Optimizing Ship Speed to Minimize Total Fuel Consumption with Multiple Time Windows

We study the ship speed optimization problem with the objective of minimizing the total fuel consumption. We consider multiple time windows for each port call as constraints and formulate the problem as a nonlinear mixed integer program. We derive intrinsic properties of the problem and develop an exact algorithm based on the properties. Computational experiments show that the suggested algorithm is very efficient in finding an optimal solution

Toxicity Studies on Secretio Bufonis: A Traditional Supplement in Asia

AbstractObjectivesThis study was performed to investigate the toxicity of Secretio Bufonis (SB) on male mice and assess its no-observed-adverse-effect-level (NOAEL).Materials and MethodsAfter feeding an aqueous solution of SB extracts to mice for either 1 or 8 weeks, their blood and urine were assayed and their liver and kidney morphology examined. The numerical data was analyzed by the Mann-Whitney U-test and analysis of variance test.ResultsMice administered SB in 50 mg/kg/day for 1 week had higher heart weights and higher aspartate transaminase activities; those administered SB in 0.01 and 0.05 mg/kg/day for 8 weeks had lower creatinine concentrations; and those administered SB in 0.5 mg/kg/day for 8 weeks had higher brain weights and higher blood urea nitrogen.ConclusionsThe extracts of SB had cardiac toxicity in the short term and hepatotoxicity in the long term. The NOAEL of the extract was under 5 mg/kg/day for 1 week and under 0.25 mg/kg/day for 8 weeks

A Toxicological Study of HangAmDan-B in Mice

AbstractThe aim of the study was to define the toxicity of HangAmDan-B (HAD-B) in mice over the short and long term. HAD-B was studied in 1-week single and 5-week repeated oral dose toxicity tests on male Imprinting Control Region mice. Doses used in 1 week single oral dose toxicity tests were 0, 0.2, 1, 5, and 25 g/kg/day and those of repeated toxicity test were 0, 0.04, 0.2, 1, and 2 g/kg/day. Blood and urine samples were assayed and their morphology observed. Numerical data were compared using Mann-Whitney U test and analysis of variance. Significantly decreased red blood cell levels in mice from S2-HAD-B, S3-HAD-B, S4-HAD-B, and S5-HAD-B groups were observed in single oral dose toxicity tests. Hemoglobin, hematocrit, and mean cell hemoglobin values in mice from the S4-HAD-B and S5-HAD-B groups were also significantly decreased. No mortalities or significant differences in all factors were observed during the dosing period of the repeated dose toxicity test. Administering 2 g/kg/day of HAD-B in mice over a 5-week period showed no significant hematological changes. However, risk of anemia with more than 5 g/kg/ day administration of HAD-B was found. In general, HAD-B appears to be safe and nontoxic, and a no observed adverse effect level in mice was established at 2 g/kg/ day. This data serves as satisfactory preclinical evidence for the safety of HAD-B should a future clinical trial for HAD-B be launched. Further studies are required to confirm these safety results and to carry out a safety trial in humans

Initial adhesion of bone marrow stromal cells to various bone graft substitutes

Purpose: The aim of this study is to determine whether certain biomaterials have the potential to support cell attachment. After seeding bone marrow stromal cells onto the biomaterials, we investigated their responses to each material in vitro. Methods: Rat bone marrow derived stromal cells were used. The biomaterials were deproteinized bovine bone mineral (DBBM), DBBM coated with fibronectin (FN), synthetic hydroxyapatite (HA), HA coated with FN, HA coated with beta-tricalcium phosphate (TCP), and pure beta-TCP. With confocal laser scanning microscopy, actin filaments and vinculin were observed after 6, 12, and 24 hours of cell seeding. The morphological features of cells on each biomaterial were observed using scanning electron microscopy at day 1 and 7. Results: The cells on HA/FN and HA spread widely and showed better defined actin cytoskeletons than those on the other biomaterials. At the initial phase, FN seemed to have a favorable effect on cell adhesion. In DBBM, very few cells adhered to the surface. Conclusions: Within the limitations of this study, we can conclude that in contrast with DBBM not supporting cell attachment, HA provided a more favorable environment with respect to cell attachment. (C) 2011 Korean Academy of Periodontology.This work was supported by a National Research Foundation of Korea Grant funded by the Government of the Republic of Korea (2008-E00580)

Damage to the cuff of EMG tube at endotracheal intubation by using a lightwand -A case report-

