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BackgroundThe current radiation dose calculation technology can only give 3D static dose results of upright human body, which cannot meet the needs of future accurate protection.PurposeThis study aims to achieve 4D dose calculation by establishing a complete method.MethodsFirstly, three algorithms, namely, the rotation matrix method, the volume graph Laplace operator method and the As-Rigid-As-Possible (ARAP) method, were employed to realize the deformation of mesh phantom. Then the phantom deformation guided by motion capture was investigated, and the tetrahedral cutting technology based on Delaunay algorithm was applied to the high speed Monte Carlo calculation. Finally, the 4D dose calculation application system was implemented and used for field test of nuclear power plant (NPP).ResultsThe comparison between the calculated and measured individual 4D dose values shows that the deviation of Hp(10) is less than 10%, and the deviations of Hp(3) and Hp(0.07) are less than 15% are verified.ConclusionsThe reliability and practicability of 4D radiation dose calculation of human body proposed in this study are verified by application results in specific radiation operation process in NPP, which is expected to achieve precise protection of personnel in the future scenarios such as NPP operation and maintenance, nuclear facility decommissioning and medical interventional treatment.

UDEC is used to analyze the surface subsidence characteristics under different steps of fully mechanized and layered mining face. The research results show that the trend of surface subsidence in the lower layer mining face and the fully mechanized mining face is basically the same, and the extreme value is in the middle back position of the goaf, but the maximum subsidence value of the lower layer face increases by about 30.9%. The sinking coefficient is reduced by about 11.5%; the extreme value of sinking speed of fully mechanized mining face increases with the increase of step of working face, and shifts to the direction of push mining, while the extreme value of sinking speed of lower layered working face relatively decreases; the horizontal movement of the stratum mining face is more violent and fluctuating than that of the fully mechanized mining face. The positive and negative values of the horizontal movement increase by approximately 45.2% and 63.6%, respectively. The influence range of the fully mechanized mining face is greater than that of the layered mining face. Compared with the fully mechanized mining face, the leading influence angle of layered mining under the layer mining face is reduced by about 4.38%, and the boundary angle is reduced by about 1.43%. The conclusion is to provide guidance for rational determination of the mining method.

Objectives: Previous observational studies have indicated correlations between various inflammatory cytokines and functional outcomes following ischemic stroke (IS); however, the causality remains unclear. We aimed to further evaluate the causal association between 41 circulating inflammatory cytokines and functional outcomes following IS. Methods: Two‐sample bidirectional Mendelian randomization (MR) analysis was used in this study. The genetic variation of 41 circulating inflammatory cytokines were derived from genome‐wide association study (GWAS) data of European ancestry (n = 8293). The corresponding genetic association of functional outcomes following IS were derived from European ancestry GWAS data (n = 6021). Results: Inverse variance weighted (IVW) analysis showed that genetically predicted increased levels of regulation and activation in normal T‐cell expression and secretion factor (RANTES/CCL5) and eosinophilic chemotactic factor (EOTAXIN/CCL11) were positively correlated with the increased adverse functional outcomes (modified Rankin Scale [mRS≥3] following IS (OR: 1.40, 95% CI: 1.002–1.96, p = 0.049; OR: 1.33, 95% CI: 1.15–1.54, p = 0.0001). Interleukin 18 (IL‐18) level might be the downstream consequence of adverse functional outcomes following IS (β: −0.09, p = 0.039). Other inflammatory cytokines and functional outcomes following IS did not appear to be causally related. Conclusions: This study suggests a causality between inflammation and adverse functional outcomes following IS. RANTES (CCL5) and EOTAXIN (CCL11) may be the upstream factors of adverse functional outcomes following IS, while IL‐18 may be the downstream effect of adverse functional outcomes following IS. Whether these cytokines can be used to predict or improve adverse functional outcomes after IS requires further researches. [ABSTRACT FROM AUTHOR]

To explore the minimum split dose of FLASH radiotherapy (FLASH). Lungs of nude mice were used to verify the capacity of normal tissue sparing of FLASH, while tumor-bearing nude mice were used to evaluate the curative power. Xenografted tumor models were established in Balb/c-nu mice using A549 cells at a concentration of 5 × 10 6 / 100 μ L. With the same total dose (20 Gy), the dose rate of FLASH was 200 Gy/s when conventional radiotherapy(CONV) was 0.033 Gy/s. Two schemes of FLASH irradiations were applied: single pulse (FLASH1) and ten pulses (FLASH10). Then, according to the different tissue types and irradiation schemes, mice were divided into eight groups: Control-T, CONV-T, FLASH1-T, FLASH10-T (T for tumor) and Control-L, CONV-L, FLASH1-L, FLASH10-L (L for lung). Evaluation of FLASH effect was based on the changes in tumor volume and pathological analysis of tumor and lung tissues before and after irradiation. Compared to control group, the mean volume of tumors in nude mice increased slowly or decreased after irradiation with both FLASH and CONV (Control-T: 233.6 ± 55.19 mm3, CONV-T: 146.1 ± 50.62 mm3, FLASH1-T: 148 ± 18.83 mm3, FLASH10-T: 119.1 ± 50.62 mm3, p ≤ . 05). Tumor cells of irradiated groups had similar degrees of dissolution damage and inflammation, while the acute radiation pneumonia induced by FLASH was less severe. The pulmonary pathology of FLASH1-L and FLASH10-L were similar, and only a few neutrophils were observed. In addition to inflammatory cells, slight thickening of alveolar septum and obvious interstitial hemorrhage were also observed in the CONV-L group. The FLASH effect was successfully reproduced in both single and fractionated irradiation, with 2 Gy being the minimum split dose to achieve the FLASH effect in existing experiments. It is suggested that the transient oxygen depletion might not be the only mechanism behind the FLASH effect. [ABSTRACT FROM AUTHOR]

