Development of an alternating integrator for magnetic measurements for experimental advanced superconducting tokamak

A high-performance integrator is one of the key electronic devices for reliably controlling plasma in the experimental advanced superconducting tokamak for long pulse operation. We once designed an integrator system of real-time drift compensation, which has a low integration drift. However, it is not feasible for really continuous operations due to capacitive leakage error and nonlinearity error. To solve the above-mentioned problems, this paper presents a new alternating integrator. In the new integrator, the integrator system of real-time drift compensation is adopted as one integral cell while two such integral cells work alternately. To achieve the alternate function, a Field Programmable Gate Array built in the digitizer is utilized. The performance test shows that the developed integrator with the integration time constant of 20 ms has a low integration drift (<15 mV) for 1000 s.

Optical peaking enhancement in high-speed ring modulators

Ring resonator modulators (RRM) combine extreme compactness, low power consumption and wavelength division multiplexing functionality, making them a frontrunner for addressing the scalability requirements of short distance optical links. To extend data rates beyond the classically assumed bandwidth capability, we derive and experimentally verify closed form equations of the electro-optic response and asymmetric side band generation resulting from inherent transient time dynamics and leverage these to significantly improve device performance. An equivalent circuit description with a commonly used peaking amplifier model allows straightforward assessment of the effect on existing communication system architectures. A small signal analytical expression of peaking in the electro-optic response of RRMs is derived and used to extend the electro-optic bandwidth of the device above 40 GHz as well as to open eye diagrams penalized by intersymbol interference at 32, 40 and 44 Gbps. Predicted peaking and asymmetric side band generation are in excellent agreement with experiments.

Diversity and potential application of endophytic bacteria in ginger

Here, 248 endophytic bacterial strains were isolated to assess the distribution and population diversity of endophytic bacteria in ginger plants. A total of 10.4 x 10(4) to 20.2 x 10(4) CFU/g fresh weight endophytic bacteria of different growth stages were isolated. Maximum bacterium numbers were obtained at the seedling stage. A total of 107 functional strains were screened, including 17 antibacterial strains and 90 indole acetic acid-producing strains. Based on 16S rDNA sequence restriction fragment length polymorphism and 16S rDNA sequences, these 107 strains were mapped and grouped into 16 genera. Bacillus and Pseudomonas were the dominant genera; however, the bacteria belonged to a tremendous range of genera, with the highest species richness being observed at the seedling stage. Sixteen strains exhibited antimicrobial activity against Pythium myriotylum Drechsler, while 7 strains exhibited antimicrobial activity against Phyllosticta zingiberi Hori. Bacillus was the dominant antibacterial strain. Pseudomonas fluorescens, B. megaterium, and Enterobacter ludwigii produced remarkably high levels of IAA. Only a few endophytic bacterial strains were inhibited in fresh ginger juice. Most of these strains were present during seedling stage, including Roseateles depolymerans, Chryseobacterium taiwanense, E. ludwigii, Agrobacterium larrymoorei, P. fluorescens, and Bacillus amyloliquefaciens. This study indicates that the community of endophytic bacteria in ginger changes with the synthesis of antibacterial substances.

Nuclear factor erythroid 2-related factor 2 rescues the oxidative stress induced by di-N-butylphthalate in testicular Leydig cells

Aim:

This study aimed to determine whether nuclear factor erythroid 2-related factor 2 antagonized the oxidative stress induced by di- N-butylphthalate (DBP) in testicular Leydig cells.

Methods:

Mouse TM3 testicular Leydig cells were treated with Nrf2 knockdown (KD) or overexpression in the presence and absence of DBP. Oxidative profiles were examined. Nrf2 target antioxidant genes were studied, and the effects of Nrf2 inducer sulphoraphane (SFN) were tested.

Results:

DBP induced intracellular oxidative stress to a similar extent with Nrf2 KD. Expression and protein levels of Nrf2 were increased together with its target genes, namely heme oxygenase 1, nicotinamide adenine dinucleotide phosphate quinone oxidoreductase 1 and peroxiredoxin 6, following DBP stimulation. Use of SFN not only restored the intracellular oxidative toxicity but also cell proliferation and testosterone secretion in response to DBP.

