Surprisingly good thermoelectric performance of monolayer C3N.

The rapid emergence of graphene has attracted numerous efforts to explore other two-dimensional materials. Here, we combine first-principles calculations and Boltzmann theory to investigate the structural, electronic, and thermoelectric transport properties of monolayer C3N, which exhibits a honeycomb structure very similar to graphene. It is found that the system is both dynamically and thermally stable even at high temperature. Unlike graphene, the monolayer has an indirect band gap of 0.38 eV and much lower lattice thermal conductivity. Moreover, the system exhibits obviously larger electrical conductivity and Seebeck coefficients for the hole carriers. Consequently, theZTvalue ofp-type C3N can reach 1.4 at 1200 K when a constant relaxation time is predicted by the simple deformation potential theory. However, such a largerZTis reduced to 0.6 if we fully consider the electron-phonon coupling. Even so, the thermoelectric performance of monolayer C3N is still significantly enhanced compared with that of graphene, and is surprisingly good for low-dimensional thermoelectric materials consisting of very light elements.

[Effect of occupational stress on depression in gas field workers].

Objective: To explore the occurrence level of depressive symptoms and it's influencing factors among gas field workers. Methods: In October 2018, a cross-sectional study was conducted in 1726 gas field workers from a gas field by using cluster sampling method. Questionaire was used to evaluate the individual factors, depressive symptoms, occupational stress factors and stress regulatory factors. The correlation between depressive symptoms and occupational stress was analyzed. Multivariate logistic regression was used to analyze the influencing factors of depressive symptoms. Results: The depressive symptoms score of gas field workers was 12.00 (7.00, 19.00) point. Correlation analysis revealed that depressive symptoms score was positively related to sleep disorders (r=0.598) , effort (r=0.186) , daily tension (r=0.478) , negative affectivity (r=0.565) , social support (r=0.446) and monotony of work (r=0.484) (P<0.01) . And it was negatively related to reward (r=-0.386) , work stability (r=-0.294) , promotion opportunities (r=-0.258) , positive affectivity (r= -0.310) , self-efficacy (r=-0.312) , contral strategy (r=-0.268) , support strategy (r=-0.209) and job satisfaction (r=-0.398) (P<0.01) . Multivariate logistic regression analysis revealed that sleep disorder, high negative affectivity, low support from colleagues, low support from family, high monotony of work and high daily tension were the risk factors for depressive symptoms of gas field worker (OR=3.423, 95%CI: 2.644-4.397; OR=2.847, 95%CI: 2.200-3.683; OR=1.646, 95%CI: 1.215-2.116; OR=1.496, 95%CI: 1.164-1.923; OR=1.578, 95%CI: 1.227-2.303; OR=1.903, 95%CI: 1.480-2.440; P<0.01) . High work stability, high self-efficacy and high job satisfaction were protective factors for depressive symptoms of gas field workers (OR=0.752, 95%CI: 0.591-0.958; OR=0.590, 95%CI: 0.465-0.749; OR=0.718, 95%CI: 0.516-0.999; P<0.05) . Conclusion: Occupational stress factors have a great influence on the depressive symptoms of gas field workers. Increased work stability, self-efficacy and job satisfaction could reduce the risk of depressive symptoms.

Risk factors and renal outcomes of low bone mineral density in patients with non-dialysis chronic kidney disease.

