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Objective To examine the features of powered mobility device-related injuries and identify the predictors of injury severity in such settings. Methods Emergency Department-based Injury In-depth Surveillance data from 2011 to 2018 were used in this retrospective study. Participants were assigned to the mild/moderate and severe groups based on their excess mortality ratio–adjusted injury severity score and their general injury-related factors and injury outcome-related factors were compared. Results Of 407 patients, 298 (79.2%) were assigned to the mild/moderate group and 109 (26.8%) to the severe group. The severe group included a higher percentage of patients aged 70 years or older (43.0% vs. 59.6%, P=0.003), injuries incurred in the daytime (72.6% vs. 82.4%, P=0.044), injuries from traffic accidents and falls (P=0.042), head injuries (38.6% vs. 80.7%, P

Background: Recent reports have revealed better clinical outcomes for extracorporeal cardiopulmonary resuscitation (ECPR) than conventional cardiopulmonary resuscitation (CPR). In this retrospective study, we attempted to identify predictors associated with successful weaning off extracorporeal membrane oxygenation (ECMO) support after ECPR. Methods: The demographic and clinical data of 30 ECPR patients aged over 18 years treated between August 2016 and January 2019 were analyzed. All clinical data were retrospectively collected. The primary endpoint was successful weaning from ECMO support after ECPR. Patients were divided into two groups based on successful or unsuccessful weaning off ECMO support (Weaned (n=14) vs. Failed (n=16)). Results: Univariate logistic regression analysis showed that age, CPR duration, ECMO complications, and loss of pulse pressure significantly predicted the results of weaning off ECMO support. However, multivariate logistic regression analysis showed that only CPR duration and loss of pulse pressure independently predicted unsuccessful weaning from ECMO support. Conclusion: We conclude that long CPR duration and loss of pulse pressure after ECPR predict unsuccessful weaning from ECMO. However, unlike CPR duration, loss of pulse pressure during post-ECPR was related to subsequent management. In patients with reduced pulse pressure after ECPR, careful management is warranted because this reduction is closely associated with unsuccessful weaning off ECMO support after ECPR.

Objective No studies have evaluated the diagnostic value of ischemia-modified albumin (IMA) for the early detection of sepsis/septic shock in patients presenting to the emergency department (ED). We aimed to assess the usefulness of IMA in diagnosing sepsis/septic shock in the ED. Methods This retrospective, observational study analyzed IMA, lactate, high sensitivity C-reactive protein, and procalcitonin levels measured within 1 hour of ED arrival. Patients with suspected infection meeting at least two systemic inflammatory response syndrome criteria were included and classified into the infection, sepsis, and septic shock groups using Sepsis-3 definitions. Areas under the receiver operating characteristic curves (AUCs) with 95% confidence intervals (CIs) and multivariate logistic regression were used to determine diagnostic performance. Results This study included 300 adult patients. The AUC (95% CI) of IMA levels (cut-off ≥85.5 U/mL vs. ≥87.5 U/mL) was higher for the diagnosis of sepsis than for that of septic shock (0.729 [0.667-0.791] vs. 0.681 [0.613-0.824]) and was higher than the AUC of procalcitonin levels (cut-off ≥1.58 ng/mL, 0.678 [0.613-0.742]) for the diagnosis of sepsis. When IMA and lactate levels were combined, the AUCs were 0.815 (0.762-0.867) and 0.806 (0.754-0.858) for the diagnosis of sepsis and septic shock, respectively. IMA levels independently predicted sepsis (odds ratio, 1.05; 95% CI, 1.00-1.09; P=0.029) and septic shock (odds ratio, 1.07; 95% CI, 1.02-1.11; P=0.002). Conclusion Our findings indicate that IMA levels are a useful biomarker for diagnosing sepsis/septic shock early, and their combination with lactate levels can enhance the predictive power for early diagnosis of sepsis/septic shock in the ED.

Objective:A disaster in the hospital is particularly serious and quite different from other ordinary disasters. This study aimed at analyzing the activity outcomes of a disaster medical assistance team (DMAT) for a fire disaster at the hospital.Methods:The data which was documented by a DMAT and emergent medical technicians of a fire department contained information about the patient’s characteristics, medical records, triage results, and the hospital which the patient was transferred from. Patients were categorized into four groups according to results of field triage using the simple triage and rapid treatment method.Results:DMAT arrived on the scene in 37 minutes. One hundred and thirty eight (138) patients were evacuated from the disaster scene. There were 25 patients (18.1%) in the Red group, 96 patients (69.6%) in the Yellow group, and 1 patient (0.7%) in the Green group. One patient died. There were 16 (11.6%) medical staff and hospital employees. The injury of the caregiver or the medical staff was more severe compared to the family protector.Conclusions:For an effective disaster-response system in hospital disasters, it is important to secure the safety of medical staff, to utilize available medical resources, to secure patients’ medical records, and to reorganize the DMAT dispatch system.

