Explicit Finite Element Formulations for the Free Vibrations and Buckling of Partial-Interaction Composite Beams with Two Sub-components

Jian-Ping Lin,Bowen Chen,Xingxi Liu,Rongqiao Xu,Guannan Wang 한국강구조학회 2023 International Journal of Steel Structures Vol.23 No.4

The variational principles and corresponding finite element formulations are developed in this work for the free vibration and buckling analysis of partial-interaction composite beams under complex engineering situations, such as axial loading conditions, non-uniform material distributions, multi-span boundaries. The composites structures consist of sub-components connected with shear connections of finite rigidities and thus suffer from the partial-interaction phenomenon, significantly affecting the structural performance. The macroscopic elements for dynamic and buckling behavior are explicitly derived by simultaneously considering the sub-elements’ deformations and interlayer slips, avoiding the stress concentrations in the contact areas existing in the commercial packages. The generated frequencies and critical loads of several orders for the single- or two-span composite structures with different boundary conditions are then validated against the analytical and numerical results in the literature with well-matched agreement. The interfacial shear connections and structural parameters are also studied of their influences on the structural dynamic and buckling behavior. The present theory is finally implemented in the theoretical analysis of the steel box-girder viaduct with non-uniformly-distributed shear braces and multi-span continuous composite beams of Jiubao Bridge. The explicit expressions of the elements are provided and can be readily implemented into the commercial software with high computational efficiency.

Analysis of Shear Connector of Steel–Concrete Composite Box-Girder Bridge Considering Interfacial Bonding and Friction

Jian-Ping Lin,ZhiBo Wu,Ying Yin,Fan Feng 한국강구조학회 2020 International Journal of Steel Structures Vol.20 No.2

Steel–concrete composite bridges consist of steel and concrete parts which are connected by shear connector such as the widely-used headed stud. Through the chemistry bonding, interface friction and mechanical action the two different materials parts are combined as a composite structure system. Because of the structural mechanism, longitudinal and lateral relative slip and normal separation between the concrete deck and steel girder flange will inevitably exist during the loading process. Further, the complex interface mechanical behavior causes difficulties with nonlinear numerical analysis. Multiple broken lines mode cohesive zone model considering bonding and friction is used in this paper to describe the tangent slip and normal crack of the interface. A zero thickness cohesive element was implemented via the user-defined element subroutine UEL in ABAQUS. Using this method, numerical simulation analysis of a two span composite continuous box-girder was carried out. Results showed load–displacement curves of the structure, relative displacement between the steel girder and the concrete slab interface, interface stress distribution, and internal force of shear studs. Discontinuous deformation numerical simulation has been realized, and effectiveness of the proposed method and accuracy of the program were verified. Although shear stress was assumed to be transmitted by shear connector in the design stage, interface bonding and friction resistance can affect the force state of the shear connector. Results of this study can be used for detailed analysis and evaluation of the composite box-girder bridge without the need to rely on the constitutive laws of shear connectors obtained from push-out tests.

Scutellaria Extract Decreases the Proportion of Side Population Cells in a Myeloma Cell Line by Down-regulating the Expression of ABCG2 Protein

Lin, Mei-Gui,Liu, Li-Ping,Li, Chen-Yin,Zhang, Meng,Chen, Yuling,Qin, Jian,Gu, Yue-Yu,Li, Zhi,Wu, Xin-Lin,Mo, Sui-Lin Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.12

Background and Aims: Scutellaria is one of the most popular traditional Chinese herbal remedies against various human diseases, including cancer. In this study, we examined the active effects of Scutellaria extract and its main flavonoid constituents on the proportion of side population cells within human multiple myeloma cell line RPMI8226 in vitro and explored the potential molecular mechanisms involved. Materials and Methods: The contents of flavonoids in ethanolic extract of Scutellaria baicalensis Georgi were determined using high performance liquid chromatography. The antiproliferative effect of the ethanolic extract on RPMI-8226 was determined by CCK assay. Apoptosis was measured by annexin combining with propidium iodide in a flow cytometer. Cell cycle analysis was performed by propidium iodide staining in combination with flow cytometry analysis. Hoechst 33342 exclusion assay was used for the identification of side population within RPMI8226 cells. The expression of ABCG2 protein was assessed by Western blotting assay. Results: The content of major flavonoids constitutents of Scutellaria extract was baicalin (10.2%), wogonoside (2.50%), baicalein (2.29%), and wogonin (0.99%), respectively. The crude Scutellaria extract did not show significant anti-proliferative effect, apoptosis induction and cell cycle arrest in RPMI-8226 within the concentrations of $1-75{\mu}g/mL$. However, the ethanolic extract, baicalein, wogonin and baicalin reduced the side population cells in RPMI-8226, and data showed that baicalein and wogonin had stronger inhibitory effects. Correspondingly, they also exhibited significant effects on decreasing the expression level of ABCG2 protein in RPMI-8226 in vitro. Conclusions: Our results for the first time demonstrated a novel mechanism of action for Scutellaria extract and its main active flavonoids, namely targeting SP cells by modulating the expression of ABCG2 protein. This study provides an insight for new therapeutic strategies targeting cancer stem cells of multiple myeloma.

