A closer look to the timing of orchidopexy in undescended testes and adherence to the AWMF-guideline.

BACKGROUND: To lower the risk of testicular malignancies and subfertility, international guidelines recommend orchidopexy for undescended testis (UDT) before the age of 12-18 months. Previous studies reported low rates of 5-15% of timely surgery. Most of these studies are based on DRG and OPS code-based data from healthcare system institutions that do not distinguish between congenital and acquired UDT. METHODS: In a retrospective study data of all boys who underwent orchidopexy in a university hospital and two outpatient surgical departments from 2009 to 2022 were analyzed. The data differentiates congenital from acquired UDT. RESULTS: Out of 2694 patients, 1843 (68.4%) had congenital and 851 (31.6%) had acquired UDT. In 24.9% of congenital cases surgery was performed before the age of 12 months. The median age at surgery for congenital UDT was 16 months (range 7-202). Over the years there was an increased rate of boys operated on before the age of 2 (40% in 2009, 60% in 2022). The median age fluctuated over the years between 21 and 11 months without a trend to younger ages.. The covid pandemic did not lead to an increase of the median age at surgery. The median time between referral and surgery was 46 days (range 1-1836). Reasons for surgery after 12 months of age were a delayed referral to pediatric surgeries (51.2%), followed by relevant comorbidities (28.2%). CONCLUSION: Compared to recent literature, out data show that a closer look at details enables a more realistic approach. Still, there is no trend towards the recommended age for surgical treatment observable, but the rate of timely operated boys with congenital UDT is significantly higher than stated in literature.

Phase-sensitive detection of bragg scattering at 1D optical lattices.

We report on the observation of Bragg scattering at 1D atomic lattices. Cold atoms are confined by optical dipole forces at the antinodes of a standing wave generated by the two counterpropagating modes of a laser-driven high-finesse ring cavity. By heterodyning the Bragg-scattered light with a reference beam, we obtain detailed information on phase shifts imparted by the Bragg scattering process. Being deep in the Lamb-Dicke regime, the scattered light is not broadened by the motion of individual atoms.

Self-synchronization and dissipation-induced threshold in collective atomic recoil lasing.

Networks of globally coupled oscillators exhibit phase transitions from incoherent to coherent states. Atoms interacting with the counterpropagating modes of a unidirectionally pumped high-finesse ring cavity form such a globally coupled network. The coupling mechanism is provided by collective atomic recoil lasing, i.e., cooperative Bragg scattering of laser light at an atomic density grating, which is self-induced by the laser light. Under the rule of an additional friction force, the atomic ensemble is expected to undergo a phase transition to a state of synchronized atomic motion. We present the experimental investigation of this phase transition by studying the threshold behavior of this lasing process.

Observation of lasing mediated by collective atomic recoil.

We observe the buildup of a frequency-shifted reverse light field in a unidirectionally pumped high-Q optical ring cavity serving as a dipole trap for cold atoms. This effect is enhanced and a steady state is reached, if via an optical molasses an additional friction force is applied to the atoms. We observe the displacement of the atoms accelerated by momentum transfer in the backscattering process and interpret our observations in terms of the collective atomic recoil laser. Numerical simulations are in good agreement with the experimental results.