Highest fusion performance without harmful edge energy bursts in tokamak.

The path of tokamak fusion and International thermonuclear experimental reactor (ITER) is maintaining high-performance plasma to produce sufficient fusion power. This effort is hindered by the transient energy burst arising from the instabilities at the boundary of plasmas. Conventional 3D magnetic perturbations used to suppress these instabilities often degrade fusion performance and increase the risk of other instabilities. This study presents an innovative 3D field optimization approach that leverages machine learning and real-time adaptability to overcome these challenges. Implemented in the DIII-D and KSTAR tokamaks, this method has consistently achieved reactor-relevant core confinement and the highest fusion performance without triggering damaging bursts. This is enabled by advances in the physics understanding of self-organized transport in the plasma edge and machine learning techniques to optimize the 3D field spectrum. The success of automated, real-time adaptive control of such complex systems paves the way for maximizing fusion efficiency in ITER and beyond while minimizing damage to device components.

A sustained high-temperature fusion plasma regime facilitated by fast ions.

Nuclear fusion is one of the most attractive alternatives to carbon-dependent energy sources1. Harnessing energy from nuclear fusion in a large reactor scale, however, still presents many scientific challenges despite the many years of research and steady advances in magnetic confinement approaches. State-of-the-art magnetic fusion devices cannot yet achieve a sustainable fusion performance, which requires a high temperature above 100 million kelvin and sufficient control of instabilities to ensure steady-state operation on the order of tens of seconds2,3. Here we report experiments at the Korea Superconducting Tokamak Advanced Research4 device producing a plasma fusion regime that satisfies most of the above requirements: thanks to abundant fast ions stabilizing the core plasma turbulence, we generate plasmas at a temperature of 100 million kelvin lasting up to 20 seconds without plasma edge instabilities or impurity accumulation. A low plasma density combined with a moderate input power for operation is key to establishing this regime by preserving a high fraction of fast ions. This regime is rarely subject to disruption and can be sustained reliably even without a sophisticated control, and thus represents a promising path towards commercial fusion reactors.

Quasisymmetric Optimization of Nonaxisymmetry in Tokamaks.

Predictive 3D optimization reveals a novel approach to modify a nonaxisymmetric magnetic perturbation to be entirely harmless for tokamaks, by essentially restoring quasisymmetry in perturbed particle orbits as much as possible. Such a quasisymmetric magnetic perturbation (QSMP) has been designed and successfully tested in the KSTAR and DIII-D tokamaks, demonstrating no performance degradation despite the large overall amplitudes of nonaxisymmetric fields and strong response otherwise expected in the tested plasmas. The results indicate that a quasisymmetric optimization is a robust path of error field correction across the resonant and nonresonant field spectrum in a tokamak, leveraging the prevailing concept of quasisymmetry for general 3D plasma confinement systems such as stellarators. The optimization becomes, in fact, a simple eigenvalue problem to the so-called torque response matrices if a perturbed equilibrium is calculated consistent with nonaxisymmetric neoclassical transport.

Malignant Peripheral Nerve Sheath Tumour in the Urinary Bladder of a Dog.

A 15-year-old neutered male miniature pinscher was presented with a pedunculated mass (4 × 1 cm) in its urinary bladder. Exploratory cystotomy revealed that the mass was located at the trigone of the bladder and projected into the lumen. The cut surface of the mass was homogeneous grey to tan in colour with focal brown pigmentation. Microscopically, the mass was predominantly composed of neoplastic spindle cells characterized by moderate cellular pleomorphism, invasion into the muscular layer of the bladder wall and few mitotic figures. The neoplastic spindle cells formed interwoven bundles intersecting at various angles. Immunohistochemically, these cells were negative for cytokeratin 7 and α-smooth muscle actin, but strongly expressed S100 and vimentin, confirming a diagnosis of a malignant peripheral nerve sheath tumour (PNST). To the best of our knowledge, this is the first report of a primary malignant PNST in the urinary bladder of a dog.

Nonambipolar Transport due to Electrons with 3D Resistive Response in the KSTAR Tokamak.

A small nonaxisymmetric (3D) magnetic field can induce nonambipolar transport of the particle species confined in a tokamak and thus a significant change of plasma rotation. This process can be in a favor of instability control in the region where the tokamak plasma is sufficiently collisional and resistive, as observed in the applications of n=1 resonant magnetic perturbations to the KSTAR tokamak. The plasma rotation can be globally accelerated due to radially drifting electrons and constrained to the electron root, if the radial transport is enhanced by an amplified 3D response. This mechanism is verified by a kinetically self-consistent magnetohydrodynamic modeling for both response and transport, which offers the quantitative explanations on the internal n=1 structure detected by electron-cyclotron-emission imaging and the cocurrent plasma spinning observed in the experiments.