Conclusion:

Increased Nrf2 activity, for example, by SFN can effectively antagonize the oxidative stress in testicular Leydig cells caused by DBP.

Conserved odontogenic potential in embryonic dental tissues

Classic tissue recombination studies have demonstrated that, in the early developing mouse tooth germ, the odontogenic potential, known as the tooth-inductive capability, resides initially in the dental epithelium and then shifts to the dental mesenchyme. However, it remains unknown if human embryonic dental tissues also acquire such odontogenic potential. Here we present evidence that human embryonic dental tissues indeed possess similar tooth-inductive capability. We found that human dental epithelium from the cap stage but not the bell stage was able to induce tooth formation when confronted with human embryonic lip mesenchyme. In contrast, human dental mesenchyme from the bell stage but not the cap stage could induce mouse embryonic second-arch epithelium as well as human keratinocyte stem cells, to become enamel-secreting ameloblasts. We showed that neither post-natal human dental pulp stem cells (DPSCs) nor stem cells from human exfoliated deciduous teeth (SHED) possess odontogenic potential or are odontogenic-competent. Our results demonstrate a conservation of odontogenic potential in mouse and human dental tissues during early tooth development, and will have an implication in the future generation of stem-cell-based bioengineered human replacement teeth.

NKG2D blockade significantly attenuates ischemia-reperfusion injury in a cardiac transplantation model

BACKGROUND

NKG2D (natural killer group 2 member D), are activating or coactivating receptor on NK cells, γδ T, and CD8(+) T cells, stimulates cytokine secretion by the former two and plays a costimulatory role for the last CD8(+) T cells.

METHODS

Male Lewis rat hearts were flushed and stored in cold Bretschneider preservation solution for 8 hours. Anti-NKG2D monoclonal antibody (mAb) was administered before transplantation into syngeneic recipients. Expressions of Troponin-T, myeloperoxidase (MPO), tumor necrosis factor (INF), (ICAM) and interleukin (IL)-17 were examined on days 1, 3, and 7 after reperfusion.

RESULTS

We observed that isografts from anti-NKG2D mAb-treated animals showed decreased cardiac troponin-T, low expression of MPO, TNF, and ICAM, and superior cardiac output. Furthermore, blockade of NKG2D significantly reduced the number of γδ T cells, which are the main source of IL-17 production.

CONCLUSION

Blockade of NKG2D significantly attenuated ischemia-reperfusion injury in a cardiac transplantation model. The effect coincided with a low expression of TNFα, ICAM and a reduced number of infiltrating IL-17-producing γδ T cells.

Efficacy and safety of enteric-coated mycophenolate sodium in patients with de novo and maintenance renal transplantation

AIMS

To evaluate the efficacy and safety of enteric-coated mycophenolate sodium (EC-MPS) in renal transplant patients treated de novo and for maintenance.

METHODS

The efficacy and safety data of EC-MPS in renal transplant patients treated de novo and for maintenance in our hospital from July 2009 to March 2013 were reviewed.

RESULTS

Thirty-one patients treated with EC-MPS de novo were included: there were 16 male and 15 female patients. The acute allograft rejection rate was 12.9% (4/31) and pneumonia occurred in 25.8% patients (8/31); the allograft survival rate was 96.7% (30/31) with a patient survival rate of 96.7% (30/31). Gastrointestinal side effects occurred in four patients (12.9%). Only one patient discontinued EC-MPS and treatment was converted to bredinin because of gastrointestinal intolerance. Thirty-nine patients receiving mycophenolate mofetil (MMF) de novo treatment served as a control group. Five (13.2%) of 38 patients developed serious acute rejection and 10 patients (26.3%) had pulmonary infection. Eight (21.1%) patients suffered abdominal distention, diarrhoea and other gastrointestinal adverse reactions; the symptoms improved significantly after treatment change to mizoribine. Compared with the MMF de novo group, the allograft function, blood cell counts and urine protein were similar in the EC-MPS de novo treatment group. The incidence of gastrointestinal side effects was obviously lower in the EC-MPS group than in the MMF group, and there was no difference in serious acute rejection and pulmonary infection between the groups. The study also included 23 renal transplantation maintenance patients who suffered from chronic diarrhoea and treatment was changed to EC-MPS treatment. This change to EC-MPS was at 77 months after transplantation. The gastrointestinal symptoms improved significantly in 21 patients after conversion. Compared with the results at 1 week, no obvious deterioration in serum creatinine, cystatin or estimated glomerular filtration rate was found at 1, 3 and 12 months after the change. In addition, there was no marked decline in blood cell counts and no significant increase in urine protein.

