Fabrication of ethyl cellulose microspheres: Chitosan solution as a stabilizer

Tian Fu Yang,Xiao Wei Li 한국화학공학회 2008 Korean Journal of Chemical Engineering Vol.25 No.5

Ethyl cellulose was dissolved in ternary mixture, which consisted of 10 ml dichloroethane, 20 ml methanol and 10 ml acetone. Then, the ethyl cellulose microspheres were shaped in 1-6% chitosan solution and at 40 oC, 70 oC and 100 oC, respectively. The characteristics of these ethyl cellulose microspheres were also investigated based on the characterization of XRD, SEM, IR and DSC. The results showed that the most suitable conditions for ethyl cellulose microsphere preparation were in 6% chitosan solution and at 70 oC, in which the ethyl cellulose microsphere prepared were small and uniform. Moreover, from the XRD, IR and DSC data, the crystallization of ethyl cellulose microspheres decreased with the increase of the temperature; on the other hand, there some interactions happened between ethyl cellulose and chitosan, which shows a strong evidence for the intermolecular interactions and good molecular compatibility between ethyl cellulose and chitosan.

Late Ordovician provenance and depositional setting in the southwestern Ordos Block, China: constraints from zircon U-Pb geochronology

Fu Yang,Gang Chen,Yu Kang,Dongmin Ma,Qilin Chen,Tian Tao,Fu Deliang 한국지질과학협의회 2020 Geosciences Journal Vol.24 No.2

The U-Pb ages of single zircon grains contained in the sandstone samples were analyzed by the LA-ICP-MS method, the sediment provenances and geological significance were discussed. The LA-ICP-MS zircon U-Pb dating from the sandstones, tuffaceous sandstones and volcanic tuffs of the Pingliang and Zhaolaoyu Formations along the southwestern Ordos Block are used to limit the maximum depositional age and material sources. The results show that: (1) The youngest ages of zircon dating in the three samples are 445 Ma, 444 Ma and 443 Ma, respectively, suggesting that the studied Formations were deposited in the Late Ordovician. (2) The detrital zircon U-Pb age analysis of the sandstones sample from the Pinliang Formation clustered in the 445–477 Ma, 588–1548 Ma and 1612–2496 Ma with the corresponding youngest peak age of 454.5 ± 3.3 Ma. (3) The distribution of zircon U-Pb age in sandstone samples showing that the sedimentary rocks detritus was mainly sourced from the North Qinling-Qilian terranes and the NCC, and has double provenance supply in the north and south. The material source of the tuffaceous sandstones and volcanic tuffs mainly comes from the volcanic and magmatic activity related to the North Qilian-North Qinling Island Arcs.

Association Between MDM2 SNP309 T>G and Risk of Gastric Cancer: A Meta-analysis

Tian, Xin,Tian, Ye,Ma, Ping,Sui, Cheng-Guang,Meng, Fan-Dong,Li, Yan,Fu, Li-Ye,Jiang, Tao,Wang, Yang,Ji, Fu-Jian,Fang, Xue-Dong,Jiang, You-Hong Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.3

Background: As a negative regulator of P53, MDM2 plays an important role in carcinogenesis; a polymorphism in its promoter region. SNP309 T>G, is known to increase the expression of MDM2, thus being considered related to higher susceptibility to neoplasia. However, no agreement has been achieved regarding its effects on gastric cancer. Methods: The present systematic meta-analysis was performed based on comprehensive literature search from Pubmed, Web of science and CBM databases. Results: It was suggested from 6 independent studies that the GG genotype is associated with a significantly increased risk of gastric cancer (Recessive: OR = 1.43, 95% CI = 1.08-1.91, P = 0.013), and subgroup analysis also confirmed the relationship (English publications-recessive model: OR = 1.45, 95% CI = 1.10-1.91, P = 0.009; Studies in China-recessive model: OR = 1.58, 95% CI = 1.08-2.30, P = 0.017). No publication bias was detected. Conclusion: The meta-analysis indicated a significant inverse association between GG genotype carriage and elevated risk of gastric cancer. However, more studies and detailed information are needed to fully address the topic.