Bone disorder is a common complication of chronic kidney disease (CKD). The clinical usefulness of bone mineral density (BMD) in CKD is not well known. Our study shows that low BMD is associated with physical activity and dietary Na/K intake ratio and can predict poor renal outcome in non-dialysis CKD. PURPOSE: Despite evidence of a link between bone mineral disorders and chronic kidney disease (CKD), the clinical implications of bone mineral density (BMD) in CKD are not well established. We investigated risk factors and renal outcomes of low BMD in CKD. METHODS: We analyzed data from the KNOW-CKD. BMD measured by dual-energy x-ray absorptiometry was classified by T score: normal (T score ≥ - 1.0), osteopenia (- 1.0 > T score > - 2.5), and osteoporosis (T score ≤ - 2.5) of the lumbar spine, hip, or femoral neck. Logistic regression analysis to assess risk factors of low BMD (T score < - 1.0) and Cox proportional hazards models to estimate risk of incident end-stage renal disease (ESRD). RESULTS: Low BMD was prevalent (osteopenia 33%; osteoporosis 8%) in 2128 adults with CKD (age 54 ± 12 years; male 61%). Over a median follow-up of 4.3 years, there were 521 cases of incident ESRD. Lower BMD was associated with female sex, older age, low eGFR, low BMI, and lifestyle factors of physical activity (odds ratio (OR) = 0.62, 95% confidence interval (0.49-0.77)) and spot urine Na/K ratio (1.07 (1.00-1.15)). In adjusted Cox models, low BMD was associated with increased incident ESRD (hazard ratio (HR) = 1.14 (0.92-1.41) for osteopenia; 1.43 (1.01-2.04) for osteoporosis, P for trend < 0.05) compared with the reference of normal BMD. The association between low BMD and ESRD was similar according to T score discordance classification. CONCLUSIONS: Low BMD was associated with modifiable lifestyle factors including low physical activity and high dietary Na/K intake ratio. The presence of low BMD is associated with poor renal outcomes in non-dialysis CKD.

Surprisingly good thermoelectric performance of a black phosphorus/blue phosphorus van der Waals heterostructure.

Thermoelectric properties of a black phosphorus/blue phosphorus van der Waals heterostructure are investigated by using first-principles calculations and Boltzmann transport theory for both electrons and phonons. It is found that the heterostructure is both energetically and kinetically stable even at higher temperature. Compared with those of the constituent black and blue phosphorus monolayers, the thermoelectric performance of the heterostructure is significantly enhanced due to sharply decreased thermal conductivity caused by the presence of van der Waals interactions, as well as obviously reduced band gaps and multi-valley structures resulting from type-II band alignment. As a consequence, the room temperature ZT value can reach 1.6, which is much higher than those of the components. Furthermore, we obtain ZT over 2.0 in a wide temperature range from 400 to 800 K, and a maximum ZT of ∼3.2 can be realized at 700 K, which is surprisingly good for systems consisting of light elements only.

[Sleep quality and occupational stress relationship analysis of field gas recovery workers].

Objective: To explore the relationship between sleep quality and occupational stress in field gas recovery workers. Methods: In October 2018, cluster sampling method was adopted to conduct cross-sectional survey on 1726 field workers in a gas production oilfield. The individual characteristics, occupational stress factors, stress regulation factors, stress response and sleep quality, social support and coping strategies were evaluated by occupational stress measurement tools and job content questionnaire. Mann Whitney U test and Kruskal Wallis H test were used to compare sleep quality scores between the groups. Spearman rank correlation analysis was used to analyze the correlation between sleep quality and occupational stress, and logistic regression analysis was used to analyze multiple factors. Results: There were significant differences in sleep quality scores among different positions, gender, marital status, age, length of service, smoking and drinking (P<0.05) . There were no significant differences in sleep quality scores between different education levels and work shift groups (P>0.05) . Spearman rank correlation analysis showed that sleep quality score was negatively correlated with job satisfaction, reward, job stability, promotion opportunity, positive emotion, respect, self-esteem, control strategy, support strategy and self-efficacy score (r(s)=-0.361, -0.311, -0.238, -0.261, -0.248, -0.212, -0.139, -0.188, -0.152, -0.226, P<0.01) , and was positively correlated with social support, giving, daily tension, negative emotion, work monotony and depression symptom (r(s)=0.312, 0.279, 0.547, 0.493, 0.429, 0.599, P<0.01) . Compared with the high sleep quality score group, the middle and low sleep quality score groups had lower giving, work monotony, daily tension, depressive symptoms, negative emotions and social support (P<0.01) , while the scores of respect, reward, job satisfaction, positive emotion, self-efficacy, job stability, promotion opportunity, control strategy and support strategy were higher (P<0.01) . Multiple depressive symptoms, high daily tension, high negative emotion and high work monotony were the risk factors for sleep disorders (OR=3.417, 2.659, 2.913, 1.543) . Conclusion: Depressive symptoms, daily tension and negative emotion have great influence on sleep quality of field gas recovery workers.

