Objective:To evaluate the efficacy of the “double-low” scanning protocol (low tube voltage and low-concentration contrast agent) combined with the artificial intelligence iterative reconstruction (AIIR) algorithm for abdominal CT enhancement in patients with obesity and to identify the optimal AIIR reconstruction algorithm level.Methods:From April 2024 to July 2024, patients with a body mass index≥30.00 kg/m2 who underwent abdominal CT enhancement at the Affiliated Hospital of Hebei University were prospectively included. All patients were randomly assigned to groups A or B. Patients in Group A accepted the conventional scanning protocol (automatic tube voltage selection and a contrast agent concentration of 350 mg/ml) with reconstruction using the Karl 3D iterative reconstruction algorithm at levels 3-5. The “double-low” protocol (a fixed tube voltage of 80 kVp and a contrast agent concentration of 320 mg/ml) with AIIR algorithm reconstruction at levels 1-5 were performed in Group B. CT values and image noises were measured, including the right posterior liver lobe at the level of the first porta hepatis and subcutaneous fat at the third lumbar level during arterial and portal venous phases, abdominal aorta at the third lumbar vertebra during the arterial phase, and portal vein trunk during the portal-venous-phase. Radiation dose, total iodine intake, signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and subjective image quality scores were recorded. The optimal reconstruction levels for arterial-phase and portal-venous-phase images were identified for each group by repeatedly measured ANOVA. The figure of merit (FOM) was calculated for the best images in both groups, and comparisons were made in terms of image quality, radiation dose, and iodine intake using an unpaired t-test or Wilcoxon test. Results:Overall, 150 patients with obesity were collected, and each group included 75 cases. In group A, compared with levels 3 and 4 ( P<0.001), the Karl 3D level 5 algorithm yielded significantly higher SNR, CNR values, and subjective scores, designating level 5 as the optimal reconstruction level. In group B, the AIIR level 4 algorithm achieved higher SNR and CNR values than level 5 and achieved higher subjective scores than levels 3 and 5 ( P<0.001), which means that level 4 was the optimal reconstruction level. Images reconstructed with AIIR level 4 in group B exhibited significantly higher CT, SNR, CNR, FOM values, and subjective scores than those reconstructed with Karl 3D level 5 in group A ( P<0.001). Compared with group A, the volume CT dose index values, dose-length product, and size-specific dose estimate based on water equivalent diameter in Group B were reduced by 56.75%, 58.29%, and 56, 71% during the arterial phase, and 56.70%, 58.27%, and 56.88% during the portal venous phase, respectively. Total iodine intake was significantly reduced by 10.71% in group B ( P<0.001). Conclusions:The “double-low” scanning protocol combined with AIIR algorithm significantly reduced radiation dose and iodine intake during abdominal CT enhancement in patients with obesity, without compromising image details, increasing noise, or altering image quality. AIIR level 4 was the optimal image reconstruction level for arterial-phase and portal-venous-phase in obese patients.

Objective:To evaluate the efficacy of the “double-low” scanning protocol (low tube voltage and low-concentration contrast agent) combined with the artificial intelligence iterative reconstruction (AIIR) algorithm for abdominal CT enhancement in patients with obesity and to identify the optimal AIIR reconstruction algorithm level.Methods:From April 2024 to July 2024, patients with a body mass index≥30.00 kg/m2 who underwent abdominal CT enhancement at the Affiliated Hospital of Hebei University were prospectively included. All patients were randomly assigned to groups A or B. Patients in Group A accepted the conventional scanning protocol (automatic tube voltage selection and a contrast agent concentration of 350 mg/ml) with reconstruction using the Karl 3D iterative reconstruction algorithm at levels 3-5. The “double-low” protocol (a fixed tube voltage of 80 kVp and a contrast agent concentration of 320 mg/ml) with AIIR algorithm reconstruction at levels 1-5 were performed in Group B. CT values and image noises were measured, including the right posterior liver lobe at the level of the first porta hepatis and subcutaneous fat at the third lumbar level during arterial and portal venous phases, abdominal aorta at the third lumbar vertebra during the arterial phase, and portal vein trunk during the portal-venous-phase. Radiation dose, total iodine intake, signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and subjective image quality scores were recorded. The optimal reconstruction levels for arterial-phase and portal-venous-phase images were identified for each group by repeatedly measured ANOVA. The figure of merit (FOM) was calculated for the best images in both groups, and comparisons were made in terms of image quality, radiation dose, and iodine intake using an unpaired t-test or Wilcoxon test. Results:Overall, 150 patients with obesity were collected, and each group included 75 cases. In group A, compared with levels 3 and 4 ( P<0.001), the Karl 3D level 5 algorithm yielded significantly higher SNR, CNR values, and subjective scores, designating level 5 as the optimal reconstruction level. In group B, the AIIR level 4 algorithm achieved higher SNR and CNR values than level 5 and achieved higher subjective scores than levels 3 and 5 ( P<0.001), which means that level 4 was the optimal reconstruction level. Images reconstructed with AIIR level 4 in group B exhibited significantly higher CT, SNR, CNR, FOM values, and subjective scores than those reconstructed with Karl 3D level 5 in group A ( P<0.001). Compared with group A, the volume CT dose index values, dose-length product, and size-specific dose estimate based on water equivalent diameter in Group B were reduced by 56.75%, 58.29%, and 56, 71% during the arterial phase, and 56.70%, 58.27%, and 56.88% during the portal venous phase, respectively. Total iodine intake was significantly reduced by 10.71% in group B ( P<0.001). Conclusions:The “double-low” scanning protocol combined with AIIR algorithm significantly reduced radiation dose and iodine intake during abdominal CT enhancement in patients with obesity, without compromising image details, increasing noise, or altering image quality. AIIR level 4 was the optimal image reconstruction level for arterial-phase and portal-venous-phase in obese patients.

