OBJECTIVE: The success of joint prosthesis greatly depends on the materials, which should be a perfect combination of physics, chemistry, biomechanics and clinical sciences in choice of them. In addition, the effect of manufacture technology can not be neglected. So, it is significant to probe into the systematic basis in materials selection of joint prosthesis.DATA SOURCES: A computer-based search was conducted in Pubmed database for articles about joint prosthesis published before April 2006 with the key words of "artificial joint materials, biomaterial", and the language was limited to English. Meanwhile, Chinese Journal Full-text Database (CJFD) and Wanfang database were looked for relevant literatures published before April 2006 with the key words of "artificial joint material, biomedical material", and the language was limited to Chinese. Besides,the standards for materials were searched in Chinese service net for standard consultation with the key words of "implants for surgery" in both Chinese and English. At the same time, relevant books were also manually searched.STUDY SELECTION: Data were checked in the first trial, and related articles according to the criteria of research were looked for the full text.Inclusion criteria: ① Requirements for artificial joint material. ② Relevant standards for artificial joint of surgical implants. Exclusion criteria: Repetitive studies were excluded.DATA EXTRACTION: A total of 390 domestic and overseas articles,which were in relation to the mechanical properties of artificial joint material and bone and measurement of the overall dimensions of knee joint,were collected. There were still 242 relevant standards, while the repetitive studies and similar researches were excluded. Ten typical articles and 25 standards in collection were summed up and reviewed.DATA SYNTHESIS: ①Close combination of physics, chemistry, biomechanics and clinical sciences is sufficiently embodied in the selection of the materials. ② Two aspects must be taken into consideration: Requirements for function of the implant and the responses inside the human body.③ Main types of materials for joint prosthesis: biomedical metallic material, biomedical inorganic material of nonmetal, bioceramic, biomedical compound materials and so on. All kinds of materials that have been adopted should accord with the international or state or trade standards.④ The final determination of materials should meet the comprehensive requirements of standards, laws and regulations, as well as strategic targeting. CONCLUSION: Based on engineering, the fundamental principles of materials selection for joint prosthesis are illustrated from the following angles: clinical requirements for materials of replacement, attentions in joint prosthesis design, commonly used biomedicine materials performance, requirements of product registration and laws & regulations related to the materials, the strategy in the choice of material standard etc. As a result, a valuable system approach is provided for joint-prosthesis designers to select materials.

Objective To establish a rapid, sensitive and selective liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the determination of acyclovir (the metabolite of valacyclovir hydrochloride) in human plasma. Methods After addition of ganciclovir as internal standard (IS), plasma samples were prepared by one-step protein precipitation using acetonitrile as precipitant, followed by an isocratic elution with 0.1% formic acid 3.5μm) column. Detection was performed on a triple-quadrupole mass spectrometer utilizing electrospray ionization (ESI) interface operating in positive ion and selected reaction monitoring (SRM) mode with the precursor to product ion transitions m/z 226.2→152.1 for acyclovir and m/z 256.2→152.1 for the IS. Results The analytical results demonstrated a good linearity over the ranges from 0.005 to 4μg/mL (r=0.9999) for valacyclovir hydrochloride. The relative standard deviations (RSD) of intra-batch and inter-batch were less than 4.06% and 9.23%, respectively. The limit of detection and lower limit of quantification in human plasma were 2ng/mL and 5ng/mL, respectively. Conclusion The method was simple, sensitive, accurate and reproducible and has been successfully applied to a bioequivalence study of valacyclovir hydrochloride capsules in Chinese healthy male volunteers.

Objective:To study the effects of ~(125)I-(α_v)ASODN on the in vitro invasive ability of heptocellular carcino-ma cell line(HepG2) through PEI-RGD-mediated receptor process. Methods: Intergrin α_v-specific antisense oligonucle-otide was labeled with ~(125)I, and PEI-RGD/~(125)I-(α_v)ASODN complex was prepared by combining ~(125)I-(α_v)ASODN with polyethyleneimine derivative PEI-RGD. PEI-RGD/~(125)I-(α_v)ASODN complex was transferred into HepG2 cells through the receptor-mediated process. The effect of PEI-RGD/~(125)I-(α_v)ASODN complex on the invasive ability of HepG2 cells was examined by Boyden chamber invasive assay. Results: (1) The labeling yield and radiochemical purity of ~(125)I-(α_v) ASODN were(73.78±4.09)% and(96.68±1.38)%, respectively, and the labeled compound had a good stability in vitro after 48 h at 37℃; (2) The ability of HepG2 cells to uptake PEI-RGD/~(125)I-(α_v)ASODN reached its peek ([12.77±0.85] % ) when PEI-RGD/~(125)I-(α_v)ASODN was at 4 μl/2 μg ([12.77±0.85] %), and then gredually decreased thereafter. So the dosage of PEI-RGD/~(125)I-(α_v)ASODN for the following experiment was chosen as 2 μl/1 μg; (3) The invasive capacity of HepG2 cells was significantly reduced in PEI-RGD/~(125)I-(α_v)ASODN group compared with those in other experiment and control groups (P <0.01 ). Conclusion: ~(125)I-(α_v)ASODN mediated by PEI-RGD can effectively inhibit the invasive capacity of HepG2 cells.

Objective:To analyze the cases referred to a higher-level hospital from the Department of Neonatology in a primary hospital, and evaluate the efficiency of clinical works related to the referrals.Methods:Data of neonates admitted to the Department of Neonatology at Maternal and Child Health Hospital of Dabu County from January 2018 to December 2020 and referred to the superior hospital were retrospectively analyzed.Results:A total of 1 670 neonates were included and 128 neonates were referred.The median age of the neonates referred was 0.5 hours(0 hours, 25 days), the median gestational age was 38 + 3(29 + 1, 42 + 4) weeks, the median weight was 3 000(1 250, 4 800) g, and the transport distance was 78 km.Twenty-four cases were assessed as critical cases before the referral, 125 cases were improved and discharged after treatment in the superior hospital, and three cases died.The referral rate in 2018, 2019 and 2020 showed a downward trend year by year (10.3%, 7.6% and 4.0%, respectively), and the difference was statistically significant( χ2=14.362, P=0.001). The proportion of critical cases in referral cases increased year by year (9.4%, 23.9% and 38.9%, respectively), and the difference was statistically significant( χ2=9.289, P=0.010). The incidence of critical case was higher in those whose mothers didn′t have regular prenatal examination during pregnancy( χ2=5.129, P=0.032). Conclusion:The ability of neonatal treatment in primary hospitals has been improved.The neonates need to be referred and critical cases are not rare in primary hospitals.More attention should be paid to the safety and effectiveness of the regional transport network.Also, enhancing the health awareness of residents and improving the primary medical technics are important to maximize the life safety and optimal transition of newborns.