L-赖氨酸盐酸盐提纯洗脱过程优化控制讨论

讨论了以淀粉为原料采用生物发酵法制取L-赖氨酸盐酸盐产品生产中原料发酵液初步提纯过程洗脱步骤控制的几个优化控制点。初流分的终止点影响产品的收益;纯流分的控制点与产品的经济性相关;洗脱剂的消耗对控制产品的成本有重大的意义;洗脱后流分的控制点直接关系排放废水的处理费用。

Minimally invasive thalamic hematoma drainage can improve the six-month outcome of thalamic hemorrhage

Objective To explore predictors of the 6-month clinical outcome ofthalamic hemorrhage, and evaluate if minimally invasive thalamic hematoma drainage （THD） could improve its prognosis. Methods A total of 54 patients with spontaneous thalamic hemorrhage were evaluated retrospectively. Clinical data, including demographics, stroke risk factors, neuroimaging variables, Glasgow Coma Score （GCS） on admission, surgical strategy, and outcome, were collected. Clinical outcome was assessed using a modified Rankin Scale, six months after onset. Univariate analysis and multivariate logistic regression analysis were performed to determine predictors of a poor outcome. Results Conservative treatnaent was performed for five patients （9.3%）, external ventricular drainage （EVD） for 20 patients （37.0%）, THD for four patients （7.4%）, and EVD combined with THD for 25 patients （46.3%）. At six months after onset, 21 （38.9%） patients achieved a favorable outcome, while 33 （61.1%） had a poor outcome. In the univariate analysis, predictors of poor 6-month outcome were lower GCS on admis- sion （P = 0.001）, larger hematoma volume （P 〈 0.001）, midline shift （P = 0.035）, acute hydrocephalus （P = 0.039）, and no THD （P = 0.037）. The independent predictors of poor outcome, according to the multivariate logistic regression analysis, were no THD and larger hematoma volume. Conclusions Minimally invasive THD, which removes most of the hematoma within a few days, with limited damage to perihematomal brain tissue, improved the 6-month outcome of thalamic hemorrhage. Thus, THD can be widely applied to treat patients with thalamic hemorrhage.

The Relationship Between Hysteresis and Liquid Flow Distribution in Trickle Beds

Experiments were conducted on a trickle bed with 0.283m ID to elucidate the relationship between hysteretic phenomena and liquid distribution. The hysteresis of pressure drop and the variance of radial liquid distribution were observed simultaneously. Residence time distribution (RTD), holdup and mean residence time (RT) of liquid phase were also found to demonstrate hysteresis of the same nature. RTD, liquid holdup and mean RT calculated with a simple model from the distribution of liquid flow rate show characteristics consistant with the experimental data, suggesting that the hyteretic phenomena originate from the multiplicity and nonuniformity of liquid flow distribution.

Therapeutic approaches for portal biliopathy: A systematic review

Portal biliopathy(PB) is defined as the presence of biliary abnormalities in patients with non-cirrhotic/nonneoplastic extrahepatic portal vein obstruction(EHPVO) and portal cavernoma(PC). The pathogenesis of PB is due to ab extrinseco compression of bile ducts by PC and/or to ischemic damage secondary to an altered biliary vascularization in EHPVO and PC. Although asymptomatic biliary abnormalities can be frequently seen by magnetic resonance cholangiopancreatography in patients with PC(77%-100%), only a part of these(5%-38%) are symptomatic. Clinical presentation includes jaundice, cholangitis, cholecystitis, abdominal pain, and cholelithiasis. In this subset of patients is required a specific treatment. Different therapeutic approaches aimed to diminish portal hypertension and treat biliary strictures are available. In order to decompress PC, surgical porto-systemic shunt or transjugular intrahepatic porto-systemic shunt can be performed, and treatment on the biliary stenosis includes endoscopic(Endoscopic retrograde cholangiopancreatography with endoscopic sphincterotomy, balloon dilation, stone extraction, stent placement) and surgical(bilioenteric anastomosis, cholecystectomy) approaches. Definitive treatment of PB often requires multiple and combined interventions both on vascular and biliary system. Liver transplantation can be considered in patients with secondary biliary cirrhosis, recurrent cholangitis or unsuccessful control of portal hypertension.

Logistic Regression for Evolving Data Streams Classification

Logistic regression is a fast classifier and can achieve higher accuracy on small training data.Moreover,it can work on both discrete and continuous attributes with nonlinear patterns.Based on these properties of logistic regression,this paper proposed an algorithm,called evolutionary logistical regression classifier(ELRClass),to solve the classification of evolving data streams.This algorithm applies logistic regression repeatedly to a sliding window of samples in order to update the existing classifier,to keep this classifier if its performance is deteriorated by the reason of bursting noise,or to construct a new classifier if a major concept drift is detected.The intensive experimental results demonstrate the effectiveness of this algorithm.

Characteristics of Earthquake-Triggered Landslides and Post-Earthquake Debris Flows in Beichuan County

