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Aimed at the existing problems revealed in a field test of 4UFD-1400 potato combine harvester, such as higher transmission speed, easy bruising on potato tuber epidermis, and blockade in potato conveying and grading bagging process, the transmission system, potato tuber conveying system, and stalk separating device of the machine were improved, and potato harvest experiments were conducted on parallel sowing dry land and double ridge sowing fully-mulching dry land. The results of field harvest contrast tests showed that the devices for soil separation, stalk separation, potato tuber conveying, grading and bagging of the improved machine work more stably and reliably compared to the original one. The improved machine exhibits good quality and adaptability to the potato harvest both in the parallel sowing dry land and double ridge sowing fully-mulching dry land, and also good ability for the separation of potato seedlings, weeds, and mulch films. It can work effectively in the conditions without clearing mulch films, potato seedlings, and weeds. The improved design of the potato vertical lifting device and additional design of a chain rod type horizontal conveying device for graded tubers effectively prevents potato tubers from stacking and being in the conveying process, and enhances the soil separation. The potato harvester enables a one-stop achievement of potato digging, soil-potato separating, stalks, weeds, and mulch films removing, potato conveying, grading, collecting, and bagging procedures. The tuber size grading can be adjusted according to the user's requirements. The potato harvesting operation requires only one tractor driver and two auxiliary workers, which effectively decreases the labor cost, simplifies the commodity potato processing links, and enhances the production efficiency. When the harvester is matched with a John Deal JDT654 type tractor with the rated power of 48 kW, its working productivity achieves 0.46 hm2/h. Meanwhile, the potato loss rate, injury rate, skin-broken rate, and impurity rate are less than 0.8%, 1.8%, 2.9%, and 1.2%, respectively. These four indicators decrease significantly compared with the original machine, which meet the requirements of the national agricultural industrial standard as NY/T 1130-2006 potato harvesting machinery. The whole structure is more compact, and beautiful, and the assembling unit mobility is better. It is suitable for harvesting the potatoes planted in the dry land and the film covering dry land with soft soil and no hardening. [ABSTRACT FROM AUTHOR]

Objective To investigate the effect of LY294002 on proliferation of cultured human glomerular mesangial cells, and to study on the mechanism underlying this proliferation. Methods Different concentrations of LY294002 (0.02, 0.2, 2, 20, 100 mg/L) were administrated to the cultured human glomerular mesangial cells. The effects of mesangial cell proliferation were measured using CCK-8 colorimetric assay. Under appropriate concentrations, proliferation of cultured mesangial cells were measured using CCK-8 at 0.5, 1, 24, 48 hours of drug administration time. Results LY294002 (0.02 mg/L) didn't obviously inhibited the growth of mesangial cells (P>0.05), the inhibition rate was 5.05%. The effect of LY294002 on the cells decreased with rising concentration (0.2 to 20 mg/L) in a dose-dependent manner (P<0.05). Mesangial cells would stop growing with the increasing concentration. LY294002 didn't obviously inhibited the growth of mesangial cells at 2 mg/L during 0 to 1 h (P>0.05), but inhibited proliferation gradually from 1 to 48 h (P < 0.05). Conclusion Within the certain range of concentration and time, the LY294002 inhibits the proliferation of human glomerular mesangial cells, and PI3K/Akt/mTOR signaling pathway may regulate the proliferation of human mesangial cell. [ABSTRACT FROM AUTHOR]

Objective To investigate the effects of 1,25-dihydroxyvitamin D3 [1,25 (OH)2D3] on PCNA expression and cell proliferation in human glomerular mesangial cells. Methods The cultured human mesangial cells, which was subcultured 3-8 generations, were randomly divided into four groups: normal control group (plus the DMEM medium containing 5% fetal bovine serum), proliferation in the control group (EGF group, plus 10μg/L of EGF), general intervention group [VD group, plus 10-8 mol/L of 1,25(OH)2D3], proliferation in the intervention group [EGF+VD group, plus 10 μg/L EGF and 10-8 mol/L 1,25v] for treatment of 48 h. The cell cycle was detected by flow cytometry, and the expression of PCNA was detected by Western blot assay in four groups. Results (1) Compared with normal control group, G1 phase cells were significantly reduced, S, G2/M phase cells were increased and PI index was higher in EGF group. And G1 phase cells were significantly increased, S and G2/M phase cells were significantly decreased, and PI index was lower in VD group. Compared with the EGF group, G1 phase cells were significantly increased in VD group and EGF + VD group, and S, G2/M phase cells decreased, PI index was lower. (2) Compared with normal control group, the expression of PCNA was higher in EGF group, and lower in VD group. Compared with EGF group, the expression of PCNA was lower in VD group and EGF+VD group. Conclusion 1,25 (OH) 2D3 inhibits the proliferation of human glomerular mesangial cells by arresting cell cycle and inhibiting the expression of PCNA protein. [ABSTRACT FROM AUTHOR]