Multi-Load Topology Optimization Design for the Structural Safety Maintenance of Low- and Intermediate-Level Radioactive Waste Packaging Containers in the Case of a Collision.

This paper presents an optimized design approach using nonlinear dynamic analysis and finite element methods to ensure the structural integrity of square-shaped containers made from ductile cast iron for intermediate- and low-level radioactive waste packaging. Ductile cast iron, with its spherical graphite structure, effectively distributes stress throughout the material, leading to a storage capacity increase of approximately 18%. Considering the critical need for containers that maintain integrity under extreme conditions like earthquakes, the design focuses on mitigating stress concentrations at the corners of square structures. Nonlinear dynamic analyses were conducted in five drop directions: three specified by ASTM-D5276 standards and two additional directions to account for different load patterns. Fractures were observed in four out of the five scenarios. For each direction where fractures occurred, equivalent loads causing similar displacement fields were applied to linear static models, which were then used for multi-load topology optimization. Three optimized models were derived, each increasing the volume by 1.4% to 1.6% compared to the original model, and the design that best met the structural integrity requirements during drop scenarios was selected. To further enhance the optimization process, weights were assigned to different load conditions based on numerical analysis results, balancing the impact of maximum stress, average stress, and plastic deformation energy. The final model, with its increased storage capacity and enhanced structural integrity, offers a practical solution for radioactive waste management, overcoming limitations in previous designs by effectively addressing complex load conditions.

Health-related quality of life of patients with aneurysmal subarachnoid hemorrhage who were classified as having "good outcomes".

BACKGROUND: This study aimed to understand the health-related quality of life (HRQoL) of patients with aneurysmal subarachnoid hemorrhage (aSAH) classified as having "good outcomes" and determine associated sociodemographic, psychological, and clinical factors. METHODS: Participants were 86 patients with aSAH with modified Rankin Scale (mRS) scores of 0-2 in our hospital between February 2003 and April 2014. Participants completed self-report questionnaires examining sociodemographic characteristics and the following self-rating scales: the hospital anxiety and depression scale, Pittsburgh sleep quality index, and EuroQoL-5 Dimension Index (EQ-5D). Further, we retrospectively reviewed clinical data from medical records and radiologic images. Average EQ-5D scores for each variable were compared using Student's t-test and analysis of variance. Correlations between EQ-5D and continuous variables were examined using Pearson correlation analysis. Factors associated with EQ-5D were then examined using univariate and stepwise multivariate analyses through simple and multiple regression. RESULTS: The mean age of the 86 participants was 56.87 ± 10.28 years (range: 29-79 years), while the mean EQ-5D value was 0.738 ± 0.169. There were 54 women (62.8 %) and 33 men (37.2 %). The participants had depressive symptoms (30.2 %), anxiety (10.5 %), and sleep problems (51.2 %). Regarding sociodemographic variables, educational level (p = 0.017) and monthly income (p = 0.037) were positively correlated with HRQoL. Depressive symptoms (r = -0.505, p < 0.001), anxiety (r = -0.498, p < 0.001), sleep problems (r = -0.265, p = 017), and mRS (r = -0.352, p = 0.001) were negatively correlated with HRQoL. Depressive symptoms, diabetes mellitus, and past psychiatric history explained 48.8 % of the variance in HRQoL in good outcome aSAH according to stepwise multiple regression analysis. CONCLUSIONS: Patients with good outcome aSAH had low EQ-5D values, which were negatively correlated with depressive symptoms, anxiety, and sleep problems. In addition, HRQoL in good outcome aSAH is associated with depressive symptoms, diabetes mellitus, and past psychiatric disease history. Depressive symptoms, anxiety, and sleep problems are frequent in patients with good outcome aSAH, and mediation of these factors may help improve HRQoL.

Proximal Junctional Kyphosis or Failure After Adult Spinal Deformity Surgery - Review of Risk Factors and Its Prevention.

