Regional classification of high PM10 concentrations in the Seoul metropolitan and Chungcheongnam-do areas, Republic of Korea.

Since the Seoul metropolitan area is a highly developed megacity, many people are often exposed to high concentrations of particulate matter (PM), with mean aerodynamic diameters equal to or less than 10 µm (PM10), in cold seasons. PM10 concentrations can be influenced by a combination of various factors, including meteorological conditions, anthropogenic emissions, atmospheric chemical reactions, transboundary transport, and geographic characteristics. However, the establishment of an efficient air quality management plan remains challenging due to the limited understanding of the regional PM concentration characteristics. Here, the Seoul metropolitan (Seoul, Gyeonggi-do, and Incheon) and Chungcheongnam-do (Chungcheongnam-do, Daejeon, and Sejong) areas were regionally classified to identify the spatiotemporal air quality in areas where megacities and emission sources are mixed. The four representative regions were determined using the K-means clustering method based on the temporal variations in the observed PM10 concentrations. The first cluster consisted of small cities in the southern and eastern parts of Gyeonggi-do and Chungcheongnam-do, respectively, while the second cluster consisted of Incheon, West Gyeonggi-do, and Seoul. In addition, the third and fourth clusters included West Chungcheongnam-do and East Gyeonggi-do, which are adjacent to the Yellow Sea and downstream area of the westerly wind, respectively. The characteristics of each cluster during the high PM10 concentration events are explainable by wind patterns and the local air pollutant emissions, including nitrogen oxides and sulfur oxides. The obtained regional classification was different from the provincial-level administrative division of South Korea. Therefore, the present study is expected to be a scientific basis for overcoming the limitations of air quality management in administrative districts.

Childhood Acute Lymphoblastic Leukemia Showing Unilateral Motor Dysfunction Prior to Chemotherapy: A Diffusion Tensor Tractography Study.

This study aimed to evaluate children with lymphoblastic leukemia and examine the potential correlation between corticospinal tract (CST) injury and motor dysfunction prior to chemotherapy using diffusion tensor tractography (DTT). Nineteen consecutive patients with childhood leukemia (mean age 7.483 ± 3.1 years, range 4-12 years) with unilateral motor dysfunction who underwent DTT prior to chemotherapy and twenty healthy individuals (mean age 7.478 ± 1.2 years; range 4-12 years) were enrolled. Motor functions were evaluated by two independent investigators. The cause of neurological dysfunction was identified based on the CST state using mean fractional anisotropy (FA), mean fiber volume (FV), and CST integrity using DTT. All patients showed disrupted integrity and significantly decreased FA and FV in the affected CST compared to the unaffected CST and the control group (p < 0.05). These DTT results also corresponded to patients' unilateral motor dysfunction. Using DTT, we demonstrated that neurological dysfunction may occur in patients with childhood acute lymphoblastic leukemia even prior to chemotherapy, and that CST injuries correlate with motor dysfunction in these patients. DTT may be a useful modality for evaluating the neural tract state in pediatric leukemia patients with neurological dysfunction.

Disruption of the Corticospinal Tract in Patients with Acute Lymphoblastic Leukemia: A Case Series.

Three patients who exhibited hemiplegic symptoms on conventional brain magnetic resonance imaging (MRI), during maintenance treatment for acute lymphoblastic leukemia, are reported. All patients exhibited unilateral motor weakness and poor hand function during chemotherapy. Conventional MRI revealed no definite abnormal lesions. However, in diffusion tensor tractography, the affected corticospinal tract on the contralateral side, consistently with clinical dysfunction, revealed disrupted integrity, decreased fractional anisotropy, and increased apparent diffusion coefficient compared to the results of the unaffected side or control participants. Control participants matched for age, sex, and duration from leukemia diagnosis, who underwent chemotherapy but had no motor impairments, exhibited preserved integrity of both corticospinal tracts. Diffusion tensor tractography can help evaluate patients with acute lymphoblastic leukemia and neurological dysfunction.

Spinal cord injury by direct damage during trigger point injection: a case report.

