Search

The α + β-type Ti-4.5Al-6.9Cr-2.3Mn alloy has been theoretically designed on the basis of assessment of the Ti-Al-Cr-Mn thermodynamic system and the relationship between the molybdenum equivalent and mechanical properties of titanium alloys. The alloy is successfully prepared by the split water-cooled copper crucible, and its microstructures and mechanical properties at room temperature are investigated using the OM, SEM, and the universal testing machine. The results show that the Ti-4.5Al-6.9Cr-2.3Mn alloy is an α + β-type alloy which is consistent with the expectation, and its fracture strength, yield strength, and elongation reach 1191.3, 928.4 MPa, and 10.7 pct, respectively. Although there is no strong segregation of alloying elements under the condition of as-cast, the segregation of Cr and Mn is obvious at the grain boundary after thermomechanical treatment. [ABSTRACT FROM AUTHOR]

High-quality epi-MgO buffer layers under different O2/Ar pressure ratios are fabricated by rf magnetron sputtering on textured IBAD-MgO templates. Under the total deposition pressure remaining constant (14 Pa), the effect of changing the ratio of O2/Ar pressure from 1:4 to 3:2 on the microstructure and surface morphology of epi-MgO films is studied. The microstructure and morphology of epi-MgO are fully characterized by x-ray diffraction, atom force microscope and scanning electron microscope. The best texture quality of epi-MgO with an out-plane Δω value of 1.8° and an in-plane ΔΦ value of 5.22° are obtained under the ratio of O2/Ar pressure 3:2. Further, the surface morphology indicates that the surface of epi-MgO is smooth with rms surface roughness about 4.7 nm at O2/Ar pressure ratio 3:2. After that, GdBa2Cu3O7–δ (GBCO) layers are deposited on the CeO2 cap layer buffered epi-MgO/IBAD-MgO templates to assess the efficiency of such a buffer layer stack. The critical current density of GBCO films (thickness of 200 nm) is higher than 3 MA/cm2, indicating that epi-MgO/IBAD-MgO is promising for depositing superconducting layers with a higher critical current density. [ABSTRACT FROM AUTHOR]

In order to overcome the weakness of large ZigBee node, complex network and high cost in the harsh environment, a design of wireless sensor network node based on super low power consumption MCU MSP430 and RF chip CC2430 is proposed, and RF front-end CC2591 is used to improve the trans-mission power and receive sensitivity, thus extending the transmission distance. The test results show that the stability of the system is improved and network coverage is increased because of the MCU and the RF front-end [ABSTRACT FROM AUTHOR]

The motion of spiral waves in excitable media driven by a weak pacing around the spiral tip is investigated numerically as well as theoretically. We presented a Bifurcations diagram containing four types of the spiral motion induced by different frequencies of pacing: rigidly rotating, inward-petal meandering, resonant drift, and outward-petal meandering spiral. Simulation shows that the spiral resonantly drifts when the frequency of pacing is close to that of the spiral rotation. We also find that the speed and direction of the drift can be efficiently controlled by means of the strength and phase of the local pacing, which is consistent with analytical results based on the framework of the weak deformation approximation. [ABSTRACT FROM AUTHOR]

BACKGROUND. Extension of type A aortic dissection (TAAD) from the sinus of Valsalva (SV) into the coronary arteries is associated with a poor prognosis and requires direct coronary repair or coronary artery bypass grafting (CABG) depending on the extent of involvement. OBJECTIVE. The purpose of this study was to assess the diagnostic performance of ECG-gated aortic CTA with surgical findings as the reference for detection and classification of coronary artery involvement in patients with TAAD involving the SV. METHODS. This retrospective study included 112 patients who underwent preoperative ECG-gated aortic CTA that showed TAAD with SV involvement. Two radiologists independently reviewed CTA images for right coronary artery (RCA) and left coronary artery (LCA) involvement. Involvement was classified according to a previously described system as type A (coronary ostial dissection), B (dissection with coronary false channel), or C (complete detachment from aortic root with dissection encircling the coronary artery). The diagnostic performance of CTA was calculated with surgical findings as the reference; interreader agreement was assessed; and surgical interventions were summarized. RESULTS. At surgery, the RCA was uninvolved in 33 patients and had type A involvement in 45, type B involvement in 19, and type C involvement in 15 patients. The LCA was uninvolved in 70 patients and had type A involvement in 34 patients, type B involvement in eight patients, and type C involvement in no patient. For the two readers, sensitivity in making the diagnosis in the RCA was 86.7% and 91.1% for type A, 79.0% and 89.5% for type B, 86.7% and 93.3% for type C, and 97.5% and 98.7% for any involvement. Sensitivity for the LCA was 85.3% and 91.2% for type A, 87.5% and 100% for type B, and 100% for any involvement. Specificity for the RCA was 94.0% and 97.0% for type A, 95.7% and 96.7% for type B, 96.9% and 96.9% for type C, and 93.9% and 97.0% for any involvement. Specificity for the LCA was 96.2% and 98.7% for type A, 96.2% and 97.1% for type B, and 97.1% and 98.6% for any involvement. Interreader agreement for types of involvement ranged from a kappa value of 0.85 to 0.96. The most common interventions were aortic repair for SV involvement alone (55.7-63.6%), coronary artery repair for types A and B involvement (53.3-87.5%), and CABG for type C involvement (86.7%). CONCLUSION. ECG-gated CTA has high diagnostic performance in the detection and classification of coronary involvement in TAAD with SV involvement. CLINICAL IMPACT. CTA findings may help guide presurgical planning for patients with TAAD.