Purpose: The present study will identify risk factors for aspiration in severe trauma patients by comparing patients who showed a sign of aspiration lung disease on chest computed tomography (CT) and those who did not. Methods: We conducted a retrospective review of the Korean Trauma Data Bank between January 2014 and December 2019 in a single regional trauma center. The inclusion criteria were patients aged ≥18 years with chest CT, and who had an Injury Severity Score ≥16. Patients with Abbreviated Injury Scale (AIS)-chest score ≥1 and lack of medical records were excluded. General characteristics and patient status were analyzed. Results: 425 patients were included in the final analysis. There were 48 patients showing aspiration on CT (11.2%) and 377 patients showing no aspiration (88.7%). Aspiration group showed more endotracheal intubation in the ER (p=0.000) and a significantly higher proportion of severe Glasgow Coma Scale (GCS) (p=0.000) patients than the non-aspiration group. In AIS as well, the median AIS head score was higher in the aspiration group (p=0.046). Median oxygen saturation was significantly lower in the aspiration group (p=0.002). In a logistic regression analysis, relative to the GCS mild group, the moderate group showed an odds ratio (OR) for aspiration of 2.976 (CI, 1.024-8.647), and the severe group showed an OR of 5.073 (CI, 2.442-10.539). Conclusions: Poor mental state and head injury increase the risk of aspiration. To confirm for aspiration, it would be useful to perform chest CT for severe trauma patients with a head injury.

PURPOSE: Coronavirus disease 2019 (COVID-19) is caused by a novel strain of coronavirus named severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that has quickly spread around the globe. Health care facilities in the United States currently do not have an adequate supply of COVID-19 tests to meet the growing demand. Imaging findings for COVID-19 are nonspecific but include pulmonary parenchymal ground-glass opacities in a predominantly basal and peripheral distribution.METHODS: Three patients imaged for non-respiratory related symptoms with a portion of the lungs in the imaged field.RESULTS: Each patient had suspicious imaging findings for COVID-19, prompting the interpreting radiologist to suggest testing for COVID-19. All 3 patients turned out to be infected with COVID-19 and one patient is the first reported case of the coincident presentation of COVID-19 and an intraparenchymal hemorrhage.CONCLUSION: Using imaging characteristics of COVID-19 on abdominal or neck CT when a portion of the lungs is included, patients not initially suspected of COVID-19 infection can be quarantined earlier to limit exposure to others.

By virtue of their semiconducting and electrolytic characteristics, hybrid organic–inorganic perovskites have received intense research attention in various applications, which include energy, electronics, and display technologies. While research studies on the semiconducting or electronic properties of perovskite materials in solar cells and light-emitting diodes have been actively investigated, studies on their electrolytic or ionic behavior have rarely been conducted. To probe the electrolyte properties of the metal halide perovskite, we have fabricated solution-processed zinc oxide (ZnO) thin-film transistors using a methylammonium lead iodide (CH3NH3PbI3) perovskite thin film as a gate insulator material. The resulting perovskite film revealed ionic characteristics, with an ionic conductivity of about 10–8 S/cm. The perovskite-gated ZnO transistors exhibited typical n-type characteristics with an average field-effect mobility of 0.047 cm2/V s at a low applied voltage below 2 V because of the electric...

The electrical performance of suspended few-layer MoTe2 field-effect-transistors with ionic liquid gating has been investigated. The suspended structure not only enhances the mobility of MoTe2 by removing the influence of the substrate but also allows ions to accumulate on both the top and the bottom surface of MoTe2. The consequent increase in the gate capacitance resulted in an improved subthreshold swing (∼73 mV/dec) and on-off ratio (106) at room temperature for suspended MoTe2 compared to substrate-supported devices. Suspended transistors with ionic liquid gating enable a larger charge density compared to ionic liquid gated supported devices and may provide a useful platform to study screening physics in 2D materials.

