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The size of the smallest detectable sample feature in an x-ray imaging system is usually restricted by the spatial resolution of the system. This limitation can now be overcome using the diffusive dark-field signal, which is generated by unresolved phase effects or the ultra-small-angle x-ray scattering from unresolved sample microstructures. A quantitative measure of this dark-field signal can be useful in revealing the microstructure size or material for medical diagnosis, security screening and materials science. Recently, we derived a new method to quantify the diffusive dark-field signal in terms of a scattering angle using a single-exposure grid-based approach. In this manuscript, we look at the problem of quantifying the sample microstructure size from this single-exposure dark-field signal. We do this by quantifying the diffusive dark-field signal produced by 5 different sizes of polystyrene microspheres, ranging from 1.0 to 10.8 µm, to investigate how the strength of the extracted dark-field signal changes with the sample microstructure size, S . We also explore the feasibility of performing single-exposure dark-field imaging with a simple equation for the optimal propagation distance, given microstructure with a specific size and thickness, and show consistency between this model and experimental data. Our theoretical model predicts that the dark-field scattering angle is inversely proportional to S , which is also consistent with our experimental data.

In recent years, a novel x-ray imaging modality has emerged that reveals unresolved sample microstructure via a “dark-field image”, which provides complementary information to conventional “bright-field” images, such as attenuation and phase-contrast modalities. This x-ray dark-field signal is produced by unresolved microstructures scattering the x-ray beam resulting in localised image blur. Dark-field retrieval techniques extract this blur to reconstruct a dark-field image. Unfortunately, the presence of non-dark-field blur such as source-size blur or the detector point-spread-function can affect the dark-field retrieval as they also blur the experimental image. In addition, dark-field images can be degraded by the artefacts induced by large intensity gradients from attenuation and propagation-based phase contrast, particularly around sample edges. By measuring any non-dark-field blurring across the image plane and removing it from experimental images, as well as removing attenuation and propagation-based phase contrast, we show that a directional dark-field image can be retrieved with fewer artefacts and more consistent quantitative measures. We present the details of these corrections and provide “before and after” directional dark-field images of samples imaged at a synchrotron source. This paper utilises single-grid directional dark-field imaging, but these corrections have the potential to be broadly applied to other x-ray imaging techniques.

The lung is a complex organ with a hierarchical structure, containing four times more air than tissue. It is in constant contact with environmental factors such as pollution and pathogens, leading to pathological alterations at various hierarchical levels. Because of its intricate structure and continuous movement, lung imaging presents significant challenges for most existing techniques. Recent advancements in phase‐contrast computed tomography and photon‐counting detectors have greatly enhanced lung imaging capabilities. Specifically, propagation‐based imaging (PBI), a phase‐contrast method that does not require optical elements, has proven particularly effective at low X‐ray dose rates due to the strong phase shifts between lung tissue and aerated regions. This study introduces an in situ imaging approach for large‐scale lungs using PBI at the Imaging and Medical Beamline (IMBL) of the Australian Synchrotron. We investigated optimal conditions for PBI, including energy and propagation distance settings, and found that an X‐ray beam energy of 70 keV combined with a 7 m propagation distance yields the highest image quality in terms of contrast‐to‐noise ratio while also delivering the lowest radiation dose. Furthermore, Monte Carlo simulations were performed on the reconstructed volume to calculate absorbed radiation doses in tissues. These findings provide valuable insights for designing future experiments aimed at minimizing radiation exposure and potentially enable in vivo applications in larger animals or even humans. A method for in situ imaging of human‐sized animal lungs using the Imaging and Medical Beamline (IMBL) at the Australian Synchrotron is presented.

Phase contrast x-ray imaging (PCXI) provides high-contrast images of weakly-attenuating structures like the lungs. PCXI, when paired with 4D X-ray Velocimetry (XV), can measure regional lung function and non-invasively assess the efficacy of emerging therapeutics. Bacteriophage therapy is an emerging antimicrobial treatment option for lung diseases such as cystic fibrosis (CF), particularly with increasing rates of multi-drug-resistant infections. Current efficacy assessment in animal models is highly invasive, typically requiring histological assessment. We aim to use XV techniques as non-invasive alternatives to demonstrate efficacy of bacteriophage therapy for treating Pseudomonas aeruginosa CF lung infections, measuring functional changes post-treatment. Time-resolved in vivo PCXI-CT scans of control, Pseudomonas-infected, and phage-treated mouse lungs were taken at the Australian Synchrotron Imaging and Medical Beamline. Using XV we measured local lung expansion and ventilation throughout the breath cycle, analysing the skew of the lung expansion distribution. CT images allowed visualisation of the projected air volume in the lungs, assessing structural lung damage. XV analysis demonstrated changes in lung expansion between infection and control groups, however there were no statistically significant differences between treated and placebo groups. In some cases where structural changes were not evident in the CT scans, XV successfully detected changes in lung function.

Propagation-based phase-contrast X-ray imaging is a promising technique for in vivo medical imaging, offering lower radiation doses than traditional attenuation-based imaging. Previous studies have focused on X-ray energies below 50keV for small-animal imaging and mammography. Here, we investigate the feasibility of high-energy propagation-based computed tomography for human adult-scale lung imaging at the Australian Synchrotron’s Imaging and Medical Beamline. This facility is uniquely positioned for human lung imaging, offering a large field of view, high X-ray energies, and supporting clinical infrastructure. We imaged an anthropomorphic chest phantom (LungMan) between 50keV and 80keV across the range of possible sample-to-detector distances, with a photon-counting and an integrating detector. Strong phase-contrast fringes were observed with the photon-counting detector, even at high X-ray energies and a large pixel size relative to previous work, whereas the integrating detector with lower spatial resolution showed no clear phase effects. Measured X-ray phase-shifting properties of LungMan aligned well with reference soft tissue values, validating the phantom for phase-contrast studies. Imaging quality assessments suggest an optimal configuration at approximately 70keV and the longest available propagation distance of 7.5m, indicating potential benefit in positioning the patient in an upstream hutch. This study represents the first step towards clinical adult lung imaging at the Australian Synchrotron.

