High amp; 8208;Resolution Kinoform X Ray Optics Printed via 405 nm 3D Laser Lithography

Efficient focusing of X rays is essential for high resolution X ray microscopy. Diffractive X ray optics called kinoforms offer the highest focusing efficiencies in theory. However, they have long remained unavailable due to their challenging nanofabrication. Recently, various X ray optic geometries including kinoforms have been realized using 3D laser lithography at near infrared wavelengths. As the smallest features period of the kinoform determines the resolving power, there is a natural drive to find ways to fabricate kinoforms with ever smaller features. Here, a custom built 3D laser lithography setup with an excitation wavelength of 405 nm is used, which allows to half the smallest period of the kinoforms compared to previous work. A 40 improvement in scanning transmission X ray microscopy image resolution, that is, a cutoff resolution of 145 nm, and an efficiency of 7.6 at 700 eV is achieved. A reconstructed pixel size of 18.5 nm, reaching the limit imposed by the design of the microscopy set up, is demonstrated through ptychographic imaging of a magnetic sample which has a strongly reduced contrast mechanism. Moreover, X ray lenses manufactured by 405 nm 3D laser lithography have the potential to become much less expensive than X ray lenses made by other mean

Single frame far field diffractive imaging with randomized illumination

We introduce a single-frame diffractive imaging method called randomized probe imaging (RPI). In RPI, a sample is illuminated by a structured probe field containing speckles smaller than the sample's typical feature size. Quantitative amplitude and phase images are then reconstructed from the resulting far-field diffraction pattern. The experimental geometry of RPI is straightforward to implement, requires no near-field optics, and is applicable to extended samples. When the resulting data are analyzed with a complimentary algorithm, reliable reconstructions which are robust to missing data are achieved. To realize these benefits, a resolution limit associated with the numerical aperture of the probe-forming optics is imposed. RPI therefore offers an attractive modality for quantitative X-ray phase imaging when temporal resolution and reliability are critical but spatial resolution in the tens of nanometers is sufficient. We discuss the method, introduce a reconstruction algorithm, and present two proof-of-concept experiments: one using visible light, and one using soft X-rays

High throughput synthesis of modified Fresnel zone plate arrays via ion beam lithography

Fresnel zone plates (FZP) are diffractive photonic devices used for high-resolution imaging and lithography at short wavelengths. Their fabrication requires nano-machining capabilities with exceptional precision and strict tolerances such as those enabled by modern lithography methods. In particular, ion beam lithography (IBL) is a noteworthy method thanks to its robust direct writing/milling capability. IBL allows for rapid prototyping of high-resolution FZPs that can be used for high-resolution imaging at soft X-ray energies. Here, we discuss improvements in the process enabling us to write zones down to 15 nm in width, achieving an effective outermost zone width of 30 nm. With a 35% reduction in process time and an increase in resolution by 26% compared to our previous results, we were able to resolve 21 nm features of a test sample using the FZP. The new process conditions are then applied for fabrication of large arrays of high-resolution zone plates. Results show that relatively large areas can be decorated with nanostructured devices via IBL by using multipurpose SEM/FIB instruments with potential applications in FEL focusing, extreme UV and soft X-ray lithography and as wavefront sensing devices for beam diagnostics

Prevalence of Brucella in raw milk: An example from Turkey

Aim: Brucellosis is a highly contagious zoonotic infection affecting livestock and human beings. This study aimed to investigate the prevalence of Brucella in raw milk collected from a provincial center and central villages in the Central Anatolian region.Materials and Methods: This cross‑sectional study was completed between March and September of 2016. The sample size for research was calculated as 263 milk samples with the Epi Info 2000 program. Samples were tested with the milk ring test, Rose Bengal test, and standard Brucella tube agglutination test. Suspicious samples according to these tests were seeded on medium for observation.Results: In this study, 202 cow’s milk samples collected from 14 central villages were researched for the presence of Brucella abortus, a Brucella species bacterium. According to the medium seeding results, 35 of 202 raw cow’s milk samples (17.32%) were identified as suspicious.Conclusion: The research investigated the prevalence of Brucella in milk samples collected from bovine farms used for consumption and production of raw milk products. The most significant infection route in our region is considered to be consumption of milk and milk products such as raw milk and fresh cheese. Especially in rural areas, households consuming their own produced milk are common. In regions with family‑style milk and milk product production and consumption, interventional studies with the aim of improving knowledge, attitudes, and behavior related to zoonotic diseases should not be neglected.Keywords: Food safety, foodborne infection, milking hygiene, prevalence, zoonosi