Low-level light therapy, which is a red or near-infrared light-employed therapeutic methodology, can act to help the brain repair in cases of traumatic brain injury and stroke. In this paper, we investigate the effects of near-infrared light therapy (NILT) for the recovery of blood flow of mice with cerebral hypoperfusion, which is a key mechanism leading to vascular dementia, induced by bilateral common carotid artery stenosis (BCAS). The mice are divided into three groups of 4-5 mice per group: a normal group (without BCAS operation), a BCAS group (without NILT), or a BCAS/NILT group. The LED with a peak wavelength of 810 nm and a power of 20 mW is arranged to illuminate on the top of the mouse head. The mice receive treatment from the LED source 3 times per week for one month. After the treatment, positron emission tomography is used to quantify the effects of NILT on whole brain and regional cerebral blood flow in the cortex, striatum, and hippocampus.

OBJECTIVE Alcohol consumption is associated with an increased risk of injuries. However, its effects on injury severity and mortality remain unclear. Specifically, the effects of alcohol intake on the severity of slip injuries have not been thoroughly investigated. Therefore, our study aimed to investigate the effects of alcohol intake on injury patterns and severity in patients experiencing slip injuries. METHODS Emergency department surveillance data collected from 2011 to 2016 were analyzed for this study. Among patients aged 15 and older who were admitted for slip injuries, we compared the type and severity of injuries between the alcohol-intake group and the no-alcohol-intake group. Injury severity was classified as non-severe and severe based on the excess mortality ratio-adjusted injury severity score. RESULTS In total, 227,548 (alcohol-intake, n=48,581; no-alcohol-intake, n=178,967) patients were included. After adjusting for age, time of injury, use of public ambulance, and season, multivariate logistic regression analysis showed that injuries were more likely to be severe in the alcohol-intake group than in the no-alcohol-intake group (odds ratio, 1.60; 95% confidence interval, 1.47-1.75). In addition, male gender and alcohol consumption had a greater synergistic effect on injury severity than the mere sum of each effect of these factors (odds ratio, 2.65; 95% confidence interval, 2.53-2.78). CONCLUSION Assessment of the patients influenced by alcohol was a challenge in the emergency department due to altered mental status. We suggest a considerate approach in testing and assessing male patients who slipped after alcohol-intake in the emergency department.

This study aimed to determine whether the combination of procalcitonin (PCT) and S100B improves prognostic performance compared to either alone in cardiac arrest (CA) patients treated with targeted temperature management (TTM). We performed a prospective cohort study of CA patients treated with TTM. PCT and S100B levels were obtained at 0, 24, 48, and 72 hours after return of spontaneous circulation. The prognostic performance was analyzed using each marker and the combination of the 2 markers for predicting poor neurological outcome at 3 months and mortality at 14 days and 3 months. A total of 97 patients were enrolled, of which 67 (69.1%) had poor neurological outcome. S100B showed a better prognostic performance (area under the curve [AUC], 0.934; sensitivity, 77.6%; and specificity, 100%) than PCT (AUC, 0.861; sensitivity, 70.2%; and specificity, 83.3%) with the highest prognostic value at 24 hours. The combination of 24-hour PCT and S100B values (S100B ≥0.2 μg/L or PCT ≥6.6 ng/mL) improved sensitivity (85.07%) compared with S100B alone. In multivariate analysis, PCT was associated with mortality at 14 days (odds ratio [OR]: 1.064, 95% confidence interval [CI]: 1.014–1.118), whereas S100B was associated with neurological outcomes at 3 months (OR: 9.849, 95% CI: 2.089–46.431). The combination of PCT and S100B improved prognostic performance compared to the use of either biomarker alone in CA patient treated with TTM. Further studies that will identify the optimal cutoff values for these biomarkers must be conducted.

Background: The aim of this study was to retrospectively evaluate and analyze the brain magnetic resonance imaging (B-MRI) findings of patients with a favorable neurological outcome following cerebral performance category (CPC) after out-of-hospital cardiac arrest (OHCA) at single university hospital emergency center. Methods: Patients with return of spontaneous circulation (> 24 h) after OHCA who were older than 16 years of age and who had been admitted to the emergency intensive care unit (EICU) for over a 57-month period between July 2007 and March 2012 and survived with a favorable neurological outcome were enrolled. B-MRI was taken after recovery of their mental status. Results: Fifty-two patients among the 305 admitted patients had a good CPC, and 33 patients’ B-MRI were analyzed (CPC 1: 26 patients, CPC 2: 7 patients). Among these, 18 (54.5%) patients had a normal finding on B-MRI. On the other hand, ischemia/infarction/microangiopathy compatible with hypoxic-ischemic encephalopathy (HIE) were found on various brain areas including subcortical white matter (7/13), cerebral cortex, central semiovlae, basal ganglia, putamen, periventricular white matter, and cerebellum. Conclusions: Survivors with a favorable neurological outcome from OHCA showed HIE on B-MRI, especially all of the patients with a CPC 2. More detail neurologic category including brain imaging would be needed to categorize patients with favorable outcome after OHCA.

