Time-dependent photobiomodulation management of neuropathic pain induced by spinal cord injury in male rats

Neuropathic pain (NP) following spinal cord injury (SCI) often lasts for a long time and causes a range of problems that reduce the quality of life. Current treatments are not generally effective; however, photobiomodulation therapy (PBMT) has made some progress in this area. Due to the novelty of this treatment, standard therapeutic protocols have not yet been agreed upon. In the present study, we compare the analgesic effect of two PBMT protocols (2 and 4 weeks of radiation). A total of thirty-two adult male Wistar rats were divided into four groups: control, SCI, 2 W PBMT, and 4 W PBMT. SCI was induced by an aneurism clip and PBMT used a 660-nm, initiated 30 min post-SCI, and continued daily for 2 or 4 weeks. Functional recovery, hyperalgesia, and allodynia were measured weekly. At the end of the study, the Gad65, interleukin 1-alpha (IL1α), interleukin 10 (IL10), IL4, and purinergic receptor (P2xR and P2yR) expressions were measured. Data were analyzed by Prism6. The results showed PBM irradiation for 2 and 4 weeks had the same effects in improving hyperalgesia. In the case of allodynia and functional recovery, 4 W PBMT was more effective (p<0.01). 4 W PBMT increased the Gad65 expression (p <0.001) and reduced P2Y4R (p <0.05) compared to SCI animals. The effects of 2 and 4 W PBMT were the same for IL1α, IL10, and P2X3 receptors. 4 W PBMT was more effective in reducing the complications of SCI such as pain and disability. PBMT therapy is an effective method aimed at immune system function modulation to reduce NP and motor dysfunction.

Single-digit-resolution nanopatterning with extreme ultraviolet light for the 2.5 nm technology node and beyond

All nanofabrication methods come with an intrinsic resolution limit, set by their governing physical principles and instrumentation. In the case of extreme ultraviolet (EUV) lithography at 13.5 nm wavelength, this limit is set by light diffraction and is ≈3.5 nm. In the semiconductor industry, the feasibility of reaching this limit is not only a key factor for the current developments in lithography technologies, but also is an important factor in deciding whether photon-based lithography will be used for future high-volume manufacturing. Using EUV-interference lithography we show patterning with 7 nm resolution in making dense periodic line-space structures with 14 nm periodicity. Achieving such a cutting-edge resolution has been possible by integrating a high-quality synchrotron beam, precise nanofabrication of masks, very stable exposures instrumentation, and utilizing effective photoresists. We have carried out exposure on silicon- and hafnium-based photoresists and we demonstrated the extraordinary capability of the latter resist to be used as a hard mask for pattern transfer into Si. Our results confirm the capability of EUV lithography in the reproducible fabrication of dense patterns with single-digit resolution. Moreover, it shows the capability of interference lithography, using transmission gratings, in evaluating the resolution limits of photoresists.