Clinical analysis of pediatric patients who visited Masan Samsung Emergency Center

Purpose : Through a clinical and retrospective analysis of pediatric patients who visited the Regional Emergency Medical Center of Masan Samsung Hospital from January 2007 to December 2008, we characterized pediatric and adolescent emergency patients to improve emergency care in future. Methods : We reviewed the medical records of 14,065 pediatric patients below 19 years of age. Results : The male to female ratio was 1.5:1, and the most common age group was less than 3 years (49.6%). The peak month was May (10.0%), the peak day of the week was Sunday (24.7%), and the peak time of day was 20:00&amp&#59;#8211&#59;20:59 (8.5%). There was no difference in the number of visits per day based on weather (sunny, rain [below 10 mm per day], snow, and fog) or daily temperature difference&#59; however, visits increased on sandy, dusty days and decreased on rainy days with more than 10 mm of rain per day. Based on the international classification of disease (ICD)-10 system, the most common disease code was code R (symptoms, sign, and abnormal clinical laboratory finding) (31.5%), and the most common symptom was fever (13.1%). Final outcomes were discharged (73.8%), admitted (25.7%), transferred (0.4%), and expired (0.1%). In adolescent patients aged 15&amp&#59;#8211&#59;19 years, the most common disease code was Injury &amp&#59; Poisoning (code S&amp&#59;T, 36.9%)&#59; the most common symptom was abdominal pain (9.6%). Conclusion : Pediatric patients visiting the emergency center were most likely to be male and under 3 years of age and to visit between 20:00 and 21:00 on Sundays and in May, and the most common symptom was fever. Differences between adolescents and pediatric patients showed that adolescents had a higher visiting rate with abdominal pain and a larger temperature difference

Comparison of very-large-scale motions of turbulent pipe and boundary layer simulations

A direct numerical simulation of a fully developed turbulent pipe flow was performed to investigate the similarities and differences of very-large-scale motions (VLSMs) to those of turbulent boundary layer (TBL) flows. The Reynolds number was set to ReD = 35 000, and the computational domain was 30 pipe radii in length. Inspection of instantaneous fields, streamwise two-point correlations, and population trends of the momentum regions showed that the streamwise length of the structures in the pipe flow grew continuously beyond the log layer (y/?? 3??), and the maximum length of the VLSMs increased up to ~30??. Such differences between the TBL and pipe flows arose due to the entrainment of large plumes of the intermittent potential flow in the TBL, creating break-down of the streamwise coherence of the structures above the log layer with the strong swirling strength and Reynolds shear stress. The average streamwise length scale of the pipe flow was approximately 1.5-3.0 times larger than that of the TBL through the log and wake regions. The maximum contribution of the structures to the Reynolds shear stress was observed at approximately 6?? in length, whereas that of the TBL was at 1??-2??, indicating a higher contribution of the VLSMs to the Reynolds shear stress in the pipe flow than in the TBL flow.open1

Studies of Converting Metal-Organic Frameworks for New Structures and Properties

Department of ChemistryMetal-organic frameworks (MOFs) are crystalline and porous solid materials formed by an extended network of metal ions (or clusters) coordinated to multidentate organic molecules. Therefore, with metal-ligand coordinative bonds stronger than hydrogen bonds, these materials have large internal surface areas, ultralow densities, and uniformly structured pores and channels. Also, the combination of their unique properties enables MOFs to have numerous promising applications, including hydrogen storage, methane storage, catalysis, sensing, and biomedical imaging. This new class of porous materials started to gain increasing interest in the 1990s, and now MOF chemistry is developing at an extraordinary pace with an explosion of papers in the chemical literature. In the line of MOF researches, it has been known that MOF structures have inherent transformability, and their dynamic properties are not only scientifically interesting but also practically applicable in various forms such as advanced nono-composite materials and stimuli-responsive smart materials. In this sense, I demonstrated the utilization of MOFs as precursors, transforming into various functional nanomaterials with a special emphasis on understanding the relationship between the intrinsic nature of the parent MOFs and the daughter nanomaterials. For example, in section 2.2, I synthesized nanoporous manganese oxides via the thermal conversion of an Mn-based MOF by introducing another aliphatic ligand. Furthermore, we could control the oxidation states of the manganese oxides (i.e., MnO, Mn3O4, Mn5O8, and Mn2O3) by optimizing the sequential conversion reactions during annealing in N2 and calcination with atmospheric oxygen. Importantly, the resultant MnO, Mn3O4, and Mn5O8 exhibited almost identical textural properties including their morphology, surface areas, pore volumes, and the size of nanocrystals composing the nanoporous frameworks. Meanwhile, a Si-centered tetracarboxylic acid ligand that was capable of charge-balancing four Li+ ions was demonstrated. This newly designed MOF containing Li and Si was converted into Li-based ceramic, Li4SiO4 with an unusual morphology. In addition to these two approaches, the targeted sulfur elements can be directly incorporated into organic ligands to construct a MOF to be used as a single precursor for the preparation of nanostructured metal sulfide catalysts. Also, I exploited the pyrolysis of bimetallic MOFs with adipate introduced as an aliphatic ligand to prepare nanoporous structures consisting of nanocrystalline frameworks of transition-metal???ceria solid solutions. Another trendy topic in the MOF field is imparting flexibility to MOF frameworks and revealing their structural dynamics so that external stimuli such as guest exchange, temperature, pressure, oxidation, and light can elicit structural rearrangement to alter the physicochemical properties of MOFs. Based on this background, I have prepared two flexible MOF crystals, a Luminescent Li-based MOF and a doubly interpenetrated Zn4O-based MOF, which are capable of transforming their structures dynamically in a single-crystal to single-crystal manner upon the introduction of various nitroaromatic compounds including explosives or different kinds of solvents. Those results have allowed us to understand structural dynamism more deeply.clos