Rock-breaking analysis model of new drill bit with tornado-like bottomhole model

Jia-lin Tian,Chang-fu Yuan,Lin Yang,Chuan-hong Fu,Gang Liu,Zhi Yang,Chun-ming Wu 대한기계학회 2015 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.29 No.4

For improving the rock-breaking efficiency of oil and gas drill bits, a new drill bit is presented with tornado-like bottomhole model(named swirling cutting bit). The new drill bit cutter breaks rock with shocking and cutting effect during the drilling process, and theelements on largest ring cross the borehole center with high speed. It can effectively improve the center rock-breaking efficiency. Meanwhile,for all cutters on different rings breaking rock at the same time, it can optimize the rock-breaking volume of each element andimprove the bit service life. To analyze the interaction features between cutters and rock, the position equations are established by thecylindrical coordinates and complex movement principles, and then the velocity and acceleration equations can be obtained. Based on thenumerical example results, this paper analyzes the bottomhole model, the contact section, and the distribution features of velocities andaccelerations on different rings. By analyzing the acceleration results, we can study the failure mechanism of cutters. At the same time,lab experiments test the bottomhole model and rock-breaking features, and it verifies the accuracy of calculation method and equations. Moreover, the analysis method and models are also applicable to other types of bits or composite bits, and the inputting parameters needcorresponding adjustment for different type of bits.

Decentralized Mobile Sensor Navigation for Hole Healing Policy in Wireless Hybrid Sensor Networks

Fu-Tian Lin,Chu-Sing Yang,Tien-Wen Sung,Bi-jar Lin 보안공학연구지원센터 2013 International Journal of Future Generation Communi Vol.6 No.6

Alterations of Amino Acid Level in Depressed Rat Brain

Yang, Pei,Li, Xuechun,Ni, Jian,Tian, Jingchen,Jing, Fu,Qu, Changhai,Lin, Longfei,Zhang, Hui The Korean Society of Pharmacology 2014 The Korean Journal of Physiology & Pharmacology Vol.18 No.5

Amino-acid neurotransmitter system dysfunction plays a major role in the pathophysiology of depression. Several studies have demonstrated the potential of amino acids as a source of neuro-specific biomarkers could be used in future diagnosis of depression. Only partial amino acids such as glycine and asparagine were determined from certain parts of rats' brain included hippocampi and cerebral cortex in previous studies. However, according to systematic biology, amino acids in different area of brain are interacted and interrelated. Hence, the determination of 34 amino acids through entire rats' brain was conducted in this study in order to demonstrate more possibilities for biomarkers of depression by discovering other potential amino acids in more areas of rats' brain. As a result, 4 amino acids (L-aspartic acid, L-glutamine, taurine and ${\gamma}$-amino-n-butyric acid) among 34 were typically identified as potentially primary biomarkers of depression by data statistics. Meanwhile, an antidepressant called Fluoxetine was employed to verify other potential amino acids which were not identified by data statistics. Eventually, we found L-${\alpha}$-amino-adipic acid could also become a new potentially secondary biomarker of depression after drug validation. In conclusion, we suggested that L-aspartic acid, L-glutamine, taurine, ${\gamma}$-amino-n-butyric acid and L-${\alpha}$-amino-adipic acid might become potential biomarkers for future diagnosis of depression and development of antidepressant.

Is Hepatectomy for Huge Hepatocellular Carcinoma (≥10cm in Diameter) Safe and Effective? A Single-center Experience

Yang, Jian,Li, Chuan,Wen, Tian-Fu,Yan, Lu-Nan,Li, Bo,Wang, Wen-Tao,Yang, Jia-Yin,Xu, Ming-Qing Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.17

Background: This retrospective study aimed to validate the safety and effectiveness of hepatectomy for huge hepatocellular carcinoma (HCC). Materials and Methods: Data of patients who underwent hepatectomy for HCC between January 2006 and December 2012 were reviewed. The patients were divided into three groups: huge HCC(${\geq}10cm$ in diameter), large HCC(${\geq}5$ but<10 cm in diameter) and small HCC(<5cm in diameter). Results: Characteristics of pre-operative patients in all three groups were homogeneously distributed except for alpha fetal protein (AFP)(p<0.001).The 30, 60, 90-day post-operative mortality rates were not different among the three groups (p=0.785, p=0.560, and p=0.549). Laboratory data at 1, 3, and 7 days after surgery also did not vary. The 5-year overall survival (OS) and 5-year disease-free survival (DFS) rates in the huge and large HCC groups were lower than that of the small HCC group (OS: 32.5% vs 36.3% vs 71.2%, p=0.000; DFS: 20.0% vs 24.8% vs 40.7%, p=0.039), but there was no difference between the huge and large HCC groups (OS: 32.5% vs 36.3%, p=0.667; DFS: 20.0% vs 24.8%, p=0.540). In multivariate analysis, five independent poor prognostic factors that affected OS were significantly associated with worse survival (p<0.05), namely, AFP level, macrovascular invasion, Edmondsone Steiner grade, surgical margin and Ishak score. AFP level, macrovascular invasion, microvascular invasion, and surgical margin influenced disease-free survival independently (p<0.05). Conclusions: The safety of hepatectomy for huge HCC is similar to that for large and small HCC; and this approach for huge HCC may achieve similar long-term survival and disease-free survival as for large HCC.