Dry eye disease (DED) has become common on a global scale in recent years. There is a wide prevalence of DED in different countries based on various ethnicities and environment. DED is a multifactorial ocular disorder. In addition to advanced age and gender, such factors as living at high altitude, smoking, pterygium, prolonged use of consumer electronics or overingesting of caffeine or multivitamins are considered to be the major risk factors of DED. We report the DED epidemiology in Taiwan firstly in this article. According to the pathophysiological factors and changes inthe composition of the tear film in DED, it can be categorized into several subtypes, including lipid anomaly dry eye, aqueous tear deficiency, allergic and toxic dry eye among others. Each subtype has its own cause and disease management; therefore, it is important for ophthalmologists to identify the type through literature review and investigation. The management of DED, relies not only on traditional medications such as artificial tears, gels and ointments, but also newer treatment options such as acupuncture, SYL1001, and nanomedicine therapy. We also conducted a comprehensive literature review including common subtypes and treatment of DED. Clearly, more clinical trials are needed to assess the efficacy and safety of the various treatments and common subtypes of DED.

To effectively diagnose, monitor and treat respiratory disease clinicians should be able to accurately assess the spatial distribution of airflow across the fine structure of lung. This capability would enable any decline or improvement in health to be located and measured, allowing improved treatment options to be designed. Current lung function assessment methods have many limitations, including the inability to accurately localise the origin of global changes within the lung. However, X-ray velocimetry (XV) has recently been demonstrated to be a sophisticated and non-invasive lung function measurement tool that is able to display the full dynamics of airflow throughout the lung over the natural breathing cycle. In this study we present two developments in XV analysis. Firstly, we show the ability of laboratory-based XV to detect the patchy nature of cystic fibrosis (CF)-like disease in β-ENaC mice. Secondly, we present a technique for numerical quantification of CF-like disease in mice that can delineate between two major modes of disease symptoms. We propose this analytical model as a simple, easy-to-interpret approach, and one capable of being readily applied to large quantities of data generated in XV imaging. Together these advances show the power of XV for assessing local airflow changes. We propose that XV should be considered as a novel lung function measurement tool for lung therapeutics development in small animal models, for CF and for other muco-obstructive diseases.

Porphyromonas gingivalis has been identified as one of the major periodontal pathogens. Activity-directed fractionation and purification processes were employed to identify the anti-inflammatory active compounds using heat-killed P. gingivalis-stimulated human monocytic THP-1 cells in vitro. Five major fractions were collected from the ethanol/ethyl acetate extract of wild bitter melon (Momordica charantia Linn. var. abbreviata Ser.) leaves and evaluated for their anti-inflammatory activity against P. gingivalis. Among the test fractions, Fraction 5 effectively decreased heat-killed P. gingivalis-induced interleukin (IL)-8 and was subjected to separation and purification by using chromatographic techniques. Two cucurbitane triterpenoids were isolated from the active fraction and identified as 5β,19-epoxycucurbita-6,23-diene-3β,19,25-triol (1) and 3β,7β,25-trihydroxycucurbita-5,23-dien-19-al (2) by comparing spectral data. Treatments of both compounds in vitro potently suppressed P. gingivalis-induced IL-8, IL-6, and IL-1β levels and the activation of mitogen-activated protein kinase (MAPK) in THP-1 cells. Both compounds effectively inhibited the mRNA levels of IL-6, tumor necrosis factor (TNF)-α, and cyclooxygenase (COX)-2 in P. gingivalis-stimulated gingival tissue of mice. These findings imply that 5β,19-epoxycucurbita-6,23-diene-3β,19,25-triol and 3β,7β,25-trihydroxycucurbita-5,23-dien-19-al could be used for the development of novel therapeutic approaches against P. gingivalis infections.

Bahasa Malaysia is the national language in Malaysia, which acts as a national symbol that raise a sense of national unity, and maintains a sense of cultural value and identity. As the country is multicultural and multilingual, the use of Bahasa Malaysia, English, Mandarin, and Tamil invite questions of comparative vitality, which is a strength evaluation of language relative to other languages that coexist in the linguistic sphere. The present study, via the indicators such as language use, dominance and preference, language attitude and motivation, and language proficiency, aims to examine the vitality of these languages and to obtain comparative information about their connections to national and ethnic identity. Vitality Questionnaire was distributed to Malaysian primary five students from vernacular Tamil and Chinese schools. Findings indicate that Bahasa Malaysia and English do not have high vitality . Yet, vernacular languages are rated as having high vitality. It is suggested that ethnic languages dominantly shape ethnic identity and that they play an important role in the students’ lives at early age as compared to Bahasa Malaysia which has not gained a stronghold. Thus, the sense of national identity appears to have taken a back seat. National aspiration in this aspect of nation building is still far from being realized if it is to be nurtured and expected to be developed at this stage of growth. Within a multilingual milieu, establishing national identity appears a complex issue and language choice and use may have long term effects on the moulding of a Malaysian national identity.