Trigger point injection (TPI) is commonly administered for myofascial pain syndrome management, but occasionally leads to complications, including bleeding, muscle hematoma, vasovagal syncope, skin infections, and pneumothorax. This report presents a case of TPI-induced iatrogenic spinal cord injury (SCI). A 59-year-old woman received TPI for myofascial pain on both thoracolumbar paraspinal muscles. She experienced an electric shock sensation throughout the lower extremities upon receiving blind TPI in the left thoracolumbar paraspinal muscle, and later complained of weakness (manual muscle test grade: 0-2) and neuropathic pain (numeric rating scale [NRS]: 7) in the lower left extremity. Thoracolumbar magnetic resonance imaging (MRI) 3 days after the TPI revealed a high-intensity T2 signal in the left T12 to L2 spinal cord segments, indicating the presence of edema or inflammation in this region. In concordance with the MRI findings, electrophysiological recordings performed 11 days after the TPI revealed no central motor conduction time response in the left leg. At 7 months post-onset, the patient had partially recovered motor function and neuropathic pain was reduced to NRS 4. Clinicians should be aware of the possibility of needle-induced SCI during paraspinal muscle TPI; imaging guidance may be helpful for accurate needle targeting during the procedure.

Ultrasonographic and magnetic resonance images of a gluteus maximus tear.

The diagnosis of a gluteal muscle tear or strain is based on clinical findings. However, for an accurate diagnosis, imaging examinations are also needed. Herein, we describe the case of a patient with a gluteus maximus muscle tear confirmed by ultrasonography (US) and magnetic resonance imaging (MRI). A 58-year-old woman complained of dull pain in the left lateral gluteal region that she had been experiencing for 8 days. In the axial US image, retraction of the left gluteus maximus muscle was noted around its insertion site in the iliotibial band. On an MRI, a partial tear in the left gluteus maximus was observed at its insertion site in the left iliotibial band. In addition, fluid infiltration due to edema and hemorrhage was observed. A partial left gluteal muscle tear was diagnosed. The patient was treated with physical therapy at the involved region and oral analgesics. She reported relief from the pain after 1 month of treatment. Based on this experience, we recommend US or MRI for accurate diagnosis of muscle tear or strain.

Correlation Between D-Dimer Level and Deep Venous Thrombosis in Patients With Acute Spinal Cord Injuries.

OBJECTIVE: Venous thromboembolism is a serious life-threatening complication of S SCI. Measurement of D-dimer levels is used as a screening test for deep vein thrombosis. However, trauma, surgery, and motor weakness are known as factors that affect D-dimer levels. Thus, the aim of this study was to examine the correlation between D-dimer levels and deep vein thrombosis in relation to the comorbidities in acute spinal cord injury. DESIGN: A retrospective observational study was conducted at a hospital's rehabilitation department. Forty-five patients without pharmacologic thromboembolic thromboprophylaxis 5-90 days after the onset of injury were enrolled. RESULTS: Fourteen patients (31%) were diagnosed with deep vein thrombosis using duplex ultrasonography. The mean ± SD D-dimer levels were 2.15 ± 2.74 and 6.98 ± 7.46 µg/ml in the deep vein thrombosis-negative and deep vein thrombosis-positive groups, respectively. The lower limb motor index scores significantly correlated with D-dimer levels regardless of the time between the onset of spinal cord injury and D-dimer testing. Patients with trauma had significantly increased D-dimer levels compared with patients without trauma. CONCLUSION: Although D-dimer levels have limitations with regard to the positive prediction of acute spinal cord injury, it is a useful screening parameter for deep vein thrombosis. Trauma and lower limb motor weakness should be considered when analyzing D-dimer levels.

Findings of lymphoscintigraphy and the severity of lymphedema according to the extent of axillary lymph node dissection.