Proximal junction kyphosis (PJK) is a common imaging finding after long-level fusion, and proximal junctional failure (PJF) is an aggravated form of the progressive disease spectrum of PJK. This includes vertebral fracture of upper instrumented vertebra (UIV) or UIV+1, instability between UIV and UIV+1, neurological deterioration requiring surgery. Many studies have reported on PJK and PJF after long segment instrumentation for adult spinal deformity (ASD). In particular, for spine deformity surgeons, risk factors and prevention strategies of PJK and PJF are very important to minimize reoperation. Therefore, this review aims to help reduce the occurrence of PJK and PJF by updating the latest contents of PJK and PJF by 2023, focusing on the risk factors and prevention strategies of PJK and PJF. We conducted a search on multiple database for articles published until February 2023 using the search keywords "proximal junctional kyphosis," "proximal junctional failure," "proximal junctional disease," and "adult spinal deformity." Finally, 103 papers were included in this study. Numerous factors have been suggested as potential risks for the development of PJK and PJF, including a high body mass index, inadequate postoperative sagittal balance and overcorrection, advanced age, pelvic instrumentation, and osteoporosis. Recently, with the increasing elderly population, sarcopenia has been emphasized. The quality and quantity of muscle in the surgical site have been suggested as new risk factor. Therefore, spine surgeon should understand the pathophysiology of PJK and PJF, as well as individual risk factors, in order to develop appropriate prevention strategies for each patient.

From the Spinopelvic Parameters to Global Alignment and Proportion Scores in Adult Spinal Deformity.

In the last 20 years, sagittal alignment and balance of the spine have become one of the most important issues in the field of spine surgery. Recent studies emphasize that sagittal balance and alignment are more important for health-related quality of life. The understanding of normal and abnormal sagittal alignment of the spine is necessary for the diagnosis and appropriate treatment of adult spinal deformity (ASD), and we will discuss the currently used classification of ASD, the parameters of sagittal alignment that are essential for the diagnosis of spinal deformity, compensatory actions to maintain sagittal balance, and the relationship between sagittal alignment and clinical symptoms. Furthermore, we will also discuss the recently introduced Global Alignment and Proportion scores. The Korean Spinal Deformity Society is publishing a series of review articles on spinal deformities to help spine surgeons better understand spinal deformities.

The Effect of Boron (B) and Copper (Cu) on the Microstructure and Graphite Morphology of Spheroidal Graphite Cast Iron.

This study examines the impacts of copper and boron in parts per million (ppm) on the microstructure and mechanical properties of spheroidal graphite cast iron (SCI). Boron's inclusion increases the ferrite content whereas copper augments the stability of pearlite. The interaction between the two significantly influences the ferrite content. Differential scanning calorimetry (DSC) analysis indicates that boron alters the enthalpy change of the α + Fe3C → γ conversion and the α → γ conversion. Scanning electron microscope (SEM) analysis confirms the locations of copper and boron. Mechanical property assessments using a universal testing machine show that the inclusion of boron and copper decreases the tensile strength and yield strength of SCI, but simultaneously enhances elongation. Additionally, in SCI production, the utilization of copper-bearing scrap and trace amounts of boron-containing scrap metal, especially in the casting of ferritic nodular cast iron, offers potential for resource recycling. This highlights the importance of resource conservation and recycling in advancing sustainable manufacturing practices. These findings provide critical insights into the effects of boron and copper on SCI's behavior, contributing to the design and development of high-performance SCI materials.

Performance Evaluation of MEMS-Based Automotive LiDAR Sensor and Its Simulation Model as per ASTM E3125-17 Standard.

Measurement performance evaluation of real and virtual automotive light detection and ranging (LiDAR) sensors is an active area of research. However, no commonly accepted automotive standards, metrics, or criteria exist to evaluate their measurement performance. ASTM International released the ASTM E3125-17 standard for the operational performance evaluation of 3D imaging systems commonly referred to as terrestrial laser scanners (TLS). This standard defines the specifications and static test procedures to evaluate the 3D imaging and point-to-point distance measurement performance of TLS. In this work, we have assessed the 3D imaging and point-to-point distance estimation performance of a commercial micro-electro-mechanical system (MEMS)-based automotive LiDAR sensor and its simulation model according to the test procedures defined in this standard. The static tests were performed in a laboratory environment. In addition, a subset of static tests was also performed at the proving ground in natural environmental conditions to determine the 3D imaging and point-to-point distance measurement performance of the real LiDAR sensor. In addition, real scenarios and environmental conditions were replicated in the virtual environment of a commercial software to verify the LiDAR model's working performance. The evaluation results show that the LiDAR sensor and its simulation model under analysis pass all the tests specified in the ASTM E3125-17 standard. This standard helps to understand whether sensor measurement errors are due to internal or external influences. We have also shown that the 3D imaging and point-to-point distance estimation performance of LiDAR sensors significantly impacts the working performance of the object recognition algorithm. That is why this standard can be beneficial in validating automotive real and virtual LiDAR sensors, at least in the early stage of development. Furthermore, the simulation and real measurements show good agreement on the point cloud and object recognition levels.

