A novel method to optimize the mode spectrum of the dynamic resonant magnetic perturbation on the J-TEXT tokamak

The dynamic resonant magnetic perturbation (DRMP) system has been developed for the J-TEXT tokamak to study the interaction between the rotating perturbation magnetic field and the plasma. When the DRMP coils are energized by two phase sinusoidal currents with the same frequency, a 2/1 rotating resonant magnetic perturbation component will be generated. But at the same time, a small perturbation component rotating in the opposite direction is also produced because of the control error of the currents. This small component has bad influence on the experiment investigations. Actually, the mode spectrum of the generated DRMP can be optimized with an accurate control of phase difference between the two currents. In this paper, a new phase control method based on a novel all-digital phase-locked loop (ADPLL) is proposed. The proposed method features accurate phase control and flexible phase adjustment. Modeling and analysis of the proposed ADPLL is presented to guide the design of the parameters of the phase controller in order to obtain a better performance. Testing results verify the effectiveness of the ADPLL and validity of the method applying to the DRMP system.

Analytical compensation of axisymmetric equilibrium fluxes picked up by locked mode detectors in tokamaks

In the detection of locked modes using saddle loops, the problem of how to remove the axisymmetric equilibrium flux picked up by the loops has still to be solved. The problem becomes more difficult when there are conductive structures located near the saddle loops. In this paper, we present an analytical model based on lumped eddy current circuits and use it to interpret the measured equilibrium flux and the corresponding eddy current fluxes. Using this model, precise compensation for fluxes induced by the horizontal field coils and the toroidal field coils, with relative errors of less than 1%, has been realized for the saddle loops in the Joint Texas Experimental Tokamak. This paper also presents a new method to compensate for the detection of equilibrium flux by the locked mode detector.

Upgraded high time-resolved x-ray imaging crystal spectroscopy system for J-TEXT ohmic plasmas

This paper presents the upgraded x-ray imaging crystal spectrometer (XICS) system on Joint Texas Experimental Tokamak (J-TEXT) tokamak and the latest experimental results obtained in last campaign. With 500 Hz frame rate of the new Pilatus detector and 5 cm × 10 cm spherically bent crystal, the XICS system can provide core electron temperature (Te), core ion temperature (Ti), and plasma toroidal rotation (VΦ) with a maximum temporal resolution of 2 ms for J-TEXT pure ohmic plasmas. These parameters with high temporal resolution are very useful in tokamak plasma research, especially for rapidly changed physical processes. The experimental results from the upgraded XICS system are presented.

p53-Based cyclotherapy: exploiting the 'guardian of the genome' to protect normal cells from cytotoxic therapy

Side effects of chemotherapy are a major impediment in the treatment of cancer. Cyclotherapy is an emerging therapeutic strategy for protecting normal cells from the side effects of chemotherapy. Low, non-genotoxic doses of known p53 activators can be used to induce p53-dependent cell cycle arrest in normal cells bearing wild-type p53. This cytostatic effect of p53 can protect normal cells from the toxicity of S- or M-phase poisons. Here, we have reviewed existing cyclotherapy regimens using two well-known p53 activators, nutlin-3 and actinomycin D. We have highlighted an exemplar clinical perspective for cyclotherapy in breast cancer. The recent development of novel stapled peptides as activators of p53 without the corresponding cytotoxicity holds great promise for cyclotherapy to enhance the therapeutic window of existing chemotherapy drugs.

Blockage of Nrf2 suppresses the migration and invasion of esophageal squamous cell carcinoma cells in hypoxic microenvironment

Nuclear factor erythroid-2-related factor 2 (Nrf2) is a critical cell protector by inducing phase two detoxifying and anti-oxidant enzymes in normal cells. But recently, numerous evidence show Nrf2 may play the same beneficial roles toward the cancer cells. Nrf2 is found upexpressed in lots of cancers and promote the proliferation and drug resistance. But studies about the role of Nrf2 in the metastases are few. It has been testified that the tumor cells are under hypoxic conditions. As an important anti-oxidant element, the expression of Nrf2 may be upregulated, which in turn promotes the tumor invasion and metastases in the hypoxic microenvironment. Our team found the expression of Nrf2 correlated with the lymph node metastasis of esophageal squamous cell carcinoma by pathological sections of esophageal carcinoma patients. Further, the mechanism beneath it was studied in this paper. It was hypothesized that the hypoxia microenvironment transformed Nrf2 a friend to a foe. First, Eca-109 cells were treated with different concentration of CoCl2 . Western blot and quantitative reverse transcription-polymerase chain reaction showed that with the increase of the concentration of CoCl2 , the expression levels of Nrf2 and hypoxia-inducible factor-1 (HIF-1) alpha were upregulated simultaneously. By analyzing the data, a significant correlation between Nrf2 and HIF-1 alpha in the protein levels was found. Further, blockage of Nrf2 mediated by shRNA suppressed the expression of HIF-1 alpha, hemeoxygenase-1 (HO-1), and matrix metalloproteinase 2 but enhanced the expression of E-cadherin. In addition, the results of wound healing and invasion assay-verified blockage of Nrf2 suppressed the migration and invasion. So it was suggested that blockage of Nrf2 repressed the migration and invasion of esophageal squamous cell carcinoma cells in the hypoxic microenvironment. HIF-1 alpha might be one of the downstream genes of Nrf2 regulated through Nrf2/HO-1 axis in the CoCl2 model. Nrf2 inhibition suppressed matrix metalloproteinase 2 and enhanced E-cadherin partly through HIF-1 alpha way.

