Objective:To investigate the prevalence of norovirus and the correlation between norovirus infection and stool traits and clinical symptoms in children with acute gastroenteritis during 2021-2022.Method:A total of 2 195 anal swab samples were collected from cases of acute gastroenteritis in Beijing Children 's Hospital Affiliated to Capital Medical University from January 2021 to December 2022. PCR fluorescent probe assay was performed to detect norovirus，the clinical information and test results were performed by statistical analysis. Results:The detection rate of norovirus was 19.09%（419/2 195）in 2 195 children. The detection rates of male and female were 17.80%（244/1 371）and 21.24%（175/824），respectively，with statistically significant differences between genders（ χ2=3.945, P<0.05）. The positivity rate of noroviruses was higher in aged 1 month to 3 years［29.09%（64/220）~40.69%（94/231）］，especially in 1 year［40.69%（94/231）］. The norovirus detection rate ranged from 2.44%（2/82）to 35.84%（62/173）in different months，with a high detection rate between January and March，higher in the winter and spring［28.36%（150/529），21.07%（146/693）］，showing a clear seasonal distribution.Clinical symptoms of both vomiting and diarrhea were significantly more common among norovirus positive than negative children，the difference was statistically significant（ χ2=57.29, P<0.05）. Conclusion:In the high incidence season of winter and spring，for infants and young children aged 1 month to 3 years with diarrhea accompanied by vomiting symptoms，especially those aged 1 year，it is recommended to undergo norovirus related testing in time. Early treatment and isolation measures should be taken for diagnosed children to reduce cross infection and prevent outbreaks.

Objective:To develop and validate a structure for broadening the Bragg peak to improve the efficiency and conformality of particle radiotherapy.Methods:Techniques of random stacking and regular stacking were employed to fabricate the mesh-stacked porous structure (MPS). In each layer of the grid, the thickness, line width and spacing were set at 0.1 mm, 0.1 mm and 0.5 mm, respectively, resulting in a total size of 10 cm ×10 cm. Monte Carlo code FLUKA was performed to simulate the transportation of 196 MeV/u carbon ion beam and a 105 MeV proton beam through the MPS. Dose distribution, fluence homogeneity, and modulation stability of the modulated beams were evaluated. Moreover, the modulation effect of MPS in clinical radiotherapy plans for nasopharyngeal carcinoma (63 Gy in 21 fractions), lung cancer (77 Gy in 22 fractions) and prostate cancer (70.4 Gy in 16 fractions) was also evaluated, respectively.Results:The MPS was capable of broadening the Bragg peak width by 1.73 mm for proton beams and 2.95 mm for carbon ion beams. For different entrance positions, regular stacking of more than 10 layers could reduce the modulation power difference of MPS to within 5%. For MPS with 30 layers of regular stacking, the modulated fluence homogeneity could achieve a value of less than 3% by transporting 18 cm distance in air. When comparing to the clinically used ripple filters, MPS reduced the isocenter spot size of proton beams by 0.91 mm. In the comparison study of the treatment plan for nasopharyngeal carcinoma, the use of MPS could shorten the treatment time by 213 s (37%) and reduce the maximum dose to the brainstem by 3.28 Gy (7.5%).Conclusions:MPS effectively broadens the Bragg peak of particle beams and improves the efficiency of clinical radiotherapy. Regularly stacked MPS demonstrates robust modulation stability, and the modulated beam achieves relatively well fluence homogeneity, making it a promising clinical application for closer to the patients and reducing lateral scattering.

