Accurate Density Prediction of Sesquiterpenoid HEDFs and the Multiproperty Computing Server SesquiterPre.

Accurate and rapid evaluation of density is crucial for evaluating the packing and combustion characteristics of high-energy-density fuels (HEDFs). This parameter is pivotal in the selection of high-performance HEDFs. Our study leveraged a polycyclic compound density data set and quantum chemical (QC) descriptors to establish a correlation with the target properties using the XGBoost algorithm. We utilized a recursive feature elimination method to simplify the model and developed a concise and interpretable density prediction model incorporating only six QC descriptors. The model demonstrated robust performance, achieving coefficients of determination (R 2) of 0.967 and 0.971 for internal and external test sets, respectively, and root-mean-square errors (RMSE) of 0.031 and 0.027 g/cm3, respectively. Compared to the other two mainstream methods, the marginal discrepancy between the predicted and actual molecular densities underscores the model's superior predictive ability and more usefulness for energy density calculation. Furthermore, we developed a web server (SesquiterPre, https://sespre.cmdrg.com/#/) that can simultaneously calculate the density, enthalpy of combustion, and energy density of sesquiterpenoid HEDFs, which greatly facilitates the use of researchers and is of great significance for accelerating the design and screening of novel sesquiterpenoid HEDFs.

Silibinin exerts antidepressant effects by improving neurogenesis through BDNF/TrkB pathway.

Classic antidepressants benefit depression patients partially by improving neurogenesis and/or brain-derived neurotrophic factor (BDNF)/TrkB pathway which were impaired in depression. In this study, we demonstrated that Silibinin (SLB), a polyphenolic flavanoid from Silybum marianum, ameliorated reserpinized mouse depressant-like behaviors. The antidepressants of SLB administration was associated with increased neural stem cells (NSCs) proliferation and further confirmed in BDNF/TrkB signaling transduction. SLB treatment reversed the decreased expression levels of BDNF and its receptor TrkB, and the reduced activation of downstream target proteins including phosphorylated extracellular-regulated protein kinase (p-ERK) and phosphorylated cAMP-response element binding protein (p-CREB) in depressived hippocampus. Furthermore, intracerebroventricular injection of GNF5837, a TrkB antagonist, abrogated antidepressant-like effects of SLB in mice along with the improved NSC proliferation, as well as enhanced levels of p-ERK and p-CREB in mice hippocampus. Taken together, these results suggest that SLB may exert antidepressant effects through BDNF/TrkB signaling pathway to improve NSC proliferation in acute depression.

[Clinical analysis of pediatric SARS cases in Beijing].

OBJECTIVE: To study clinical characteristics of pediatric SARS cases in Beijing. METHODS: Eighteen pediatric cases with SARS diagnosed on admission were analyzed. The cases were admitted to Beijing Children's Hospital and Ditan Hospital (pediatric ward) from April 8 to May 12. RESULTS: The 18 children aged 5 months to 15 years (10 male and 8 female) had epidemiologically linked findings. Fourteen cases had close contact with SARS patients. Four cases were living in the community where adult SARS patients were found. All the 18 patients but one presented with fever and cough. Most of them had high fever, 2 cases had bradycardia, 2 had diarrhea, and another 2 had tachypnea. Malaise and headache were noted only in 3 cases respectively which were much less frequently seen than in adult patients. Symptoms and signs of the children were much less severe and aggressive than adults cases. Thirteen children had chest radiographic consolidation. Of them, 9 cases had progressive changes after admission, then improved quickly. We did not find significant lower hemoglobin and platelet levels. Most patients had leukopenia and lymphopenia. Serologic test was performed for 15 cases and 8 were positive for SARS virus-IgG and 6 for IgM antibody. Of the 4 cases who had close contact with SARS adults and without chest radiograph abnormal findings, 3 were negative for SARS virus-antibodies. Part of the patients had temporary abnormality of myocardial enzyme and liver function. All these children finally had rapid improvement on chest radiograph. The patients were treated with antiviral agents and corticosteroid. Only two cases required oxygen therapy. No child needed assisted ventilation and no death, nor lung fibrosis occurred. After hospitalization, all patients were improved and discharged when this paper was being written. The average hospital stay of these patients was 14.6 days (6 - 22 days). CONCLUSION: Compared with adults, pediatric SARS patients seemed to have their own clinical characteristics. The disease in children had lower severity and infectivity than that in adults. The mechanisms of the disease in children should be studied in well-designed clinical trials. Cases like the 4 children who had close contact with SARS adult patients but without chest radiographic changes deserve further studies with the help of more reliable and sensitive etiologic tests.