Design of polarizers for a mega-watt long-pulse millimeter-wave transmission line on the large helical device

The polarizer is one of the critical components in a high-power millimeter-wave transmission line. It requires full and highly efficient coverage of any polarization states, high-power tolerance, and low-loss feature. Polarizers with rounded shape at the edge of the periodic groove surface are designed and fabricated by the machining process for a mega-watt long-pulse millimeter-wave transmission line of the electron cyclotron resonance heating system in the large helical device. The groove shape of λ/8- and λ/4-type polarizers for an 82.7 GHz transmission line is optimally designed in an integral method developed in the vector theories of diffraction gratings so that the efficiency to realize any polarization state can be maximized. The dependence of the polarization states on the combination of the two polarizer rotation angles (Φλ/8, Φλ/4) is examined experimentally in a low-power test with the newly developed polarization monitor. The results show that the measured polarization characteristics are in good agreement with the calculated ones.

Clinical outcome of deep-seated atypical lipomatous tumor of the extremities with median-term follow-up study

AIMS

There is no consensus on the best surgical treatment for deep-seated atypical lipomatous tumor (ALT) of the extremities; furthermore, the appropriate duration for follow-up observation remains unclear. We investigated clinical and functional median-term outcomes in the primary operations for ALT of the extremities in order to find its best treatment methods and observation periods.

METHODS

From 1996 to 2009, we diagnosed 41 patients with deep-seated ALT of the extremities. Wide resection was performed on 11 patients and marginal resection was performed on 30 patients. The minimum follow-up was 5 years (median, 8.5; range, 5-17.4). Patients were evaluated for their local recurrence, dedifferentiation, and post-operative function using the ISOLS/MSTS scoring system.

RESULTS

Recurrence and dedifferentiation rates were both 0% for the wide resection group, while the rates were 23% (7/30) and 3% (1/30) for the marginal resection group, respectively. Median duration before recurrence was 7.2 years (range, 4.0-14.2). Local recurrence-free survival rate was significantly higher in the wide resection group (P = 0.013). In the marginal resection group, 10% (3/30) of the cases showed residual tumor. The localization of these tumors was all intermuscular. The ISOLS/MSTS scores were 98% (range, 90-100) for wide resection and 99% (range, 93-100) for marginal resection, with no statistical difference (P = 0.694). No ALT-related deaths occurred during the observation period.

CONCLUSIONS

In addition to long-term (at least 8 years) of continuous observation, a wide resection is necessary in order to prevent recurrence, dedifferentiation, and residual tumor.

Power and polarization monitor development for high power millimeter-wave

A new type monitor of power and polarization states of millimeter-waves has been developed to be installed at a miter-bend, which is a part of transmission lines of millimeter-waves, for electron cyclotron resonance heating on the Large Helical Device. The monitor measures amplitudes and phase difference of the electric field of the two orthogonal polarizations which are needed for calculation of the power and polarization states of waves. The power and phase differences of two orthogonal polarizations were successfully detected simultaneously.

Electron cyclotron beam measurement system in the Large Helical Device

In order to evaluate the electron cyclotron (EC) heating power inside the Large Helical Device vacuum vessel and to investigate the physics of the interaction between the EC beam and the plasma, a direct measurement system for the EC beam transmitted through the plasma column was developed. The system consists of an EC beam target plate, which is made of isotropic graphite and faces against the EC beam through the plasma, and an IR camera for measuring the target plate temperature increase by the transmitted EC beam. This system is applicable to the high magnetic field (up to 2.75 T) and plasma density (up to 0.8 × 10(19) m(-3)). This system successfully evaluated the transmitted EC beam profile and the refraction.

Development of fast steering mirror control system for plasma heating and diagnostics

A control system for a fast steering mirror has been newly developed for the electron cyclotron heating (ECH) launchers in the large helical device. This system enables two-dimensional scan during a plasma discharge and provides a simple feedback control function. A board mounted with a field programmable gate array chip has been designed to realize feedback control of the ECH beam position to maintain higher electron temperature by ECH. The heating position is determined by a plasma diagnostic signal related to the electron temperature such as electron cyclotron emission and Thomson scattering.