BACKGROUND: Lymphedema of the upper extremity is a common disease in breast cancer patients following breast cancer operation accompanied by lymphadenectomy. However, clinically, there is a discrepancy between the extent of axillary lymph node dissection (ALND) and the severity of lymphedema. Therefore, we investigated the relationship between the severity of lymphedema following breast cancer operation, including ALND, and axillary lymph node findings on lymphoscintigraphy. METHODS: Eighty-two patients with lymphedema following breast cancer operation with ALND (82 women; mean age 55.57 ± 9.39, range 36-65) were retrospectively recruited. Lymphoscintigraphy was conducted after an average of 5.44 ± 2.01 months following operation. Percentage differences in the circumference of the upper extremities between affected and unaffected sides were used as a severity index. RESULTS: Percentage differences in the circumference of the upper extremities in a positive and negative group in lymphoscintigraphy were 3.42 ± 2.47% and 12.87 ± 10.23% in the mid-arm respectively (p < 0.05), and 3.36 ± 3.80% and 12.83 ± 10.00% in the mid-forearm respectively (p < 0.05). However, the extent of lymph node dissection and the difference in the circumference of mid-arm and mid-forearm volume did not have a statistically significant relationship. CONCLUSION: Lymph node activity in the proximal upper extremity is not related to the extent of ALND. The existence of a bypass connection and remainder function of a lymph node is crucial for the severity of lymphedema.

The Relation Between Loss of Consciousness, Severity of Traumatic Brain Injury, and Injury of Ascending Reticular Activating System in Patients With Traumatic Brain Injury.

OBJECTIVE: Loss of consciousness is an indicator of the severity of traumatic brain injury and the ascending reticular activating system has been considered as a main structure for consciousness. However, no study on the relation between loss of consciousness and ascending reticular activating system injury in traumatic brain injury has been reported. We investigated the relation between loss of consciousness, severity of traumatic brain injury, and ascending reticular activating system injury using diffusion tensor tractography. DESIGN: One hundred twenty patients were recruited. Three components of ascending reticular activating system, fractional anisotropy, and tract volume were measured. RESULTS: In lower dorsal and ventral ascending reticular activating system, fractional anisotropy and tract volume value in mild group were higher than those of moderate and severe groups, and there was no difference between moderate and severe groups. In upper ascending reticular activating system, fractional anisotropy value in mild group was higher than in moderate group, and it was higher than in moderate group than in severe group. Tract volume value in mild group was higher than in severe group. Loss of consciousness showed moderate negative correlations with tract volume value of lower dorsal ascending reticular activating system (r = -0.348), fractional anisotropy value of lower ventral ascending reticular activating system (r = -0.343), and fractional anisotropy value of upper ascending reticular activating system (r = -0.416). CONCLUSIONS: Injury severity was different among the three traumatic brain injury groups in upper ascending reticular activating system but did not differ between moderate and severe groups in lower dorsal and ventral ascending reticular activating system.

Size-dependent characteristics of diurnal particle concentration variation in an underground subway tunnel.

Understanding characteristics of diurnal particle concentration variation in an underground subway tunnel is important to reduce subway passengers' exposure to high levels of toxic particle pollution. In this study, real-time particle monitoring for eight consecutive days was done at a shelter located in the middle of a one-way underground subway tunnel in Seoul, Republic of Korea, during the summer of 2015. Particle mass concentration was measured using a dust monitor and particle number concentration using an optical particle counter. From the diurnal variations in PM10, PM2.5, and PM1, concentrations of particles larger than 0.54 µm optical particle diameter were affected by train frequency whereas those of particles smaller than 0.54 µm optical particle diameter were not changed by train frequency. Number concentration of particles smaller than 1.15 µm optical particle diameter was dependent on outdoor ambient air particle concentration level, whereas that of particles larger than 1.15 µm optical particle diameter was independent of outdoor ambient air due to low ventilation system transmission efficiency of micrometer-sized particles. In addition, an equation was suggested to predict the diurnal particle concentration in an underground tunnel by considering emission, ventilation, and deposition effects.

Functional identification of oleate 12-desaturase and ω-3 fatty acid desaturase genes from Perilla frutescens var. frutescens.