5 nm Ultrathin Crystalline Ferroelectric P(VDF-TrFE)-Brush Tuned for Hysteresis-Free Sub 60 mV dec-1 Negative-Capacitance Transistors.

Negative-capacitance field-effect transistors (NC-FETs) have gathered enormous interest as a way to reduce subthreshold swing (SS) and overcome the issue of power dissipation in modern integrated circuits. For stable NC behavior at low operating voltages, the development of ultrathin ferroelectrics (FE), which are compatible with the industrial process, is of great interest. Here, a new scalable ultrathin ferroelectric polymer layer is developed based on trichloromethyl (CCl3 )-terminated poly(vinylidene difluoride-co-trifloroethylene) (P(VDF-TrFE)) to achieve the state-of-the-art performance of NC-FETs. The crystalline phase of 5-10 nm ultrathin P(VDF-TrFE) is prepared on AlOX by a newly developed brush method, which enables an FE/dielectric (DE) bilayer. FE/DE thickness ratios are then systematically tuned at ease to achieve ideal capacitance matching. NC-FETs with optimized FE/DE thickness at a thickness limit demonstrate hysteresis-free operation with an SS of 28 mV dec-1 at ≈1.5 V, which competes with the best reports. This P(VDF-TrFE)-brush layer can be broadly adapted to NC-FETs, opening an exciting avenue for low-power devices.

Sacropelvic Fixation for Adult Deformity Surgery Comparing Iliac Screw and Sacral 2 Alar-Iliac Screw Fixation: Systematic Review and Updated Meta-Analysis.

OBJECTIVE: Two commonly used techniques for spinopelvic fixation in adult deformity surgery are iliac screw (IS) and sacral 2 alar-iliac screw (S2AI) fixations. In this article, we systematically meta-analyzed the complications of sacropelvic fixation for adult deformity surgery comparing IS and S2AI. METHODS: The PubMed, Embase, Web of Science, and Cochrane clinical trial databases were systematically searched until March 29, 2023. The proportion of postoperative complications, including implant failure, revision, screw prominence, and wound complications after sacropelvic fixation, were pooled with a random-effects model. Subgroup analyses for the method of sacropelvic fixation were conducted. RESULTS: Ten studies with a total of 1,931 patients (IS, 925 patients; S2AI, 1,006 patients) were included. The pooled proportion of implant failure was not statistically different between the IS and S2AI groups (21.9% and 18.9%, respectively) (p = 0.59). However, revision was higher in the IS group (21.0%) than that in the S2AI group (8.5%) (p = 0.02). Additionally, screw prominence was higher in the IS group (9.6%) than that in the S2AI group (0.0%) (p < 0.01), and wound complication was also higher in the IS group (31.7%) than that in the S2AI group (3.9%) (p < 0.01). CONCLUSION: IS and S2AI fixations showed that both techniques had similar outcomes in terms of implant failure. However, S2AI was revealed to have better outcomes than IS in terms of revision, screw prominence, and wound complications.

Damage-Free Charge Transfer Doping of 2D Transition Metal Dichalcogenide Channels by van der Waals Stamping of MoO3 and LiF.

To dope 2D semiconductor channels, charge-transfer doping has generally been done by thermal deposition of inorganic or organic thin-film layers on top of the 2D channel in bottom-gate field-effect transistors (FETs). The doping effects are reproducible in most cases. However, such thermal deposition will damage the surface of 2D channels due to the kinetic energy of depositing atoms, causing hysteresis or certain degradation. Here, a more desirable charge-transfer doping process is suggested. A damage-free charge-transfer doping is conducted for 2D MoTe2 (or MoS2 ) channels using a polydimethylsiloxane stamp. MoO3 or LiF is initially deposited on the stamp as a doping medium. Hysteresis-minimized transfer characteristics are achieved from stamp-doped FETs, while other devices with direct thermal deposition-doped channels show large hysteresis. The stamping method seems to induce a van der Waals-like damage-free interface between the channel and doping media. The stamp-induced doping is also well applied for a MoTe2 -based complementary inverter because MoO3 - and LiF-doping by separate stamps effectively modifies two ambipolar MoTe2 channels to p- and n-type, respectively.

Dramatic Reduction of Contact Resistance via Ultrathin LiF in Two-Dimensional MoS2 Field Effect Transistors.

