Creating and Transforming a Second-Rank Antisymmetric Field- Strength Tensor F αβ in Minkowski Space using MATHEMATICA

As the laws of physics are expressed in a manner that makes their invariance under coordinate transformations manifest, they should be written in terms of tensors. Furthermore, tensors make manifest the characteristics and behaviors of electromagnetic fields through inhomogeneous, anisotropic, and compressible media. Electromagnetic fields are expressed completely in tensor form, Fαβ, which implies both electric field E and magnetic field B rather than separately in the vector fields. This study presents the Mathematica platform that generates and transforms a second-rank antisymmetric field-strength tensor Fαβ and whiskbroom pattern in Minkowski space. The platforms enhance the capabilities of students and researchers in tensor analysis and improves comprehension of the elegant features of complete structure in physics

The long-term evaluation of the prognosis of implants with acid-etched surfaces sandblasted with alumina: a retrospective clinical study

Background The aim of this study was to evaluate the long-term clinical stability of implants with acid-etched surfaces sandblasted with alumina using retrospective analyses of the survival rate, success rate, primary and secondary stability, complications, and marginal bone loss of the implants. Methods Patients who had implants placed (TS III SA, SS II SA, SS III SA, and U III SA) with SA surfaces from Osstem (Osstem Implant Co., Busan, Korea) at the Seoul National University Bundang Hospital, from January 2008 to December 2010 were selected for the study. Patients medical records and radiographs (panorama, periapical view) were retrospectively analyzed to investigate sex, age, location of implantation, diameter, and length of the implants, initial and secondary stability, presence of bone grafting, types of bone grafting and membranes, early and delayed complications, marginal bone loss, and implant survival rate. Results Ninety-six implants were placed in 45 patients. Five implants were removed during the follow-up period for a total survival rate of 94.8%. There were 14 cases of complications, including 6 cases of early complications and 8 cases of delayed complications. All five implants that failed to survive were included in the early complications. The survival of implants was significantly associated with the occurrence of complications and the absorption of bone greater than 1 mm within 1 year after prosthetic completion. In addition, the absorption of bone greater than 1 mm within 1 year after prosthetic completion was significantly associated with the occurrence of complications, primary stability, and implant placement method. Five cases that failed to survive were all included in the early complications criteria such as infection, failure of initial osseointegration, and early exposure of the fixture. Conclusions Of the 96 cases, 5 implants failed resulting in a 94.8% survival rate. The failed implants were all cases of early complications such as infection, failure of initial osseointegration, and early exposure of the fixtures. Peri-implantitis was mostly addressed through conservative and/or surgical treatment and resulted in very low prosthetic complications. Therefore, if preventive measures are taken to minimize initial complications, the results can be very stable

Development of a clinical scoring system for appendicitis in children with presumed appendicitis

Purpose To develop a clinical scoring system for children with presumed appendicitis who visit the emergency department. Methods A registry based-retrospective study was conducted in the pediatric emergency department between September 2015 and December 2016. Patients aged 4 to 17 years who had a > 1 of 5 Likert scale for possibility of appendicitis were included. Multiple logistic regressions based on Akaike information criterion were performed using variables regarding clinical features and inflammatory markers to develop the clinical scoring system. Results A total of 233 patients were included, and 93 (39.9%) had the final diagnosis of appendicitis. The final model with the lowest Akaike information criterion (171.7) consisted of 5 variables, including vomiting (1 point), absence of watery diarrhea (1 point), duration of symptoms ≤ 3 days (1 point), rebound tenderness (1 point), and white blood cell count > 10.0 × 109/L (2 points). If the clinical score was ≥ 4 of 6 points, the area under the receiver operating characteristic curve was 0.78 (95% confidence interval, 0.71-0.86) with a 78.9% sensitivity, 66.7% specificity, positive and negative predictive values of 70.0% and 76.2%, respectively, and positive and negative likelihood ratios of 2.4 and 0.3, respectively. Conclusion The 5-item clinical scoring system shows a fair performance for prediction of pediatric appendicitis. This simple tool could be applied to predict the pediatric appendicitis, and to avoid the use of potentially unnecessary computed tomography

Long-term changes in computed tomography and ultrasound utilization in a pediatric emergency department

