The migration of total dissolved solids during natural freezing process in Ulansuhai Lake

High total dissolved solids （TDS） content is one of the most important pollution contributors in lakes in arid and semiarid areas. Ulansuhai Lake, located in Urad Qianqi, Inner Mongolia, China, was selected as the object of study. Temperatures and TDS contents of both ice and under-ice water were collected together with corresponding ice thickness. TDS profiles were drawn to show the distribution of TDS and to describe TDS migration. The results showed that about 80% （that is 3.602x108 kg） of TDS migrated from ice to water during the whole growth period of ice. Within ice layer, TDS migration only occurred during initial ice-on period, and then perished. The TDS in ice decreased with increasing ice thickness, following a negative exponential-like trend. Within un- der-ice water, the TDS migrated from ice-water interface to the entire water column under the effect of concentra- tion gradient until the water TDS content was uniform. In winter, 6.044x 107 kg （16.78% of total TDS） TDS migrated from water to sedirnent, which indicated that winter is the best time for dredging sediment. The migration effect gives rise to TDS concentration in under-ice water and sediment that is likely to affect ecosystem and water quality of the Yellow River. The trend of transfer flux of ice-water and water-sediment interfaces is similar to that of ice growth rate, which reveals that ice growth rate is one of the determinants of TDS migration. The process and mechanism of TDS migration can be referenced by research on other lakes with similar TDS content in cold and arid areas.

Clinical significance of S100A7 protein in predicting recurrence of breast cancer in patients undergoing breast-conserving surgery with radiotherapy

Objective To investigate the relationship between the expression of S100A7 protein and prediction of recurrence and prognosis of breast cancer in patients undergoing breast-conserving surgery combined with radiotherapy.Methods 349 samples of carcinoma tissue wax blocks were selected from January 2011 to January 2014 in Qingdao Central Hospital.All the patients had undergone breast-conserving surgery.We analyzed S100A7 expression in tumor tissue by immunohistochemical staining.Using univariate and multivariate analyses,we evaluated the relationship between S100A7 and clinical results,to explore independent risk factors for local regional recurrence(LRR).Results The positive expression of S100A7 in the recurrence group(66.7%)was significantly higher than in the non-recurrence group(38.4%),P=0.025.A log-rank test showed that high S100A7 expression was significantly correlated with 5-year regional recurrence free survival rate(RFS)(94.9%vs 89.5%,P=0.0408),distant metastasis free survival rate(DFS)(95.4%vs 83.5%,P<0.001),and overall survival rate(OS)(99.0%vs 92.5%,P=0.0011).Histological grade,vessel carcinoma embolus,lymph node metastasis,S100A7 expression,and tumor size were factors that influenced RFS.Multivariate analysis of the Cox proportional hazard model showed that high S100A7 expression was an independent risk factor that affected breast cancer RFS(HR=6.864,95%CI:1.575-29.915,P=0.01).Thus,we concluded that high S100A7 expression is associated with increased risk of LRR and distant metastasis of breast cancer after breast-conserving surgery and postoperative radiotherapy.S100A7 can be used as a molecular marker to screen for patients with high recurrence risk after breast-conserving surgery.

Multiobjective maintenance optimization of the continuously monitored deterioration system

With the development of the monitoring technology,it is more and more common that the system is continuously monitored.Therefore,the research on the maintenance optimization of the continuously monitored deterioration system is important.The deterioration process of the discussed system is described by a Gamma process.The predictive maintenance is considered to be imperfect and formulated.The expected interval of two continuous preventive maintenances is derived.Then,the maintenance optimization model of the continuously monitored deterioration system is presented.In the model,the minimization of the expected operational cost per unit time and the maximization of the system availability are the optimization objectives.The improved ideal point method with the normalized objective functions is employed to solve the proposed model.The validity and sensitivity of the proposed multiobjective maintenance optimization model are analyzed by a numerical example.

