Experimental and simulation studies on similitude design method for shock responses of beam-plate coupled structure

The similitude theory helps to understand the physical behaviors of large structures through scaled models. Several papers have studied the similitude of shock issues. However, the dynamic similitude for shock responses of coupled structures is rarely incorporated in open studies. In this paper, scaling laws are derived for the shock responses and spectra of coupled structures. In the presented scaling laws, the geometric distortion and energy loss are considered. The ability of the proposed scaling laws is demonstrated in the simulation and experimental cases. In both cases, the similitude prediction for the prototype's time-domain waveform and spectrum is conducted with the scaled model and scaling laws. The simulation and experimental cases indicate that the predicted shock responses and spectra agree well with those of the prototype, which verifies the proposed scaling laws for predicting shock responses.

Association of -238G/A polymorphism of tumor necrosis factor-alpha gene promoter region with outcomes of hepatitis B virus infection in Chinese Han population

AIM: To clarify whether -238G/A polymorphism of tumor necrosis factor-a (TNF-a) gene promoter region was associated with outcomes of hepatitis B virus (HBV) infection in Han population of northern China, and to analyze the geneenvironment interaction between -238G/A polymorphism and cigarette smoking or alcohol consumption. METHODS: A case-control study was conducted to analyze the association of TNF-a gene promoter polymorphism with HBV infection outcomes. A total of 207 patients with chronic hepatitis B (HB) and 148 cases of self-limited HBV infection from Ditan Hospital and Shunyi District Hospital in Beijing, respectively were recruited. History of smoking and alcohol drinking was inquired by a questionnaire. The -238G/A polymorphism of TNF-a gene promoter was genotyped by polymerase chain reaction-restricted fragment length polymorphism (PCR-RFLP). RESULTS: The frequencies of GG and GA genotypes were 98.07% and 1.93% in chronic HB patients and 93.24% and 6.76% in self-limited HBV infection individuals, respectively (X^2=5.30, P=-0.02). The frequency of G allele was significantly higher in patients with chronic HB that in individuals with self-limited HBV infection (99.03% vs 96.62%, X^2=5.20, P=0.02). Only modestly increased risk of onset of chronic HB was found in smokers (OR=1.40, 95% CI： 0.87-2.28, P=0.14) and drinkers (OR=-1.26, 95%CI： 0.78-2.05, P=-0.32). There was a positive interaction between genotype GG and cigarette smoking with an interaction index (Ⅱ) of 2.95, or alcohol consumption with an Ⅱ of 1.64. CONCLUSION: The -238G/A polymorphism of TNF-a gene promoter region is independently associated with different outcomes of HBV infection.

Pancreatic cancer mortality in China(1991-2000)

AIM: To describe the mortality rate of pancreatic cancer and its distribution in China during the period of 1991-2000.METHODS: Based on the data of demography and death collected through China′s Disease Surveillance Point System (DSPS) over the period of 1991-2000, the distribution of death rate of pancreatic cancer was described in terms of age group, gender, calendar year, rural/urban residence and administrative district.RESULTS: A total of 1 619 death cases attributed to pancreatic cancer (975 men and 644 women) were reported by DSPS during 1991-2000. The reported, adjusted and agestandardized mortality rates increased from 1.46, 1.75, and 2.18 per 100 000 populations in 1991 to 2.38, 3.06, and 3.26per 100 000 populations in 2000. The majority (69.62 %) of the deaths of pancreatic cancer were seen in the age group of 60 years and older. The mortality rate was higher in men than in women, but the male to female death rate ratios decreased during the 10 years. Our data also showed that the death rate of pancreatic cancer in urban areas was about 2-4 fold higher than that in rural areas, and in Northeast and East China, the death rates were higher than those in the other 5 administrative districts.CONCLUSION: The death rate due to pancreatic cancer was rising during the period of 1991-2000 and the peak mortality of pancreatic cancer might arrive in China.

Expression of e-cadherin and β-catenin in human esophageal squamous cell carcinoma: relationships with prognosis

