Sung-Hyun Kim

Brain stem herniation secondary to cerebrospinal fluid drainage in ruptured aneurysm surgery: a case report

AbstractBackgroundA lumbar drainage catheter is frequently placed intra-operatively to decrease fluid pressure on the brain in aneurysmal subarachnoid cases. In rare cases, this catheter placement can lead to intracranial hypotension, resulting in brain stem herniation termed “brain sag” and it can lead to neurological injury and may prove to be fatal. We present our patient with brain sag secondary to intraoperative lumbar drainage.nCase descriptionA 56-year-old woman was admitted with a sudden onset of severe headache. A computed tomography (CT) scan revealed diffuse subarachnoid hemorrhage with ruptured anterior communicating artery aneurysm. After general anesthesia, a lumbar drainage catheter was placed intra-operatively to reduce pressure on the brain and 50xa0cc of CSF was removed during a 5-h period. Three to five days after operation, her neurologic symptoms became worse with an altered mental state and pupillary asymmetry. CT and magnetic resonance imaging (MRI) showed slit lateral ventricles, effacement of the cisterns and an elongated brain stem. After placing the patient in the Trendelenburg position, the patient rapidly recovered to her baseline neurologic state.nDiscussionTypical complications of subarachnoid hemorrhage such as vasospasm or hydrocephalus also manifest as neurological deterioration, but their treatments differ greatly from those for brain sag. Thusly, it is important to distinguish between causes. Treatments such as lumbar or extra-ventricular drainage, induced hypertension or administration of mannitol must be stopped once brain sag is suspected. Also, care should be taken for typical imaging features of brain sag on CT or MRI scan. For brain sag, placing the patient in the Trendelenburg position can improve neurological status in a rapid fashion.ConclusionsBrain sag is a rare but serious condition and can be fatal if not rapidly diagnosed and treated. We therefore recommend including brain sag in the differential diagnosis, along with vasospasm, hydrocephalus or cerebral edema as part of possible complications following subarachnoid hemorrhage treatment. We hope our clinical and imaging data from this case study contribute to the correct diagnosis of brain sag, as its early detection is important.

Ideal or Young-Looking Brow Height and Arch Shape Preferred by Koreans.

AbstractThe aim of this study is to see which brow height and arch shape is preferred as ideal or young-looking by Koreans.A survey was conducted between June and Dec 2014 on 186 women who visited the brow bar (“Benefit” of Incheon city). They were asked to choose which they believed ideal and youngest amongst the 3 brow archetypes according to their height and 4 types of modification of Anastasia (rotation of medial and lateral arms), which was illustrated.Approximately half (52.5%) of the respondents answered that their brow matches them very well or well. Most (81.2%) believed there might be a method to yield an ideal brow archetype and almost all (97.3%) would change the brow shape if the expert advised. The most preferred ideal brow height was of a middle height (63.2%, the distance from the lateral canthus to the lateral end of eyebrow, which was 2/3 of the eye width). The most preferred ideal brow arch shape was the arched type (57.6% arches on a line drawn from the center of the nose through the center of the pupil). The most preferred young-looking brow height was of an upper height (46.2%, the distance from the lateral canthus to the lateral end of eyebrow was 3/4 of the eye width) followed by a middle height (39.7%). The most preferred young-looking brow arch shape was the head-up position (53.3%, medial arm of the brow was rotated upward to the horizontal plane).The result of this study might be useful in facial rejuvenation surgeries as well as in brow esthetics or tattooing of the eyebrows.

Enhancement of Mechanical Strength Using Nano Aluminum Reinforced Matrix for Molten Carbonate Fuel Cell

Abstract >> 용융탄산염 연료전지 상용화를 위해서 40,000 시간이상 장기 운전이 가능해야 한다. 장기운전을 위해크랙 발생이 적고 기계적 강도가 높은 강화 매트릭스의 개발이 절실히 요구되고 있다. 본 연구에서는 LiAlO 2 에알루미늄 나노입자를 첨가하여 매트릭스의 기계적 강도를 향상시키는 연구를 수행하였다. 나노 알루미늄 첨가LiAlO 2 그린 시트를 수소 분위기에서 열처리한 결과, 공기 분위기에서 열처리한 매트릭스에 비해 기계적 강도가1.5배 증가함을 확인하였다. 이는 환원분위기에서 열처리를 할 경우, 알루미늄의 입자간의 소결으로 인한 neck이형성 되어 LiAlO 2 입자 간에 다리를 만들어주는 효과가 나타나 매트릭스의 기계적 강도가 크게 증진되었으리라판단된다. Key words : MCFC(용융탄산염전지), Reinforced matrix(강화매트릭스), Sintering(소성), Aluminium(알루미늄),Reducing atmosphere(환원성 분위기) † Corresponding author : jhan@kist.re.krKimsh@korea.ac.kr [ 접수일 : 2012.3.28 수정일 : 2012.4.23 게재확정일 : 2012.4.27 ] 1. Introduction The molten carbonate fuel cell (MCFC) has been regarded as a promising alternative energy source for power generation systems because its electrochemical conversion efficiency is high, it offers fuel flexibility, it is environment friendly, and it provides combined heat and power (CHP) 1-3) . Nowadays, MCFC pre-pares to enter the stage of commercialization. For commercialization, a 40,000h operation time of the MCSC stacks should be guaranteed. One of the most important factors for long-term operation is ensuring the stability of the matrix that plays an important role both as a reservoir of liquid electrolyte and as an