CONCLUSION

The outcome of EC-MPS treatment in clinical practice of de novo kidney transplant patients was good, with high patient and graft survivals. In maintenance patients it induced an improvement in gastrointestinal side effects and a stable allograft function.

Revealing of the transition from n- to p-type conduction of InN:Mg by photoconductivity effect measurement

We report evidence of the transition from n- to p-type conduction of InN with increasing Mg dopant concentration by using photoconductivity (PC) measurement at room temperature. This transition is depicted as a conversion from negative to positive PC under above-bandgap optical excitation. The n- to p-type transition in InN:Mg is further confirmed by thermopower measurements. PC detection method is a bulk effect since the optical absorption of the surface electron accumulation is negligibly low due to its rather small thickness, and thus shows advantage to detect p-type conduction. This technique is certainly helpful to study p-type doping of InN, which is still a subject of discussions.

The FEN1 E359K germline mutation disrupts the FEN1-WRN interaction and FEN1 GEN activity, causing aneuploidy-associated cancers

Polymorphisms and somatic mutations in Flap Endonuclease 1 (FEN1), an essential enzyme involved in DNA replication and repair, can lead to functional deficiencies of the FEN1 protein and a predisposition to cancer. We identified a FEN1 germline mutation which changed residue E359 to K in a patient whose family had a history of breast cancer. We determined that the E359K mutation, which is in the protein-protein domain of FEN1, abolished the interaction of FEN1 with Werner Syndrome protein (WRN), an interaction which is critical for resolving stalled DNA replication forks. Furthermore, although the flap endonuclease activity of FEN1 E359K was unaffected, it failed to resolve bubble structures, which requires the FEN1 gap dependent endonuclease (GEN) activity. To determine the etiological significance of E359K, we established a mouse model containing this mutation. E359K mouse embryonic fibroblasts (MEF) were more sensitive to DNA cross-linking agents that cause replication forks to stall. Cytological analysis suggested that the FEN1-WRN interaction was also required to for telomere stability; mutant cell lines had fragile telomeres, increased numbers of spontaneous chromosomal anomalies and higher frequencies of transformation. Moreover, the incidence of cancer was significantly higher in mice homozygous for FEN1 E359K than in wild-type mice, suggesting that the FEN1 E359K mutation is oncogenic.

Co-culture of spleen stromal cells with bone marrow mononuclear cells leads to the generation of a novel macrophage subset

Macrophages adopt diverse activation states depending on the microenvironment. Recently, stromal cells have been demonstrated to be organizers of the microenvironment. Here, using splenic stromal cells to mimic the splenic microenvironment in vivo, we show that spleen stromal cells can programme bone marrow-derived mononuclear cells to differentiate and polarize into a novel macrophage subset. These differentiated macrophages (Diff-Mφ) exhibited pronounced production of IL-10, IL-6 and TNF-α, but diminished the production of IL-12 in response to LPS. The generation of Diff-Mφ depended on cell-cell contact as well as on soluble factors. Diff-Mφ directly suppressed the antigen-non-specific (CD3/CD28) CD4(+) T cell proliferative response and induced cell death of activated CD4(+) T cells. As for cytokine production in CD4(+) T cells, Diff-Mφ promoted IL-10 and IL-17 production, whereas inhibited IL-4 production and did not alter IFN-γ production. Besides, Diff-Mφ also expressed iNOS, CD16/CD32, CD54, CD43, CCR7, CD44, PD-L1 and FasL, which might be involved in the function of Diff-Mφ. These results suggest that splenic microenvironment may physiologically induce a novel type of macrophages differentiation.