AIM: To elucidate the expression of E-cadherin and β-catenincorrelating with its clinical outcome in patients withesophageal squamous cell carcinoma (ESCC), by analyzingtheir interrelationship with clinicopathological variables andtheir effects on progress and prognosis.METHODS: Expression of E-cadherin and β-catenin wasdetermined by SP immunohistochemical technique inpatients with ESCC consecutively, their correlation withclinical characteristics was evaluated and analyzed bymultivariate analysis.RESULTS: The rate of expression of E-cadherin decreasedto 66.03 % (70/106) in ESCC and the protein level wasnegative correlated with histologic grade, tumor size, clinicalstaging, lymph node metastasis and venous invasion.Whereas the expression rate of β-catenin was reduced to69.8 % (74/106) and the level of protein expressioncorrelated only with histologic grade. There obviously existedinverse correlation between level of E-cadherin protein andsurvival, especially in .stage I, IIa, IIb (P=0.0033), Patientswith low-expressing tumors for β-catenin and non-expressingtumors for E-cadherin/β-catenin had lower survival periodthan those with normal-expressing ones (P=0.0501 andP=0.0080, respectively). Patients with diminished expressionof E-cadherin as grade Ⅱ or Ⅲ had shorter survival periodthan those with normally expressing and grade Ⅰ, nosignificance existed between grade I and grade Ⅱ or Ⅲwith respect to different status of E-cadherin expression.Furthermore, Correlation analysis showed level of E-cadherincorrelated with that of β-catenin (P=0.005). Cox proportionalhazards model analysis suggested downregulation of E-cadherin was an important factor indicating poor prognosis.CONCLUSION: As a probable independent prognosticfactor, it correlates with overall and disease free survivalperiod, expression of E-cadherin but not β-catenin maypredict prognosis in patients with ESCC.

Involvement of regulatory volume decrease in the migration of nasopharyn-geal carcinoma cells

The transwell chamber migration assay and CCD digital camera imaging techniques were used to investigate the relationship between regulatory volume decrease (RVD) and cell migration in nasopharyngeal carcinoma cells (CNE-2Z cells). Both migrated and non-migrated CNE-2Z cells, when swollen by 47% hypotonic solution, exhibited RVD which was inhibited by extracellular application of chloride channel blockers adenosine 5’-triphosphate (ATP), 5-nitro-2-(3- phenylpropylamino) benzoic acid (NPPB) and tamoxifen. However, RVD rate in migrated CNE-2Z cells was bigger than that of non-migrated cells and the sensitivity of migrated cells to NPPB and tamoxifen was higher than that of non- migrated cells. ATP, NPPB and tamoxifen also inhibited migration of CNE-2Z cells. The inhibition of migration was positively correlated to the blockage of RVD, with a correlation coefficient (r) = 0.99, suggesting a functional relation- ship between RVD and cell migration. We conclude that RVD is involved in cell migration and RVD may play an important role in migratory process in CNE-2Z cells.

Evaluation of diffusion in gel entrapment cell culture within hollow fibers

AIM: To investigate diffusion in mammalian cell culture by gel entrapment within hollow fibers. METHODS: Freshly isolated rat hepatocytes or human oral epidermoid carcinoma (KB) cells were entrapped in type I collagen solutions and statically cultured inside microporous and ultrafiltration hollow fibers. During the culture time collagen gel contraction, cell viability and specific function were assessed. Effective diffusion coefficients of glucose in cell-matrix gels were determined by lag time analysis in a diffusion cell. RESULTS: Significant gel contractions occurred in the collagen gels by entrapment of either viable hepatocytes or KB cells. And the gel contraction caused a significant reduction on effective diffusion coefficient of glucose. The cell viability assay of both hepatocytes and KB cells statically cultured in hollow fibers by collagen entrapment further confirmed the existence of the inhibited mass transfer by diffusion. Urea was secreted about 50% more by hepatocytes entrapped in hollow fibers with pore size of 0.1 μm than that in hollow fibers with MWCO of 100 ku. CONCLUSION: Cell-matrix gel and membrane pore size are the two factors relevant to the limited mass transfer by diffusion in such gel entrapment of mammalian cell culture.

Polymorphisms of Exon 17 of Insulin-Receptor Gene in Pathogenesis of Human Disorders With Insulin Resistance

Objective To investigate the relationship between polymorphisms of insulin-receptor (INSR) gene and insulin resistance in a population-based study in China. Methods Polymerase Chain Reaction (PCR) was used to the amplify Exon 17 of INSR gene and all amplified products were analyzed by direct sequencing. Results Six single-nucleotide polymorphisms (SNPs) were found at the following loci: T to TC at the locus of 10699 (Tyr984), G to GC at the locus of 10731 (Glu994), Deletion G at the locus of 10798 (Asp1017), C to T/TC at the locus of 10923 (His1058), C to CA at the locus of 10954 (Leu1069), and T to TA at the locus of 10961 (Phe1071), which might not change the amino acid sequence. The data were in agreement with the test of Hardy-Weinberg balance (P>0.05). Among the 345 cases, all clinical indices were higher in males than in females except for HDL cholesterol (P<0.05). The proportion of insulin resistance in males (64.4%) was higher than that in females (35.6%, OR=1.83). It implied that the relative risk of developing insulin resistance in males was 1.83 times as high as that in females. The biochemical indices in different loci on Exon 17 showed that the individuals with deletion G on the locus of 10798 had lower TG (P=0.052) and higher HDL (P=0.027) than those without deletion G on the same site. Homa-Index was lower in those with deletion G than in those without deletion G (P>0.05). After sex stratification in analysis, all allele frequencies on the six loci of SNPs of Exon 17 had different distributions between the insulin resistant group and the control group, but P>0.05. Conclusion SNPs of Exon 17 of INSR gene are unlikely to play a direct role in the pathogenesis of human disorders with insulin resistance.

