BACKGROUND:The risk factors for patellofemoral pain syndrome are still unclear and research on risk factors is gradually becoming a hot topic in order to improve the therapeutic outcome of this disease. OBJECTIVE:To investigate the relationship between lower limb alignment and patellofemoral pain syndrome in young male runners. METHODS:In the same running population,21 patients with bilateral knee pain,29 patients with single knee pain and 20 normal runners were collected from January 2021 to July 2022.Full-length X-ray examination of both lower limbs in standing position was performed in all subjects.The lateral distal femoral angle,medial tibial proximal angle,joint line congruence angle,hip-knee-ankle angle,and knee physical valgus angle were measured and statistically analyzed. RESULTS AND CONCLUSION:There was no significant difference in the parameters between the left and right knees in each group(P>0.05).Compared with the normal group,no significant changes in lateral distal femoral angle,medial tibial proximal angle,joint line congruence angle,and hip-knee-ankle angle were observed in the single knee pain group and double knee pain group,while the knee physical valgus angle was significantly increased in these two groups(P<0.05).To conclude,increased knee physical valgus angle may be a risk factor for patellofemoral pain syndrome.

Chromochloris zofingiensis represents an industrially relevant and unique green alga, given its capability of synthesizing triacylglycerol (TAG) and astaxanthin simultaneously for storage in lipid droplets (LDs). To further decipher lipid metabolism, the nitrogen deprivation (ND)-induced LDs from C. zofingiensis were isolated, purified, and subjected to proteomic analysis. Intriguingly, many C. zofingiensis LD proteins had no orthologs present in LD proteome of the model alga Chlamydomonas reinhardtii. Seven novel LD proteins (i.e., two functionally unknown proteins, two caleosins, two lipases, and one l-gulonolactone oxidase) and the major LD protein (MLDP), which were all transcriptionally up-regulated by ND, were selected for further investigation. Heterologous expression in yeast demonstrated that all tested LD proteins were localized to LDs and all except the two functionally unknown proteins enabled yeast to produce more TAG. MLDP could restore the phenotype of mldp mutant strain and enhance TAG synthesis in wild-type strain of C. reinhardtii. Although MLDP and caleosins had a comparable abundance in LDs, they responded distinctly to ND at the transcriptional level. The two lipases, instead of functioning as TAG lipases, likely recycled polar lipids to support TAG synthesis. For the first time, we reported that l-gulonolactone oxidase was abundant in LDs and facilitated TAG accumulation. Moreover, we also proposed a novel working model for C. zofingiensis LDs. Taken together, our work unravels the unique characteristics of C. zofingiensis LDs and provides insights into algal LD biogenesis and TAG synthesis, which would facilitate genetic engineering of this alga for TAG improvement.