Surgical Results after Unilateral Laminectomy for the Removal of Spinal Cord Tumors

Objective To reduce the risk of postoperative spinal instability or deformity, unilateral laminectomy (UL) has been recommended to remove spinal space-occupying lesions. The purpose of this study was to determine whether there were any advantages of UL for removal of spinal cord tumors. Methods From May 1995 to May 2010, 94 patients with spinal cord tumors, who underwent tumor removal via UL in our institute, were enrolled in this study. Intramedullary spinal cord tumors were excluded. Simple radiographs were obtained for accessing the restoration of the spinal column. Spinal magnetic resonance imaging (MRI) was also obtained during the follow-up period to evaluate tumor recurrence. Results There were 51 women and 43 men; their mean age was 47.8 years (range, 9-83 years). The mean follow-up period was 52.6 months (range, 24 month-16 years). The sites of the tumors were cervical in 21 cases, thoracic in 37, lumbar in 33, and sacral in 3. These cases included 85 intradural extramedullary (IDEM) and 9 extradural (ED) lesions. IDEM tumors consisted mainly of neurilemmomas (56.3%) and meningiomas (22.3%).Tumors were totally removed in 80 cases and subtotally removed in 14 cases. Postoperative neurological status was improved in 53 cases, unchanged in 31 cases, and worsened in 10 cases. During follow-up, MRI showed tumor recurrence in 4 patients. Histopathologically, three cases were meningiomas and one case was neurilemmoma. None of the patients showed spinal instability or kyphotic deformity at last follow-up. Conclusion UL is an optimal approach for providing sufficient exposure of spinal cord tumors without development of postoperative spinal instability and regional sagittal imbalance in any location of spinal column. In cases of meningioma, careful long-term follow up is needed due to its relatively high recurrence rate after removal via UL.

Contralateral Hemispheric Brain Atrophy After Primary Intracerebral Hemorrhage

OBJECTIVEnIn patients with intracerebral hematoma (ICH), it is well known that brain atrophy occurs in the hemisphere ipsilateral to the hematoma. The present study aimed to investigate contralateral hemispheric volume changes in patients with ICH as well as related factors.nnnMETHODSnOf 112 patients with ICH who were surgically treated at our hospital between January 2011 and December 2015, 44 were included in the present study. We measured contralateral hemispheric brain areas in 3 planes of axial brain computed tomography images. We obtained the proportion of contralateral hemispheric parenchyma to the hemispheric intracranial area to adjust for individual differences in head size. We analyzed the relationship between various factors and volume changes in the contralateral hemisphere.nnnRESULTSnThe average volume percentages of preoperative and follow-up contralateral hemispheric parenchyma were 92.3% versus 88.8%, 90.3% versus 85.3%, and 86.9% versus 82.5% in the level of foramen of Monro, septum pellucidum, and lateral ventricle, respectively. These decreases were all statistically significant (paired t-test; Pxa0<xa00.001). As far as the causes of these decreases, the presence of intraventricular hematoma was the most significant factor for a decrease (Pxa0= 0.006). Glasgow coma scale score on arrival, as well as, smoking were independent factors in a multivariate analysis (Pxa0= 0.016, 0.039).nnnCONCLUSIONSnContralateral parenchymal volumes were significantly decreased at the 3-month follow-up brain computed tomography scan. These findings may offer important clinical information on the remote brain injury of ICH.