Objective Many studies have proposed reducing unnecessary use of computed tomography (CT), and ongoing studies in pediatric populations are aiming to decrease radiation dosages whenever possible. We aimed to evaluate the long-term changes in the utilization patterns of CT and ultrasound (US) in pediatric emergency departments (PEDs). Methods This retrospective study reviewed the electronic medical data of patients who underwent CT and/or US in the PED of a tertiary referral hospital from 2000 to 2014. We compared the changes in utilization patterns of brain and abdominal CT scans in pediatric patients and analyzed changes in abdominal US utilization in the PED. Results During the study period, 196,371 patients visited the PED. A total of 12,996 brain and abdominal CT scans and 12,424 abdominal US were performed in the PED. Comparison of CT use in pediatric patients before and after 2007 showed statistically decreasing trends after 2007, expressed as the coefficient values of the differences in groups. The numbers of brain and abdominal CT scans showed a significant decreasing trend in children, except for abdominal CT in adolescents. The abdominal US/CT ratio in the PED showed a statistically significant increase (2.68; 95% confidence interval, 1.87 to 3.49) except for the adolescent group (5.82; 95% confidence interval, -2.06 to 13.69). Conclusion Overall, CT use in pediatric patients has decreased since 2007. Pediatric US use has also shown a decreasing trend; however, the abdominal US/CT ratio in pediatric patients showed an increasing trend, except for adolescents

Extensive Systemic Sarcoidosis with Testicular Involvement Mimicking Metastatic Testicular Cancer

Sarcoidosis is an idiopathic, multisystem disease that rarely involves the genitourinary tract. Here we present an unusual case of testicular sarcoidosis with extensive lymphadenopathy that mimicked a metastatic testicular tumor. A 27-year-old male presented with a palpable right testicular mass accompanied by multiple palpable inguinal lymph nodes. The scrotal ultrasound showed a hypoechoic lesion at the inferior portion of the right testis. Extensive enlarged lymph nodes were noted in multiple areas on the abdominal computed tomography. Preoperative testicular tumor markers were within the normal range. Exploration of the right testis with a frozen section analysis of the right testicular mass and of a palpable right inguinal lymph node showed granulomatous inflammation. The testis was salvaged and the final pathological diagnosis was sarcoidosis. Treatment with high-dose corticosteroids resulted in complete resolution of the intratesticular mass and a significant decrease in the extent of the lymphadenopathy

Evaluation of the Efficacy and Cross-Protectivity of Recent Human and Swine Vaccines against the Pandemic (H1N1) 2009 Virus Infection

The current pandemic (H1N1) 2009 virus remains transmissible among humans worldwide with cases of reverse zoonosis, providing opportunities to produce more pathogenic variants which could pose greater human health concerns. To investigate whether recent seasonal human or swine H1N1 vaccines could induce cross-reactive immune responses against infection with the pandemic (H1N1) 2009 virus, mice, ferrets or mini-pigs were administered with various regimens (once or twice) and antigen content (1.77, 3.5 or 7.5 µg HA) of a-Brsibane/59/07, a-CAN01/04 or RgCA/04/09xPR8 vaccine. Receipt of a-CAN01/04 (2-doses) but not a-Brisbane/59/07 induced detectable but modest (20–40 units) cross-reactive serum antibody against CA/04/09 by hemagglutinin inhibition (HI) assays in mice. Only double administration (7.5 µg HA) of both vaccine in ferrets could elicit cross-reactivity (30–60 HI titers). Similar antigen content of a-CAN01/04 in mini-pigs also caused a modest ∼30 HI titers (twice vaccinated). However, vaccine-induced antibody titers could not suppress active virus replication in the lungs (mice) or virus shedding (ferrets and pigs) of immunized hosts intranasally challenged with CA/04/09. Furthermore, neither ferrets nor swine could abrogate aerosol transmission of the virus into naïve contact animals. Altogether, these results suggest that neither recent human nor animal H1N1 vaccine could provide complete protectivity in all animal models. Thus, this study warrants the need for strain-specific vaccines that could yield the optimal protection desired for humans and/or animals

Quality improvement activity for improving pain management in acute extremity injuries in the emergency department