Up-regulation of calmodulin involved in the stress response to cyantraniliprole in the whitefly, Bemisia tabaci (Hemiptera: Aleyrodidae)

Cyantraniliprole is the first diamide insecticide to have cross-spectrum activity against a broad range of insect orders.The insecticide,like other diamides,selectively acts on ryanodine receptor,destroys Ca^(2+) homeostasis,and ultimately causes insect death.Although expression regulations of genes associated with calcium signaling pathways are known to be involved in the response to diamides,little is known regarding the function of calmodulin(CaM),a typical Ca^(2+)sensor central in regulating Ca^(2+) homeostasis,in the stress response of insects to the insecticide.In this study,we cloned and identified the full-length complementary DNA of CaM in the whitefly,Bemisia tabaci(Gennadius),named BtCaM.Quantitative real-time reverse transcription polymerase chain reaction-based analyses showed that the messenger RNA level of BtCaM was rapidly induced from l.5l-to 2.43-fold by cyantraniliprole during 24 h.Knockdown of BtCaM by RNA interference increased the toxicity of cyantraniliprole in whiteflies by 42.85%.In contrast,BtCaM expression in Sf9 cells significantly increased the cells,tolerance to cyantraniliprole as much as 2.91-fold.In addition,the expression of BtCaM in Sf9 cells suppressed the rapid increase of intracellular Ca^(2+) after exposure to cyantraniliprole,and the maximum amplitude in the Sf9-BtCaM cells was only 34.9%of that in control cells(Sf9-PIZ/V5).These results demonstrate that overexpression of BtCaM is involved in the stress response of B.tabaci to cyantraniliprole through regulation of Ca^(2+)concentration.As CaM is one of the most evolutionarily conserved Ca^(2+) sensors in insects,outcomes of this study may provide the first details of a universal insect response to diamide insecticides.

Antiviral function of peptidoglycan recognition protein in Spodoptera exigua(Lepidoptera:Noctuidae)

Peptidoglycan recognition proteins(PGRPs)are a class of molecules that play a critical role in insect immunity.Understanding the function of PGRPs is important to improve the efficiency of microbial insecticides.In this study,we investigated the role of PGRP-LB(a long type PGRP)in insect immunity against viruses using Spodoptera exigua and Spodoptera exigua multiple nucleopolyhedrovirus(SeMNPV)as an insect-virus model.We cloned and identified a PGRP-LB gene from S.exigua;the gene consisted of 7 exons that encoded a polypeptide of 234 amino acids with a signal peptide and a typical amidase domain.Expression analysis revealed that the abundance of SePGRP-LB transcripts in the fat body was greater than in other tissues.Overexpression of SePGRP-LB resulted in a significant decrease of 49%in the rate of SeMNPV-infected cells.In addition,the multiplication of SeMNPV was significantly decreased:a decrease of 79%in the production of occlusion-derived virion(ODV),and a maximum decrease of 50%in the production of budded virion(BV).In contrast,silencing of SePGRP-LB expression by RNA interference resulted in a significant 1.65-fold increase in the rate of SeMNPV-infected cells,a significant 0.54-fold increase in ODV production,a maximum 1.57-fold increase in BV production,and the larval survival dropped to 21%.Our findings show that SePGRP-LB has an antiviral function against SeMNPV,and therefore this gene may provide a target for lepidopteran pest control using virus insecticides.

Expression profile of CYP402C1 and its role in resistance to imidacloprid in the whitefly, Bemisia tabaci

Bemisia tabaci(Gennadius)(Hemiptera:Aleyrodidae)is a cosmopolitan insect pest causing serious damage to crop production.Cytochromes P450(CYPs)of B.tabaci are widely known to be involved in the metabolic resistance to a variety of insecticides,continuously increasing the difficulty in controlling this pest.In this study,four P450 genes(CYP6CMI,CYP6CXl,CYP6CX3,and CYP402CI)in B.tabaci exhibited correlations with the resistance to imidacloprid.We have focused on trying to understand the function and metabolism capacity of CYP402C1.The expression profiles of CYP402C1 were examined by reverse transcription quantitative real-time PCR and fluorescence in situ hybridizations.Its role in resistance to imidacloprid was investigated by RNA interference,transgenic Drosophila melanogaster,and heterologous expression.The results showed that CYP402CI was highly expressed in the active feeding stages of B.tabaci,such as nymphs and female adults.CYP402C1 was mainly expressed in midguts of nymphs and adults,especially in the filter chamber.Knockdown of CYP402CI significantly decreased the resistance of B.tabaci to imidacloprid by 3.96-fold(50%lethal concentration:186.46 versus 47.08 mg/L).Overexpression of CYP402CI in a transgenic D.melanogaster line(Gal4>UAS-CYP402CI)significantly increased the resistance to imidacloprid from 12.68-to 14.92-fold(129.01 and 151.80 mg/L versus 1925.14 mg/L).The heterologous expression of CYP402CI showed a metabolism ability of imidacloprid(imidacloprid decreased by 12.51%within 2 h).This study provides new insights for CYP402C1 function in B.tabaci and will help develop new strategies in B.tabaci control and its insecticide resistance.