Sexual satisfaction of infertile couples assessed using the Golombok-Rust Inventory of Sexual Satisfaction (GRISS)

Recently, infertility treatment-related psychological effects are receiving increased attention. However, whether sexual satisfaction is reduced amongst infertile couples remains to be elucidated. In this study, sexual satisfaction of Japanese infertile couples was assessed using a validated questionnaire designed to assess the male and female partner individually, and the couple as a whole for the first time. This study randomly included 170 infertile couples seen at the outpatient clinic and 170 couples that had recently achieved spontaneous pregnancy. All couples were given the Japanese version of the Golombok-Rust Inventory of Sexual Satisfaction (GRISS). In couples aged 35 years or older, the male partners showed significantly worse sexual satisfaction scores than the female partners. Sexual satisfaction also deteriorated with therapeutic interventions, with mental factors affected more than physical factors. Therapeutic interventions such as timed sexual intercourse and assisted reproductive technology were considered emotionally stressful for infertile couples, with sexual satisfaction accordingly lower in this group than in couples achieving spontaneous pregnancy. GRISS successfully evaluated lower sexual satisfaction associated with infertility, and hence is a useful tool for identifying couples whose sexual satisfaction could be enhanced by counselling or other stress-reduction modalities.

The incidence of monozygotic twinning in assisted reproductive technology: analysis based on results from the 2010 Japanese ART national registry

PURPOSE

To assess the incidence of monozygotic twinning (MZT) among cases undergoing assisted reproductive technology (ART) treatment.

METHODS

We performed a retrospective observational study and analyzed the data of patients who were registered in the national ART registry system of Japan from January to December 2010; only the data of patients with single embryo transfer (ET) were included.

RESULTS

Of 30,405 pregnancies, 425 resulted in MZT following fresh and frozenthawed ET. The MZT incidence among women undergoing ART was 1.4 %. Multiple logistic regression analysis indicated that cases undergoing fresh and frozen-thawed ET, blastocyst transfer had a significantly increased MZT rate (P < 0.01). Assisted hatching (AH) and frozen-thawed ET and maternal age did not significantly affect the MZT incidence. Of 8510 fresh ET pregnancies, 104 resulted in MZT. Multiple logistic regression analysis indicated that blastocyst transfer significantly increased the MZT rate in cases undergoing fresh ET. Ovarian stimulation, intracytoplasmic sperm injection, AH, and maternal age did not significantly affect the MZT incidence.

CONCLUSIONS

Blastocyst transfer was associated with an increased MZT incidence. We have to be aware of the potential risk of MZT caused by blastocyst transfer. However, further studies are required to assess the correlation among specific AH types, embryo culture conditions, and MZT incidence.

Efficacy, safety, and trends in assisted reproductive technology in Japan-analysis of four-year data from the national registry system

PURPOSE

This study aimed to evaluate the efficacy, safety, and trends in assisted reproductive technology (ART) in Japan.

METHODS

Data pertaining to treatment cycles, pregnancy rate, live birth rate, age distribution, single embryo transfer rate, and multiple pregnancy rate were analyzed for patients registered in the national ART registry system of Japan from 2007 to 2010.

RESULTS

The total number of treatment cycles was 161,164, 190,613, 213,800, and 242,161 in 2007, 2008, 2009, and 2010, respectively. The number of ART treatments administered to patients aged ≥40 years was 31.2 %, 32.1 %, 33.4 %, and 35.7 %, respectively, showing an increasing trend from 2007 to 2010. In each of these years, the total pregnancy rate per embryo transfer was 24.4 %, 21.9 %, 22.3 %, and 21.9 % for fresh cycles, respectively, and 32.0 %, 32.1 %, 32.5 %, and 33.7 % for frozen cycles, respectively. The single embryo transfer rate was 49.9 %, 63.6 %, 70.6 %, and 73.0 %, respectively, showing an increasing trend, while the multiple pregnancy rate was 11.5 %, 6.8 %, 5.3 %, and 4.8 %, respectively, showing a decreasing trend.

CONCLUSIONS

From 2007 to 2010 in Japan, the number of ART treatment cycles, number of elderly patients treated, and the single embryo transfer rate increased, while the multiple pregnancy rate decreased. However, the overall pregnancy rate remained stable during the study period.