Molybdenum disulfide (MoS2) has been regarded as one of the most important n-type two-dimensional (2D) transition metal dichalcogenide semiconductors for nanoscale electron devices. Relatively high contact resistance (RC) remains as an issue in the 2D-devices yet to be resolved. Reliable technique is very compelling to practically produce low RC values in device electronics, although scientific approaches have been made to obtain a record-low RC. To resolve this practical issue, we here use thermal-evaporated ultrathin LiF between channel and source/drain metal to fabricate 2D-like MoS2 field effect transistors (FETs) with minimum RC. Under 4-bar FET method, RC less than ∼600 Ω·µm is achieved from the LiF/Au contact MoS2 FET. Our normal 2-bar FET with LiF thus shows the same mobility as that of 4-bar FET that should have no RC in principle. On the basis of these results, ultrathin LiF is also applied for transparent conducting oxide contact, successfully enabling transparent MoS2 FETs.

High-Performance van der Waals Junction Field-Effect Transistors Utilizing Organic Molecule/Transition Metal Dichalcogenide Interface.

Two-dimensional (2D) transition metal dichalcogenide (TMD) hetero PN junctions with a van der Waals (vdW) interface have received much attention, because PN diodes are basically important to control the vertical current across the junction. Interestingly, the same vdW PN junction structure can be utilized for junction field-effect transistors (JFETs) where in-plane current is controlled along the junction. However, 2D vdW JFETs seem rarely reported, despite their own advantages to achieve when good vdW junction is secured. Here, we present high-performance p-MoTe2 JFETs using almost perfect vdW organic Alq3/p-MoTe2 junctions and demonstrate organic NPB/n-MoS2 JFETs. The p- and n-channel JFETs stably show high mobilities of 60-80 and ∼800 cm2/V s, respectively, along with a high ON/OFF current ratio (>1 × 105) and minimal gate leakage at 5 V even after a few months. Such performances are attributed to a quality vdW junction at organic layer/TMD interfaces.

Clinical Features and Treatment Outcomes of Acute Multiple Thoracic and Lumbar Spinal Fractures : A Comparison of Continuous and Noncontinuous Fractures.

OBJECTIVE: The treatment of multiple thoracolumbar spine fractures according to fracture continuity has rarely been reported. Herein we evaluate the clinical features and outcomes of multiple thoracolumbar fractures depending on continuous or noncontinuous status. METHODS: From January 2010 to January 2016, 48 patients with acute thoracic and lumbar multiple fractures who underwent posterior fusion surgery were evaluated. Patients were divided into two groups (group A : continuous; group B : noncontinuous). We investigated the causes of the injuries, the locations of the injuries, the range of fusion levels, and the functional outcomes based on the patients' general characteristics. RESULTS: A total of 48 patients were enrolled (group A : 25 patients; group B : 23 patients). Both groups had similar pre-surgical clinical and radiologic features. The fusion level included three segments (group A : 4; group B : 5) or four segments (group A : 19; group B : 5). Group B required more instrumented segments than did group A. Group A scored 23.5 and group B scored 33.4 on the Korean Oswestry Disability Index (KODI) at the time of last follow-up. In both groups, longer fusion was associated with worse KODI score. CONCLUSION: In this study, due to the assumption of similar initial clinical and radiologic features in both group, the mechanism of multiple fractures is presumed to be the same between continuous and noncontinuous fractures. The noncontinuous fracture group had worse KODI scores in long-term follow-up, thought to be due to long fusion level. Therefore, we recommend minimizing the number of segments that are fused in multiple thoracolumbar and lumbar fractures when decompression is not necessary.

Impact of Organic Molecule-Induced Charge Transfer on Operating Voltage Control of Both n-MoS2 and p-MoTe2 Transistors.

Since transition metal dichalcogenide (TMD) semiconductors are found as two-dimensional van der Waals materials with a discrete energy bandgap, many TMD based field effect transistors (FETs) are reported as prototype devices. However, overall reports indicate that threshold voltage ( Vth) of those FETs are located far away from 0 V whether the channel is p- or n-type. This definitely causes high switching voltage and unintended OFF-state leakage current. Here, a facile way to simultaneously modulate the Vth of both p- and n-channel FETs with TMDs is reported. The deposition of various organic small molecules on the channel results in charge transfer between the organic molecule and TMD channels. Especially, HAT-CN molecule is found to ideally work for both p- and n-channels, shifting their Vth toward 0 V concurrently. As a proof of concept, a complementary metal oxide semiconductor (CMOS) inverter with p-MoTe2 and n-MoS2 channels shows superior voltage gain and minimal power consumption after HAT-CN deposition, compared to its initial performance. When the same TMD FETs of the CMOS structure are integrated into an OLED pixel circuit for ambipolar switching, the circuit with HAT-CN film demonstrates complete ON/OFF switching of OLED pixel, which was not switched off without HAT-CN.