[Correlation between social support and occupational stress among gas production workers in the field].

Objective: To investigate the level of social support and its correlation with occupational stress among gas production workers in the field. Methods: In October 2018, the cluster sampling method was used to perform a cross-sectional survey for 1726 gas production workers in the field, and related data of these workers were collected, including age, education level, marital status, level of social support, and related factors for occupational stress. A Spearman's rank correlation analysis was used to investigate the correlation between social support and occupational stress, and the levels of occupational stress-related factors were compared between the groups with different social support scores. Results: The gas production workers in the field had a median (25th percentile, 75th percentile) social support score of 24.00 (19.00, 28.00) , and there was a significant difference in social support score between the workers with different posts or work shifts (P<0.01) . Social support score was positively correlated with effort, daily stress, negative emotion, and job routinization (P<0.05) and was negatively correlated with job satisfaction, reward, working stability, and promotion opportunity (P<0.05) . The group with a high social support score had significantly higher scores of effort, job routinization, sleep disorders, and daily stress than the other two groups (P<0.01) , and the group with a low social support score had significantly higher scores of reward, self-efficacy, positive affection, and job satisfaction than the other two groups (P<0.01) . Conclusion: High-level social support plays an important role in alleviating occupational stress and protecting mental health among gas production workers in the field.

Ex vivo magnetic resonance imaging using hyaluronic acid fillers: Differences between monophasic and biphasic fillers.

BACKGROUND/PURPOSE: Hyaluronic acid (HA) is an anionic, non-sulfated glycosaminoglycan distributed throughout the human skin and injectable HA fillers are the most commonly used in aesthetic field. This study aimed to determine if differences in physical characteristics of HA products (monophasic or biphasic fillers) affect the patterns of magnetic resonance imaging (MRI). METHODS: Twenty biphasic fillers and nine monophasic fillers were obtained from a commercial source, and examined with a 3.0 Tesla MRI scanner. Visual assessments and measurements of signal intensity for region of interest (ROI) were performed. A non-parametric Wilcoxon rank sum test was used to compare the ROI values. RESULTS: Visual assessments by a radiologist did not show significant differences between the two types of fillers. While the signal intensity between the two types of filler did not differ significantly for T1-weighted images, the signal intensity of the biphasic filler was lower than that of the monophasic filler for T2-weighted images (P<.01). CONCLUSION: Monophasic and biphasic HA fillers exhibited different MRI properties. Our findings may provide better insights into the use of in vivo MRI to evaluate aesthetic, procedure-related complications.

Devising negative pressure within intercuff space reduces microaspiration.

