OBJECTIVE: Current guidelines recommend a low threshold for computerized tomography (CT) scanning in older patients presenting with low-energy trauma (LET). With the ageing of the population, this results in increased use of healthcare resources and costs. We aim to assess (1) the number of CT scans performed as part of the initial trauma screening, (2) their traumatic clinical implications, and (3) their non-traumatic clinical implications.
METHODS: A retrospective study in patients ≥ 70 years presenting at a Dutch trauma centre with a proximal femur fracture following a LET between 2021 and 2022. We collected data concerning demographics, Clinical Frailty Scale, Injury Severity Score, number of CT scans and whether the results of these scans altered clinical management.
RESULTS: We included 278 patients. Median age was 83.0 years (IQR 77.0-89.0), median ISS was 9 (IQR 9-10) and, most common mechanism of injury was a ground level fall (n = 159, 57.2%). In 49 patients (17.6%) one or more CT scans were performed. These scans did not reveal co-existing traumatic injuries altering clinical management. In 2 patients (0.7%) incidental findings were found that immediately affected treatment.
CONCLUSIONS: Our study concludes that (1) approximately one in five patients with a proximal femur fracture received a CT scan as part of the initial trauma screening, resulting in (2) no traumatic and (3) minimal non-traumatic clinical implications. Therefore, a restrictive policy can be justified in patients with no additional clinical signs or symptoms and admission to the hospital. Further prospective research would be valuable to confirm our results.

A 15-year-old male was attacked by a large white shark while surfing. CT examination revealed an above-knee amputation of the right lower extremity with stripping of soft tissues from the groin distally. 3-dimensional volume rendering did not show any fragments of shark teeth but did reveal linear gouges, areas of shaving of cortical bone and an inverted \'V\'-shaped defect at the distal margin of the femoral shaft. At autopsy these injuries were confirmed in addition to areas with fine parallel cross-striations matching the marginal serrations of the teeth of a white shark. Thus, while post mortem CT with 3-dimensional reconstruction at high resolution can show the nature and number of the bony injuries following shark attack, it is complimented by pathological examination which may find fine parallel grooves from teeth serrations. Post mortem 3-dimensional volume rendering may also help to find or exclude fragments of teeth, and silicone casting may provide a permanent record of bone lesions.

Domestic rabbits have teeth that grow throughout the animal\'s life and are prone to disease. Clinical signs of dental disease in domestic rabbits are non-specific, and, therefore, a definitive diagnosis usually requires additional methods. This study was carried out on a group of 105 domestic rabbits aged 3 to 9 years. In total, 90 domestic rabbits with dental disease visible on CT images and other secondary diseases of the head area qualified for this study. Malocclusion was found in 57 (63.3%). Retrograde elongation of the tooth apices in the mandible was present in 39 (43.3%), and it was present in the maxilla in 48 (53%). Clinical tooth crowns were overgrown in 39 (43%). Dental abscesses were present in 54 (63%). Secondary to the presence of a dental abscess, osteomyelitis was found in 43 (79% of the animals with a dental abscess). Dental inflammatory resorption was found in 36 (40%). Secondary to dental disease, nasal cavity inflammation was found in 18 (20%). Otitis media was present in six (6.7%). The most common dental disease found in this study\'s animals was malocclusion secondary to abnormal clinical crown abrasion and abnormal tooth growth. In domestic rabbits, osteomyelitis is a common complication of dental abscesses. Computed tomography is an invaluable diagnostic method in the diagnosis of dental disease and secondary diseases of the head area, such as inflammation of the nasal cavities or otitis media, in pet rabbits.

Bulk density and porosity have great influence on the technical performance of an emulsified asphalt mixture, so in order to enhance the strength of the asphalt mixture, bulk density should be improved and porosity should be reduced. Considering the forming process of the emulsified asphalt mixture, the decrease in porosity can ensure the state of the mixture. In order to reduce the porosity of the emulsified asphalt mixture, an innovative forming process is proposed to improve the performance of the emulsified asphalt mixture, and its strength formation mechanism is explored in this paper. Three groups of emulsified asphalt mixtures (ARC-8 + SBR, SMA-5 + EVA, SMA-5 + SBR) were prepared by a conventional mixing process and novel mixing process. Marshall test of the emulsified asphalt mixture, CT scanning test of the emulsified asphalt mixture, workability test and analysis were manufactured and tested. The results show that, compared with conventional methods, the innovative forming method can increase the bulk density of the mixture and reduce the porosity, and thus improve its technical performance. The reason is that most of the water in the mixture of the innovative forming method sticks to the outer surface of the fine aggregate, and the water is more easily discharged. Secondly, the fine aggregate of the innovative forming method is directly mixed with the emulsion, and the volume is smaller. The emulsion wraps the fine aggregate in it due to the surface tension, which enhances the adhesion effect, thus improving the strength of the mixture.

