Inscribing diffraction grating inside silicon substrate using a subnanosecond laser in one photon absorption wavelength.

Using focused subnanosecond laser pulses at [Formula: see text] wavelength, modification of silicon into opaque state was induced. While silicon exhibits one-photon absorption at this wavelength, the modification was induced inside [Formula: see text]-thick silicon substrate without damaging top or bottom surfaces. The depth range of the focus position was investigated where inside of the substrate can be modified without damaging the surfaces. Using this technique, diffraction gratings were inscribed inside silicon substrate. Diffraction from the gratings were observed, and the diffraction angle well agreed with the theoretical value. These results demonstrate that this technique could be used for fabricating infrared optical elements in silicon.

Two years of bicalutamide monotherapy in patients with biochemical relapse after radical prostatectomy.

BACKGROUND: Salvage treatments for biochemical relapse (BCR) after radical prostatectomy (RP) have several problems in terms of indications or adverse events. We studied the possibility of 2 years of bicalutamide monotherapy for BCR after RP. METHODS: Patients who showed BCR (prostate-specific antigen (PSA) ≥ 0.2 ng/ml) after RP were recruited. Protocol treatment was planned as 2 years of bicalutamide (80 mg/day) followed by observation. Protocol treatment failure was defined as PSA re-elevation of ≥0.2 ng/ml, clinical progression, any other treatments, or discontinuation or restart of bicalutamide. Primary endpoint of this study is time to protocol treatment failure from initiation of bicalutamide. RESULTS: A total of 91 patients were registered between 2003 and 2009. Median age and PSA at initiating bicalutamide were 68 (range, 55-78) years and 0.32 (range, 0.19-7.91) ng/ml. Twenty-four (26.4%) patients could not complete 2 years of bicalutamide mainly due to progression of disease. Of the 91 patients, 2- and 5-year protocol treatment failure-free survivals were 74.6% and 33.0%, with a median follow-up of 76 (range, 11-118) months. Median time from initiating bicalutamide to treatment failure was 43 (95% confidence interval, 33-47) months. High-risk status at RP and time to BCR after RP < 6 months were significant predictors of second BCR. CONCLUSIONS: Two years of bicalutamide monotherapy should not be recommended as standard management for BCR after RP, but might be feasible for selected patients who do not have high-risk status at RP and short time to BCR.

A prospective multicenter study of intermittent chemotherapy with docetaxel and prednisolone for castration-resistant prostate cancer.

OBJECTIVE: The optimal schedule of docetaxel chemotherapy for castration-resistant prostate cancer is unknown, although continuous administration is accepted as the standard. We conducted a Phase II trial to evaluate the outcome of intermittent docetaxel and prednisolone therapy in castration-resistant prostate cancer. METHODS: The patients were treated using a 28-day cycle of docetaxel (70 mg/m2 on Day 1) and oral prednisolone (10 mg/day). After three consecutive administrations of docetaxel, a holiday was taken until prostate specific antigen levels returned to the baseline. The therapy was continued intermittently until the disease progressed, drug toxicity occurred, or the patients refused further treatment. The primary endpoint was overall survival. Time to treatment failure, adverse events, the duration of chemotherapy holiday and quality of life were also evaluated. RESULTS: A total of 120 patients were enrolled. The median age and pretreatment prostate specific antigen level were 72 years and 37.5 ng/ml, respectively. Sixty (50.0%) patients resumed chemotherapy after the first holiday, and a maximum of six courses were administered to four patients. The median period of the first, second and third-to-fifth holiday was 18.6, 11.0 and 4.9 weeks, respectively. Toxicity was moderate, except for two fatal adverse events. The median time to treatment failure and overall survival from the initiation of docetaxel and prednisolone therapy in all patients were 17.5 and 35.0 months, respectively. All quality-of-life scores were unchanged statistically from the start of docetaxel and prednisolone therapy to the beginning of the second course. CONCLUSIONS: Intermittent docetaxel and prednisolone therapy might be a feasible treatment option for castration-resistant prostate cancer with comparable outcome and successful chemotherapy holidays.

Spontaneous formation of 10-µm-scale periodic patterns in transverse-scanning femtosecond laser processing.