Strategy and long-term outcomes of endovascular treatment for Budd-Chiari syndrome complicated by inferior vena caval thrombosis

OBJECTIVES

The aim of this study was to evaluate the strategy and long-term outcomes of endovascular treatment of Budd-Chiari syndrome (BCS) complicated by inferior vena cava (IVC) thrombosis.

METHODS

The treatment strategy and outcomes of BCS complicated by IVC thrombosis were retrospectively evaluated in a single-center study. The treatment was aimed at the IVC thrombus, not hepatic vein occlusion. All 133 patients with BCS complicated by IVC thrombosis from February 2003 to March 2013 underwent endovascular treatment. For the fresh thrombus group (n=75) recanalization was performed after transcatheter thrombolysis with urokinase. For the mixed thrombus group (n=19) a small balloon pre-dilation of the IVC was performed first, followed by transcatheter thrombolysis using urokinase and a large balloon dilation of the IVC. For the old thrombus group (n=39) a large balloon dilation or/and stent placement was performed directly. Pre- and post-treatment follow-ups were recorded.

RESULTS

The endovascular treatment was successful in 131 out of 133 patients (98.5%). Thirty seven patients had synchronous hepatic vein occlusion. The incidence of serious complications was 4.5% (6/133). Symptomatic pulmonary embolism occurred in three cases, cerebral hemorrhage in two, and cardiac tamponade in one. The cumulative 1-, 5-, and 10-year primary patency rate was 96.3%, 84.0%, and 64.6%, respectively. The cumulative 1-, 5-, and 10-year secondary patency rate was 99.0%, 96.1% and 91.3%, respectively. Segmental occlusion of the IVC and duration of anticoagulant therapy less than 6 months were independent risk factors for reocclusion.

CONCLUSIONS

For patients with BCS complicated by IVC thrombosis, an individualized treatment strategy based on the property of the thrombus can result in excellent long-term patency.

Calumenin-15 facilitates filopodia formation by promoting TGF-β superfamily cytokine GDF-15 transcription

Filopodia, which are actin-rich finger-like membrane protrusions, have an important role in cell migration and tumor metastasis. Here we identify 13 novel calumenin (Calu) isoforms (Calu 3-15) produced by alternative splicing, and find that Calu-15 promotes filopodia formation and cell migration. Calu-15 shuttles between the nucleus and cytoplasm through interacting with importin α, Ran GTPase, and Crm1. The phosphorylation of the threonine at position 73 (Thr-73) by casein kinase 2 (CK2) is essential for the nuclear import of Calu-15, and either Thr-73 mutation or inhibition of CK2 interrupts its nuclear localization. In the nucleus, Calu-15 increases the transcription of growth differentiation factor-15 (GDF-15), a member of the transforming growth factor-β (TGF-β) superfamily, via binding to its promoter region. Furthermore, Calu-15 induces filopodia formation mediated by GDF-15. Together, we identify that Calu-15, a novel isoform of Calu with phosphorylation-dependent nuclear localization, has a critical role in promoting filopodia formation and cell migration by upregulating the GDF-15 transcription.

Hidden T-linear scattering rate in Ba0.6K0.4Fe2As2 revealed by optical spectroscopy

The optical properties of Ba0.6K0.4Fe2As2 have been determined in the normal state for a number of temperatures over a wide frequency range. Two Drude terms, representing two groups of carriers with different scattering rates (1/τ), well describe the real part of the optical conductivity σ1(ω). A "broad" Drude component results in an incoherent background with a T-independent 1/τb, while a "narrow" Drude component reveals a T-linear 1/τn resulting in a resistivity ρn≡1/σ1n(ω→0) also linear in temperature. An arctan(T) low-frequency spectral weight is also strong evidence for a T-linear 1/τ. A comparison to other materials with similar behavior suggests that the T-linear 1/τn and ρn in Ba0.6K0.4Fe2As2 originate from scattering from spin fluctuations and hence that an antiferromagnetic quantum critical point is likely to exist in the superconducting dome.