Field investigations and aerial photography after the earthquake of May 12, 2008 show a large number of geo-hazards in the zone of extreme earthquake effects. In particular, landslides and debris flows, the geo-hazards that most threaten post-disaster reconstruction, are widely distributed. We describe the characteristics of these geo-hazards in Beichuan County using high-resolution remote sensing of landslide distribution, and the relationships between the area and volume of landslides and the peak-discharges of debris flows both pre- and post-earthquake. The results show： 1） The concentration （defined as the number of landslide sources per unit area： Lc） of earthquake- triggered landslides is inversely correlated with distance from the earthquake （DF） fault. The relationship is described by the following equation： Lc = 3.2264exp（-0.0831DF） （R2 = 0.9246）; 2） 87 % of the earthquake-triggered landslides were less than 15× 10^4 m2 in area, and these accounted only for 5o% of the total area; 84% of the landslide volumes were less than 60×10^4 m3, and these accounted only for 50% of the total volume. The probability densities of the area and volume distributions are correlated： landslide abundance increases with landslide area and volume up to maximum values of 5 ×10^4m2 and 30 ×10^4 m3, respectively, and then decreases exponentially. 3） The area （AL） and volume （VL） of earthquake-triggered landslides are correlated as described with the following equation： VL=6.5138AL1.0227 （R2 = 0.9231）; 4）Characteristics of the debris flows changed after the earthquake because of the large amount of landslide material deposited in the gullies. Consequently, debris flow peak-discharge increased following the earthquake as described with the following equation： Vpost = 0.8421Vprel-0972 （R2 = 0.9821） （Vpre is the peak discharge ofpre-earthquake flows and the Vpost is the peak discharge of post-earthquake flows）. We obtained the distribution of the landslides based on the above analyses, as well as the magnitude of both the landslides and the post-earthquake debris flows. The results can be useful for guiding post-disaster reconstruction and recovery efforts, and for the future mitigation of these geo-hazards. However, the equations presented are not recommended for use in site-specific designs. Rather, we recommend their use for mapping regional seismic landslide hazards or for the preliminary, rapid screening of sites.

The Role of Mouse Wnt9a in MA891 Breast Cancer Cell Proliferation

Wnts are powerful regulators of cell proliferation and differentiation. Activation of Wnt signalling in many tissues has also been associated with cancer. RNAi is a process of posttranscriptional gene silencing, by which dsRNA induces sequence-specific degradation of homologous gene transcripts. In many eukaryotes, expression of nuclear-encoded mRNA can be strongly inhibited by the presence of a small double-stranded RNA corresponding to exon sequences in the mRNA. In this study the pAVU6＋27 vector, which has Sail and Xbal clone sites, was used to construct the siRNA expression vectors for mouse wnt9a. Four kinds of small interfering RNA inserts were designed, synthesized and visually tested for efficacy by in situ hybridization, the results demonstrated that dramatically reduced wnt9a signals were observed in the cells transfected with U6＋27 cassettes with anti-wnt9a hairpin siRNA inserts compared with the untransfected. The results of flow cytometry analysis showed that the cell proliferation was promoted after lowering expression of the mouse wnt9a in MA891 cells by RNAi. All that suggest the expression level of mouse wnt9a in breast cancer MA891 cells may play a role in adjusting the rate of proliferation.

Analysis of related factors affecting prognosis of shunt surgery in patients with secondary normal pressure hy- drocephalus

Objective： The management of se- condary normal pressure hydrocephalus （sNPH） is controversial. Many factors may affect the surgery effect. The purpose of this study was to identify the possible fac- tors influencing prognosis and provide theoretical basis for clinical treatment of sNPH. Methods： A retrospective study was carried out to investigate the results of 31 patients with sNPH who under- went ventriculoperitoneal shunt surgery from January 2007 to December 2011. We processed the potential influencing factors by univariate analysis and the result further by mul- tivariate logistic regression analysis. Results： Factors including age, disease duration and Glasgow coma scale （GCS） score before surgery significantly influenced the prognosis of sNPH （P〈0.05）. Further logistic regression analysis showed that all the three factors are independent influencing factors. Conclusion： Age, disease duration and GCS score before surgery have positive predictive value in estimating favorable response to surgical treatment for sNPH.

Analysis of the secondary instability of the incompressible flows over a swept wing

The crossflow instability of a three-dimensional (3-D) boundary layer is an important factor which affects the transition over a swept-wing.In this report,the primary instability of the incompressible flow over a swept wing is investigated by solving nonlinear parabolized stability equations (NPSE).The Floquet theory is applied to study the dependence of the secondary and high-frequency instabilities on curvature,Reynolds number and angle of swept (AOS).The computational results show that the curvature in the present case has no significant effect on the secondary instabilities.It is generally believed that the secondary instability growth rate increases with the magnitude of the nonlinear mode of crossflow vortex.But,at a certain state,when the Reynolds number is 3.2 million,we find that the secondary instability growth rate becomes smaller even when the magnitude of the nonlinear mode of the crossflow vortex is larger.The effect of the angle of swept at 35,45 and 55 degrees,respectively,is also studied in the framework of the secondary linear stability theory.Larger angles of swept tend to decrease the spanwise spacing of the crossflow vortices,which correspondingly helps the stimulation of 'z' mode.

Full-Annulus Simulation of the Surge Inception in a Transonic Centrifugal Compressor

Full annulus simulations of the flow which develops in a transonic centrifugal compressor are performed at two stable operating points （peak efficiency and near surge） and during the path to surge. At stable conditions, the flow field properties are analyzed by comparisons with experimental data and numerical simulations using a phase lagged approach previously carried out. Regarding the stage overall performance, an excellent agreement is obtained between the numerical results （both with time lagged approach and full-annulus calculation） and the ex- periments. From the full-annnlus simulations, the change in flow pattern from peak efficiency to surge is found to be perfectly similar to that obtained from the simulations using the time lagged approach. In particular, pro- vided that the operating point is stable, the flow proves to be chorochronic. The full-annulus simulations were continued after a unique small change in the throttle law applied at the exit of the numerical domain. The mass flow, pressure ratio and efficiency then significantly drop all the more the time progresses. The simulation becomes unstable and the surge inception well underway. The path to surge is found to be due to the enlargement of the boundary layer separation on the suction side of the diffuser vanes in accordance with the conclusions drawn from the chorochronic simulations and experiments. But as the time progresses, the flow loses its chorochronic character. Stall cells rotating at around 7% of the rotor speed develop and lead to surge in around 5 revolutions.