Advanced laser development and plasma-physics studies on the multiterawatt laser.

The multiterawatt (MTW) laser, built initially as the prototype front end for a petawatt laser system, is a 1053 nm hybrid system with gain from optical parametric chirped-pulse amplification (OPCPA) and Nd:glass. Compressors and target chambers were added, making MTW a complete laser facility (output energy up to 120 J, pulse duration from 20 fs to 2.8 ns) for studying high-energy-density physics and developing short-pulse laser technologies and target diagnostics. Further extensions of the laser support ultrahigh-intensity laser development of an all-OPCPA system and a Raman plasma amplifier. A short summary of the variety of scientific experiments conducted on MTW is also presented.

[Fusion biopsy of the prostate].

AIM: to compare the prostate cancer (PCa) detection rate, accuracy and safety of prostate image-guided fusion biopsy methods (cognitive fusion, software-fusion and HistoScanning-guided biopsy) on the basis of published studies in patients from 48 to 75 years with suspected prostate cancer during primary or repeat biopsy. To identify the limitations of these methods and improve the efficiency of fusion biopsy of the prostate in a further clinical trial. MATERIALS AND METHODS: search was carried out in the PubMed, Medline, Web of Science and eLibrary databases using following requests: (prostate cancer OR prostate adenocarcinoma) AND (MRI or magnetic resonance) AND (targeted biopsy); (prostate cancer OR prostate adenocarcinoma) AND (PHS OR Histoscanning) AND (targeted biopsy) and (prostate cancer OR prostate adenocarcinoma) AND (MRI or magnetic resonance) AND (targeted biopsy) AND (cognitive registration), targeted prostate biopsy, prostate histoscanning, histoscanning, cognitive prostate biopsy. RESULTS: a total of 672 publications were found, of which 25 original scientific papers were included in the analysis (n=4634). According to the results, PCa detection rate in patients with an average age of 62.5 years. (48-75) and an average PSA of 6.3 ng/ml (4.1-10.8), who underwent cognitive fusion biopsy under MRI control (MR-fusion) was 32.5%, compared to 30% and 35% for histoscanning in combination with a systematic biopsy and combination of methods (MR-fusion biopsy and histoscanning-guided biopsy), respectively. The accuracy of cognitive MR-fusion biopsy was 49.8% (20.8%-82%), the accuracy of the software MR-fusion biopsy was 52.5% (26.5%-69.7%), the accuracy of histoscanning-guided targeted biopsy was 46.8% (26%-75.8%). The highest values were observed in the patients undergoing primary biopsy (75.8%). DISCUSSION: Currently, imaging methods allow us to change the approach to the diagnosis of PCa by improving the efficiency of prostate biopsy, the only formal method for verifying PCa. A common method for PCa diagnosis in 2018 is a systematic prostate biopsy. However, due to the its drawbacks, fusion biopsy under control of MRI or ultrasound has being introduced into clinical practice with superior results. So far, there is a lack of sufficient scientific data to select a specific technique of the fusion biopsy of the prostate. According to the analysis, it was concluded that the incidence of complications didnt increase when performing targeted biopsy in addition to the systematic protocol. CONCLUSION: The efficiency of cognitive MR-fusion biopsy is comparable to software MR-fusion biopsy. Histoscanning-guided biopsy has lower diagnostic value than MR-guided target biopsy using software. The lack of solid conclusions in favor of a particular prostate fusion biopsy technique stresses on the relevance of further research on this topic.

[Vesicourethral anastomotic strictures and urinary incontinence following radical prostatectomy: relationship and impact on patients quality of life before and after endoscopic correction].