We report spontaneous formation of 10-µm-scale periodic patterns in transverse-scanning femtosecond (fs) laser processing inside a glass substrate. The formation of the periodic patterns was critically dependent on the distance of the focus from the back surface; they formed only when fs pulses were focused slightly inside (∼ a few micrometers) from the back surface. The periods ranged from 7 to 16 µm, which is much longer than the distance between neighboring irradiation spots (0.1-1 µm in the present experiments), the diameter of the individual modified spots (about 2 µm), and the wavelength (0.8 µm). The patterns formed without any intentional modulation; just by scanning the sample at a constant speed during irradiation of fs laser pulses. The dependence on scanning speed and repetition rate of the laser were also investigated, and a possible formation scenario for this "long" periodic pattern was described.

[An intravesical foreign body by migration of remnant gauze into the bladder: a case report].

A 35-year-old female, who had undergone Caesarean sections in 2000 and 2001, presented with repeated candida vaginitis and cystitis. She reported that a piece of gauze was excreted through the urethra in 2005. The patient visited an outpatient clinic, but no foreign body was identified by cystoscopy. She again visited the clinic in 2012 complaining of miction pain, and a calcified mass was identified in the bladder. The patient was then referred to our hospital. During a transurethral operation, crushed stones, which included the gauze, were removed from the bladder. We concluded that remnant gauze left in the abdominal cavity during the previous pelvic surgery, had migrated into the bladder and formed a calcified mass.

High-frame-rate observation of single femtosecond laser pulse propagation in fused silica using an echelon and optical polarigraphy technique.

We have demonstrated high-frame-rate observations of a single femtosecond laser pulse propagating in transparent medium using the optical polarigraphy technique and an echelon. The echelon produced a spatially encoded time delay for the probe pulse to capture directly four successive images of an intense propagating pulse with picosecond time interval and femtosecond time resolution. Using this method, we observed the propagation process of a single femtosecond laser pulse in fused silica. The influence of pulse-energy fluctuation on the spatial and temporal distribution of the single laser pulse was visualized using the single-shot measurements.

Reduction of pulse-to-pulse fluctuation in laser pulse energy using the optical Kerr effect.

An all-optical stabilization method of laser pulse energy is proposed using the optical Kerr effect (OKE). The method uses the OKE induced by a portion of the laser pulse as a power controller. The decrease (increase) in the throughput of the optical setup for OKE compensates for the increase (decrease) in pulse energy, thereby stabilizing the pulse-to-pulse fluctuation in pulse energy. The validity of this principle was proven by experiments with a femtosecond laser.

Clearance and safety of the radiocontrast medium iopamidol in peritoneal dialysis patients.

Although the characteristics and safety of radiocontrast media in peritoneal dialysis (PD) patients are not yet well defined, their use in PD patients is considered generally safe. In this study, we evaluated clearance and adverse events of iopamidol in PD patients. We measured the iopamidol concentration in the plasma, dialysate, and urine of 11 patients. Iopamidol clearance from patient plasma was delayed with a half-life of 33.3 h, and the elimination ratio was 83.6% for 96 h. We retrospectively investigated adverse events occurring in a total of 50 stable PD patients who underwent a total of 64 angiographic computed tomography (CT) scans. In 64 angiographic CT scans, two cases of adverse events were observed. Our results suggest that iopamidol can be eliminated by regular PD and careful observation for adverse events are necessary for the safe use of radiocontrast media.

Matrix calculus for axially symmetric polarized beam.

The Jones calculus is a well known method for analyzing the polarization of a fully polarized beam. It deals with a beam having spatially homogeneous polarization. In recent years, axially symmetric polarized beams, where the polarization is not homogeneous in its cross section, have attracted great interest. In the present article, we show the formula for the rotation of beams and optical elements on the angularly variant term-added Jones calculus, which is required for analyzing axially symmetric beams. In addition, we introduce an extension of the Jones calculus: use of the polar coordinate basis. With this calculus, the representation of some angularly variant beams and optical elements are simplified and become intuitive. We show definitions, examples, and conversion formulas between different notations.

Applications of a microlens array and a photomask to the laser microfabrication of a periodic photopolymer rod array.