Electromyogpraphic endotracheal tube (EMG tube) is a new device used to monitor recurrent laryngeal nerve integrity during thyroid surgery. The EMG tube has 2 pairs of electrodes on the surface of silicon-based tube reached to inner space of tube cuff. We experienced an unusual endotracheal tube-related problem from the distinct structural feature of the EMG tube. In this case, we intubated a patient who had difficult airway with the EMG tube using a lightwand. After successful endotracheal intubation, we could not expand the pilot balloon and ventilate the patient effectively. We removed the EMG tube and found that one of electrodes of the EMG tube is bended and made a right angle with the long axis of the tube, and perforated the tube cuff. So we report this case to make anesthesia providers aware that much more attention is needed to use EMG tube during endotracheal intubation

Regional Anticoagulation with Citrate is Superior to Systemic Anticoagulation with Heparin in Critically Ill Patients Undergoing Continuous Venovenous Hemodiafiltration

Background/Aims: Short hemofilter survival and anticoagulation-related life-threatening complications are major problems in systemic anticoagulation with heparin (SAH) for continuous renal replacement therapy (CRRT). The present study examined if regional anticoagulation with citrate (RAC) using commercially available solutions can overcome the associated problems of SAH to produce economical benefits. Methods: Forty-six patients were assigned to receive SAH or RAC. We assessed the coagulation state, clinical outcomes, and adverse events. A Kaplan-Meier analysis was used to estimate hemofilter life span. The economical benefit related to the prolonged hemofilter survival was examined on the basis of the average daily cost. Results: The mean age of patients was 66.5 ± 13.8 years and the majority were male (60.9%). While elective discontinuation was most common cause of early CRRT interruption in the RAC group (34.3%, p < 0.01), hemofilter clotting was most prevalent in the SAH group (82.2%, p < 0.01). The patient metabolic and electrolyte control and survival rate were not different between the two groups. When compared with the RAC group, the anticoagulation-associated bleeding was a major complication in the SAH group (15.0% vs. 61.5%, p < 0.01). Regional anticoagulated hemofilters displayed a significantly longer survival time than systemic anticoagulated hemofilters (59.5 ± 3.8 hr vs. 15.6 ± 1.3 hr, p < 0.01). Accordingly, the mean daily continuous venovenous hemodiafiltration costs in the RAC and SAH groups were 575 ± 268 and 1,209 ± 517, respectively (p < 0.01). Conclusions: RAC prolonged hemofilter survival, displaying an economical benefit without severe adverse effects. The present study therefore demonstrates that RAC, using commercially available solutions, may be advantageous over SAH as a cost-effective treatment in CRRT. (Korean J Intern Med 2011;26:68-75

A Survey of Diabetic Educators and Patients for the Revision of Korean Food Exchange Lists

BackgroundFood exchange lists are one of the main methods of nutritional education. However, Korean food exchange lists have not been revised since 1994. Therefore, we surveyed the opinions of diabetes educators and patients with diabetes regarding the need for revision of the current food exchange lists.MethodsFor two weeks beginning on 10 March 2008, a 12-item questionnaire regarding the opinion and need for revision of the current food exchange lists was e-mailed to diabetes educators nationwide. Another 15-question survey was administered to patients with diabetes in 13 hospitals located in the Seoul and Gyeonggi regions of Korea.ResultsWe obtained survey responses from 101 diabetes educators and 209 patients; 65 (64.3%) of the educators answered that the current food exchange lists should be revised. The items that needed revision were the glycemic index, addition of new foods and reaffirmation of exchange standard amounts. The patients demanded specific education about choosing appropriate foods, a balanced meal plan, proper snacks, and dining intake.ConclusionOur survey results demonstrate the need to revise the Korean food exchange lists. This process should focus on glycemic index, the addition of new foods and reconfirmation of one exchange reference unit

Emergence and Wide Dissemination of CTX-M-type ESBLs, and CMY-2- and DHA-1-type AmpC β-Lactamases in Korean Respiratory Isolates of Klebsiella pneumoniae

Respiratory isolates of Klebsiella pneumoniae in Korea during 2002-2003 were studied to determine the prevalence and types of extended-spectrum β-lactamases (ESBLs) and plasmid-mediated AmpC β-lactamases (PABLs). ESBL-production was tested by double-disk synergy, and genotypes of β-lactamases were determined by PCR and sequencing. ESBLs were detected in 28.4% of 373 isolates, and the most prevalent types were SHV-12 (63 isolates) and CTX-M-14 (9 isolates). Forty of 75 ESBL-producers (53.5%) also had PABLs: 21 isolates with CMY-2-like, 17 with DHA-1-like. Pulsed-field gel electrophoresis showed 19 types and 25 of 74 isolates had an identical pattern, indicating nosocomial spread. Dissemination of ESBL- and PABL-producing K. pneumoniae strains in Korea is a particular concern, as it limits the choice of antimicrobial agents for treatment of infections