AIM: To assess the incidence and grade of concomitant stress urinary incontinence (SUI) and the quality of life before and after endoscopic correction of vesicourethral anastomotic strictures (VAS) and the impact of the number of endoscopic interventions on these indicators. MATERIALS AND METHODS: This is a retrospective study of medical records and a telephone survey of patients who underwent radical prostatectomy (RP) at our clinic from 2010 to 2015 and subsequently presented with VAS. The survey included data on the severity of SUI and quality of life using QoL questionnaire before and after endoscopic VAS correction; the factors primarily affecting the quality of life (SUI or obstructive symptoms) were identified. RESULTS: During the above period, 1453 RP were performed. There were 60 VAS cases, of which 56 (93%) were included in the study. Stress urinary incontinence after RP occurred in 64.3% of patients, the average QoL score was 3.95 ( = 0.64; Cv = 16.2%). Before endoscopic VAS correction, 87.5% of patients reported obstructive symptoms as the main cause of dissatisfaction. After endoscopic VAS correction, SUI was observed in 82.1% of patients. De novo incontinence occurred in 15 patients, higher SUI grade was observed in 29 (51.8%) patients. The observed change in the of SUI grade was not statistically significant (paired Students t-test 1.98, p> 0.05). Mean QoL score after endoscopic correction was 2.54 ( = 0.73; Cv = 28.6%, paired Students t-test 5.08, p <0.05). After endoscopic correction of VAS, 78.6% of the patients reported that SUI was the most important factor for decreased quality of life. CONCLUSIONS: The study revealed a high incidence of VAS combined with SIU. There was a significant improvement in patients quality of life after endoscopic correction of VAS, which resulted from a change in the pattern of voiding dysfunction producing a major negative impact on the quality of life. There were no statistically significant correlations between the number of endoscopic corrections of VAS and the SUI grade and the patients quality of life.

Highly efficient room-temperature Yb:YAG ceramic laser and regenerative amplifier.

A room-temperature, diode-pumped, pulsed Yb:YAG ceramic free-running laser with a 78% slope efficiency has been demonstrated. It has been shown that fine tuning of the mode diameter to the diameter of the pumped volume with a ratio of the pump to the mode diameter of 0.6 is important for achieving maximum laser efficiency with a Gaussian-like beam profile. A regenerative Yb:YAG ceramic amplifier with a maximum output energy of 14.5 mJ and a super-Gaussian beam profile is demonstrated.

Characterization of highly stable mid-IR, GaSb-based laser diodes.

Highly stable room-temperature, mid-IR, GaSb-based laser diodes have been characterized at various temperatures and driver currents. Up to 54 mW of output power was demonstrated in a 3150- to 3180-nm-wavelength range with <20-nm FWHM spectral width.

Optical differentiation and multimillijoule approximately 150 ps pulse generation in a regenerative amplifier with a temperature-tuned intracavity volume Bragg grating.

An optical differentiation in a regenerative amplifier with a temperature-tuned volume Bragg grating (VBG) as an intracavity spectral filter is demonstrated for the first time, to the author's knowledge. 12 mJ approximately 150 ps pulses with a TEM(00) beam profile have been generated at the 5 Hz repetition rate in the nanosecond-pulse-seeded regenerative amplifier with a VBG that is temperature detuned from the central wavelength.

A stable mid-IR, GaSb-based diode laser source for the cryogenic target layering at the Omega Laser Facility.

A stable 3-microm-wavelength, GaSb-based diode operated at room temperature has been investigated as a potential laser source for cryogenic target layering at the Omega Laser Facility for inertial confinement fusion (ICF) experiments. More than 50 mW of output power has been achieved at 14 degrees C with high spectral and output-power stability.

Optical parametric chirped-pulse-amplification contrast enhancement by regenerative pump spectral filtering.

We demonstrate an approach to fundamentally improve the contrast of optical parametric chirped-pulse amplifiers (OPCPA). The instantaneous parametric gain couples the temporal variations of the pump-pulse intensity to spectral variations of the intensity of the stretched signal pulse being amplified, which significantly degrade the temporal contrast of the amplified pulse after recompression. Simple and efficient pump-intensity noise reduction in an OPCPA system using a volume Bragg grating in a regenerative amplifier demonstrates contrast improvements up to 30 dB.

High-contrast optical-parametric amplifier as a front end of high-power laser systems.

A high-contrast preamplifier based on optical-parametric amplification with a short pump pulse is demonstrated. A gain larger than 10(5) and measurement-limited contrast higher than 10(11) are obtained over a large temporal range extending within less than 10 ps of the peak of the pulse, because of the high instantaneous parametric gain provided by a short pump pulse in a nonlinear crystal. The energy gain and high contrast of this preamplifier make it a good seed source for high-power laser systems.