Morphological and molecular data on a new species of Plagiorhynchus Lühe, 1911 (Acanthocephala: Plagiorhynchidae) from the long-billed curlew (Numenius americanus) from northern Mexico.

A new species of the genus Plagiorhynchus Lühe, 1911 from the intestine of the long-billed curlew (Numenius americanus) from northern Mexico is described. Plagiorhynchus (Plagiorhynchus) aznari n. sp. is morphologically distinguished from other congeneric species from the Americas by having a trunk expanded anteriorly and a cylindrical proboscis, armed with 19 longitudinal rows of hooks, with 14-15 hooks each row. Nearly complete sequences of the small subunit and large subunit of the nuclear ribosomal DNA of the new species were determined and compared with available sequences from GenBank. Phylogenetic analyses inferred from the two molecular markers consistently showed that P. (Plagiorhynchus) aznari n. sp. is closely related to P. (Plagiorhynchus) allisonae, and this clade is sister to a clade formed by P. (Prosthorhynchus) transversus and P. (Prosthorhynchus) cylindraceus from Plagiorhynchidae. The new species represents the second record of the genus in Mexico and the fourth species in the Americas. The phylogenetic relationships among the members of the order Polymorphida in this study provide significant insights into the evolution of ecological associations between parasites and their definitive hosts. Our analyses suggest that the colonization of marine mammals, fish-eating birds and waterfowl in Polymorphidae might have occurred independently, from a common ancestor of Centrorhynchidae and Plagiorhynchidae that colonized terrestrial birds and mammals.

Ultrasound-guided versus blind temporomandibular joint injections: a pilot cadaveric evaluation.

Temporomandibular disorders are painful conditions that require precise injection therapy in selected patients. This pilot cadaveric study was undertaken to compare the accuracy of temporomandibular joint (TMJ) injection between the anatomical landmark-based (blind) technique and an ultrasound-guided technique. TMJ injections using the blind technique or the ultrasound-guided technique were performed in 10 non-embalmed cadavers. After dissection, the accuracy of the TMJ injections was found to be significantly greater for the ultrasound-guided injections than for the blind technique (blind 55% vs. ultrasound 95%, P=0.008). For injections into the upper joint space of the TMJ, the success rate of the injection was comparable for the two techniques (blind 80% vs. ultrasound 100%, P=0.474). However, ultrasound-guided injections into the lower joint space had a much higher success rate than the blind technique (blind 30% vs. ultrasound 90%, P=0.020). The blind technique was associated with a considerable proportion of failed or inappropriate injections, especially for lower joint space injections. Ultrasound-guided TMJ injections were accomplished with a higher accuracy than the conventional blind technique, especially in the case of injections targeting the lower joint space of the TMJ.

Sequence variations of the locus-specific 5' untranslated regions of SLA class I genes and the development of a comprehensive genomic DNA-based high-resolution typing method for SLA-2.

The genetic diversity of the major histocompatibility complex (MHC) class I molecules of pigs has not been well characterized. Therefore, the influence of MHC genetic diversity on the immune-related traits of pigs, including disease resistance and other MHC-dependent traits, is not well understood. Here, we attempted to develop an efficient method for systemic analysis of the polymorphisms in the epitope-binding region of swine leukocyte antigens (SLA) class I genes. We performed a comparative analysis of the last 92 bp of the 5' untranslated region (UTR) to the beginning of exon 4 of six SLA classical class I-related genes, SLA-1, -2, -3, -4, -5, and -9, from 36 different sequences. Based on this information, we developed a genomic polymerase chain reaction (PCR) and direct sequencing-based comprehensive typing method for SLA-2. We successfully typed SLA-2 from 400 pigs and 8 cell lines, consisting of 9 different pig breeds, and identified 49 SLA-2 alleles, including 31 previously reported alleles and 18 new alleles. We observed differences in the composition of SLA-2 alleles among different breeds. Our method can be used to study other SLA class I loci and to deepen our knowledge of MHC class I genes in pigs.

Relationship between serum vitamin D concentrations and clinical outcome of community-acquired pneumonia.