KEY MESSAGE: We described identification, expression, subcellular localization, and functions of genes that encode fatty acid desaturase enzymes in Perilla frutescens var. frutescens. Perilla (Perilla frutescens var. frutescens) seeds contain approximately 40 % of oil, of which α-linolenic acid (18:3) comprise more than 60 % in seed oil and 56 % of total fatty acids (FAs) in leaf, respectively. In perilla, endoplasmic reticulum (ER)-localized and chloroplast-localized ω-3 FA desaturase genes (PfrFAD3 and PfrFAD7, respectively) have already been reported, however, microsomal oleate 12-desaturase gene (PfrFAD2) has not yet. Here, four perilla FA desaturase genes, PfrFAD2-1, PfrFAD2-2, PfrFAD3-2 and PfrFAD7-2, were newly identified and characterized using random amplification of complementary DNA ends and sequence data from RNAseq analysis, respectively. According to the data of transcriptome and gene cloning, perilla expresses two PfrFAD2 and PfrFAD3 genes, respectively, coding for proteins that possess three histidine boxes, transmembrane domains, and an ER retrieval motif at its C-terminal, and two chloroplast-localized ω-3 FA desaturase genes, PfrFAD7-1 and PfrFAD7-2. Arabidopsis protoplasts transformed with perilla genes fused to green fluorescence protein gene demonstrated that PfrFAD2-1 and PfrFAD3-2 were localized in the ER, and PfrFAD7-1 and PfrFAD7-2 were localized in the chloroplasts. PfrFAD2 and perilla ω-3 FA desaturases were functional in budding yeast (Saccharomyces cerevisiae) indicated by the presence of 18:2 and 16:2 in yeast harboring the PfrFAD2 gene. 18:2 supplementation of yeast harboring ω-3 FA desaturase gene led to the production of 18:3. Therefore, perilla expresses two functional FAD2 and FAD3 genes, and two chloroplast-localized ω-3 FA desaturase genes, which support an evidence that P. frutescens cultivar is allotetraploid plant.

Detection of Carbonaceous Aerosols Released in CNT Workplaces Using an Aethalometer.

OBJECTIVES: Black carbon (BC) originating from various combustion sources has been extensively surveyed to characterize the effects of BC on global warming and human health, and many online monitors are available. In this study, BC was considered as a surrogate for carbon-based nanomaterials in an occupational health study. METHODS: Specifically, BC concentrations were monitored continuously with an aethalometer for 24h at four carbon nanotube (CNT) workplaces located in rural, urban, and industrial areas, which had different background air pollution levels. Average BC concentrations for both nonworking (background) and working periods were compared with the recommended exposure limit (REL) of 1 µg m(-3) for elemental carbon that was suggested by the National Institute for Occupational Safety and Health (NIOSH). RESULTS: Diurnal variation of BC concentrations indicated that BC measurements corresponded well with carbonaceous aerosols such as vehicle exhaust particles and CNT aerosols. In the rural CNT workplace, the average background BC concentration (0.36 µg m(-3)) was lower than the REL, but the BC concentration without background correction was higher than the REL during manufacturing hours. In this case, BC measurement is useful to estimate CNT exposure for comparison with the REL. Conversely, in the urban and industrial CNT workplaces, average background BC concentrations (2.05, 1.82, and 2.64 µg m(-3)) were well above the REL, and during working hours, BC concentrations were substantially higher than the background level at workplace C; however, BC concentrations showed no difference from the background levels at workplaces B and D. In these cases (B and D), it is hard to determine CNT exposure because of the substantial environmental exposures. CONCLUSION: Most of the urban ambient BC concentrations were above the REL. Therefore, further analysis and test methods for carbonaceous aerosols need to be developed so that the exposure assessment can be easily carried out at CNT workplaces with high background BC levels such as in urban and industrial areas.

Generation of Nanoparticles from Friction between Railway Brake Disks and Pads.

In this study, we measured the size distribution of particles ranging in size from 5.6 to 560 nm that were emitted between brake disks and pads under various braking conditions to observe and analyze changes to the resulting particle size distribution over braking time. A peak of 178-275 nm (200 nm peak) was observed in all braking conditions. However, the generation of spherical particles of a 10 nm range was observed only when the disk speed and brake force were above certain levels and intensified only when speed and brake force further increased. The total number concentration of ultrafine particles (no larger than 0.1 µm; PM0.1) generated was found to correlate with disk speed and brake force. Thus, the generation of nanoparticles resulting from disk speed and brake force was attributable primarily to increases in the contact surface temperature. The critical temperature for the generation of nanoparticles of a 10 nm range was found to be about 70 °C, which is the average temperature between the surface and the inside of the disk. If the speed or brake force was higher, that is, the temperature of the contact surface reached a certain level, evaporation and condensation took place. Vapor then left the friction surface, met with the air, and quickly cooled to form nanoparticles through nucleation. When the newly generated particles became highly concentrated, they grew through coagulation to form agglomerates or the vapor condensed directly onto the surface of existing particles of about 200 nm (formed by mechanical friction).