Langerhans Cell Histiocytosis of the Thoracic Spine in an Adult.

We report a case of a 45-year-old man with a complaint of both leg weakness and hypoesthesia. Radiological evaluation revealed an osteolytic lesion of the ninth thoracic vertebra. The patient underwent posterior corpectomy with total excision of the tumor, mesh cage insertion with posterior screw fixation and subsequent radiotherapy. Histology confirmed the diagnosis of Langerhans cell histiocytosis (LCH). This case report presents the diagnostic work-up, histopathological evaluation, and the treatment procedures of rare LCH in the thoracic spine.

Posterior Vertebrectomy and Circumferential Fusion for the Treatment of Advanced Thoracolumbar Kümmell Disease with Neurologic Deficit.

STUDY DESIGN: Single-center, retrospective case series. PURPOSE: To investigate the effectiveness of posterior vertebrectomy and circumferential fusion in patients with advanced Kümmell disease with neurologic deficit. OVERVIEW OF LITERATURE: Various surgical options exist for the treatment of Kümmell disease, and determination of the appropriate treatment is based on the clinical and radiologic status of the patient. However, surgical intervention is required for patients with advanced Kümmell disease accompanied by neurologic deficit. METHODS: We retrospectively analyzed 22 neurologically compromised patients with advanced Kümmell disease who were treated surgically at Ewha Womans Hospital between January 2011 and January 2014. The surgical approach used by us was a posterior vertebrectomy with mesh cage insertion and segmental cement-augmented pedicle screw fixation. The tissue from the corpectomy was histopathologically examined. Anterior vertebral height, kyphotic angle, visual analog scale (VAS) score, and the Frankel classification were used to evaluate the efficacy of the procedure. RESULTS: The mean follow-up period was 26 months (range, 13-40 months). VAS score, anterior vertebral height, kyphotic angle, and neurologic state were significantly improved immediately postoperatively and at the last follow-up compared with preoperatively (p<0.05). Most patients exhibited intravertebral clefts on imaging, and postoperative pathology revealed bone necrosis. CONCLUSIONS: Posterior vertebrectomy with mesh cage insertion and segmental cement-augmented pedicle screw fixation is an effective approach for treating patients with advanced Kümmell disease with neurologic deficit.

Evaluation of Global Sagittal Balance in Koreans Adults.

OBJECTVIE: The global sagittal postural patterns as characterized by Roussouly classification have been previously described in various ethnicities, there were no studies investigated in Koreans. To analyze the distribution of the global sagittal postural patterns in Korean adults using Roussouly classification, the author prospectively studied. METHODS: 252 asymptomatic Korean adults was recruited. Data was obtained by reviewing the films for each subject. Spinopelvic parameters were measured and sagittal postural patterns were then determined according to Roussouly classification. We compared the data across different ethnicities from our study and a previous study to further characterize Korean sagittal postures. RESULTS: The subject included 151 males and 101 females, with mean age of 33.2±8.2 years. The average descriptive results were as below: thoracic kyphosis 28.6±7.7°, lumbar lordosis 48.3±10.2°, sacral slope 37.8±5.8°, pelvic incidence 45.1±7.5°, pelvic tilt 9.4±6.7°, spinosacral angle 130.1±5.4°, and sagittal vertical axis 16.25±22.5 mm. 125 subjects among 252 (49.6%) belonged to Roussouly type 3 (namely neutral). There were also 58 (23%), 33 (13.1%), and 36 (14.3) subjects in type 1, 2, and 4 (namely non-neutral), respectively. CONCLUSION: Enrolling 252 asymptomatic Korean adults, this prospective study found that 49.6% of asymptomatic Korean adults possessed a sagittal posture of Roussouly type 3. All radiologic parameters follows general concept of spinal sagittal balance pattern. Overall, this study might be a basis for further investigation of spinal sagittal balance.

The Change of Range of Motion at Anterior Compression of the Cervical Cord after Laminoplasty in Patients with Cervical Spondylotic Myelopathy.