Organisms that have repeatedly evolved similar morphologies owing to the same selective pressures provide excellent cases in which to examine specific morphological changes and their relevance to the ecology and evolution of taxa. Hosts of permanent parasites act as an independent evolutionary experiment, as parasites on these hosts are thought to be undergoing similar selective pressures. Parasitic feather lice have repeatedly diversified into convergent ecomorphs in different microhabitats on their avian hosts. We quantified specific morphological characters to determine (i) which traits are associated with each ecomorph, (ii) the quantitative differences between these ecomorphs, and (iii) if there is evidence of displacement among co-occurring lice as might be expected under louse-louse competition on the host. We used nano-computed tomography scan data of 89 specimens, belonging to four repeatedly evolved ecomorphs, to examine their mandibular muscle volume, limb length and three-dimensional head shape data. Here, we find evidence that lice repeatedly evolve similar morphologies as a mechanism to escape host defences, but also diverge into different ecomorphs related to the way they escape these defences. Lice that co-occur with other genera on a host exhibit greater morphological divergence, indicating a potential role of competition in evolutionary divergence.

A certain number of hole-like defects will occur in aluminum alloys under cyclic loading. The internal holes will reduce the strength of the material and cause stress concentration, which will aggravate the development of fatigue damage. A classification method of defect features based on X-ray CT damage data is proposed. The random hole distribution model is established through the linear congruence method and the region division method. The hole parameter is introduced as the intermediate variable of the 3D reconstruction model of internal defects. In the mesoscopic stage, the function relationship between the distribution of random holes and the fatigue life is established based on the coupling relationship between the number and proportion of pores and the fatigue life. In the macroscopic stage, the relationship between the random holes and the macroscopic crack growth life is established by taking the crack length as the damage variable. The crack propagation rate decreased with the increase in the number of holes. The prediction model of the whole life stage is established using the life function from microcrack initiation to macroscopic crack propagation. Finally, the validity of the whole stage fatigue life prediction model is demonstrated through the comparison and verification of experiments, which provides a certain engineering value for the life estimation of 6061-T6 aluminum alloy materials.

Rock fracture is a macroscopic fracturing process resulting from the initiation and propagation of microscopic cracks. Therefore, it is crucial to comprehend the damage and fracture mechanism of rock under ultrasonic vibration by investigating the evolutionary pattern of the meso-pore fracture structure in response to high-frequency vibrational loads, as explored in this study. Standard red sandstone samples with a diameter of 50 mm and height of 100 mm were subjected to ultrasonic high-frequency vibration tests. NMR and CT scans were conducted on the rock samples at different stages of ultrasonic vibration excitation to obtain the corresponding transverse relaxation time (T2) spectra and CT scan images for each layer. The NMR test results revealed that smaller pores formed within the rock under high-frequency vibration loads, with a noticeable expansion observed in micropores. Three-dimensional reconstruction analysis based on two-dimensional CT images demonstrated an increase in pore count by 145.56%, 122.67%, and 98.87%, respectively, for the upper, middle, and lower parts of the rock after 120 s of ultrasonic vibration excitation; furthermore, the maximum pore volume increased by 239.42%, 109.16%, and 18.99%, respectively, for these regions during this period as well. These findings contribute towards a deeper understanding regarding the mechanisms underlying rock fragmentation when exposed to high-frequency vibrational loads.