Due to the increased availability of digital human models, the need for knowing human movement is important in product design process. If the human motion is derived rapidly as design parameters change, a developer could determine the optimal parameters. For example, the optimal design of the door panel of an automobile can be obtained for a human operator to conduct the easiest ingress and egress motion. However, acquiring motion data from existing methods provides only unrealistic motion or requires a great amount of time. This not only leads to an increased time consumption for a product development, but also causes inefficiency of the overall design process. To solve such problems, this research proposes an algorithm to rapidly and accurately predict full-body human motion using an artificial neural network (ANN) and a motion database, as the design parameters are varied. To achieve this goal, this study refers to the processes behind human motor learning procedures. According to the previous research, human generate new motion based on past motion experience when they encounter new environments. Based on this principle, we constructed a motion capture database. To construct the database, motion capture experiments were performed in various environments using an optical motion capture system. To generate full-body human motion using this data, a generalized regression neural network (GRNN) was used. The proposed algorithm not only guarantees rapid and accurate results but also overcomes the ambiguity of the human motion objective function, which has been pointed out as a limitation of optimization-based research. Statistical criteria were utilized to confirm the similarity between the generated motion and actual human motion. Our research provides the basis for a rapid motion prediction algorithm that can include a variety of environmental variables. This research contributes to an increase in the usability of digital human models, and it can be applied to various research fields.

A helmet is critical for preventing head injuries during motorcycle accidents. However, South Korean motorcyclists have a lower prevalence of wearing a helmet, compared to developed countries. Therefore, we aimed to evaluate whether helmet wearing was associated with the clinical outcomes in Korean motorcycle accidents. Data were obtained from the Emergency Department-based Injury In-depth Surveillance database 2011-2015. We considered the patients had experienced a motorcycle accident and were only diagnosed with a craniocerebral trauma (CCT). The primary outcome was mortality and the secondary outcomes were the severity and hospitalization duration. The patients were separated whether they were wearing a helmet and the outcomes were compared using multivariate logistic regression after propensity score matching (PSM). Among 1,254,250 patients in the database, 2,549 patients were included. After PSM, 1,016 patients in each group were matched. The univariate analyses revealed that helmet wearing was associated with lesser severity (P < 0.001) and shorter hospitalization (P < 0.001). The regression analysis revealed that mortality was also lower in a helmet-wearing group (odds ratio: 0.34, 95% confidence interval: 0.21-0.56). In conclusion, wearing a helmet may reduce the mortality from a CCT after a motorcycle accident and associated with lesser severity and shorter hospitalization.

Nonporous silica nanoparticles (SiNPs) have potential as promising carriers for ophthalmic drugs. However, the in vivo safety of ocular topical SiNPs remains unclear. This study investigated the in vivo safety of oral and ocular topical applications of 100 nm-sized SiNPs in Sprague-Dawley rats. The rats were divided into the following four groups: low-dose oral administration (total 100 mg/kg of SiNPs mixed with food for one week), high-dose oral administration (total 1000 mg/kg of SiNPs mixed with food for one week), ocular topical administration (10 mg/ml concentration, one drop, applied to the right eyes four times a day for one month), or a negative control (no SiNP treatment). The rats were observed for 12 weeks to investigate any signs of general or ocular toxicity. During the observation period, no differences were observed in the body weights, food and water intakes, behaviors and abnormal symptoms of the four groups. No animal deaths occurred. After 12 weeks, hematologic, blood biochemical parameters and ophthalmic examinations revealed no abnormal findings in any of the animals. The lack of toxicity of the SiNPs was further verified in autopsy findings of brain, liver, lung, spleen, heart, kidneys, intestine, eyeballs, and ovaries or testes.