BACKGROUND: Microaspiration past the tracheal tube cuffs causes ventilator-associated pneumonia. The objective of the current study was to evaluate whether creating negative pressure between the tracheal double cuffs could block the fluid passage past the tracheal tube cuffs. METHODS: A new negative pressure system was devised between the double cuffs through a suction hole in the intercuff space. Blue-dyed water was instilled above the cuff at negative suction pressures of - 54, - 68, - 82, - 95, - 109, - 122, and - 136 cmH2O, and the volume leaked was measured in an underlying water trap after 10 min. Leakage tests were also performed during positive pressure ventilation, and using higher-viscosity materials. The actual negative pressures delivered at the hole of double cuffs were obtained by placing microcatheter tip between the intercuff space and the artificial trachea. RESULTS: No leakage occurred past the double cuff at - 136 cmH2O suction pressure at all tracheal tube cuff pressures. The volume leaked decreased significantly as suction pressure increased. When connected to a mechanical ventilator, no leakage was found at - 54 cmH2suction pressure. Volume of the higher-viscosity materials (dynamic viscosity of 63-108 cP and 370-430 cP) leaked was small compared to that of normal saline (0.9-1.1 cP). The pressures measured in the intercuff space corresponded to 3.8-5.9% of those applied. CONCLUSIONS: A new prototype double cuff with negative pressure in the intercuff space completely prevented water leakage. The negative pressure transmitted to the tracheal inner wall was a small percentage of that applied.

Anti-inflammatory and antioxidant properties of Schisandrin C promote mitochondrial biogenesis in human dental pulp cells.

AIM: To examine the properties of Schisandrin C as an anti-inflammatory and antioxidant compound, and whether its characteristics promote mitochondrial biogenesis in human dental pulp cells (HDPCs). METHODOLOGY: HDPCs were extracted from fresh third molars and cultured for experiments. Reactive oxidative stress (ROS) and nitric oxide (NO) formation were analysed by a Muse cell analyser. Western blotting and gelatin zymography were used to identify the presence of antioxidants, as well as anti-inflammatory and mitochondrial biogenesis with specific antibody. An unpaired Student's t-test was used for statistical analysis. RESULTS: Schisandrin C inhibited lipopolysaccharide-stimulated inflammatory molecules; interleukin 1 beta, tumour necrosis factor alpha, intracellular adhesion molecule-1, vascular cell adhesion molecule-1, matrix metalloproteinase-2 and -9, NO production, ROS formation, nuclear factor kappa B translocation (P < 0.05) through the mitogen-activated protein kinase pathway. Schisandrin C increased the expression of superoxide dismutase enzymes as well as haem oxygenase-1 and peroxisome proliferator-activated receptor gamma coactivator 1-alpha through the phosphorylated-protein kinase B (p-Akt) and nuclear factor erythroid 2-related factor-2 pathways (P < 0.05). The anti-inflammatory and antioxidant properties of Schisandrin C promoted mitochondrial biogenesis. CONCLUSIONS: Schisandrin C has the potential to reduce inflammation and oxidation and to promote mitochondrial biogenesis. Therefore, Schisandrin C may be considered for use as an anti-inflammatory compound for oral inflammation through mitochondrial biogenesis.

Full-step Class II Correction Using a Modified C-palatal Plate for Total Arch Distalization in an Adolescent.

A 13-year-old adolescent male patient had a convex profile, severe overjet, and deep overbite with a skeletal Class II pattern. His maxillary dentition was distalized using a modified C-palatal plate (MCPP), and the treatment outcome was stable. After 37 months of total treatment, a pleasing profile and a favorable Class I occlusion was successfully achieved with 5 mm of distalization in the maxillary dentition. MCPP is a viable treatment option for full-step Class II in adolescents, especially when the patients/parents decline the extraction option.

Randomized clinical trial of immersive virtual reality tour of the operating theatre in children before anaesthesia.