Measurement of 2∕1 intrinsic error field of Joint TEXT tokamak

The amplitude and spatial phase of the intrinsic error field of Joint TEXT (J-TEXT) tokamak were measured by scanning the spatial phase of an externally exerted resonant magnetic perturbation and fitting the mode locking thresholds. For a typical plasma with current of 180 kA, the amplitude of the 2∕1 component of the error field at the plasma edge is measured to be 0.31 G, which is about 1.8 × 10(-5) relative to the base toroidal field. The measured spatial phase is about 317° in the specified coordinate system (r, θ, ϕ) of J-TEXT tokamak. An analytical model based on the dynamics of rotating island is developed to verify the measured phase.

Characterization of 236 novel alleles at the HLA-A, -B, -C, -DRB1, -DQB1 and -DPB1 loci from China Marrow Donor Program

Two hundred and thirty-six novel human leukocyte antigen (HLA) alleles are described from volunteer donors of the China Marrow Donor Program: 71 HLA-A alleles, 79 HLA-B alleles, 43 HLA-C, 16 HLA-DRB1 alleles, 26 HLA-DQB1 and 1 HLA-DPB1. Two hundred and thirteen (90.3%) of the 236 novel alleles are single nucleotide substitution variants when compared with their most homologous allele. Seventy-eight of these single nucleotide variants are silent substitutions. The remaining novel alleles differ from their most similar allele by two to four nucleotide substitutions. Some of the novel alleles encode amino acid changes at positions not previously reported to be polymorphic, such as codons 57, 62, 67, 41 and 52 in HLA-A alleles; codons 133, 156, 201 and 215 in HLA-B alleles; codons 74, 208 and 225 in HLA-C; codons 25, 32 and 72 in HLA-DRB1; codons 20, 39 and 77 in HLA-DQB1.

New printed circuit boards magnetic coils in the vacuum vessel of J-TEXT tokamak for position measurement

Four sets of magnetic diagnostic coils, which are printed on machinable ceramic printed circuit boards (PCB), are designed, fabricated, installed, and tested in the Joint Texas Experimental Tokamak (J-TEXT) vacuum vessel for detecting the plasma radial and vertical displacements relative to the geometric center of the vacuum vessel in Ohmic discharges. Each coordinate is determined by a pair of variable cross-section Rogowski and saddle coils, which measure the tangential and normal magnetic fields (relative to the coil surface). These coils are suitable for mass production and offer advantages in vacuum compatibility and temperature tolerance that are important for J-TEXT. Position measurements using PCB coils are compared with those from soft x-ray image system and match the position well.

Overcoming the barriers experienced in conducting a medication trial in adults with aggressive challenging behaviour and intellectual disabilities

BACKGROUND

Aggressive challenging behaviour in people with intellectual disability (ID) is frequently treated with antipsychotic drugs, despite a limited evidence base.

METHOD

A multi-centre randomised controlled trial was undertaken to investigate the efficacy, adverse effects and costs of two commonly prescribed antipsychotic drugs (risperidone and haloperidol) and placebo.

RESULTS

The trial faced significant problems in recruitment. The intent was to recruit 120 patients over 2 years in three centres and to use a validated aggression scale (Modified Overt Aggression Scale) score as the primary outcome. Despite doubling the period of recruitment, only 86 patients were ultimately recruited.

CONCLUSIONS

Variation in beliefs over the efficacy of drug treatment, difficulties within multidisciplinary teams and perceived ethical concerns over medication trials in this population all contributed to poor recruitment. Where appropriate to the research question cluster randomised trials represent an ethically and logistically feasible alternative to individually randomised trials.

Preventive efficacy of hydroalcoholic extract of Cymbopogon citratus against radiation-induced DNA damage on V79 cells and free radical scavenging ability against radicals generated in vitro

This study presents the findings of free radical scavenging and antigenotoxic effect of hydroalcoholic extract of Cymbopogon citratus (CCE). The CCE at a concentration of 60 μg/mL resulted in a significant scavenging ability of 2,2-diphenyl-2-picryl hydrazyl (DPPH; (85%), 2,2-azinobis (3-ethyl benzothiazoline-6-sulphonic acid) (ABTS; 77%), hydroxyl (70%), superoxide (76%), nitric oxide (78%) free radicals generated using in vitro and also a moderate anti-lipid peroxidative effect (57%). Further, the radiation-induced antigenotoxic potential of CCE was assessed in Chinese hamster lung fibroblast cells (V79) using micronucleus assay. The CCE resulted in a dose-dependent decrease in the yield of radiation-induced micronuclei, with a maximum effect at 125 μg/mL CCE for 1 h before 2 Gy of radiation. Similarly, there was a significant ( P < 0.05–0.0001) decrease in percentage of micronuclei when V79 cells were treated with optimal dose of CCE (125 μg/mL) before exposure to different doses of gamma radiation, that is, 0.5–4 Gy, compared with radiation alone groups. The results of the micronucleus study indicated antigenotoxic effect demonstrating the radioprotective potential of CCE and, which may partly due to its and antioxidant capacity as it presented its ability to scavenge various free radicals in vitro and anti-lipid peroxidative potential.