To explore the effect of adipose-derived mesenchymal stem cells (ADMSCs) on ovarian damage induced by cyclophosphamide (CTX) and its mechanism.
 Methods: ADMSCs isolated from adipose tissue of female SD rats were cultured and divided into a blank group and a CTX group (n=15 in each group). CTX (75 mg/kg) was injected intraperitoneally to establish a model of ovarian damage in rats. A total of 45 female SD rats were also divided into 3 groups: Group A (15 rats, only injected intraperitoneally with 75 mg/kg CTX diluted with 1 mL 0.9% saline), Group B [15 rats, injected intraperitoneally with 75 mg/kg CTX diluted with 1 mL 0.9% saline, after 4 estrus cycles, injected 0.6 mL ADMSCs (6×105 cells) by the tail vein], and Group C [15 rats, injected intraperitoneally with 75 mg/kg CTX diluted with 1 mL 0.9% saline, after 4 estrus cycles, injected 40 mL ADMSCs (20 mL per side, 2×104 cells) in situ ovarian]. After 4 estrus cycles, the changes of quality of life, ponderal growth were recorded, the sex hormone levels [estradiol (E2), follicle-stimulating hormone (FSH)] were tested by ELISA, and the morphology of ovarian tissue and follicle count were observed by HE staining. The expression of BMP-15, Bcl-2 and Bax in ovarian tissues were tested by immunohistochemistry, real-time PCR or Western blotting. The apoptosis rate of follicular cells was detected by TdT-mediated dUTP nick end labeling (TUNEL) assay.
 Results: After transplantation of ADMSCs, compared with the Group A, their quality of life of rats in the Group B and C was improved, and the ponderal growth was increased (both P<0.01). Compared with the Group A, the serum E2 levels in the Group B and the Group C were increased (P<0.01, P<0.05), and the FSH levels in the Group B and C were decreased (both P<0.01). The granular cell layer, the number of corpus lutein and the count of various grade follicles were significantly increased, and many new follicles and mature oocytes were observed in the Group B and C. Compared with Group A, the count of primitive follicles, sinusoidal follicles, pre-ovulation follicles and total follicles, and pre-sinusoidal follicles were dramatically increased in the Group B. The follicle at all levels count was increased in the Group C than that in the Group A (all P<0.01). Comparing with the Group A, the expressions of BMP-15 and Bcl-2 were increased (all P<0.01), the expressions of Bax was decreased (both P<0.01), and the apoptosis rates of follicular cells were decreased in the Group B and C (both P<0.01). However, there was no difference between the Group B and the Group C in the above indexes (all P>0.05).
 Conclusion: ADMSCs transplantation can effectively repair ovarian damage induced by CTX in rats, which may be achieved by inhibiting mitochondrial apoptosis of granulosa cells.
Animals ; Cyclophosphamide ; Female ; Mesenchymal Stem Cells ; Ovary ; Quality of Life ; Rats ; Rats, Sprague-Dawley

Alkali-salinity exerts severe osmotic, ionic, and high-pH stresses to plants. To under-stand the alkali-salinity responsive mechanisms underlying photosynthetic modulation and reactive oxygen species (ROS) homeostasis, physiological and diverse quantitative proteomics analyses of alkaligrass (Puccinellia tenuiflora) under Na2CO3 stress were conducted. In addition, Western blot,real-time PCR, and transgenic techniques were applied to validate the proteomic results and test the functions of the Na2CO3-responsive proteins. A total of 104 and 102 Na2CO3-responsive proteins were identified in leaves and chloroplasts, respectively. In addition, 84 Na2CO3-responsive phospho-proteins were identified, including 56 new phosphorylation sites in 56 phosphoproteins from chloro-plasts, which are crucial for the regulation of photosynthesis, ion transport, signal transduction, and energy homeostasis. A full-length PtFBA encoding an alkaligrass chloroplastic fructose-bisphosphate aldolase (FBA) was overexpressed in wild-type cells of cyanobacterium Synechocystis sp. Strain PCC 6803, leading to enhanced Na2CO3 tolerance. All these results indicate that thermal dissipation, state transition, cyclic electron transport, photorespiration, repair of pho-tosystem (PS) Ⅱ, PSI activity, and ROS homeostasis were altered in response to Na2CO3 stress, which help to improve our understanding of the Na2CO3-responsive mechanisms in halophytes.