BACKGROUND: A virtual reality (VR) tour of the operating theatre before anaesthesia could provide a realistic experience for children. This study was designed to determine whether a preoperative VR tour could reduce preoperative anxiety in children. METHODS: Children scheduled for elective surgery under general anaesthesia were randomized into a control or VR group. The control group received conventional information regarding anaesthesia and surgery. The VR group watched a 4-min video showing Pororo, the famous little penguin, visiting the operating theatre and explaining what is in it. The main outcome was preoperative anxiety, assessed using the modified Yale Preoperative Anxiety Scale (m-YPAS) before entering the operating theatre. Secondary outcomes included induction compliance checklist (ICC) and procedural behaviour rating scale (PBRS) scores during anaesthesia. RESULTS: A total of 69 children were included in the analysis, 35 in the control group and 34 in the VR group. Demographic data and induction time were similar in the two groups. Children in the VR group had a significantly lower m-YPAS score than those in the control group (median 31·7 (i.q.r. 23·3-37·9) and 51·7 (28·3-63·3) respectively; P < 0·001). During anaesthesia, the VR group had lower ICC and PBRS scores than the control group. CONCLUSION: This preoperative VR tour of the operating theatre was effective in alleviating preoperative anxiety and increasing compliance during induction of anaesthesia in children undergoing elective surgery. Registration number: UMIN000025232 (http://www.umin.ac.jp/ctr).

Donepezil 23 mg in Asian patients with moderate-to-severe Alzheimer's disease.

BACKGROUND: Ethnic diversity between different populations may affect treatment safety and efficacy. AIMS AND METHODS: A subanalysis to a global trial (study 326) was carried out to ascertain the safety and efficacy of donepezil 23 mg/day compared with donepezil 10 mg/day in Asian patients with moderate-to-severe Alzheimer's disease. Changes in cognition and global functioning were measured by the Severe Impairment Battery (SIB) and Clinician's Interview-Based Impression of Change Plus Caregiver Input (CIBIC-Plus), respectively, at week 24. RESULTS: Cognitive improvement measured by SIB score was greater with donepezil 23 mg than with donepezil 10 mg (+1.36 vs -1.56]; difference, 2.92). There was no difference between the groups in global function measured by the CIBIC-Plus (3.94 and 3.95, respectively). Overall, 119 patients (82.1%) receiving donepezil 23 mg and 56 (71.8%) receiving donepezil 10 mg experienced ≥1 treatment emergent adverse events (TEAEs). In the donepezil 23 mg group, the incidence of TEAEs was higher among patients of lower weight (<55 kg) at baseline than in those of higher weight (64 of 75 patients [85.3%] vs 55 of 70 patients [78.5%]). CONCLUSIONS: The benefits and risks associated with donepezil 23 mg in Asian patients are comparable to those of the global study population.

The utility of intra-operative frozen section for the evaluation of microscopic extrathyroidal extension in papillary thyroid carcinoma.

OBJECTIVES: This study was designed to evaluate the usefulness of intra-operative frozen section for the evaluation of microscopic extrathyroidal extension (ETE) in papillary thyroid carcinoma (PTC). DESIGN: Retrospective cohort study. SETTING: Dong-A University Medical Center, Busan, Korea. PARTICIPANTS: Three hundred and sixty-four patients who underwent thyroid surgery from January 2000 to December 2010 with PTC confined to one unilateral lobe as diagnosed using preoperative ultrasonography were enrolled. MAIN OUTCOME MEASURES: The patients who had microscopic ETE on frozen section were classified into "group A," and those who did not have microscopic ETE on frozen section were classified into "group B." Clinicopathologic factors including age, gender, size of the tumour, extent of operation, ETE, multifocality, bilaterality, lymph node metastasis and recurrence were compared between the two groups. RESULTS: Of the 364 patients enrolled, ETE was confirmed in 100 patients (group A, 27.5%) on frozen biopsy. The nodule size in group A (0.94±0.87 cm) was larger than that in group B (0.86±0.79 cm) (P=.042). In group A, 15 patients (15%) showed multifocality and 11 patients (14.47%) showed bilaterality. In group B, 37 patients (14.02%) showed multifocality and seven patients (43.35%) showed bilaterality. They did not differ significantly between the two groups (P=.811, P=.182). There was a higher frequency of lymph node metastases in group A (52/86, 60.47%) than in group B (7/16, 43.75%, P=.214). Recurrence was observed in only two patients who had received thyroid lobectomy as the initial surgery in group A. CONCLUSIONS: Intra-operative frozen biopsy can be a useful method for identifying the microscopic ETE. During the surgery, it can also help the surgeon to decide the optimal extent of surgery and the need for central compartment neck dissection in PTC patients.