SETTING: Hospitalised patients with community-acquired pneumonia (CAP) in a tertiary referral hospital in South Korea. OBJECTIVE: To determine the burden of vitamin D deficiency in patients hospitalised with CAP and to investigate whether vitamin D deficiency affected clinical outcomes. DESIGN: Serum 25-hydroxyvitamin D (25[OH]D) levels were measured at admission; vitamin D deficiency was defined as 25(OH)D <20 ng/ml. Data were retrospectively analysed for incidence of vitamin D deficiency. The primary outcome was the relationship between serum vitamin D concentration and 28-day all-cause mortality in CAP. RESULTS: The mean age was 68.1 years (standard deviation [SD] ± 14.6), and the mean pneumonia severity index was 98.0 (± SD 28.6). Of the 797 patients (males 66.0%), 641 (80.4%) had vitamin D deficiency. Overall mean serum 25(OH)D level was 14.0 ± 7.4 ng/ml. The 28-day all-cause mortality rate in vitamin D-deficient patients was significantly higher than in non-deficient patients (8.3% vs. 2.6%, P = 0.01), and serum vitamin D level was negatively associated with risk of 28-day mortality in CAP after adjustment for pneumonia severity index and serum lactate levels (OR 0.94, 95%CI 0.90-0.99, P < 0.01). CONCLUSION: The prevalence of vitamin D deficiency was ~80% in patients hospitalised with CAP. Vitamin D deficiency was also a significant predictor of increased 28-day all-cause mortality.

Three-dimensional drift kinetic response of high-ß plasmas in the DIII-D tokamak.

A quantitative interpretation of the experimentally measured high-pressure plasma response to externally applied three-dimensional (3D) magnetic field perturbations, across the no-wall Troyon ß limit, is achieved. The self-consistent inclusion of the drift kinetic effects in magnetohydrodynamic (MHD) modeling [Y. Q. Liu et al., Phys. Plasmas 15, 112503 (2008)] successfully resolves an outstanding issue of the ideal MHD model, which significantly overpredicts the plasma-induced field amplification near the no-wall limit, as compared to experiments. The model leads to quantitative agreement not only for the measured field amplitude and toroidal phase but also for the measured internal 3D displacement of the plasma. The results can be important to the prediction of the reliable plasma behavior in advanced fusion devices, such as ITER [K. Ikeda, Nucl. Fusion 47, S1 (2007)].

Observation of a multimode plasma response and its relationship to density pumpout and edge-localized mode suppression.

Density pumpout and edge-localized mode (ELM) suppression by applied n=2 magnetic fields in low-collisionality DIII-D plasmas are shown to be correlated with the magnitude of the plasma response driven on the high-field side (HFS) of the magnetic axis but not the low-field side (LFS) midplane. These distinct responses are a direct measurement of a multimodal magnetic plasma response, with each structure preferentially excited by a different n=2 applied spectrum and preferentially detected on the LFS or HFS. Ideal and resistive magneto-hydrodynamic (MHD) calculations find that the LFS measurement is primarily sensitive to the excitation of stable kink modes, while the HFS measurement is primarily sensitive to resonant currents (whether fully shielding or partially penetrated). The resonant currents are themselves strongly modified by kink excitation, with the optimal applied field pitch for pumpout and ELM suppression significantly differing from equilibrium field alignment.

Pedestal bifurcation and resonant field penetration at the threshold of edge-localized mode suppression in the DIII-D Tokamak.

Rapid bifurcations in the plasma response to slowly varying n=2 magnetic fields are observed as the plasma transitions into and out of edge-localized mode (ELM) suppression. The rapid transition to ELM suppression is characterized by an increase in the toroidal rotation and a reduction in the electron pressure gradient at the top of the pedestal that reduces the perpendicular electron flow there to near zero. These events occur simultaneously with an increase in the inner-wall magnetic response. These observations are consistent with strong resonant field penetration of n=2 fields at the onset of ELM suppression, based on extended MHD simulations using measured plasma profiles. Spontaneous transitions into (and out of) ELM suppression with a static applied n=2 field indicate competing mechanisms of screening and penetration of resonant fields near threshold conditions. Magnetic measurements reveal evidence for the unlocking and rotation of tearinglike structures as the plasma transitions out of ELM suppression.

In vitro differentiation of human liver-derived stem cells with mesenchymal characteristics into immature hepatocyte-like cells.