Unusually Broadened Spectral Profiles Observed in Solar Prominences

After surveying the spectra of 39 prominences observed by the Multi-channel Infrared Solar Spectrograph at Purple Mountain Observatory and the 25 cm coronagraph at the Norikura Solar Observatory, we found that about 28% of them show small spatial scale (6''–8'') and short time scale (tens of seconds to a few minutes), unusual large broadening and large shift velocities in spectral lines including Hα, Hβ, H, Ca II H, Ca II K, Ca II 8542?, He I D3 and He I 10830?. We present in detail two typical events observed respectively on 2002 May 27 and 1981 August 2. The full-width at half maximum of the widest profile of the 2001 prominence is 1.8? for Hα and 2.9 ? for He I 10830?, while that of the 1981 prominence is 5.3 ? for Hβ, 3.6 ? for Ca II K, 4.0 ? for Ca II H and 2.8 ? for He I D3. Such broadenings generally occur at a level of several-thousand kilometres above the chromosphere. Further, most of these prominences manifest a rotation of (0.4–1.35)×10-2 rads s?1 pointing to the Sun and large line-of-sight velocities of 20–200 km s?1. Some of these events correspond in time to an enhancement or a small peak in the GOES X-ray flux, indicating the existence of high energy process at work. These prominences generally display discernible changes in the Hα morphology around the time of large broadening, but do not show Hα brightening or overall eruption except for a few small surge-like events, hence, they are hardly observed in daily Hα patrols. According to the characteristics of their Hα structures and spectral properties, we infer these events are small-scale eruptions similar to nano-flares, which may contribute to the mass and energy transported into the corona. Large turbulent velocities of 25–120 km s?1 are responsible for the observed broadenings.

Analysis of the Aconitine Alkaloids in Chuanwu by Electrospray Ionization/Tandem Mass Spectrometry

An electrospray ionization / tandem mass spectrometric (ESI/MS/MS) method was developed for the simultaneous identification and analysis of three aconitine alkaloids [ mesacontine (MA), hypaconitine (HA), and aconitine (A)] as intact molecules at low nanogram level in Chinese traditional medicine Chuanwu decoction as well as in human whole blood extract without chromatographic separation.

INFLUENCE OF NON-PROCESS ELEMENTS ON REED PULP'S CHARACTERS DURING OXYGEN DELIGNIFICATION

A series of Reed Pulps were prepared in which the level of Non-Process Elements(NPEs), including calcium, manganese,copper,iron were seclectively enriched and depleted, these pulps were then oxygen delignification,and the pulps were characterized according to kappa number,viscosity,brightness. The results indicated that the enrichment of NPEs have an important effulence on delignification,pulp viscosity and brightness, iron is the most harmful during oxygen delignification but manganese is just like a kind of aid and can enhance brightness and delignification.

SOURCE, FORMATION,POLLUTION AND ITS COUNTERMEASURE OF DIOXIN IN PAPERMAKING INDUSTRY

Dioxins are believed the most poisonous compounds in the world. Dioxin pollution is a strategic problem in papermaking industry which must be solved. Dioxin not only exists in pulp, paper products, but also in the volatile of woods, hips or other non-wood fiber material which are treated with PCP, even in the exhaust gas of chemical recovery system. So there are great needs to know what is dioxin, the channel and mechanism of the formation of it in paper making industry. With these understanding, herein those are discussed as follows, the harness measure of dioxin: dioxin in wastewater, in exhaust gas, from raw material. And some countermeasure to decrease the content of dioxin. Furthermore, several novel treatment technologies of dioxin in China and abroad were introduced. The fundamental measure to eliminate the pollution of dioxin is presented with the aim to control the origin, decrease the use of bleacher containing chlorine or without the use of chlorine. Elemental Chlorine Free and Total Chlorine Free bleaching are advocated.

An Efficient Algorithm for the Optimal Market Timing over Two Stocks

In this paper, the optimal trading strategy in timing the market by switching between two stocks is given. In order to deal with a large sample size with a fast turnaround computation time, we propose a class of recursive algorithm. A simulation is given to verify the effectiveness of our method.