Correct Plane of the Sylvian Vein Dissection for Middle Cerebral Artery Aneurysm Using Indocyanine Green Videoangiography

BACKGROUNDnPreservation of the superficial Sylvian veins (SSVs) is essential to prevent neurologic deficits during Sylvian dissection. We describe an appropriate surgical approach for unruptured middle cerebral artery (MCA) aneurysms to preserve these veins by using indocyanine green videoangiography (ICG-VA).nnnMETHODSnBetween August 2014 and August 2015, we performed microsurgical clipping for 37 unruptured MCA aneurysms in 36 patients. We classified all of the cases into 3 types according to the location between the Sylvian fissure and the SSV. We defined 3 surgical approaches (frontosylvian, intersylvian, and temporo-sylvian) based on the SSV and investigated the proper surgical approach according to the type of case.nnnRESULTSnIn our study, most SSVs were located above the Sylvian fissure (fissure type, 64.9%). The SSV was located on the temporal lobe in 10 cases (temporal type) and on the frontal lobe in 3 cases (frontal type). The frontosylvian approach (splitting between the SSV and frontal lobe) was performed in all of the patients with temporal type; the temporo-sylvian approach (splitting between the SSV and temporal lobe) was performed in all of the patients with frontal type and single SSV of fissure type. The intersylvian approach (splitting between the frontal and temporal SSV, or among multiple SSVs) was successfully performed in the patients with double or multiple SSVs of fissure type. No venous complications occurred that were related to the surgical approach.nnnCONCLUSIONSnCorrect dissection strategy using intraoperative ICG-VA is greatly useful to define the optimal surgical approach without vein injury.

Solar tracking system for lighting fiber

We demonstrate a simple and effective solar tracking system for collection of sunlight in an optical fiber. The system incorporates a mirror whose axes were controlled based on the known equation of solar motion.

Theoretical and Experimental Analyses of Particle Trapping in a Capillary Tube Using a Flexural Acoustic Wave

Acoustic trapping of particles in a capillary tube using a flexural acoustic wave was studied both theoretically and experimentally. Acoustic force potential was calculated using numerical simulation based on the finite element method. The distribution of particles which resulted from the force potential was categorized into four cases, depending on the physical properties of particles and fluid. Acoustic trapping was demonstrated using a robust, compact acoustic transducer, providing arbitrary interaction length. Theoretical estimation was successfully confirmed experimentally.

Laminotomy with Continuous Irrigation in Patients with Pyogenic Spondylitis in Thoracic and Lumbar Spine

OBJECTIVEnPyogenic spondylitis often results in acute neurological deterioration requiring adequate surgical intervention and appropriate antibiotic treatment. The purpose of this study was to conduct an analysis of the clinical effect of continuous irrigation via laminotomy in a series of patients with pyogenic spondylitis in thoracic and lumbar spine.nnnMETHODSnThe authors conducted a retrospective investigation of 31 consecutive patients with pyogenic thoracic and lumbar spondylitis who underwent continuous irrigation through laminotomy from 2004 to 2008. The study included 22 men and 9 women, ranging in age from 38 to 78 years (mean 58.1 years). The average follow-up duration was 13.4 months (range, 8-34 months). We performed debridement and abscess removal after simple laminotomy, and then washed out epidural and disc space using a continuous irrigation system. Broad spectrum antibiotics were administered empirically and changed according to the subsequent culture result. Clinical outcomes were based on the low back outcome scale (LBOS), visual analogue scale (VAS) score, and Frankel grade at the last follow-up. Radiological assessment involved plain radiographs, including functional views.nnnRESULTSnCommon predisposing factors included local injection for pain therapy, diabetes mellitus, chronic renal failure, and liver cirrhosis. Causative microorganisms were identified in 22 cases (70.9%) : Staphylococcus aureus and Streptococcus spp. were the main organisms. After surgery, LBOS, VAS score, and Frankel grade showed significant improvement in most patients. Spinal stability was maintained during the follow-up period, making secondary reconstructive surgery unnecessary for all patients, except one.nnnCONCLUSIONnSimple laminotomy with continuous irrigation by insertion of a catheter into intervertebral disc space or epidural space was minimally invasive and effective in the treatment of pyogenic spondylitis. This procedure could be a beneficial treatment option in patients with thoracolumbar spondylitis combined with minimal or moderate destructive change of vertebrae.

On-Demand Modulation of Bacterial Cell Fates on Multifunctional Dynamic Substrates

This paper reports unprecedented dynamic surfaces based on zwitterionic low-density self-assembled monolayers (LDSAMs) of alkanethiolates on gold, which integrate three interconvertible states-bacteria-adherable, bactericidal, and nonfouling states-through electrical modulations. The conformations of alkanethiolates were electrically modulated to generate zwitterionic, anionic, and cationic surfaces, which responded differently to bacteria and determined the fate of bacteria. Furthermore, the reversible switching of multifunctions of the surface was realized for killing bacteria and subsequently releasing dead bacteria from the surface. For practical application of our strategy, we examined the selective antibacterial effect of our surface for eradication of mycoplasma contaminants in contaminated mammalian cell cultures.