Neuroleptics in the treatment of aggressive challenging behaviour for people with intellectual disabilities: a randomised controlled trial (NACHBID)

OBJECTIVE(S)

To assess the effects and cost-effectiveness of haloperidol, risperidone and placebo on aggressive challenging behaviour in adults with intellectual disability.

DESIGN

A double-blind randomised controlled trial of two drugs and placebo administered in flexible dosage, with full, independent assessments of aggressive and aberrant behaviour, global improvement, carer burden, quality of life and adverse drug effects at baseline, 4, 12 and 26 weeks, and comparison of total care costs in the 6 months before and after randomisation. At 12 weeks, patients were given the option of leaving the trial or continuing until 26 weeks. Assessments of observed aggression were also carried out with key workers at weekly intervals throughout the trial.

SETTING

Patients were recruited from all those being treated by intellectual disability services in eight sites in England, one in Wales and one in Queensland, Australia.

PARTICIPANTS

Patients from all severity levels of intellectual disability; recruitment was extended to include those who may have been treated with neuroleptic drugs in the past.

EXCLUSION CRITERIA

treatment with depot neuroleptics/another form of injected neuroleptic medication within the last 3 months; continuous oral neuroleptic medication within the last week; those under a section of the Mental Health Act 1983 or Queensland Mental Health Act 2000.

INTERVENTIONS

Randomisation to treatment with haloperidol (a typical neuroleptic drug), risperidone (an atypical neuroleptic drug) or placebo using a permuted blocks procedure. Dosages were: haloperidol 1.25-5.0 mg daily; risperidone 0.5-2.0 mg daily.

MAIN OUTCOME MEASURES

Primary: reduction in aggressive episodes between baseline and 4 weeks using Modified Overt Aggression Scale. Secondary: Aberrant Behaviour Checklist; Uplift/Burden Scale; 40-item Quality of Life Questionnaire; Udvalg for Kliniske Undersøgelser scale; Clinical Global Impressions scale. Economic costs recorded using a modified version of Client Service Receipt Inventory for 6 months before and after randomisation.

RESULTS

There were considerable difficulties in recruitment because of ethical and consent doubts. Twenty-two clinicians recruited a total of 86 patients. Mean daily dosages were 1.07 mg rising to 1.78 mg for risperidone and 2.54 mg rising to 2.94 mg for haloperidol. Aggression declined dramatically with all three treatments by 4 weeks, with placebo showing the greatest reduction (79%, versus 57% for combined drugs) (p = 0.06). Placebo-treated patients showed no evidence of inferior response in comparison to patients receiving neuroleptic drugs. An additional study found that clinicians who had not participated in clinical trials before were less likely to recruit. Mean total cost of accommodation, services, informal care and treatment over the 6 months of the trial was 16,336 pounds for placebo, 17,626 pounds for haloperidol and 18,954 pounds for risperidone.

CONCLUSIONS

There were no significant important benefits conferred by treatment with risperidone or haloperidol, and treatment with these drugs was not cost-effective. While neuroleptic drugs may be of value in the treatment of aggressive behaviour in some patients with intellectual disability, the underlying pathology needs to be evaluated before these are given. The specific diagnostic indications for such treatment require further investigation. Prescription of low doses of neuroleptic drugs in intellectual disability on the grounds of greater responsiveness and greater liability to adverse effects also needs to be re-examined.

Prognostic factors for local and distant control in Ewing sarcoma family of tumors

BACKGROUND

Advances in the treatment of Ewing sarcoma family of tumors (ESFT) are the result of improvements in systemic and local therapies. The individual contributions of each treatment component cannot be analyzed separately; improvements in local and systemic control can influence each other.

PATIENTS AND METHODS

We reviewed the records of 220 patients treated on institutional protocols from 1979 to 2004. Factors predictive of local and distant recurrence were analyzed.

RESULTS

The median age at diagnosis was 13.7 years. Ninety-five patients relapsed at a median of 1.6 years. The 5-year overall survival estimate was 63.5% +/- 3.5%. The estimated 5-year cumulative incidence (CI) of local failure was 25.1% +/- 3.0%. Local failure was associated with treatment era (P < 0.001), tumor size (P = 0.037) and type of local control (P = 0.021). Systemic treatment intensification improved local control. The estimated 5-year CI of distant recurrence was 22.5% +/- 2.9%. Patients with localized disease (P < 0.001), smaller tumors (P = 0.018) and those who received surgery +/- radiation for local control (P = 0.023) had lower CI of distant failure.

CONCLUSIONS

Successful treatment of ESFT requires optimal systemic and local therapy. Both treatment modalities are intertwined and the control of both local and distant disease is the result of the combined approach.