Alterations of Amino Acid Level in Depressed Rat Brain

Pei Yang,Xuechun Li,Jian Ni,Jingchen Tian,Fu Jing,Changhai Qu,Longfei Lin,Hui Zhang 대한약리학회 2014 The Korean Journal of Physiology & Pharmacology Vol.18 No.5

Amino-acid neurotransmitter system dysfunction plays a major role in the pathophysiology ofdepression. Several studies have demonstrated the potential of amino acids as a source of neuro-specificbiomarkers could be used in future diagnosis of depression. Only partial amino acids such as glycineand asparagine were determined from certain parts of rats’ brain included hippocampi and cerebralcortex in previous studies. However, according to systematic biology, amino acids in different areaof brain are interacted and interrelated. Hence, the determination of 34 amino acids through entirerats’ brain was conducted in this study in order to demonstrate more possibilities for biomarkers ofdepression by discovering other potential amino acids in more areas of rats’ brain. As a result, 4 aminoacids (L-aspartic acid, L-glutamine, taurine and γ -amino-n-butyric acid) among 34 were typicallyidentified as potentially primary biomarkers of depression by data statistics. Meanwhile, anantidepressant called Fluoxetine was employed to verify other potential amino acids which were notidentified by data statistics. Eventually, we found L-α -amino-adipic acid could also become a newpotentially secondary biomarker of depression after drug validation. In conclusion, we suggested thatL-aspartic acid, L-glutamine, taurine, γ-amino-n-butyric acid and L-α-amino-adipic acid might becomepotential biomarkers for future diagnosis of depression and development of antidepressant.

Aerodynamic performance of high-lift blades in low-pressure turbines with periodic upstream wakes

Siyu Yang,Baopeng Xu,Fu Tian,Bin Wang 대한기계학회 2023 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.37 No.5

The aerodynamic performance of high-lift blades was experimentally investigated at different Reynolds numbers ranging from 0.8×10 5 to 1.8×10 5 . Upstream wakes, inherent in real aero-engines, were generated by moving bars operating at reduced frequencies (Fr) of 0.3 and 0.6. Measurements were carried out by pneumatic probes and static pressure taps on the blade surfaces. The results show that high-lift blades experience a significant rise in profile loss under steady conditions, which is mitigated by upstream wakes due to the suppressed separation bubble. The loading distributions relate the non-dimensional flow deceleration rate (DR) to the profile loss. It is found that the variation pattern depends on the flow state, which is classified into parabolic increase, linear increase, and concave parabolic variation. A single hot-wire probe was employed to measure the boundary layer at the trailing edge. The results are used to examine the modified loss model based on Denton’s method.

Structure and electrical properties of Pr6O11-doped CaCu3Ti4O12 NTC ceramics

Zuo Yang,Tian Jian,Tian Yuxin,Miao Guangtan,Fu Peng 한국세라믹학회 2023 한국세라믹학회지 Vol.60 No.3

The xPr6O11–(1 − x)CaCu3Ti4O12 (CCTO) ceramics with perovskite structure were prepared by the solid-state reaction method. The effects of Pr 6O11 addition on the microstructure and electrical properties of the CCTO ceramics were studied. The addition of Pr 6O11 promoted the sintering of CCTO ceramics, and the mean grain sizes increased gradually from 2.13 to 5.08 μm with increasing Pr 6O11 content. All the samples had noticeable negative temperature coefficient (NTC) effect, and both the grain and grain boundary effects contributed to their NTC characteristics. The thermistor characteristic parameter B25/75 decreased from 6883 to 5291 K as Pr 6O11 contents increased from 0.00 to 0.08. The analysis shows that the conductivity of Pr 6O11–CCTO ceramics arises mainly from the electron hopping transport mechanism. The GB resistances are noticeably higher than grain resistances at the same Pr 6O11 content. All the samples showed electrical relaxation behavior. The above observations indicate that the structures and electrical properties of CCTO ceramics can be attuned precisely by adjusting the Pr 6O11 concentration.