Liver transplantation is severely limited by donor shortage although it is the only effective treatment for end-stage liver disease. So the best alternative is hepatocyte transplantation. For obtaining human hepatocytes, some stem cells originating from extrahepatic or intraheptic tissues have been isolated and characterized. Previously we have reported that human liver-derived stem cells (HLSCs) could be isolated and expanded from donated livers unsuitable for transplantation; they expressed some markers of mesenchymal stem cells but neither hematopoietic nor oval cells. In this study, we isolated and expanded HLSCs with mesenchymal characteristics from another adult human liver. They showed mesenchymal morphology and grew well under serum condition similar to our previous reports. Also, they expressed some markers of mesenchymal stem cells, such as CD44, CD73, CD90, and CD105, through fluorescence-activated cell sorting analysis. When HLSCs were sequentially exposed to fibroblast growth factor-1 (FGF-1), FGF-4, and hepatocyte growth factor (HGF) followed by FGF-4, HGF, oncostatin M, and dexamethasone, they became round or polygonal, and expressed some hepatic markers such as albumin and α1-antitrypsin in the gene or protein level. Also, they showed urea synthesis activity 7 days after treatment of FGF-4, HGF, oncostatin M, and dexamethasone. These results provided that HLSCs would be a useful cell source in the field of regenerative medicine as well as liver cell biology.

Decreased tumour necrosis factor-α production by monocytes of granulomatosis with polyangiitis.

OBJECTIVES: We hypothesized that monocytes in patients with granulomatosis with polyangiitis (GPA) are polarized towards alternative activation with decreased tumour necrosis factor (TNF)-α production and that tissue-infiltrating monocytes/macrophages in granulomatous GPA lesions express CD163, a marker of alternative macrophage activation. METHOD: CD16+ monocytes in peripheral blood mononuclear cells (PBMCs) were quantified by flow cytometry. Monocytes were stimulated with increasing concentrations of lipopolysaccharide (LPS), and TNF-α production was measured at 4 and 24 h. CD163 expression in lung biopsies of patients with GPA was detected by immunohistochemistry. RESULTS: Circulating CD16+ monocytes were more frequent in GPA patients compared to controls (4.7 ± 2.8% vs. 1.9 ± 1.2%, p < 0.001). Upon activation with LPS, TNF-α production did not differ between CD16+ and CD16- monocytes. Stimulated monocytes from GPA patients produced significantly less TNF-α compared with monocytes from healthy controls (2903 ± 1320 pg/mL vs. 8335 ± 4569 pg/mL, p < 0.001). Macrophages expressing CD163 were enriched in granulomatous lung lesions of GPA patients. CONCLUSIONS: Decreased TNF-α production by circulating monocytes and CD163 overexpression by tissue monocytes/macrophages in granulomatous pulmonary lesions may suggest that monocytes/macrophages are alternatively activated in GPA.

Reduction in dental plaque in patients with mental disorders through the dental hygiene care programme.

OBJECTIVE: To develop a dental hygiene care programme based on the specific needs of patients with mental disorders and to suggest practical guidelines to improve the oral health care of these patients. METHODS: A total of 73 patients with mental illness participated in the study. The patients were randomly classified into three groups and followed over 12 weeks at 4-week intervals. A newly designed dental hygiene care programme using flash-based video, brochures and a toothpick method was implemented by five dental hygienists. Plaque index, stimulated saliva, subjective oral dryness and dental caries activity were analysed as outcome variables. RESULTS: Results showed that the dental plaque index significantly decreased after each session (P < 0.0001) in all three groups, and significant differences were found between groups (P = 0.036). Patients' oral dryness decreased significantly, but stimulated saliva and dental caries activity did not improve. CONCLUSION: The results of this study suggest that the dental hygiene care programme, which made use of a short, 10-min flash-based video and brochures every 4 weeks, was effective in reducing the dental plaque index of patients with mental disorders.

Rotation and kinetic modifications of the tokamak ideal-wall pressure limit.

The impact of toroidal rotation, energetic ions, and drift-kinetic effects on the tokamak ideal wall mode stability limit is considered theoretically and compared to experiment for the first time. It is shown that high toroidal rotation can be an important destabilizing mechanism primarily through the angular velocity shear; non-Maxwellian fast ions can also be destabilizing, and drift-kinetic damping can potentially offset these destabilization mechanisms. These results are obtained using the unique parameter regime accessible in the spherical torus NSTX of high toroidal rotation speed relative to the thermal and Alfvén speeds and high kinetic pressure relative to the magnetic pressure. Inclusion of rotation and kinetic effects significantly improves agreement between measured and predicted ideal stability characteristics and may provide new insight into tearing mode triggering.