The pedicle screw fixation system has been used for various spinal disorders. Many studies have been conducted on the fixation ability of the pedicle screw, but variable results have been reported based on bone qualities, pedicle screw properties, insertion techniques, and experimental methods.An experimental and biomechanical study.To evaluate the geometric factors of screws affecting fixation ability after assessing pullout strength based on various pedicle screw designs and different bone densities.Nine types of pedicle screws were prepared according to the outer diameter shape (cylindrical or conical), the inner diameter shape (cylindrical or conical), and thread shape (V shape, buttress shape, and square shape). The pedicle screws were inserted into standardized polyurethane foams of Grades 5, 15, and 20. The pullout strength of each pedicle screw was determined using an MTS 858 machine (Material Testing System Corp., Minneapolis, MN, USA), and the results were analyzed statistically.Pullout strength based on the shape of thread was the highest in the V shape and lowest in the square shape for all foam grades (p.05). The outer cylindrical and inner conical shape of pedicle screw showed the highest pullout strength in Grades 5 and 15 foam (p.05). An outer cylindrical and inner conical shape with a V-shaped thread showed the highest pullout strength in all foam grades (p.05).Pedicle screw with an outer cylindrical and inner conical configuration with a V-shaped thread may have maximum pullout strength, regardless of bone density.

Human capital variables have been considered as very important determinants of career success. In this study have two purposes. The first is to examine the relationship between informal networking and career success. And gender moderated the relationship between informal networking and employability. The major findings of the study are summarized as follows: First, informal networking had positive effect on the career success. The relationship between members of the organization in the formation of informal relationships between the trust and if the organization`s members to form a supportive organizational culture and organizational citizenship behaviors through which organizations such as the positive outcomes will be achieved. So informal networking have been considered as very important determinants of career success. Second, regarding the moderating effect of gender on the informal networking and employability, and informal networking played more important roles for men than woman in employability.

For high capacitance aluminum electrode was selectively etched with square of tunnel pits. SU-8 photoresist as etching mask was patterned on aluminum by UV-assisted thermal imprint lithography and then surface area of aluminum was increased by electrochemical etching, where tunnel pits were generated regularly and were approximately 20@mm in length, 3.5@mm in width, resulting in 10^6 tunnels per cm^2 of surface. Consequently, the capacitance of the dielectric showed an increase of up to four times higher than the unpatterned surface.

In this paper, an eye tracking method is presented by using on iterated spatial moment adapting weighted gray level that can accurately detect and track user`s eyes under the complicated background. The region of face is detected by using Haar-like feature before extracting region of eyes to minimize an region of interest from the input picture of CCD camera. And the region of eyes is detected by using eigeneye based on the eigenface of Principal component analysis. Also, feature points of eyes are detected from darkest part in the region of eyes. The tracking of eyes is achieved correctly by using iterated spatial moment adapting weighted gray level.

Cachexia-anorexia syndrome, which is called cancer cachexia, is a common and important indicator of cancer and occurs in 30% to 80% of cancer patients. Cancer cachexia is characterized by a severe progressive body wasting, accompanied by loss of adipose tissue and skeletal muscle mass. The presence of cachexia is associated with a worsened prognosis and contributes to up to 20% of cancer deaths. In most cases, cancer cachexia patients clinically show anorexia caused through a complex system of hormones and neuropeptides. To investigate efficacy in development of new medicine, an optimized animal model is essentially required. Although several cancer cachexia animal models have been established, we focused on developing a better animal model particularly for efficacy evaluation with advanced bioimaging evaluation methods. First of all, we confirmed that an appropriate mouse strain is CDF1 in comparison with DBA1 and Balb/c after xenografting of Colon26. As the second step, we checked cell numbers with pattern of tumor growth. In human clinics, cure of cancer cachexia is usually performed with surgical removal of tumor. To make the animal model similar to clinical circumstances, we tested recovery time and pattern after removal of tumor. With optimized mouse model we tested efficacy of anticancer drug Megace 200 mg/kg as a positive control. In addition, we applied advanced bioimaging equipment such as MRI and CT to visualize actual tumor and fat with body composition. We expect that optimized animal model of cancer cachexia will prepare the way for more accurate efficacy test in preclinical state to go to a clinical trial. Citation Format: Jiyeong Bae, Ig Jun Cho, Jung Hyu Shin, Hyung Soo Yuh, Hyung Ho Moon, Hye Lim Lee, Yeong Nang Jo, Yeon Ju Park, Woo Sung Choi, Byung Hwa Hyun. Optimization of a cachexia animal model for efficacy evaluation of candidates [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2017 Oct 26-30; Philadelphia, PA. Philadelphia (PA): AACR; Mol Cancer Ther 2018;17(1 Suppl):Abstract nr A017.

