## 4 Discussion and Conclusions  
In this paper, we presented a compact, table-top transmission water-window microscope, based on a Z-pinching capillary discharged plasma source operating at 2.88 nm. The microscope allows the capture of images of a specimen with a magnification between 190\(\times\) and 400\(\times\) with a 75 nm half-pitch spatial resolution. In terms of its spatial resolution, it provides a complementary imaging technique between conventional visible light microscopes and transmission electron microscopes, with the advantage of imaging relatively thick samples (up to 10 \(\upmu\)m), and does not require fluorescent markers or staining that modifies the morphology of the sample. Although the spatial resolution of this microscope cannot compete with the electron-based system, it provides a much better spatial resolution than conventional light microscopes, as is demonstrated by the imaging of the green algae (_Desmodesumumuis_) in Figure 6.  
This microscopic system is easy to operate, affordable, and accessible--providing an alternative to large-scale facilities--although it has a longer exposure time and lower spatial resolution by a factor of 5 compared to synchrotron-based SXR microscopes. Nevertheless, compact SXR microscopic systems have already found applications, not only in biomedicine, but also in material science, nanotechnology, and microelectronics, among others. These cost-effective table-top sources allow access to this imaging technique for the broader scientific community, and the future development of compact, table-top sources promises to broaden access to soft X-ray imaging in other laboratories.  
Figure 6: Comparison of the images of dried _Desmodesumuis_ deposited on a 50 nm thick Si\({}_{3}\)N\({}_{4}\) membrane. (**a**) A soft X-ray (SXR) image was acquired with 1400 SXR pulses (12 min). Scale bar is 5 \(\upmu\)m. The black, dashed rectangle represents a zoomed area with a 2 \(\upmu\)m scale bar. (**b**) The image was taken with a visible light microscope (VIS). The area marked by a white, dashed rectangle represents the field of view in image **a**.  
**Author Contributions:** [PERSON] designed and constructed the water-window microscope, performed the imaging experiments, and wrote the paper; [PERSON] and [PERSON] developed and constructed the discharge source; [PERSON] prepared the biological samples; [PERSON] cooperated on the development of the water-window microscope, and [PERSON] conceived the water-window microscope. All authors have read and agreed to the published version of the manuscript.  
**Funding:** This work was supported by a grant from the Ministry of Education, Youth and Sports of the Czech Republic LTT17015 Research in the Frame of the International Center for Dense Magnetized Plasmas, by the CZ.02.1.01/0.0/0.0/16-019/0000778 Centre of Advanced Applied Sciences-CAAS grant, and by the CTU Student grant competition SGS19/084/OHK4/17/17.  
**Conflicts of Interest:** The authors declare no conflict of interest. The funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript; or in the decision to publish the results.