Blood blister-like aneurysms (BBAs) are rare, fragile vascular lesions most commonly arising from non-branching segments of the internal carotid artery. Basilar artery BBAs are exceptionally uncommon and present significant diagnostic and management challenges. We report the case of a woman in her late 50s who presented with sudden-onset occipital headache, neck stiffness, and subarachnoid haemorrhage. Digital subtraction angiography identified a 3 mm blister-like aneurysm in the basilar artery, considered the presumed culprit lesion, along with an incidental basilar artery fenestration. Endovascular flow-diversion was recommended; however, the patient declined intervention after informed counselling and was managed conservatively with intensive neurocritical monitoring. The patient recovered without residual neurological deficit. This case highlights the diagnostic overlap between aneurysmal and perimesencephalic subarachnoid haemorrhage, the importance of careful vascular imaging, and the management challenges posed by rare posterior circulation BBAs and associated vascular variants.

Exposure to microgravity is associated with stature increases, moderate-to-severe back/neck pain and elevated lumbar and cervical intervertebral disc (IVD) herniation risk post-flight. Whilst lumbar pathophysiology has been investigated, little attention has been placed on the cervical spine. Thus, the aim of this study was to determine the effect of 4 h of hyper-buoyancy flotation (HBF) and subsequent 15 min of upright 1 g exposure on stature, cervical IVD height, cervical muscle cross-sectional area (CSA) and thickness, passive cervical vertebral stiffness, and their association with stature changes and/or neck pain. To investigate this, 12 healthy volunteers (five male; 30.2 ± 7.2 years, 66.1 ± 11.7 kg, 173.4 ± 8.5 cm) participated. Stature was assessed at Pre HBF, after 4 h of supine HBF (Post HBF), and following 15 min of upright 1 g exposure (Post 1G). Cervical IVD height (C3-T1), longus colli and semispinalis cervicis CSA and thickness, passive vertebral stiffness (C2-L5), and neck pain were assessed at Pre HBF, HBF0, HBF2, HBF4 and Post 1G. Results indicated that 4 h HBF significantly increased stature (+1.6 ± 0.5 cm), which was partially reduced after acute 1 g exposure (-0.4 ± 0.3 cm). Cervical IVD height increased at all levels following HBF, with partial reversal at Post 1G, particularly in the lower cervical region. Longus colli and semispinalis cervicis CSA and thickness were unchanged. Passive vertebral stiffness significantly decreased (across the entire column and most regions) following HBF and was only partially restored after 1 g exposure. Neck pain increased during HBF and was reduced after 1 g exposure. No associations were observed between neck pain and stature or IVD changes. However, neck pain at HBF4 was positively correlated with mid-cervical vertebral stiffness (R = 0.587, P = 0.045). Overall, 4 h HBF induced mild neck pain, increased stature and cervical IVD height, all of which were partially reduced after 15 min of upright 1 g exposure. No changes in longus colli or semispinalis cervicis muscle thickness or CSA were observed. Passive cervical vertebral stiffness decreased following HBF and remained below baseline after 1 g exposure. A positive correlation between neck pain at HBF4 and mid-cervical vertebral stiffness suggests modulation of vertebral column stabilisation may contribute to symptoms. The lack of association between neck pain and IVD expansion suggests that vertebral flattening may play a role and therefore warrants direct evaluation with HBF and following spaceflight.

This study presents a comprehensive multiscale comparison of LPBF-fabricated A286 and IN718 lattice structures across three architected topologies (BCC/BCCz, Gyroid/Hexstar and Honeycomb) to elucidate how alloy microstructure and geometry jointly control deformation and failure mechanisms. Quasi-static compression tests revealed a consistent topology-dependent strength hierarchy, with Honeycomb achieving the highest peak stresses (A286: 3.3 GPa; IN718: 2.89 GPa), followed by BCC/BCCz and Gyroid/Hexstar designs. A286 exhibited higher initial stiffness (9.3-11.2 GPa) but experienced early instability due to particle detachment and oxide-assisted cracking, whereas IN718 demonstrated smoother strain hardening and superior energy absorption, with W₆₀ values of 1.71-2.04 MJ/m³ compared to 1.32-1.85 MJ/m³ for A286. XRD analysis showed more compressive residual stresses in A286 (to - 585 MPa) than IN718 (to - 504 MPa), alongside higher microstrain (ε ≈ 5.6 × 10⁻³) and smaller crystallite size (27 nm vs. 43 nm), indicating greater lattice distortion in A286. FTIR spectra revealed stronger carbide- and oxide-related bands in A286, while IN718 displayed predominantly O-H and CO₂ signatures consistent with ductile surface formation. FESEM and EDS analyses confirmed fundamentally different failure pathways: A286 failed via particle pull-out, sinter-neck rupture and oxide-decorated cracking, whereas IN718 deformed through slip-dominated smearing, laminated tearing and blunted microcracks. Collectively, the results establish that topology governs global deformation, while alloy chemistry dictates whether collapse proceeds through brittle-assisted rupture (A286) or ductile, slip-mediated flow (IN718). This framework provides design guidelines for tailoring alloy-topology combinations for lightweight, impact-resistant applications.

Bone scaffolds are porous artificial structures that replace damaged bone tissue and promote bone regeneration. In clinical settings, bone cement is used to provide initial fixation stability between the bone scaffold and surrounding bone tissue. To analyze the performance of bone scaffolds more accurately, the cement mantle should be considered. This study considers the cement mantle between the bone scaffold and surrounding bone tissue and the structural behavior according to variations in the elastic modulus of the cement mantle and the pore size of the bone scaffold. The results showed that the cement mantle energy ratio increased with increasing pore size, particularly in the femoral head and intertrochanteric region. In the femoral head with a pore size of 1.50 mm, increasing the cement mantle elastic modulus from 7 to 24 GPa reduced the mean strain energy within the bone scaffold from 3.79 μJ to 2.51 μJ, corresponding to a decrease of approximately 33.8%. These findings suggest that as cement mantle stiffness increases, external loads may not be sufficiently transferred to the bone scaffold interior, and the proportion of the load borne by the cement mantle may increase. In the femoral neck, the cement mantle energy ratio also increased with increasing pore size; however, the magnitude of this change was more limited than that in the other regions of interest. These findings highlight the mechanical importance of the cement mantle and suggest that both cement stiffness and scaffold pore size should be jointly considered to ensure appropriate load sharing for bone regeneration.

Musculoskeletal complaints of the shoulder/pelvic girdle are symptoms frequently described in patient care and are attributed to degenerative changes associated with increasing patient age. Polymyalgia rheumatica(PMR) is the second most common differential diagnosis of an inflammatory genesis after rheumatoid arthritis and should be ruled out. Patients diagnosed with PMR exhibit symptoms such as acute weakness, pain, morning stiffness in the neck, shoulders and pelvis. The manifestation of B-symptoms is possible. The clinical examination should encompass differential diagnoses and complications, such as giant cell arteritis. Laboratory testing shows elevated levels of inflammatory markers in almost all cases. Arthrosonography reveals tenosynovitis of the biceps tendon, bursitis or joint effusion of the hip. The initial treatment for PMR is the administration of steroids. In cases of disease activity, methotrexate, sarilumab or rituximab may be considered as potential treatment options.