Objective To investigate the bacterial community diversity in human Demodex mites, so as to provide insights into unraveling the role of human Demodex mites in them caused infectious diseases. Methods From June to July 2023, Demodex mites were collected from the faces of college students in a university in Wuhu City using the adhesive tape method, and the V4 region of 16S ribosomal RNA (16S rRNA) gene and the internal transcribed spacer (ITS) gene of nuclear ribosomal DNA were amplified on an Illumina PE250 high-throughput sequencing platform. Sequencing data were spliced according to the overlapping relations and filtered to yield effective sequences, and operational taxonomic units (OTUs) was clustered. The diversity index of obtained OUTs was analyzed, and the structure of the bacterial community was analyzed at various taxonomic levels. Results A total of 57 483 valid sequences were obtained using 16S rRNA gene sequencing, and 159 OUTs were classified according to similarity. Then, OUTs at a 97% similarity were included for taxonomic analyses, and the bacteria in Demodex mites belonged to 14 phyla, 20 classes, 51 orders, 72 families, and 94 genera. Proteobacteria was the dominant phylum, and Vibrio, Bradyrhizobium and Variovorax were dominant genera. A total of 56 362 valid sequences were obtained using ITS gene sequencing, and 147 OTUs were obtained, which belonged to 5 phyla, 17 classes, 34 orders, 68 families, and 93 genera and were annotated to Ascomycota, Basidiomycota and Chytridiomycota, with Ascomycota as the dominant phylum, and Alternaria alternata, Epicoccum, Penicillium, and Sarocladium as dominant genera. Conclusions There is a high diversity in the composition of bacterial communities in human Demodex mites, with multiple types of microorganisms and high species abundance.

Objective To investigate the activity of Acorus tatarinowii extracts against dust mites, and to isolate and characterize active ingredient of A. tatarinowii extracts. Methods The essential oil components were extracted from A. tatarinowii rhizome powder by rotary evaporation with methanol as solvents, followed by petroleum ether extraction and rotary evaporation. The essential oil was mixed with Tween-80 at a ratio of 1:1 and diluted into concentrations of 1.000 00%, 0.500 00%, 0.250 00%, 0.125 00%, 0.062 50% and 0.031 25%, while diluted Tween-80 served as controls. A. tatarinowii essential oil at each concentration (200 μL) was transferred evenly to filter papers containing 100 adult mites, with each test repeated in triplicate, and controls were assigned for each concentration. Following treatment at 25 °C and 75% relative humidity for 24 h, the mean corrected mortality of mites was calculated. The essential oil components were separated by silica gel column chromatography, and the essential oil was prepared in the positive column of medium pressure; and then, each component was collected. Silica gel column chromatography was run with the mobile phase that consisted of petroleum ether solution containing 10% ethyl acetate and pure ethyl acetate, detection wavelength of 254 nm, positive silica gel column as the chromatography column, and room temperature as the column temperature. Each component of the purified A. tatarinowii essential oil was diluted into 1.000 00% for acaricidal tests. The components with less than 100% acaricidal activity were discarded, and the remaining components were diluted into 50% of the previous-round tests for subsequent acaricidal tests. The components with acaricidal activity were subjected to high-performance liquid chromatography, liquid chromatography-mass spectrometry and pulsed-Fourier transform nuclear magnetic resonance spectroscopy. The structure of active monomer compounds was determined by standard spectral library retrieval and literature review. Results A. tatarinowii essential oil at concentrations of 1.000 00%, 0.500 00%, 0.250 00% and 0.125 00% killed all dust mites, and the corrected mortality was all 100%. Exposure to A. tatarinowii extracts at an effective concentration of 0.062 50% for 24 hours resulted in 94.33% mortality of dust mites. Six components (A to F) were separated using gel column chromatography, and components D and E both showed a 100% acaricidal activity against dust mites at a concentration of 0.50000%. In addition, Component D was identified as isoeugenol methyl ether, and Component E as β-asarinol. Conclusion The extract of A. tatarinowii essential oil has acaricidal activity, and the isoeugenol methyl ether shows a remarkable acaricidal activity against dust mites.