Nitrogen source is one of the important factors that affect the microalgae growth and lipid accumulation. We studied the effects of various nitrogen sources (i.e. NaNO3, CO(NH2)2, NH4Cl and CH3COONH4) and amount on the growth density, lipid yield, and eicosapentaenoic acid (EPA) content of Nannochloropsis oculata by single factor experimental method. The results show that N. oculata preferred NH4+ as nitrogen source rather than NO3- and CO(NH2)2. NH4+ could promote the growth and lipid accumulation of N. oculata. With the increase of nitrogen concentration, the biomass and the content of polyunsaturated fatty acid (PUFA) increased, but the content of lipid decreased. CH3COONH4 was the most suitable for growth, accumulation of lipid and EPA of N. oculata among the four investigated nitrogen sources. The optimal concentration was 5.29 mmol/L.
Eicosapentaenoic Acid ; metabolism ; Lipids ; biosynthesis ; isolation & purification ; Microalgae ; growth & development ; metabolism ; Nitrogen ; analysis ; metabolism ; Stramenopiles ; growth & development ; metabolism

Objective: To explore the correlation between menopausal hormone therapy（MHT）and breast lesions in perimenopausal women,and to provide evidence for safe use of MHT. Methods: The 40-60 year-old women who visited Hangzhou Women's Hospital and met the diagnostic criteria for perimenopausal syndrome were recruited. The intervention group received MHT and was divided into three subgroups according to the MHT regimen：estrogen-progesterone cycle therapy（A）,estrogen-progesterone continuous therapy（B）,estrogen therapy（C）. The control group did not receive MHT. All the patients received regular mammography to quantify and evaluate breast lesions. The generalized estimating equation was used to analyze the changes of breast lesions between different groups. Results: There were 80 cases in the intervention group,with 49 in group A,26 in group B,5 in group C,and 80 cases in the control group. After two years of follow-up,there was no statistically significant differences of time,group and interaction in breast density,volume of breast fibrous tissue and the volume of breast between three intervention groups and the control group（P>0.05）; there was no statistically significant differences of group and interaction in positive rate of calcification and breast mass between the intervention group and the control group（P>0.05）. Conclusion Receiving MHT intervention for two years did not increase the risk of breast lesions.

Objective To compare the differences in lower limb joint kinematics and muscle activation between Asian squat (AS) and Western squat (WS). Methods Eleven healthy adults were recruited to complete the biomechanical test of AS and WS. The 3D motion analysis system, force plates and surface electromyography (EMG) were used to collect kinematics, kinetics and muscle activation data of the subjects during two squats, and muscle force of the lower limb was also calculated by OpenSim. Results AS showed pelvis forward flexion, while WS showed pelvis backward extension at the time of peak knee flexion angle. Compared with the AS, a significant smaller hip flexion, larger knee flexion, larger hip abduction and hip rotation angles were found in WS at the time of peak knee flexion angle. Compared with AS, a significant greater peak force of soleus was found in WS during descent and ascent phases of squat. Additionally, a smaller peak force of anterior tibia was found in WS than that in AS during descent and ascent phases of the squat. No significant differences were found in other muscle peak force and the time of peak force between AS and WS. Conclusions The combined tibialis anterior activation and proximal joint flexion might be beneficial to stabilization during AS. The soleus muscle activation was significant in WS with heel lifting. The muscle activation pattern of proximal joint was similar between AS and WS. This study provides theoretical guidance for the design of clinical squat rehabilitation programs or the selection of squat training.

AIM: To study the inhibitory and scavenging effects of ambroxol combined with levofloxacin on the bacterial biofilm of Klebsiella pneumoniae, and to provide a new strategy to treat and antagonize the formation of the biofilm. METHODS: We collected Klebsiella pneumoniae of different resistance and divided them into sensitive group (wild bacteria group), ESBLs group and CRKP group with 15 strains in each group and performed biological semi-quantitative detection of its biofilm by crystalline violet staining method. After selecting 3 strains with similar membrane yields from each group, we determined the minimum inhibitory concentration (MIC) of ambroxol and levofloxacin against Klebsiella pneumoniae by micro broth dilution method.In addition, we determined the effects of ambroxol in different concentrations on the MIC of levfloxacin by the micrdilution checkerboard techniques and calculated the partial inhibitory concentration index (FIC) to determine the joint effect and select the best synergistic concentration. Finally, the effects of ambroxol and levofloxacin in different concentrations on the inhibition formation test and removal test of Klebsiella pneumoniae biofilm were observed by crystal violet method combined with confocal laser scanning microscopy. RESULTS: We found that all three groups of bacterial biofilms became mature on the 5th day, and the sensitive group was easier to form and produce biofilm more than the ESBLs and CRKP groups (F=3.725, P=0.032). It was showed that the geometric average of levofloxacin MIC value in the three groups decreased significantly. And the selected strains all showed a synergistic effect on the two-drug combination.In the biofilm test, as the concentration of ambroxol increased, its inhibition rate reached more than 75%, but its biofilm removal rate did not reach 70%. CONCLUSION: Our study support that ambroxol combined with levofloxacin can inhibit the bacterial biofilm of Klebsiella pneumoniae early, and its optimal synergistic concentration is 0.49 mg/mL (ambroxol) + 4 μg/mL (levofloxacin).