High Performance ZrNbAl Alloy with Low Thermal Expansion Coefficient

Thermal expansion is a common phenomenon in both metals and alloys, which is important for metallic material applications in modern industry, especially in nuclear and aerospace industries. A lower thermal expansion coefficient may cause lower thermal stress and higher accuracy. A new Zr-based alloy is developed and presented.The XRD diffraction results demonstrate that only a close-packed hexagonal phase（α or α＇ phase） exists in the microstructure. The thermal expansion and mechanical properties are studied. According to the experimental results, the new Zr-based alloy presents a low thermal expansion coefficient and good mechanical properties.Also,its thermal expansion coefficient is stable through solution treatment.

Mixed extragonadal germ cell tumor arising from the prostate： a rare combination

Dear Editor, We report a rare case of a mixed germ cell tumor （GCT） that most likely arose from the prostate and included four components： an immature teratoma, a seminoma, an embryonal carcinoma and an endodermal sinus tumor （EST）.

Dependence of Soil Respiration on Soil Temperature and Soil Moisture in Successional Forests in Southern China

The spatial and temporal variations in soil respiration and its relationship with biophysical factors In forests near the Tropic of Cancer remain highly uncertain. To contribute towards an Improvement of actual estimates, soil respiration rates, soil temperature, and soil moisture were measured In three successional subtropical forests at the Dlnghuahan Nature Reserve （DNR） In southern China from March 2003 to February 2005. The overall objective of the present study was to analyze the temporal variations of soil respiration and Its biophysical dependence in these forests. The relationships between biophysical factors and soil respiration rates were compared In successional forests to test the hypothesis that these forests responded similarly to biophysical factors. The seasonality of soil respiration coincided with the seasonal climate pattern, with high respiration rates in the hot humid season （April-September） and with low rates In the cool dry season （October-March）. Soil respiration measured at these forests showed a clear Increasing trend with the progressive succession. Annual mean （± SD） soil respiration rate In the DNR forests was （9.0 ± 4.6） Mg CO2-C/hm^2 per year, ranging from （6.1 ± 3.2） Mg CO2-C/hm^2 per year in early successional forests to （10.7 ± 4.9） Mg CO2-C/hm^2 per year in advanced successional forests. Soil respiration was correlated with both soil temperature and moisture. The T/M model, where the two biophysical variables are driving factors, accounted for 74%-82% of soil respiration variation In DNR forests. Temperature sensitivity decreased along progressive succession stages, suggesting that advanced-successional forests have a good ability to adjust to temperature. In contrast, moisture Increased with progressive succession processes. This increase is caused, in part, by abundant respirators In advanced-successional forest, where more soil moisture is needed to maintain their activities.

Chromosome band 11q23 deletion predicts poor prognosis in bone marrow metastatic neuroblastoma patients without MYCN amplification

Background:Interphase fluorescence in situ hybridization(FISH)of bone marrow cells has been confirmed to be a direct and valid method to assess the v-myc avian myelocytomatosis viral oncogene neuroblastoma derived homolog(MYCN)amplification in patients with bone marrow metastatic neuroblastoma.MYCN amplification alone,however,is insufficient for pretreatment risk stratification.Chromosome band 11q23 deletion has recently been included in the risk stratification of neuroblastoma.In the present study,we aimed to evaluate the biological characteristics and prog-nostic impact of 11q23 deletion and MYCN amplification in patients with bone marrow metastatic neuroblastoma.Methods:We analyzed the MYCN and 11q23 statuses of 101 patients with bone marrow metastatic neuroblastoma using interphase FISH of bone marrow cells.We specifically compared the biological characteristics and prognostic impact of both aberrations.Results:MYCN amplification and 11q23 deletion were seen in 12(11.9%)and 40(39.6%)patients.The two mark-ers were mutually exclusive.MYCN amplification occurred mainly in patients with high lactate dehydrogenase(LDH)and high neuron-specific enolase(NSE)levels(both P<0.001),and MYCN-amplified patients had more events(tumor relapse,progression,or death)than MYCN-normal patients(P=0.004).11q23 deletion was associated only with age(P=0.001).Patients with MYCN amplification had poorer outcomes than those with normal MYCN(3-year event-free survival[EFS]rate:8.3±8.0%vs.43.8±8.5%,P<0.001;3-year overall survival[OS]rate:10.4±9.7%vs.63.5%±5.7%,P<0.001).11q23 deletion reflected a poor prognosis only for patients with normal MYCN(3-year EFS rate:34.3±9.5%vs.53.4±10.3%,P=0.037;3-year OS rate:42.9±10.4%vs.75.9±6.1%,P=0.048).Those with both MYCN amplification and 11q23 deletion had the worst outcome(P<0.001).Conclusions:Chromosome band 11q23 deletion predicts poor prognosis only in bone marrow metastatic neuroblastoma patients without MYCN amplification.Combined assessment of the two markers was much superior to single-marker assessment in recognizing the patients at a high risk of disease progression.

Fully integrated modeling of surface water and groundwater in coastal areas

This paper presents an improved model based on a three-dimensional non-hydrostatic wave model NHWAVE to simulate the interactions between the surface water and the groundwater affected by tides or waves in coastal areas. With the model, both the surface water flow and the groundwater flow are calculated based on the well-balanced Volume-averaged Reynolds-averaged Navier-Stokes equations. The spatially varying porosity and hydraulic conductivity are used to identifiy the domains for the surface water and the groundwater. The model is calibrated and validated using a wide range of laboratory measurements reported in the literature, involving the tide propagation through a sandy embankment, the tide-induced groundwater table fluctuation in a sandy beach, and the wave setup in a sloping sandy beach. The interactions between the surface water and the groundwater are analyzed and the influencing factors on the groundwater flow are discussed. The phase lag between the surface water elevation and the groundwater table fluctuation is mainly influenced by the hydraulic conductivity of the porous media. The wave attenuation in the groundwater is proportional to its propagation distance. The computed wave setup elevationin the permeable beach is smaller than in the impermeable beach. It is shown that the fully integrated model is capable of simulating the interactions between the surface water and the groundwater affected by tides or waves in coastal areas. It can be an efficient tool to study the tide and wave dynamics in the permeable sandy beach.