An animal model of Kashin-Beck disease induced by a low-nutrition diet and exposure to T-2 toxin

OBJECTIVE

We investigated the combined roles of a low-nutrition diet (low levels of protein, iodine, and selenium) and T-2 toxin in bone development and to establish an experimental animal model of Kashin-Beck disease (KBD) that reliably mimics the disease's pathological changes for further study of the pathogenesis and prevention of the disease.

METHODS

Sprague-Dawley rats were randomly divided among four groups: group A, normal diet; group B, normal diet plus T-2 toxin; group C, low-nutrition diet; and group D, low-nutrition diet plus T-2 toxin exposure. The radiographic and histopathological changes in the tibial growth zone, plate cartilage and metaphysis were examined.

RESULTS

In group D, all epiphyseal plates were blurred, thin, and irregular. Tibias were significantly shorter in group D than in groups A and B. After 4 weeks, epiphyseal plates showed chondrocyte necrosis, with the more obvious necrosis appearing in groups C and D. The positive rate of lamellar necrosis was significantly higher in group D than in groups B and A (P < 0.01). In group D, metaphyseal trabecular bone was sparse, disordered, and disrupted, and massive transverse trabecular bone appeared in the metaphysis at 12 weeks.

CONCLUSIONS

A rat model of KBD induced by a low-nutrition diet and T-2 toxin exposure demonstrated radiographic and histopathological abnormalities of the proximal epiphyseal plate and the tibial metaphysis that are very similar to the bone changes found in patients with KBD. This animal model will be helpful for further study of the pathogenesis and prevention of KBD.

Is there reduced polyethylene wear and longer survival when using a mobile-bearing design in total knee replacement?

The purpose of this study was to undertake a meta-analysis to determine whether there is lower polyethylene wear and longer survival when using mobile-bearing implants in total knee replacement when compared with fixed-bearing implants. Of 975 papers identified, 34 trials were eligible for data extraction and meta-analysis comprising 4754 patients (6861 knees). We found no statistically significant differences between the two designs in terms of the incidence of radiolucent lines, osteolysis, aseptic loosening or survival. There is thus currently no evidence to suggest that the use of mobile-bearing designs reduce polyethylene wear and prolong survival after total knee replacement.

Cite this article: Bone Joint J 2013;95-B:1057–63.

Effects of strontium impurity on the structure and dynamics of Al88Si12 liquid

The effects of strontium modification on the structure and dynamics of Al88Si12 liquid are studied by means of ab initio molecular dynamics simulations. By replacing 0.5% and 4.0% of Al with Sr, we show that the addition of Sr lowers the self-diffusion of Al and Si of the liquid and reduces the nearest-neighbor correlation between Si atoms. The simulation provides an explanation for the change in morphology of the eutectic phases observed in rapidly solidified Al-Si alloys modified with Sr.

Magnetic topology changes induced by lower hybrid waves and their profound effect on edge-localized modes in the EAST tokamak

Strong mitigation of edge-localized modes has been observed on Experimental Advanced Superconducting Tokamak, when lower hybrid waves (LHWs) are applied to H-mode plasmas with ion cyclotron resonant heating. This has been demonstrated to be due to the formation of helical current filaments flowing along field lines in the scrape-off layer induced by LHW. This leads to the splitting of the outer divertor strike points during LHWs similar to previous observations with resonant magnetic perturbations. The change in the magnetic topology has been qualitatively modeled by considering helical current filaments in a field-line-tracing code.

Superselective renal artery embolization in the treatment of renal hemorrhage

BACKGROUND

Renal hemorrhage is a potentially life-threatening event that may follow trauma, operation, biopsy, and sudden spontaneous rupture of renal tumors or aneurysms. Superselective renal artery embolization (SRAE) is a well-established method for such cases.

OBJECTIVES

To assess the effectiveness of SRAE in the treatment of renal hemorrhage at our institute.

MATERIALS AND METHODS

We respectively reviewed the medical records of patients who underwent SRAE for renal hemorrhage from January 2005 to June 2012. Data on patients' characteristics, indications, requirement of pre-embolization blood transfusion, angiographic finding, location of bleeding site, embolization agents, post-embolization transfusion requirement, complications and the outcome were recorded.