The aim of this study was to explore the epidermal barrier structure and function of re-harvested skin from non-scalp donor sites. Six patients with large-area deep burns who met the inclusion and exclusion criteria were subjected to split-thickness skin excision three times on the same healthy non-scalp donor sites, with an interval of 14 days. The donor skin thus harvested was labeled as primary skin (S1), secondary skin (S2), and tertiary skin (S3). The transepidermal water loss (TEWL) and stratum corneum water content (SCH) of donor skin were detected before each surgery, and the donor skin was harvested during the surgery. The donor skin was stained with hematoxylin and eosin (HE) and involucrin, loricrin, filaggrin, small molecule proline-rich protein 3 (SPRR3), ZO-3, JAM-A, and JAM-C, or observed by transmission electron microscopy. The epidermal barrier function of the re-harvested skin from the non-scalp donor sites became impaired. The histopathological structure of the re-harvested skin from non-scalp donor sites became abnormal. The barrier of the epidermal stratum corneum of the re-harvested skin from non-scalp donor sites was damaged. The epidermal tight junction barrier in the re-harvested skin from non-scalp donor sites was damaged. As the number of harvesting increases, the epidermal barrier function of the skin decreased, and the damage to the barrier structure increased. Hence, it is vitally important to restore the epidermal barrier function for re-harvesting in non-scalp donor sites. [ABSTRACT FROM AUTHOR]

Introduction Acute kidney injury (AKI) is a common complication in severe burn patients with poor prognosis and high mortality. Reduced kidney perfusion induced by the decreased effective circulating blood volume after severe burn is a common cause of AKI. Routine intravenous resuscitation (IR) is difficult or delayed in extreme conditions such as war and disaster sites. Peritoneal resuscitation (PR) is a simple, rapid resuscitation strategy via a puncture in the abdominal wall. This study investigated whether PR is a validated resuscitation strategy for AKI after severe burns in rats and explored its mechanisms. Materials and Methods Eighty Sprague–Dawley rats were randomized into four groups: (1) sham group; (2) IR group, which was characterized by the full thickness burn of 50% of the total body surface area received IR immediately post-injury; (3) early PR group, in which rats with the same burn model received PR immediately post-injury; and (4) delayed resuscitation (DR) group, in which rats with the same burn model received no resuscitation within 3-hour post-injury. PR and DR groups animals received IR after 3-hour post-injury. The survival rate, mean arterial pressure, renal histopathology, renal function, indicators of renal injury, and renal hypoxia-inducible factor-1α and NADPH oxidase 4 (NOX4) proteins of rats were measured at 3 h, 12 h, and 24 h post-injury. Results Compared with rats in the DR group, rats in the PR group had a significantly improved survival rate (100% vs. 58.3% at 24 h, P  = 0.0087), an increased mean arterial pressure (92.6 ± 6.6 vs. 65.3 ± 10.7, 85.1 ± 5.7 vs. 61.1 ± 6.9, 90.1 ± 8.7 vs. 74.9 ± 7.4 mmHg, at 3 h, 12 h, and 24 h, P  < 0.01), a reduced renal water content rate (51.6% ± 5.0% vs. 70.1% ± 6.8%, 57.6% ± 7.7% vs. 69.5% ± 8.7%, at 12 h and 24 h, P  < 0.01), attenuated histopathological damage, reduced serum creatinine expression (36.36 ± 4.27 vs. 49.98 ± 2.42, 52.29 ± 4.31 vs. 71.32 ± 5.2, 45.25 ± 2.55 vs. 81.15 ± 6.44 μmol/L, at 3 h, 12 h, and 24 h, P  < 0.01) and BUN expression (7.62 ± 0.30 vs. 10.80 ± 0.58, 8.61 ± 0.32 vs. 28.58 ± 1.99, 8.09 ± 0.99 vs. 20.95 ± 1.02 mmol/L, at 3 h, 12 h, and 24 h, P  < 0.01), increased kidney injury markers neutrophil gelatinase-associated lipocalin expression (95.09 ± 7.02 vs. 101.75 ± 6.23, 146.77 ± 11.54 vs. 190.03 ± 9.87, 112.79 ± 15.8 vs. 194.43 ± 11.47 ng/mL, at 3 h, 12 h, and 24 h, P  < 0.01) and cystatin C expression (0.185 ± 0.006 vs. 0.197 ± 0.006, 0.345 ± 0.036 vs. 0.382 ± 0.013, 0.297 ± 0.012 vs. 0.371 ± 0.028 ng/mL, at 3 h, 12 h, and 24 h, P  < 0.01), and reduced renal hypoxia-inducible factor-1α and NADPH oxidase 4 protein expression (P  < 0.01). There was no significant difference between rats in the PR group and the IR group in the above indicators. Conclusions Early PR could protect severe burn injury rats from AKI. It may be an alternative resuscitation strategy in severe burn injury when IR cannot be achieved. [ABSTRACT FROM AUTHOR]