A two-dimensional device simulator SNU-2D based on the hydrodynamic model is developed for the simulation and analysis of submicron devices. The simulator has the capacity for both self-consistent steady-state and transient-state simulation. To obtain better convergence and numerical stability, we adopt an improved discretization scheme for the carrier energy flux equation and a new strategy for the transient simulation. In steady-state simulation the new discretization scheme shows a considerable improvement in convergence rate and numerical accuracy compared with the existing schemes. A transient simulation study is carried out on a deep submicron n-MOSFET used in the sense amplifier of SRAM cells to investigate the gate-switching characteristic. It is found that the behavior of carrier temperature is quasi-static during the switching time even for very fast switching speed, while the behavior of impact ionization under transient mode deviates from that under dc mode as the switching speed increases. >

Objective. Pressure-controlled manometric discography is used by clinicians to evaluate discogenic pain. However, some would improve diagnostic accuracy. The goal of this study was to investigate potential confounding factors that might affect discographic results. Pressure differences depending on different speed of injection, lengths of connecting tubing and locations of sensors were evaluated using an in vitro model system. Methods. Two sets of automated discography devices were arranged to record post-syringeal pressure pressures (PSPs) and intradiscal pressures (IDPs) in an “air chamber disk model” representing intradiscal pressure. PSPs and IDPs were measured simultaneously while varying injection speeds, and using intrasyringeal and extrasyringeal pressure sensors and contrast medium-filled tubing of different lengths. All pressure/volume curves were collected and viewed dynamically, and stored for further analysis. Results. At injection speed of 0.1 cc/second, the mean pressure difference (mean Δ P ) between PSP and IDP was 38.1 psi. As injection speed was reduced, mean Δ P was proportionally decreased. Mean Δ P was 5.3 psi at injection speed of 0.01 cc/second and 0.7 psi at 0.005 cc/second. Mean Δ P values were significantly higher when pressures were recorded using intrasyringeal sensor: at injection speed of 0.1 cc/second, PSP and IDP values were 82.9 and 30.1 psi, respectively, compared with 50.6 and 12.5 psi measured by extrasyringeal sensor. Mean Δ P due to increased length of tubing was not significant. Conclusion. Discography can be better performed with low speed injection (≤0.01 cc/second), using an extrasyringeal sensor. Difference of length of connecting tubings did not cause significant pressure differences. These data suggest that automated discography is a helpful adjunct to improve diagnostic accuracy, due to extrasyringeal location of pressure sensor and greater control of injection speed.