RESULTS

A total of 46 patients, aged 26-73 years, underwent SRAE because of hemorrhage after percutaneous nephrolithotomy (n = 25), partial nephrectomy (n = 6), renal biopsy (n = 2), trauma (n = 2), rupture of angiomyolipoma (n = 4), renal aneurysm (n = 1), and renal ateriovenous malformations (n = 6). A total of 41 patients (80.8 %) underwent successful embolization. Treatment failed in 5 patients with hemorrhage caused by percutaneous nephrolithotomy. Of these, four patients underwent a secondly superselective embolization and had a successful outcome. The remaining one was managed by conservative therapy with repeated blood transfusions. No patient required nephrectomy to save the life of the patient. No serious procedure-related complications occurred.

CONCLUSIONS

SRAE is an effective and minimal invasive method for the control of renal hemorrhage. Our experience strongly recommended the first-line use of SRAE for severe renal hemorrhage.

Inhibitor discovery of full-length New Delhi metallo-β-lactamase-1 (NDM-1)

New Delhi metallo-β-lactmase-1 (NDM-1) has recently attracted extensive attention for its biological activities to catalyze the hydrolysis of almost all of β-lactam antibiotics. To study the catalytic property of NDM-1, the steady-kinetic parameters of NDM-1 toward several kinds of β-lactam antibiotics have been detected. It could effectively hydrolyze most β-lactams (k_cat/K_m ratios between 0.03 to 1.28 µmol⁻¹.s⁻¹), except aztreonam. We also found that thiophene-carboxylic acid derivatives could inhibit NDM-1 and have shown synergistic antibacterial activity in combination with meropenem. Flexible docking and quantum mechanics (QM) study revealed electrostatic interactions between the sulfur atom of thiophene-carboxylic acid derivatives and the zinc ion of NDM-1, along with hydrogen bond between inhibitor and His189 of NDM-1. The interaction models proposed here can be used in rational design of NDM-1 inhibitors.

Shock-front injector for high-quality laser-plasma acceleration

We report the generation of stable and tunable electron bunches with very low absolute energy spread (ΔE ≈ 5 MeV) accelerated in laser wakefields via injection and trapping at a sharp downward density jump produced by a shock front in a supersonic gas flow. The peak of the highly stable and reproducible electron energy spectrum was tuned over more than 1 order of magnitude, containing a charge of 1-100 pC and a charge per energy interval of more than 10 pC/MeV. Laser-plasma electron acceleration with Ti:sapphire lasers using this novel injection mechanism provides high-quality electron bunches tailored for applications.

Hypoxia differentially regulates human nucleus pulposus and annulus fibrosus cell extracellular matrix production in 3D scaffolds

OBJECTIVE

We hypothesize that intervertebral disc (IVD) cells from distinct region respond differently to oxygen environment, and that IVD cells from patients with disc degeneration can benefit from hypoxia condition. Therefore, we aimed to determine the transcriptional response and extracellular matrix (ECM) production of nucleus pulposus (NP) and annulus fibrosus (AF) cells to different oxygen tension.

METHOD

Human NP and AF from degenerated IVD were seeded in 3D scaffolds and subjected to varying oxygen tension (2% and 20%) for 3 weeks. Changes in ECM were evaluated using quantitative real-time reverse transcriptase polymerase chain reaction, histological and immunohistological analyses.

RESULTS

Hypoxia significantly enhances NP cells phenotype, which resulted in greater production of sulfated glycosaminoglycan (GAG) and collagen type II within the constructs and the cells expressed higher levels of genes encoding NP ECM. A significantly stronger fluorescent signal for hypoxia-inducible factor (HIF-1α) as also found in the NP cells under the hypoxic than normoxic condition. However, there was little effect of hypoxia on the AF cells.

CONCLUSIONS

The NP and AF cells respond differently to hypoxia condition on the 3D scaffold, and hypoxia could enhance NP phenotype. When used in concert with appropriate scaffold material, human NP cells from degenerated disc could be regenerated for tissue engineering application.