly to the culture tube. Bacterial growth was evaluated by measuring the optical density of the culture medium and the number of viable bacteria was determined by a direct count of the colony forming units (CFU) on agar plates. For the in vivo study, mice were orally infected with 100 µL (5×108 cfu/mL) of H. felis four times at a day’s interval, accompanied by a daily administration of crude G-NANA or vehicle. A day after the last infection, the mice were daily administered the crude G-NANA (0, 75, and 300 mg/mL) for 10 days and euthanized. Their stomachs were collected and bacterial colonization was determined by quantitative real-time PCR. Crude G-NANA inhibited H. pylori’s growth and reduced the number of viable bacteria in a dose-dependent manner. Furthermore, crude G-NANA inhibited bacterial colonization in the mice. These results showed that crude G-NANA has antibacterial activity against Helicobacter and demonstrated its therapeutic potential for the prevention of chronic gastritis and gastric carcinogenesis induced by Helicobacter infection in humans.2