Rotational resonance of nonaxisymmetric magnetic braking in the KSTAR tokamak.

One of the important rotational resonances in nonaxisymmetric neoclassical transport has been experimentally validated in the KSTAR tokamak by applying highly nonresonant n=1 magnetic perturbations to rapidly rotating plasmas. These so-called bounce-harmonic resonances are expected to occur in the presence of magnetic braking perturbations when the toroidal rotation is fast enough to resonate with periodic parallel motions of trapped particles. The predicted and observed resonant peak along with the toroidal rotation implies that the toroidal rotation in tokamaks can be controlled naturally in favorable conditions to stability, using nonaxisymmetric magnetic perturbations.

Mitigation of Alfvén activity in a tokamak by externally applied static 3D fields.

The application of static magnetic field perturbations to a tokamak plasma is observed to alter the dynamics of high-frequency bursting Alfvén modes that are driven unstable by energetic ions. In response to perturbations with an amplitude of δB/B∼0.01 at the plasma boundary, the mode amplitude is reduced, the bursting frequency is increased, and the frequency chirp is smaller. For modes of weaker bursting character, the magnetic perturbation induces a temporary transition to a saturated continuous mode. Calculations of the perturbed distribution function indicate that the 3D perturbation affects the orbits of fast ions that resonate with the bursting modes. The experimental evidence represents an important demonstration of the possibility of controlling fast-ion instabilities through "phase-space engineering" of the fast-ion distribution function, by means of externally applied perturbation fields.

Stage-specific embryonic antigen-1 expression by undifferentiated spermatogonia in the prepubertal boar testis.

The objective of this study was to use fluorescence-activated cell sorting (FACS) and spermatogonial stem cell (SSC) xenotransplantation to identify cell surface markers of putative porcine SSC. Analysis of porcine testis cells enriched for spermatogonia using FACS indicated that nearly half of stage-specific embryonic antigen-1 (SSEA-1) expressing testis cells expressed the undifferentiated spermatogonia marker protein gene product 9.5 (PGP 9.5) whereas significantly fewer (P < 0.05) cells selected for thymus cell antigen-1 (Thy-1), also known as cluster of differentiation 90 (CD90), cluster of differentiation 9 (CD9), or other SSC markers expressed PGP 9.5. Immunocytochemical analysis indicated that promyelocytic leukemia zinc finger (PLZF) protein and germ cell lineage marker VASA homolog (VASA), also known as DEAD box protein 4 (DDX4), were expressed by SSEA-1 expressing germ cells. Spermatogonial stem cell xenotransplantation of testis cell populations enriched for cells expressing SSEA-1 generated significantly (P < 0.05; greater than 15-fold) more colonies of donor derived germ cells than unselected testis cells. In conclusion, these data indicate that SSC markers identified in rodents are likely not entirely conserved in pigs and that SSEA-1 is a marker for porcine undifferentiated spermatogonia including SSC in prepubertal boars and its expression may serve as a target for the further study of porcine germ cells.

Characterization of low-pathogenicity H5 and H7 Korean avian influenza viruses in chickens.

To date, all isolated highly pathogenic avian influenza (HPAI) viruses that cause systemic infection with a high mortality rate in poultry species have been known to belong to either the H5 or H7 subtypes. The HPAI viruses may originate because of the insertion of multiple basic amino acids at the cleavage site of the hemagglutinin protein after the low-pathogenic H5 and H7 viruses have been introduced into poultry. In the present study, we investigated the phylogenetic characteristics of the H5 (n = 4) and H7 (n = 3) low-pathogenic avian influenza (LPAI) viruses isolated from wild birds in Korea by using nucleotide sequences of all 8 gene segments of the viral genome. Further, we evaluated the infectivity, transmissibility, and pathogenic potential of these viruses in chickens. Phylogenetic analysis showed that all viruses used in the study clustered in the Eurasian lineage and were similar to the viruses isolated in Asian countries that share the East Asian-Australasian migratory bird flyway. Our H5N2 isolates could not be replicated and transmitted in chickens, but the H7N8 isolates could efficiently be replicated and transmitted to contact-exposure chickens. In addition, because our H7N8 isolates caused watery diarrhea in chickens, these viruses cannot only serve as progenitors of novel HPAI strains but also potentially cause clinical disease in poultry. Although there have been no reports of LPAI mutation to HPAI in these regions, the wild bird surveillance effort should focus on monitoring the introduction and transmission of the HPAI H5N1 and LPAI H5 and H7 viruses.