Study Design. Electrophysiologic recordings were obtained from a lumbar paraspinal nerve or muscle in the anesthetized cat while electrically stimulating a paraspinal nerve or facet capsule in an adjacent lumbar segment. A variety of approaches were used to demonstrate the reflex nature of both the nerve and the muscle response. Objective. The primary purpose of this study was to seek electrophysiologic evidence for the presence of intersegmental reflexes between adjacent lumbar vertebral segments. A second purpose of this study was to confirm a previous procedure used to evoke paraspinal reflexes. This previous work had shown that electrical stimulation of the L1–L2 facet joint capsule elicits electromyographic activity from multifidus muscle one to two vertebral segments caudal to the stimulated facet in a porcine preparation. Summary of Background Data. Biomechanical approaches have stressed the need for spinal stability to avoid conditions that could give rise to low back dysfunction. It seems reasonable to believe that reflex interactions between vertebral segments contribute to the sensorimotor integration of lumbar paraspinal tissues. It also seems reasonable to believe that alterations or abnormal elicitation of these reflexes could contribute to biomechanical changes associated with low back pain and paraspinal muscle spasm. Methods. Experiments were performed on 23 α-chloralose anesthetized adult cats. In eight cats the L3, L4, and L5 medial branch from each dorsal ramus was exposed and placed on a bipolar hook electrode. In six cats the L4 medial branch was stimulated and a compound action potential was recorded from the L3 medial branch. In three of the six cats the L5 medial branch was stimulated and a compound action potential was recorded from the L3 medial branch. In one cat the L4 medial branch was stimulated and a compound action potential was recorded from the L5 medial branch. In one cat the L3 medial branch was stimulated and a compound action potential was recorded from the L5 medial branch. At the end of each protocol the medial branch was cut just proximal to the stimulating electrode to confirm that the compound action potential was reflexive in nature and not initiated by volume conduction. In 15 cats three approaches were used to confirm that multifidus electromyographic activity evoked by electrical stimulation of a lumbar facet capsule was reflexive in nature: 1) by anesthetizing the site of the sensory endings, i.e., the facet capsule, 2) by injecting lidocaine intrathecally to block neural conduction centrally, i.e., within the spinal canal, or 3) by cutting the afferent pathway, i.e., the medial branch of the dorsal ramus. Results. Electrical stimulation of the medial branch of the dorsal ramus innervating the medial-most lumbar paraspinal tissues evoked a compound action potential in the medial branch innervating the medial-most paraspinal tissues one and two segments away. Stimulating voltages between 2 and 70 V were necessary to evoke the compound action potential. Each compound action potential was reflexive in nature because cutting the lumbar medial branch proximal to its contact with the stimulating electrode abolished each compound action potential. The conduction velocity of the reflex ranged from 3.5 to 6.1 m/sec. Electrical stimulation of a lumbar facet capsule evoked lumbar multifidus muscle electromyographic activity. However, injecting lidocaine intrathecally or transecting the medial branch of the dorsal ramus had no effect on electromyographic activity. Injecting lidocaine into the facet or into the multifidus muscle around the facet joint (near the stimulating electrode) significantly decreased the magnitude of the multifidus electromyography. Conclusion. These results indicate that afferent impulses conveyed by the medial branch of the dorsal ramus reflexly altered efferent activity to an adjacent lumbar segment. This intersegmental paraspinal reflex may span at least one or two vertebral segments. The data suggest that electrical stimulation of the facet joint capsule may not have reflexly elicited multifidus activity because neither chemical interruption (intrathecal lidocaine) nor physical interruption (nerve transection) of the presumed reflex pathway diminished or abolished the electromyographic response. Volume conduction of the stimulating currents likely elicited multifidus activity during electrical stimulation of the facet capsule. When using electrical stimulation of neural paraspinal tissues to evoke reflex muscle activity, appropriate control experiments must be performed to clearly demonstrate the reflexive nature of the response.

Bisphosphonates are used effectively for many medical conditions, such as multiple myeloma, Paget ’ s disease, osteoporosis, etc. However, recently, osteonecrosis of the jaw was observed in patients receiving long-term bisphosphonate therapy, including oral administration. Th is osteonecrosis is refractory, and complete recovery is not guaranteed despite a standard treatment protocol being established by many association s related to oral and maxillofacial surgery. The treatment outcome of oral bisphosphonate-related osteonecrosis of jaw (BRONJ) is reported with a rev iew of the relevant literature.