Heterologous Reconstitution of Omega-3 Polyunsaturated Fatty Acids in Arabidopsis.

Reconstitution of nonnative, very-long-chain polyunsaturated fatty acid (VLC-PUFA) biosynthetic pathways in Arabidopsis thaliana was undertaken. The introduction of three primary biosynthetic activities to cells requires the stable coexpression of multiple proteins within the same cell. Herein, we report that C22 VLC-PUFAs were synthesized from C18 precursors by reactions catalyzed by Δ(6)-desaturase, an ELOVL5-like enzyme involved in VLC-PUFA elongation, and Δ(5)-desaturase. Coexpression of the corresponding genes (McD6DES, AsELOVL5, and PtD5DES) under the control of the seed-specific vicilin promoter resulted in production of docosapentaenoic acid (22:5 n-3) and docosatetraenoic acid (22:4 n-6) as well as eicosapentaenoic acid (20:5 n-3) and arachidonic acid (20:4 n-6) in Arabidopsis seeds. The contributions of the transgenic enzymes and endogenous fatty acid metabolism were determined. Specifically, the reasonable synthesis of omega-3 stearidonic acid (18:4 n-3) could be a useful tool to obtain a sustainable system for the production of omega-3 fatty acids in seeds of a transgenic T3 line 63-1. The results indicated that coexpression of the three proteins was stable. Therefore, this study suggests that metabolic engineering of oilseed crops to produce VLC-PUFAs is feasible.

Workplace Exposure to Titanium Dioxide Nanopowder Released from a Bag Filter System.

Many researchers who use laboratory-scale synthesis systems to manufacture nanomaterials could be easily exposed to airborne nanomaterials during the research and development stage. This study used various real-time aerosol detectors to investigate the presence of nanoaerosols in a laboratory used to manufacture titanium dioxide (TiO2). The TiO2 nanopowders were produced via flame synthesis and collected by a bag filter system for subsequent harvesting. Highly concentrated nanopowders were released from the outlet of the bag filter system into the laboratory. The fractional particle collection efficiency of the bag filter system was only 20% at particle diameter of 100 nm, which is much lower than the performance of a high-efficiency particulate air (HEPA) filter. Furthermore, the laboratory hood system was inadequate to fully exhaust the air discharged from the bag filter system. Unbalanced air flow rates between bag filter and laboratory hood systems could result in high exposure to nanopowder in laboratory settings. Finally, we simulated behavior of nanopowders released in the laboratory using computational fluid dynamics (CFD).

Senescence-inducible LEC2 enhances triacylglycerol accumulation in leaves without negatively affecting plant growth.

The synthesis of fatty acids and glycerolipids in wild-type Arabidopsis leaves does not typically lead to strong triacylglycerol (TAG) accumulation. LEAFY COTYLEDON2 (LEC2) is a master regulator of seed maturation and oil accumulation in seeds. Constitutive ectopic LEC2 expression causes somatic embryogenesis and defects in seedling growth. Here, we report that senescence-inducible LEC2 expression caused a threefold increase in TAG levels in transgenic leaves compared with that in the leaves of wild-type plants. Plant growth was not severely affected by the accumulation the TAG in response to LEC2 expression. The levels of plastid-synthesized lipids, mono- and di-galactosyldiacylglycerol and phosphatidylglycerol were reduced more in senescence-induced LEC2 than in endoplasmic reticulum-synthesized lipids, including phosphatidylcholine, phosphatidylethanolamine and phosphatidylinositol. Senescence-induced LEC2 up-regulated the expression of many genes involved in fatty acid and TAG biosynthesis at precise times in senescent leaves, including WRINKLED1 (WRI1), which encodes a fatty acid transcription factor. The expressions of glycerol-3-phosphate dehydrogenase 1 and phospholipid:diacylglycerol 2 were increased in the transgenic leaves. Five seed-type oleosin-encoding genes, expressed during oil-body formation, and the seed-specific FAE1 gene, which encodes the enzyme responsible for the synthesis of C20:1 and C22:1 fatty acids, were also expressed at higher levels in senescing transgenic leaves than in wild-type leaves. Senescence-inducible LEC2 triggers the key metabolic steps that increase TAG accumulation in vegetative tissues.