We report the simultaneous multipoint fabrication of polymer rods by the femtosecond laser processing of a negative photoresist using a microlens array (MLA). The rods were periodically arranged in the form of an array corresponding to the MLA and free-standing on a glass substrate. The use of a photomask enabled us to define the contour of the rod array. Furthermore, sample translation techniques were demonstrated for the effective fabrication of large-area structures.

Holographic lithography of periodic two- and three-dimensional microstructures in photoresist SU-8.

Micro-fabrication of periodic structures was performed by holographic lithography technique in SU-8 photoresist using a simple and versatile experimental arrangement based on a diffractive beam-splitter. High-fidelity two- and three-dimensional microstructures fabricated with sub-micrometric resolution in large areas of approximately 1 mm diameter. The structures are potentially usable as elements of micro-fluidic systems (e.g., Brownian ratchets), and templates for photonic crystal devices (e.g., mirrors, collimators, superprisms).

Control of the molecular alignment inside liquid-crystal droplets by use of laser tweezers.

Here, we demonstrate how the light-induced birefringence due to the dipole molecular realignment and anisotropic polarizability of a nematic liquid crystal inside a droplet changes the droplet's radial (and thus optically isotropic) structure into a birefringent one. This intensity-dependent change of birefringence can be understood in terms of the anisotropic polarizability and orientational optical nonlinear effect. Birefringence induced by laser tweezers changes the momentum of the passing light. In turn, for the circularly polarized tweezers, this change generates an angular momentum change large enough to spin micrometer-sized droplets. For the linearly polarized tweezers, the molecular ordering generates momentum, which laterally displaces the droplet. It is shown that the optical nonlinearity can be "large" enough to have mechanical (ponderomotive) implications, that is, it allows control of the movement and position of micro-objects with submicrometer resolution. The optically induced molecular alignment controlled by the polarization and power of the laser tweezers allows one to actuate, rotate, and translate objects which are up to 10(3)-10(4) times larger than the constituent molecules themselves.

Plasma exchange for hypertriglyceridemic acute necrotizing pancreatitis: report of two cases.

We report two cases of hypertriglyceridemic necrotizing pancreatitis treated by plasma exchange (PE). The outcome of each case was quite different according to the timing of PE. A 36 year old man presented with abdominal pain, and a diagnosis of severe acute pancreatitis was made. His serum triglyceride (TG) level was 6,460 mg/dl. He did not undergo PE at first, however, his condition never improved and PE was performed 20 days after the onset of his illness. Finally, he died of multiple organ failure and sepsis. In contrast, a 52 year old man with acute necrotizing pancreatitis was referred to our department. He received PE quickly after hospital admission. His serum TG level, which was 3,540 mg/dl at hospital admission, dramatically returned to normal limits, and he was discharged from the hospital 62 days after admission. The prognosis of severe necrotizing pancreatitis due to hypertriglyceridemia is extremely poor. PE should be applied for the treatment of hypertriglyceridemic necrotizing pancreatitis immediately after its onset.

Health-related quality of life of ileocecal rectal bladder compared with ileal conduit diversion: a questionnaire survey.

BACKGROUND: The ileocecal rectal bladder (IRB) after cystectomy has been devised, in which continence is controlled by the anal sphincter. To assess how this procedure influences postoperative health-related quality of life (QOL), IRB patients were compared with ileal conduit (IC) patients using a questionnaire mail-out. METHODS: The questionnaire consisted of 35 questions. The questions were multiple choice and the answers were rated on a Linkert rank-type four-point scale. The IRB operation was performed on 29 patients between March 1990 and July 1998. The questionnaire was mailed to 21 of 29 IRB and 34 IRC patients, who underwent either operation during the same period abd had no persistent or recurrent tumor. Statistical analysis was performed by Mann-Whitney U-test. RESULTS: All 21 IRB patients (100%) and 24 IC patients (71%) responded to the questionnaire. The mean age and follow-up time of both groups were not significantly different. The IRB group had better scores in many items, especially, in those of self-care, turning over freely during sleep,and tension. However, 43% of IRB patients used pads for small amounts of incontinence (spotting) and worried about flatus. CONCLUSION: These findings show that many functional and symptomatic health related QOL scores are better after IRB and support the use of this procedure of urinary diversion for selected patients.