UTE-ΔR2 -ΔR2 * combined MR whole-brain angiogram using dual-contrast superparamagnetic iron oxide nanoparticles.

The ability to visualize whole-brain vasculature is important for quantitative in vivo investigation of vascular malfunctions in cerebral small vessel diseases, including cancer, stroke and neurodegeneration. Transverse relaxation-based ΔR2 and ΔR2 * MR angiography (MRA) provides improved vessel-tissue contrast in animal deep brain with the aid of intravascular contrast agents; however, it is susceptible to orientation dependence, air-tissue interface artifacts and vessel size overestimation. Dual-mode MRA acquisition with superparamagnetic iron oxide nanoparticles (SPION) provides a unique opportunity to systematically compare and synergistically combine both longitudinal (R1 ) and transverse (ΔR2 and ΔR2 *) relaxation-based MRA. Through Monte Carlo (MC) simulation and MRA experiments in normal and tumor-bearing animals with intravascular SPION, we show that ultrashort TE (UTE) MRA acquires well-defined vascularization on the brain surface, minimizing air-tissue artifacts, and combined ΔR2 and ΔR2 * MRA simultaneously improves the sensitivity to intracortical penetrating vessels and reduces vessel size overestimation. Consequently, UTE-ΔR2 -ΔR2 * combined MRA complements the shortcomings of individual angiograms and provides a strategy to synergistically merge longitudinal and transverse relaxation effects to generate more robust in vivo whole-brain micro-MRA. Copyright © 2016 John Wiley & Sons, Ltd.

The structural connectivity of the recurrent transient global amnesia.

BACKGROUND: One of recent interesting hypotheses of transient global amnesia (TGA) pathophysiology is the preexisting vulnerability of the memory network in patients with TGA. AIM OF THE STUDY: To verify the hypothesis that patients with recurrent amnestic attacks may have more disrupted structural connectivity than patients of a single TGA event, we compared the brain imaging of patients with repeated episodes of TGA with those who experienced a single attack. METHODS: Seven patients who were having recurrent TGA and 14 age- and sex-matched control subjects who had only a single episode of TGA participated in the study. Diffusion tensor images from both groups were assessed and analyzed using tract-based spatial statistics. RESULTS: The fractional anisotropy and mean diffusivity values were not reduced in any lesion within the memory pathway of recurrent patient group when compared with those of single event group. CONCLUSION: No disruptions in the structural connectivity of the memory pathway were observed in patients with recurrent TGA attacks, refuting the hypothesis that recurrent TGA patients present predisposing weakness of the memory network. The stability of structural connectivity suggests that repeated hippocampal lesions associated with TGA do not affect the microstructure of the brain.

Effects of intraoperative protective lung ventilation on postoperative pulmonary complications in patients with laparoscopic surgery: prospective, randomized and controlled trial.

BACKGROUND: Respiratory functions are usually impaired during pneumoperitoneum for laparoscopic surgery. This randomized, controlled and single-blinded study was performed to evaluate whether intraoperative protective lung ventilation influences postoperative pulmonary complications after laparoscopic hepatobiliary surgery. METHODS: Sixty-two patients were randomized to receive either conventional ventilation with alveolar recruitment maneuver (tidal volume of 10 ml/kg with inspiratory pressure of 40 cmH2O for 30 s after the end of pneumoperitoneum, group R), or protective lung ventilation (low tidal volume of 6 ml/kg with positive end-expiratory pressure [PEEP] of 5 cmH2O, group P). Induction and maintenance of anesthesia were done with balanced anesthesia. Respiratory complications such as atelectasis, pneumonia or desaturation were observed postoperatively. The length of hospital stay, arterial blood gas analysis, peak inspiratory pressure and hemodynamic variables were also recorded. Results are presented as mean ± SD or number of patients (%). RESULTS: Postoperative pulmonary complications (P = 0.023) and desaturation below 90 % (P = 0.016) occurred less frequently in group P than in group R. Eight patients of group R and 3 patients of group P showed atelectasis. Pneumonia was diagnosed in 1 patient of group R. No differences were observed in the length of hospital stay, arterial blood gas analysis (pH, PaO2, PaCO2 and PAO2) and hemodynamic variables except PAO2, AaDO2 and peak inspiratory pressure between the two groups. CONCLUSION: Protective lung ventilation (low tidal volume with PEEP) during pneumoperitoneum was associated with less incidences of pulmonary complications than conventional ventilation with alveolar recruitment maneuver after laparoscopic hepatobiliary surgery.