Translating building information modeling to building energy modeling using model view definition.

This paper presents a new approach to translate between Building Information Modeling (BIM) and Building Energy Modeling (BEM) that uses Modelica, an object-oriented declarative, equation-based simulation environment. The approach (BIM2BEM) has been developed using a data modeling method to enable seamless model translations of building geometry, materials, and topology. Using data modeling, we created a Model View Definition (MVD) consisting of a process model and a class diagram. The process model demonstrates object-mapping between BIM and Modelica-based BEM (ModelicaBEM) and facilitates the definition of required information during model translations. The class diagram represents the information and object relationships to produce a class package intermediate between the BIM and BEM. The implementation of the intermediate class package enables system interface (Revit2Modelica) development for automatic BIM data translation into ModelicaBEM. In order to demonstrate and validate our approach, simulation result comparisons have been conducted via three test cases using (1) the BIM-based Modelica models generated from Revit2Modelica and (2) BEM models manually created using LBNL Modelica Buildings library. Our implementation shows that BIM2BEM (1) enables BIM models to be translated into ModelicaBEM models, (2) enables system interface development based on the MVD for thermal simulation, and (3) facilitates the reuse of original BIM data into building energy simulation without an import/export process.

Performance evaluation of advanced industrial SPECT system with diverging collimator.

An advanced industrial SPECT system with 12-fold-array diverging collimator was developed for flow visualization in industrial reactors and was discussed in the previous study. The present paper describes performance evaluation of the SPECT system under both static- and dynamic- flow conditions. Under static conditions, the movement of radiotracer inside the test reactor was compared with that of color tracer (blue ink) captured with a high-speed camera. The comparison of the reconstructed images obtained with the radiotracer and the SPECT system showed fairly good agreement with video-frames of the color tracer obtained with the camera. Based on the results of the performance evaluation, it is concluded that the SPECT system is suitable for investigation and visualization of flows in industrial flow reactors.

Coexpression of multiple genes reconstitutes two pathways of very long-chain polyunsaturated fatty acid biosynthesis in Pichia pastoris.

The introduction of novel traits to cells often requires the stable coexpression of multiple genes within the same cell. Herein, we report that C22 very long-chain polyunsaturated fatty acids (VLC-PUFAs) were synthesized from C18 precursors by reactions catalyzed by delta 6-desaturase, an ELOVL5 involved in VLC-PUFA elongation, and delta 5-desaturase. The coexpression of McD6DES, AsELOVL5, and PtD5DES encoding the corresponding enzymes, produced docosatetraenoic acid (C22:4 n-6) and docosapentaenoic acid (C22:5 n-3), as well as arachidonic acid (C20:4 n-6) and eicosapentaenoic acid (C20:5 n-3) in the methylotrophic yeast Pichia pastoris. The expression of each gene increased within 24 h, with high transcript levels after induction with 0.5 or 1 % methanol. High levels of the newly expressed VLC-PUFAs occurred after 144 h. This expression system exemplifies the recent progress and future possibilities of the metabolic engineering of VLC-PUFAs in oilseed crops.

Development of advanced industrial SPECT system with 12-gonal diverging-collimator.

Industrial single photon emission computed tomography (SPECT) is a promising diagnosis technique to investigate the dynamic behavior of process media. In the present study, a 12-gonal industrial SPECT system was developed using diverging collimators, and its performance was compared with those of hexagonal and 24-gonal systems. Of all of the systems, the 12-gonal type showed the best performance, providing (1) a detection-efficiency map without edge artifacts, (2) the best image resolution, and (3) reconstruction images that correctly furnish multi-source information. Based on the performance of the three different types of configurations, a SPECT system with 12-gonal type configuration was found most suitable for investigating and visualization of flow dynamics in industrial process systems.