OBJECTIVE: Degenerative diseases of the spine, such as cervical spondylotic myelopathy (CSM), are increasing among the old age population, and surgical treatment of CSM is becoming more and more common. The aim of this study was to investigate how functional recovery can be influenced by anterior compression of the spinal cord (ACS) after laminoplasty for treatment of patients with CSM. METHODS: We retrospectively analyzed 32 patients admitted to Ewha Womans Mok-Dong Hospital with CSM who underwent open-door laminoplasty from January 2012 to December 2014. We divided patients into 2 groups according to whether ACS was or not preoperatively. Each group was analyzed clinical and radiological parameters which were Japanese Orthopedic Association (JOA) scores and its recovery rate, sagittal alignment and range of motion (ROM). RESULTS: The mean duration of symptom was 11.2 months (range, 6-22 months). A significant difference in recovery rate of the total JOA score was shown between the 2 groups, especially upper extremity motor function. No difference in preoperative JOA score between the 2 groups, but recovery rate of each group was 20.05%±18.1%, 32.21%±25.4%, statistically significant (p<0.005). Upper motor and sensory function was not significantly different in the 2 groups. Preoperative, postoperative and preservation of ROM was 44.3°±10.1°, 41.8°±15.7°, 87.9%±35.4% each at ACS (-) group. A significant difference in postoperative ROM was identified between ACS (-) and ACS (+) group. Postoperative anterior compression of the spinal cord was recognized 14 cases which were classified from its causes. CONCLUSION: Cervical ROM decreased significantly after laminoplasty, but 85.3% of the preoperative ROM was preserved. The postoperative reduction of ROM in group with anterior compression of spinal cord was identified.

An assessment of survival among Korean elderly patients initiating dialysis: a national population-based study.

BACKGROUND: Although the proportion of the elderly patients with incident end-stage renal disease (ESRD) patients has been increasing in Korea, there has been a lack of information on outcomes of dialysis treatment. This study aimed to assess the survival rate and to elucidate predictors for all-cause mortality among elderly Korean patients initiating dialysis. METHODS: We analyzed 11,301 patients (6,138 men) aged 65 years or older who had initiated dialysis from 2005 to 2008 and had followed up (median, 37.8 months; range, 3-84 months). Baseline demographics, comorbidities and mortality data were obtained using the database from the Health Insurance Review & Assessment Service. RESULTS: The unadjusted 5-year survival rate was 37.6% for all elderly dialysis patients, and the rate decreased with increasing age categories; 45.9% (65∼69), 37.5% (70∼74), 28.4% (75∼79), 24.1% (80∼84), and 13.7% (≥85 years). The multivariate Cox proportional hazard model revealed that age, sex, dialysis modality, the type of insurance, and comorbidities such as diabetes mellitus, myocardial infarction, congestive heart failure, peripheral vascular disease, cerebrovascular disease, dementia, chronic pulmonary disease, hemiparesis, liver disease, and any malignancy were independent predictors for mortality. In addition, survival rate was significantly higher in patients on hemodialysis compared to patients on peritoneal dialysis during the whole follow-up period in the intention-to-treat analysis. CONCLUSIONS: Survival rate was significantly associated with age, sex, and various comorbidities in Korean elderly patients initiating dialysis. The results of our study can help to provide relevant guidance on the individualization strategy in elderly ESRD patients requiring dialysis.

Unusual Intracranial Parasagittal Meningioma Extending into the Internal Jugular Vein through the Sinuses.

Meningiomas frequently invade cerebral venus sinuses, especially parasagittal meningioma to superior sagittal sinus. However, most invasions do not reach internal jugular vein. We present a case of parasagittal meningioma extending into the internal jugular vein through the sinuses. Radiological investigation revealed that the tumor was invading the sagittal, transverse, sigmoid sinus and junction of the internal jugular vein to subclavian vein, which was filled with tumor. The histopathological examinations revealed that both the cerebral tumor and mass in the internal jugular vein contributed to the transitional meningioma. This is a rare case of a meningioma extending into the internal jugular vein through the sinuses. According to this case, the frontal parasagittal meningioma could invade directly the internal jugular vein. The significance of this association to cerebral venus sinuses and internal jugular vein are discussed.

Hydrothorax due to migration of ventriculoperitoneal shunt catheter.

A cerebrospinal fluid hydrothorax is a very rare complication following ventriculoperitoneal (VP) shunt and usually reported in children. We report a case of 47-year-old woman who developed massive hydrothorax and respiratory distress following intrathoracic migration of distal shunt catheter. After the confirmation of catheter in thoracic cavity using radionuclide shuntogram, the patient was successfully treated with laparoscopic shunt catheter reposition.