Objective To obtain the parameters of optimal spectral scanning mode in chest spectral CT imaging,radiation doses,image quality,CNR and subjective scores are compared in spectral and conventional scan modes with anthropomorphic chest phantom.Methods An anthropomorphic chest phantom underwent both conventional scan and spectral scan using three different protocols:GSI assist mode (protocol A);GSI mode with mean tube current (protocol B);GSI mode with maximum tube current (protocol C).All above scans were performed with the noise index (NI) as 9 and 11 respectively.The radiation dose was recorded,and the SD values of adipose tissue and muscle tissue of 5 different sections were measured in regions of interest (ROls) to evaluate the image quality.All scans were subjectively scored in 5 score system by two senior radiologists on lung markings and branches with the lung window technique.Results The effective dose (E) values of conventional CT scan and protocols A,B and C were 8.0,8.5,6.2,10.4 and 5.3,5.1,4.3,6.2 mSv.When NI =9,the difference of SD values had statistically significance between conventional scan and protocols A,C (F =4.496,P ＜ 0.05).When NI =11,there was statistically significant difference of SD value between conventional scan and protocols A,B,C (F =8.425,P ＜ 0.05).In conventional chest scan,the difference of SD values was statistically significant between NI =9 and 11 (t =-2.570,P ＜ 0.05),while other protocols had no statistically significant difference (P ＞ 0.05).The difference of CNR and subjective score had no statistically significance in either the same NI different scanning modes or the same scanning mode with different NIs.Conclusions Appropriate spectral scanning mode had no significant difference with conventional CT scanning in radiation dose,yet higher image quality can be obtained.Furthermore,appropriate NI can reduce the radiation dose obviously while the similar image quality was achieved.Considering the two factors,GSI assist mode can achieve balance between radiation dose and image quality.

Objective:To explore the application effect of rotating skin flap in the repair of skin and soft tissue defects in the perineum.Methods:A retrospective analysis was conducted on the data of 9 patients with perineal soft tissue defects treated in the Department of the First Affiliated Hospital, Wenzhou Medical University from January 2022 to March 2024. Among them, 8 cases were soft tissue defects after extensive resection of Paget′s disease in the perineum, and 1 case was soft tissue defects after treatment of severe urethral stricture. The defect area ranged from 4 cm×1.5 cm to 30 cm×35 cm, and all wounds were repaired with rotating skin flaps, For patients with excessive area, rotating skin flaps were used to cover important areas, combined with autologous skin and artificial skin to cover the remaining wounds. Patients with urethral stricture were treated with free oral mucosal reconstruction of the urethra combined with rotational skin flap coverage. The donor site was directly sutured or autologous skin was transplanted.Results:After surgery, the recipient skin flaps of 9 patients survived and the donor area healed. After a follow-up of 9-15 months, the skin flap survived well, with skin color approaching normal, and the donor site wound healed well. Eight patients with Paget′s disease did not show any recurrence, among which one patient with extensive wound expansion had good recovery of the perineal skin flap coverage area, and small-scale chronic ulcers appeared in the skin graft area. The skin flap of the patient with urethral stricture had recovered well, and the shape of the penis was good, without any urethral stricture, urinary fistula, sinus tract, etc.Conclusions:The rotational skin flap has a clear therapeutic effect on perineal soft tissue defects and is suitable for repairing perineal skin and soft tissue defects.

With the extensive application of nuclear technology in industry, agriculture, and medicine, the safety issues associated with neutron radiation have become increasingly prominent. Due to their high penetrability and strong ionization effect, neutrons can cause serious health risks by directly damaging DNA or inducing secondary γ radiation. Therefore, the neutron radiation protection has become a core challenge in radiation protection, especially the research and development of neutron shielding materials. To ensure the safe development of nuclear technology, neutron shielding materials are indispensable and constitute a fundamental core technology for radiation protection. This paper reviews the theory of neutron radiation protection and the research progress of neutron shielding materials, with a focus on the current application status and existing problems of neutron shielding materials. This article also discusses the future development trends. This review aims to provide theoretical support and technical references for the safe application and development of nuclear technology.

OBJECTIVETo build a protocol of separation and induction of megakaryocytes derived from cord blood mononuclear cells.

METHODSRed blood cells were precipitated by hydroxyethyl starch (HES). Mononuclear cells were obtained by density gradient centrifugation with Ficoll. The inducing efficiencies of megakaryocytes by using of different cytokine cocktails and culture media were analyzed.

RESULTSThe best choice for erythrocyte sedimentation and high efficiency of nucleated cells retrieving were obtained by using of 1.5% HES. The isolated cord blood mononuclear cells were cultured with domestic serum-free medium supplemented with 116t (IL-11, IL-6, TPO), st36(SCF, TPO, IL-3, IL-6), pt36 (PDGF,TPO,IL-3,IL-6) or pst36 for 7 days. St36 group (50 ng/ml SCF, 50 ng/ml TPO, 20 ng/ml IL-3 and 50 ng/ml IL-6) yielded the most CD41/CD61 positive [(6.79±1.97)×10⁴]. The cell viability [(82.85 ± 0.64)%] of st36 group by using of imported serum-free medium was better than [(60.90±6.93)%] that in domestic medium on day 7 after induction, and CD41/CD61 positive cells count [(18.60±1.97)×10⁴] were more than domestic serum-free medium group. Therefore, we chose imported serum-free medium containing st36 to induce cord blood mononuclear cells. After a prolonged culture, the total cell numbers increased accompanied with an elevated percentage of CD41/CD61 positive cells, which reached (54.27 ± 6.31)% on day 14. Wright-Giemsa staining showed that different phase cells, such as megakaryoblast, promegakaryocyte and granular megakaryocyte, occurred after 10 days'culture. Clone forming unit-megakarocytes (CFU-MK) assay showed that the colonies count increased with the prolonged incubation. CFU-MK colonies were [1 236.0±32.9] on day 14, which was higher than that in medium without induction (P<0.01). Platelets from megakaryocytes showed agglutination function after 10 days'culture.

CONCLUSION1.5% HES was the best solution to precipitate erythrocytes. The combination of an imported serum-free medium with IL-3, IL-6, SCF and TPO showed better induction efficiency than domestic medium or other cytokine cocktails. Meanwhile, induced megakaryocytes produced functional platelets.

Cell Culture Techniques ; Cell Differentiation ; Cell Division ; Cell Separation ; methods ; Cells, Cultured ; Culture Media, Serum-Free ; Fetal Blood ; cytology ; Humans ; Megakaryocyte Progenitor Cells ; cytology