BACKGROUND: The mechanosensory lateral line system is an important sensory modality in fishes, informing multiple behaviours related to survival including finding food and navigating in dark environments. Given its ecological importance, we may expect lateral line morphology to be under disruptive selection early in the ecological speciation process. Here we quantify the lateral line system morphology of two ecomorphs of the cichlid fish Astatotilapia calliptera in crater Lake Masoko that have diverged from common ancestry within the past 1,000 years.
RESULTS: Based on geometric morphometric analyses of CT scans, we show that the zooplanktivorous benthic ecomorph that dominates the deeper waters of the lake has large cranial lateral line canal pores, relative to those of the nearshore invertebrate-feeding littoral ecomorph found in the shallower waters. In contrast, fluorescence imaging revealed no evidence for divergence between ecomorphs in the number of either superficial or canal neuromasts. We illustrate the magnitude of the variation we observe in Lake Masoko A. calliptera in the context of the neighbouring Lake Malawi mega-radiation that comprises over 700 species.
CONCLUSIONS: These results provide the first evidence of divergence in this often-overlooked sensory modality in the early stages of ecological speciation, suggesting that it may have a role in the broader adaptive radiation process.

OBJECTIVE: This study aims to analyse the clinical value of computed tomography (CT) scanning parameters combined with serum teratoma-derived growth factor-1 (Cripto-1) in the diagnosis of renal cell carcinoma (RCC).
METHODS: A retrospective analysis was conducted on 256 patients with renal tumour admitted to our hospital from July 2020 to December 2022. They were divided into malignant group (n = 180) and benign group (n = 76) based on the final pathological results. All subjects underwent CT scans and serum Cripto-1 testing. The CT signs and serum Cripto-1 levels of the patients were analysed, and their diagnostic efficacy was evaluated.
RESULTS: The pathological diagnosis results showed 180 cases of malignant tumours, including 73 cases of clear cell carcinoma, 60 cases of papillary RCC and 47 cases of chromophobe cell carcinoma as well as 76 cases of benign tumour, including 31 cases of renal angiomyolipoma, 25 cases of eosinophilic tumour and 20 cases of renal fibroma. The malignant group had significantly higher incidence of cystic necrosis, uneven enhancement and rapid progression than the benign group (p < 0.01). The incidence of calcification was not statistically different between the two groups (p > 0.05). The malignant group had lower CT value of focus (p < 0.01) and relative corrected CT value of the renal cortex (p < 0.05), and significantly higher serum levels of Cripto-1 (p < 0.01) than the malignant group. The area under the curve of the combined diagnosis was significantly higher than that of serum Cripto-1 alone and comprehensive diagnosis of CT parameters (pcombined diagnosis vs serum Cripto-1 < 0.001, pcombined diagnosis vs comprehensive diagnosis of CT parameters = 0.002). The sensitivity of the combined diagnosis was also higher than that of serum Cripto-1 and CT parameters alone.
CONCLUSIONS: The combination of CT scanning parameters and serum Cripto-1 has high value in the diagnosis of renal tumours, and the area under the curve and sensitivity of the combined diagnosis are high. This work provides reference for clinical diagnosis and treatment of renal tumours.

OBJECTIVE: To investigate the correlation between changes in the thickness and density of diseased small-bowel wall and small-bowel ischemia and necrosis (SBN) on CT imaging when small-bowel obstruction (SBO) occurs.
METHODS: We retrospectively analyzed 186 patients with SBO in our hospital from March 2020 to June 2023. The patients were divided into simple SBO (control group) and SBN (case group) groups. We used logistic regression analysis, the chi-square test, and Fisher\'s exact test to analyze the correlation between the changes in the thickness and density of the diseased intestinal wall and the SBN. A receiver operating characteristic (ROC) curve was used to calculate the accuracy of the multivariate analysis.
RESULTS: Of the 186 patients with SBO, 98 (52.7%) had simple SBO, 88 (47.3%) had SBN, and the rate of SBN was 47.3% (88/186). Multivariate regression analysis revealed that six CT findings were significantly correlated with SBN (p < 0.05), namely, thickening of the diseased intestinal wall with the target sign (OR = 21.615), thinning of the diseased intestinal wall (OR = 48.106), increase in the diseased intestinal wall density (OR = 13.696), mesenteric effusion (OR = 21.635), decrease in the diseased intestinal wall enhancement on enhanced scanning (OR = 41.662), and increase in the diseased intestinal wall enhancement on enhanced scanning (OR = 15.488). The AUC of the multivariate analysis reached 0.987 (95% CI 0.974-0.999). Specifically, the target sign was easily recognizable on CT images and was a significant CT finding for predicting SBN.
CONCLUSIONS: We identified 6 CT findings that were significantly associated with SBN, and may be helpful for clinical treatment.