타액선의 폐쇄성 질환은 흔히 관찰되는 것으로 타액선 도관, 문(hilum), 타액선 자체에 석회화 또는 유기물에 의한 것이다. 그 중에서 석회화된 침전물이 존재하는 것을 타석 증(sialolithiasis)이라 한다. 대다수의 타석증이 악하선에서 호발하며, 다음으로 이하선에서 발생되고 설하선에서는 매우 드물게 관찰되는 것으로 알려져 있다. 호발하는 성 별은 남성, 연령대는 10대에서는 드문 것으로 보고되고 있 다. 타석증을 감별하기 위한 검사로 임상적으로는 환자 의 병력 청취, 증상, 촉진 등을 통해서, 방사선적으로는 표 준방사선사진(하악 교합 촬영, 하악골 측사 촬영 등), computed tomography (CT) scan, 타액선 조영술 등을 통해서, 그 외에 magnetic resonance imaging (MRI), 초음파 촬영, 타액 선내시경(sialoendosopy) 등을 통해서도관찰할 수있다. 타석증의 일반적인 임상 증상은 도관 폐쇄로 인한 해당 타액선의 부종, 동통 등으로 주로 식사시에 증가했다가 휴 식기에 완화되는 특징이 있다. 이는 저작 시 타액선의 타액 분비가 증가됨에 따라 폐쇄된 도관의 압통으로 인한 것으 로 알려져있다. 타석증의 처치는 증상을 없애기 위하여 타석을 제거하는 것이 주된 초점이다. 타석이 매우 작거나 도관 입구부에 있 는 경우 타액의 배출 촉진 및 해당 부위의 마사지를 통해서 타석의 제거를 유도하기도 하지만 증상이 있는 대다수의 경우 이러한 처치로 개선되지 않는 경우가 많다. 타석의 위 치에 따라 외과적으로 타액선 내시경과 같은 기구를 이용 또는 동반한 단순한 제거나 도관부의 절개를 통해 제거가 가능한 경우가 있고, 부피가 크거나 위치가 도관의 근심부 또는 타액선 실질에 근접한 경우 타액선의 적출이나 쇄석 술을 사용하는경우도 있다. 관찰되는 타석의 성분은 유기물과 무기물의 혼합체로 발 생기전에 대하여는 많은 논란이 있으나 일반적으로 타액 이 저류되는 부분에서 오랜 기간 동안 핵이 되는 유기물 주 변으로 칼슘과 인 등의 무기물이 침착되어 생성된다고 알 려져 있다. 타석의 크기는 매우 다양하다. 대다수는 10 mm 이하의 길이를 가지며 15 mm 이상의 길이를 가지는 타석은 그 빈 도가 매우 적다. 명확히 크기에 대하여 규정된 바는 없으나 일반적으로 15 mm 이상의 큰 타석이 관찰되는 경우 거대 타석증(megalith, giant sialolithiasis)으로 부르며 매우 드물 이 상 화 150-713 서울특별시영등포구여의도동 62 가톨릭대학교여의도성모병원구강악안면외과 Sang-Hwa Lee Department of Oral and Maxillofacial Surgery, Yeouido St. Mary’s Hospital, The Catholic University of Korea 62 Yeouido-dong, Yeongdeungpo-gu, Seoul, 150-713, Korea TEL: +82-2-3779-2014 FAX: +82-2-769-1689 E-mail: justina@catholic.ac.kr 악하선에서 발생한 거대 타석증: 증례 보고

The effect of Si doping in MgO has been investigated in order to improve the material properties of the MgO protecting layer in plasma display panels. A small amount of Si was added to the MgO pellet while the MgO layer was being deposited by using an electron-beam evaporation method. Both the surface characteristics of the protecting layer and the electro-optical properties of 4in. test panels were investigated, such as firing and sustain voltages, luminous efficacy, addressing jitter, and image sticking. The firing voltage is minimized when the Si concentration is 0.03%∼0.04%, where the luminous efficacy increases up to 35% compared with that of the conventional MgO film, and the boundary image sticking also shows good characteristics around the Si concentration level by 0.04%.

The piriformis syndome is a rare condition characterized by pain and paresthesia in the buttock, often radiating to the posterior thigh. Symptoms are made worse by hip adduction and internal rotation of the hip joint. We report two cases of piriformis syndrome caused by an atypical sciatic nerve pathway combined with hamstring hypertrophy.

Closed reduction of a dislocated bipolar hemiarthroplasty may induce dissociation between polyethylene and inner prosthetic ball head. This rare complication should be treated by open reduction. If dislocation of the bipolar hemiarthroplasty occurs, gentle closed reduction techniques with satisfactory anesthesia and muscle relaxation are recommended. We report our experience of 3 cases.

Background Multiple myeloma (MM) is characterized by a neoplastic proliferation of plasma cells primarily in the bone marrow. Bisphosphonates (BP) are used as supportive therapy in the management of MM. This study aimed to analyze the incidence, risk factors, and clinical outcomes of medication-related necrosis of the jaw (MRONJ) in MM patients. Methods One hundred thirty MM patients who had previous dental evaluations were retrospectively reviewed. Based on several findings, we applied the staging and treatment strategies on MRONJ. We analyzed gender, age, type of BP, incidence, and local etiological factors and assessed the relationship between these factors and the clinical findings at the first oral examination. Results MRONJ was found in nine male patients (6.9%). The mean patient age was 62.2 years. The median BP administration time was 19 months. Seven patients were treated with a combination of IV zoledronate and pamidronate, and two patients received single-agent therapy. The lesions were predominantly located in the mandible (n = 8), and the most common predisposing dental factor was a history of prior extraction (n = 6). Half of the MRONJ were related to diseases found on the initial dental screen. Patients with MRONJ were treated with infection control and antibiotic therapy. When comparing between the MRONJ stage and each factor (sign, location, etiologic factor, BP type, treatment, and outcome), there were no significant differences between stages, except for between the stage and sign (with or without purulence). Conclusions For prevention of MRONJ, we recommend routine dental examinations and treatment prior to starting BP therapy.