Polymorphic microsatellite markers for the endangered fish, the slender shiner Pseudopungtungia tenuicorpa and cross-species amplification across five related species.

The slender shiner Pseudopungtungia tenuicorpa (Cypriniformes; Cyprinidae; Gobioninae) is an endangered freshwater fish species endemic to Korea. The current strategies for its conservation involve the study of population genetic characters and identification of management units. These strategies require suitable molecular markers to study genetic diversity and genetic structure. Here, we developed nine polymorphic microsatellite markers for P. tenuicorpa for the first time by applying an enrichment method from a size-selected genomic library. The developed microsatellite markers produced a total of 101 alleles (average 11.2). The observed and expected heterozygosities averaged 0.805 and 0.835, respectively. Among the nine identified markers, five markers showed successful amplification across five related Korean Gobioninae species. Thus, the microsatellite markers developed in this study will be useful to establish conservation strategies for both P. tenuicorpa and other related species.

Posttraumatic myositis ossificans of the hand : A locally aggressive malignancy-mimicking tumor.

Posttraumatic myositis ossificans (PTMO) is the most common form of myositis ossificans, but it rarely affects the hand. Due to the aggressive behavior of this unusual tumor, it is commonly misdiagnosed as malignancy or local infection. This report describes a case of PTMO of the hand in a 25-year-old women, and reviews the clinical, radiologic, and histologic characteristics. By understanding the disease characteristics and maturation process, physicians can avoid a misdiagnosis that may lead to functional impairment or improper treatment.

Robust MR assessment of cerebral blood volume and mean vessel size using SPION-enhanced ultrashort echo acquisition.

Intravascular superparamagnetic iron oxide nanoparticles (SPION)-enhanced MR transverse relaxation rates (∆R2(⁎) and ∆R2) are widely used to investigate in vivo vascular parameters, such as the cerebral blood volume (CBV), microvascular volume (MVV), and mean vessel size index (mVSI, ∆R2(⁎)/∆R2). Although highly efficient, regional comparison of vascular parameters acquired using gradient-echo based ∆R2(⁎) is hampered by its high sensitivity to magnetic field perturbations arising from air-tissue interfaces and large vessels. To minimize such demerits, we took advantage of the dual contrast property of SPION and both theoretically and experimentally verified the direct benefit of replacing gradient-echo based ∆R2(⁎) measurement with ultra-short echo time (UTE)-based ∆R1 contrast to generate the robust CBV and mVSI maps. The UTE acquisition minimized the local measurement errors from susceptibility perturbations and enabled dose-independent CBV measurement using the vessel/tissue ∆R1 ratio, while independent spin-echo acquisition enabled simultaneous ∆R2 measurement and mVSI calculation of the cortex, cerebellum, and olfactory bulb, which are animal brain regions typified by significant susceptibility-associated measurement errors.

Identification of a novel HLA-A*29 allele, HLA-A*29:01:09, by sequence-based typing in a Korean individual.

HLA-A*29:01:09 differs from A*29:01:01:01 by one nucleotide difference at nucleotide position 414.