Scale growth of structures in the turbulent boundary layer with a rod-roughened wall

Direct numerical simulation of a turbulent boundary layer over a rod-roughened wall is performed with a long streamwise domain to examine the streamwise-scale growth mechanism of streamwise velocity fluctuating structures in the presence of two-dimensional (2-D) surface roughness. An instantaneous analysis shows that there is a slightly larger population of long structures with a small helix angle (spanwise inclinations relative to streamwise) and a large spanwise width over the rough-wall compared to that over a smooth-wall. Further inspection of time-evolving instantaneous fields clearly exhibits that adjacent long structures combine to form a longer structure through a spanwise merging process over the rough-wall; moreover, spanwise merging for streamwise scale growth is expected to occur frequently over the rough-wall due to the large spanwise scales generated by the 2-D roughness. Finally, we examine the influence of a large width and a small helix angle of the structures over the rough-wall with regard to spatial two-point correlation. The results show that these factors can increase the streamwise coherence of the structures in a statistical sense.open

Mesenteric extraskeletal osteosarcoma with telangiectatic features: a case report

<p>Abstract</p> <p>Background</p> <p>Extraskeletal osteosarcoma is a rare malignant mesenchymal tumor, with a predominant occurrence in the extremities. Only two cases of mesenteric extraskeletal osteosarcoma have been documented. We describe an unusual case of extraskeletal osteosarcoma with telangiectatic features occurring in the mesentery.</p> <p>Case presentation</p> <p>A 67-year-old male presented with blood-tinged stool of 1-month's duration. On colonoscopy, a solid mass was detected protruding from the colon wall. Computed tomography showed a 15 × 9.7 cm heterogeneously enhancing mass, with mottled calcification and a cystic portion, occupying the left upper quadrant of the abdominal cavity. Curative resection of the tumor was performed, and the excised tumor was composed of large multilocular cysts containing old hematomas and necrotic debris. The histology revealed an osteosarcoma showing osteoid formation and blood-filled spaces lined with atypical cells. Despite postoperative chemotherapy, he developed a recurrent peritoneal mass and multiple lung metastases 3 months postoperatively.</p> <p>Conclusion</p> <p>Given the rarity of cases of mesenteric extraskeletal osteosarcoma, its biologic behavior at this location remains to be determined. However, extraskeletal osteosarcoma with telangiectatic features is an uncommon entity to be recognized because of the possible fatal outcome related to the tumors.</p

Interpreting positive signs of the supraspinatus test in screening for torn rotator cuff.

The purpose of this study was to investigate the validity of the supraspinatus test as a screening test for detecting torn rotator cuff and to determine what its valuable positive signs were. Both the empty-can test and full-can test were performed on 200 shoulders diagnosed by magnetic resonance imaging (MRI)-and in some cases, surgical findings-to have full-thickness or partial-thickness torn rotator cuff s, or no tear in the rotator cuff . During the maneuver, the presence of pain or weakness or both pain and weakness were recorded as positive signs, and the distribution of these signs were analyzed according to the degree of tear. The predictive values were calculated in 2 ways by considering (1) only full-thickness tears as tears and (2) both full- and partial-thickness tears as tears. The 2 tests and the 2 ways of considering partial-thickness tears were compared. Pain and weakness were severity-dependent, and the empty-can test had a higher incidence of pain. The sensitivities of the 2 supraspinatus tests in all positive signs were higher when including partial-thickness tears in the tear group ; however, their specificities were higher when excluding partial-thickness tears. Both pain and weakness were interpretive for the supraspinatus test, and both tests were sensitive to full- and partial- thickness tears and specific for full-thickness tears

The Role of Echocardiography in Evaluating Cardiovascular Diseases in Patients with Diabetes Mellitus

Patients with diabetes mellitus are highly susceptible to cardiovascular complications, which are directly correlated with cardiovascular morbidity and mortality. In addition to coronary artery disease, there is growing awareness of the risk and prevalence of heart failure (HF) in patients with diabetes. Echocardiography is an essential diagnostic modality commonly performed in patients with symptoms suggestive of cardiovascular diseases (CVD), such as dyspnea or chest pain, to establish or rule out the cause of symptoms. Conventional echocardiographic parameters, such as left ventricular ejection fraction, are helpful not only for diagnosing CVD but also for determining severity, treatment strategy, prognosis, and response to treatment. Echocardiographic myocardial strain, a novel echocardiographic technique, enables the detection of early changes in ventricular dysfunction before HF symptoms develop. This article aims to review the role of echocardiography in evaluating CVD in patients with diabetes mellitus and how to use it in patients with suspected cardiac diseases