Objective The aim of this study was to investigate the effectiveness of a quality improvement activity for pain management in patients with extremity injury in the emergency department (ED). Methods This was a retrospective interventional study. The patient group consisted of those at least 19 years of age who visited the ED and were diagnosed with International Classification of Diseases codes S40–S99 (extremity injuries). The quality improvement activity consisted of three measures: a survey regarding activities, education, and the triage nurse’s pain assessment, including change of pain documentation on electronic medical records. The intervention was conducted from January to April in 2014 and outcome was compared between May and August in 2013 and 2014. The primary outcome was the rate of analgesic prescription, and the secondary outcome was the time to analgesic prescription. Results A total of 1,739 patients were included, and 20.3% of 867 patients in the pre-intervention period, and 28.8% of 872 patients in the post-intervention period received analgesics (P< 0.001). The prescription rate of analgesics for moderate-to-severe injuries was 36.4% in 2013 and 44.5% in 2014 (P=0.026). The time to analgesics prescription was 116.6 minutes (standard deviation 225.6) in 2013 and 64 minutes (standard deviation 75.5) in 2014 for all extremity injuries. The pain scoring increased from 1.4% to 51.6%. Conclusion ED-based quality improvement activities including education and change of pain score documentation can improve the rate of analgesic prescription and time to prescription for patients with extremity injury in the ED

The Clinical Usefulness of the SD Bioline Influenza Antigen Test® for Detecting the 2009 Influenza A (H1N1) Virus

Though the 2009 worldwide influenza A (H1N1) pandemic has been declared to have ended, the influenza virus is expected to continue to circulate from some years as a seasonal influenza. A rapid antigen test (RAT) can aid in rapid diagnosis and allow for early antiviral treatment. We evaluated the clinical usefulness of RAT using SD Bioline Influenza Antigen Test® kit to detect the influenza virus, considering various factors. From August 1, 2009 to October 10, 2009, a total of 938 patients who visited the outpatient clinic at Korea University Guro Hospital with influenza-like illnesses were enrolled in the study. Throat or nasopharyngeal swab specimens were obtained from each of the patients. Using these specimens, we evaluated the influenza detection rate by rapid antigen test based on the real-time reverse-transcriptase polymerase chain reaction (rRT-PCR) method. In comparison with rRT-PCR, the sensitivity and specificity of the RAT were 44.0% and 99.9%, respectively. The cyclic threshold values of RAT negative specimens were higher than RAT positive specimens (30.1±3.1 vs. 28.3±3.9, p=0.031). The sensitivity of the RAT kit was higher in patients who visited clinics within two days of symptom onset (60.4% vs. 11.1%, p=0.026). The results of this study show that the RAT cannot be recommended for general use in all patients with influenza-like illness because of its low sensitivity. The RAT may be used, only in the settings with limited diagnostic resources, for patients who visit a clinic within two days of symptom onset

Epidemiologic features of pediatric genital injury in emergency departments in Korea

Purpose Genital injury is a common pediatric injury. Given the lack of nationwide data, the authors aimed to show age group-related epidemiologic features of genital injury in Korea. Methods We reviewed the data from 2011-2016 Emergency Department-based Injury In-depth Surveillance registry, which involves 23 emergency departments in Korea. From the dataset, we included children (< 18 years) with the International Classification of Diseases, 10th Revision codes related to genital injury as the final diagnosis with excluding those with other codes or combined injuries. Age groups were defined as follows; infants (< 1 year), toddlers (1-3), preschoolers (4-6), schoolers (7-12), and adolescents (13-17). The clinical features and outcomes were analyzed. Results A total of 3,030 children were included with the median age of 6 years (interquartile range, 4-10) and the proportion of girls of 53.0%. Only 144 children (4.8%) were transported by the emergency medical service providers. The most common mechanism and place were blunt injury (1,826 [60.3%]) and home (1,535 [50.7%]), respectively. Of the codes, “Contusion of external genital organs (S30.2)” was most common (1,574 [51.9%]). As for outcomes, 2,770 children (91.4%) were discharged, 252 (8.3%) were hospitalized (intensive care units, 1 child [0.03%]), and 108 (3.6%) underwent surgery. Severe injury occurred in 111 children (3.7%) without a mortality. With increasing age in the age groups, non-accidental injury, school and sports-related injuries, hospitalization, and surgery (All Ps < 0.001). Conclusion Genital injury may occur at evening, in spring and summer, at home, and in the form of accidental or blunt injury. Most children are discharged. Contrary to these general features, older children tend to undergo more frequently non-accidental injury, school and sports-related injuries, hospitalization, and surgery. Thus, we need age-specific strategies for injury prevention