This study was aimed to quantitatively analyze the mRNA level of bcr-abl fusion gene in K562/A02 cell line by real-time quantitative reverse transcriptase polymerase chain reaction (RQ-RT-PCR) technique. After being cultured for a period of time, the K562/A02 cell line was collected and RNA was extracted using TRIzoL kit. The real-time quantitative reverse transcriptase polymerase chain reaction technology was used to detect the level of bcr-abl fusion gene and internal reference abl gene. The results showed that a fine reproducibility was obtained between 10(7) and 10(3) copies/ml, reproducible sensitivity of RQ-RT-PCR was 10(-5). The expression of bcr-abl fusion gene in K562/A02 cells was higher and the level of bcr-abl mRNA was more than 100% in K562/A02 cells. It is concluded that RQ-RT-PCR is a reliable, sensitive and reproducible method for detecting mRNA level of bcr-abl fusion gene, which may be useful in monitoring the chronic myeloid leukemia.

This study was purposed to investigate the effects of magnetic nanoparticle of Fe3O4 (Fe3O4-MNPs) on murine immune system. ICR mice were assigned randomly into four groups which were treated with normal saline, low, middle and high dose of MNP-Fe3O4 respectively. The mice were killed after being exposed by intragastric administration for 2 weeks. The ratios of spleen weight to body weight, lymphocyte transformation rate in spleen suspension and phagocytic index of macrophage in abdominal cavity were detected. The results showed that the ratios of spleen weight to body weight in Fe3O4-MNP groups were not significantly different in comparison with the control (p > 0.05). The lymphocyte transformation rate in spleen suspension in Fe3O4-MNP groups were all higher than that in control group (-0.1775 +/- 0.0246), especially in the middle dose group (0.1833 +/- 0.0593) (p < 0.05), and the phagocytic index of macrophages in abdominal cavity of middle dose group (0.2051 +/- 0.0213) was higher than that of control group and other two Fe3O4-MNP group (low dose 0.1538 +/- 0.0100, high dose 0.1511 +/- 0.0184) (p < 0.05). It is concluded that suitable dose of Fe3O4-MNP can enhance the cellular immune activity and phagocytic function of macrophages of mice.

The M-FISH includes multi-colour FISH and multiplex FISH, it represents one of the most significant developments in molecular cytogenetics of the past decade. This technique was originally designed to generate 24 colour karyotyping in human's 23 pair chromosome, now the technique has many variations and has been used in different fields. In leukaemia cytogenetics, the M-FISH now is used in detection for AL patients with following chromosome abnormality: (1) harbouring minimal chromosome translocation is respected; (2) chromosome translocation with complex abnormal karyotypes exists in patients with leukemia which are difficulty detected by using conventional method. The final results detected by M-FISH have guide significance for diagnosis, therapy and prognosis of AL patients. In this article the technical basis with commonly used probe for M-FISH, application of M-FISH in diagnosis, evaluation of therapeutic efficacy and prognostic analysis of AL patients are summarised.

The aim of this study is to study the effect of calcium dobesilate on streptozotocin (STZ)-induced early diabetic nephrophathy (DN) in rats. All male Wistar rats were randomly divided into six groups: normal group; DN blank group; calcium dobesilate 75, 150, and 300 mg x kg(-1) groups and perindopril 0.4 mg x kg(-1) group. Blood glucose and the 24 h urinary albumin were measured dynamically during the experiment, after 8 weeks administration, the level of glycosylated hemoglobin (HbA1c) was determined, the expressions of plasminogen activator inhibitor-1 (PAI-1) and matrix metalloprotein-9 (MMP-9) in cortex of kidney were examined with immunohistochemical staining. The endothelin (ET) in plasma and kidney cortex was measured with radioimmunoassay, renal pathomorphism was observed with light and electron microscopes. Calcium dobesilate could decrease the 24 h urinary albumin and ET in plasma and kidney cortex, down-regulate the expression of PAI-1, and up-regulate MMP-9 in kidney. These findings suggested that calcium dobesilate could protect blood vessel endothelium, inhibit kidney fibrous degeneration, ameliorate renal pathological damage, and protect kidney function in many ways.