In this paper, alpha-tricalcium phosphate (alpha-TCP) and tetracalcium phosphate (TTCP) respectively were chosen as basic compositions of phosphate bone cements. Other auxiliary materials such as hydroxyapatite (HAP), dicalcium phosphate dihydrate (DCPD), calcium carbonate (CaCO3), calcium oxide (CaO) and amorphous calcium silicate (CaSiO3) were added in the cements. Six kinds of composite bone cements were decided with 1.50 as their Ca/P ratio. Then the primary properties of them were studied. Ringer's simulated body fluid (SBF) tests were carried out for the samples. The changes of pH value in SBF and the compressive strength of the samples with the immersion time were studied. The results showed: the mixing liquid 0.25 M K2HPO4/KH2PO4 and amorphous CaSiO3 were effective for accelerating the setting of the cements; the initial setting time (It) was about 4-5.5 min and the final setting time (Ft) was about 18-19. 5 min. Amorphous calcium silicate can increase the compressive strength of the bone cements remarkably; the compressive strength of the alpha-TCP bone cement with the addition of suitable amount amorphous CaSiO3 reached 45.3 MPa after immersion in SBF for 14 days.
Bone Cements ; chemical synthesis ; chemistry ; Calcium Compounds ; chemistry ; Calcium Phosphates ; chemistry ; Compressive Strength ; Humans ; Silicates ; chemistry

Objective To explore the relationship between the levels of serum dopamine,5-hydroxytryptamine,homovanillic acid and cognitive dysfunction in patients with Parkinson's disease.Methods A total of 118 Parkinson's disease patients admitted to Bazhong Central Hospital from February 2020 to February 2022 were selected as the disease group,and 106 healthy patients who underwent physical examination in the hospital during the same period were selected as the control group.The levels of serum do-pamine,5-hydroxytryptamine and homovanillic acid were measured in all subjects,and the cognitive function was evaluated with Montreal Cognitive Assessment Scale(MoCA).Parkinson's disease patients were divided into cognitive impairment group and non cognitive impairment group according to MoCA score.The serum do-pamine,5-hydroxytryptamine,homovanillic acid levels of the cognitive impairment group and the non cogni-tive impairment group were compared.Pearson correlation analysis was used to analyze the correlation be-tween serum dopamine,5-hydroxytryptamine and homovanillic acid levels and cognitive function of Parkinson's disease patients,and the receiver operating characteristic curve was drawn to analyze the evaluation value of serum dopamine,5-hydroxytryptamine and homovanillic acid levels on cognitive dysfunction of Parkinson's disease patients.Results The levels of serum dopamine,5-hydroxytryptamine,homovanillic acid and MoCA score in the disease group were lower than those in the control group,with statistical significance(P＜0.05).The levels of serum dopamine,5-hydroxytryptamine,homovanillic acid and MoCA score in advanced patients were lower than those in early patients,and the difference was statistically significant(P＜0.05).The levels of serum dopamine,serotonin and homovanillic acid in the cognitive dysfunction group were lower than those in the non-cognitive dysfunction group,and the difference was statistically significant(P＜0.05).The results of Pearson analysis showed that the levels of serum dopamine,5-hydroxytryptamine and homovanillic acid in Parkinson's disease patients were positively correlated with MoCA score(P＜0.05).The sensitivity of the combined assessment of serum dopamine,serotonin and homovanillic acid in Parkinson's disease patients was higher than that in Parkinson's disease patients alone(x2=7.413,P=0.006;x2=9.714,P=0.002;x2=8.541,P=0.003),the area under the curve(AUC)was higher than the AUC for assessing cognitive impair-ment in Parkinson's disease alone(Z=2.479,P=0.013;Z=2.271,P=0.023;Z=2.451,P=0.014).Conclusion There are differences in serum levels of dopamine,5-hydroxytryptamine,homovanillic acid and cognitive function among different stages of Parkinson's disease patients.Serum levels of dopamine,5-hydroxytryptamine,and homovanillic acid are closely related to cognitive function in Parkinson's disease pa-tients,all of which have evaluation value for the occurrence of cognitive dysfunction in Parkinson's disease pa-tients.However,the combination of the three serum indicators is more helpful for clinical evaluation and diag-nosis.

During coronavirus disease 2019 epidemic, the treatment of severe trauma has been impacted. The Consensus on emergency surgery and infection prevention and control for severe trauma patients with 2019 novel corona virus pneumonia was published online on February 12, 2020, providing a strong guidance for the emergency treatment of severe trauma and the self-protection of medical staffs in the early stage of the epidemic. With the Joint Prevention and Control Mechanism of the State Council renaming "novel coronavirus pneumonia" to "novel coronavirus infection" and the infection being managed with measures against class B infectious diseases since January 8, 2023, the consensus published in 2020 is no longer applicable to the emergency treatment of severe trauma in the new stage of epidemic prevention and control. In this context, led by the Chinese Traumatology Association, Chinese Trauma Surgeon Association, Trauma Medicine Branch of Chinese International Exchange and Promotive Association for Medical and Health Care, and Editorial Board of Chinese Journal of Traumatology, the Chinese expert consensus on emergency surgery for severe trauma and infection prevention during coronavirus disease 2019 epidemic ( version 2023) is formulated to ensure the effectiveness and safety in the treatment of severe trauma in the new stage. Based on the policy of the Joint Prevention and Control Mechanism of the State Council and by using evidence-based medical evidence as well as Delphi expert consultation and voting, 16 recommendations are put forward from the four aspects of the related definitions, infection prevention, preoperative assessment and preparation, emergency operation and postoperative management, hoping to provide a reference for severe trauma care in the new stage of the epidemic prevention and control.