The Relationship between HIF-2α and VEGF with Radiographic Severity in the Primary Osteoarthritic Knee

Zhou Jian-lin,Fang Hong-song,Peng Hao,Deng Shuang,Chen Shen,Li Jian-ping,Qiu Bo,Weng Jin-qing,Liu Feng 연세대학교의과대학 2016 Yonsei medical journal Vol.57 No.3

Purpose: The aim of this study was to determine the relationship of hypoxia-inducible factor-2 (HIF-2α) and vascular endothelial growth factor (VEGF) with radiographic severity in primary osteoarthritis (OA) of the knee. Expression of these two factors in cartilagesamples from OA knee joints was examined at mRNA and protein levels. Materials and Methods: Knee joints were examined using plain radiographs, and OA severity was assessed using the Kellgren and Lawrence (KL) grading system. Specimens were collected from 29 patients (31 knees) who underwent total knee replacementbecause of severe medial OA of the knee (KL grades 3 and 4), 16 patients who underwent knee arthroscopy (KL grade 2), and 5 patients with traumatic knees (KL grade 0). HIF-2α and VEGF expression was quantified by real-time polymerase chain reactionand western blotting. Results: Cartilage degeneration correlated with the radiographic severity grade. OA severity, determined using the Mankin scale, correlated positively with the KL grade (r=0.8790, p<0.01), and HIF-2α and VEGF levels with the radiographic severity of knee OA (r=0.7001, p<0.05; r=0.6647, p<0.05). Conclusion: In OA cartilage, HIF-2α and VEGF mRNA and protein levels were significantly and positively correlated. The expressionof both factors correlated positively with the KL grade. HIF-2α and VEGF, therefore, may serve as biochemical markers as well as potential therapeutic targets in knee OA.

Atom Transfer Radical Polymerization of Hexadecyl Acrylate Using CuSCN as the Catalyst

Wen Jian Xu,Xiu Lin Zhu,Zhen Ping Cheng,Jian Ying Chen,Jian Mei Lu 한국고분자학회 2004 Macromolecular Research Vol.12 No.1

Falcine Sinus: Incidence and Imaging Characteristics of Three-Dimensional Contrast-Enhanced Thin-Section Magnetic Resonance Imaging

Ling Lin,Jin-Hua Lin,Jian Guan,Xiao-Ling Zhang,Jian-Ping Chu,Zhi-Yun Yang 대한영상의학회 2018 Korean Journal of Radiology Vol.19 No.3

Objective: To evaluate the incidence, characteristics, and variations of the falcine sinus with contrast-enhanced threedimentional (3D) thin-section magnetic resonance (MR) images. Materials and Methods: A retrospective review identified 1531 patients (745 males and 786 females, 2 months to 85 years) who underwent cranial MR imaging including T1-weighted imaging, T2-weighted imaging, T2-weighted fluid-attenuated inversion recovery, contrast-enhanced 3D thin-section sagittal scans, and MR venography, from June 2014 to January 2016. The incidence, characteristics of the falcine sinus, and coexisted intracranial lesions were confirmed by two neuroradiologists. Results: Falcine sinuses were identified in 81 (38 males and 43 females) cases (5.3%, 81/1531, 5 months to 76 years of age) with calibers ranging from 2.3 mm to 17.0 mm. Three major forms of falcine sinuses were defined: arch-like (n = 47), stick-like (n = 22), and bifurcated (n = 12). Persistent falcine sinuses were found in 57 cases, among which 3 cases showed complicated cerebral anomalies, and 2 cases showed smaller straight sinuses. Recanalization of falcine sinuses were found in 24 cases, including 17 cases with tumor compression, 6 cases with cerebral venous sinus thrombosis, and one case with hypertrophic meningitis. Conclusion: Falcine sinus is not as rare as has been reported previously. Most falcine sinuses are not associated with congenital cerebral abnormalities. Diseases that cause increased pressure in the venous sinus may lead to recanalization of falcine sinus. Illustrating the characteristics of falcine sinus may prompt a more comprehensive understanding and diagnosis of associated diseases, and avoid potential surgical damage in the future.

Effect of Preoperative Tumour Under-Staging on the Long-Term Survival of Patients Undergoing Radical Gastrectomy for Gastric Cancer

Mi Lin,Qi-Yue Chen,Chao-Hui Zheng,Ping Li,Jian-Wei Xie,Jia-Bin Wang,Jian-Xian Lin,Chang-Ming Huang 대한암학회 2021 Cancer Research and Treatment Vol.53 No.4

Purpose This study aimed to evaluate the effect of preoperative tumor staging deviation (PTSD) on the long-term survival of patients undergoing radical gastrectomy for gastric cancer (RGGC). Materials and Methods Clinicopathological data of 2,346 patients who underwent RGGC were retrospectively analyzed. The preoperative tumor-lymph node-metastasis (TNM) under-staging group (uTNM) comprised patients who had earlier preoperative TNM than postoperative TNM, and the no preoperative under-staging group (nTNM) comprised the remaining patients. Results There were 1,031 uTNM (44.0%) and 1,315 nTNM cases (56.0%). Cox prognostic analysis revealed that PTSD independently affected the overall survival (OS) after surgery. The 5-year OS was lower in the uTNM group (41.8%) than in the nTNM group (71.6%). The patients less than 65 years old, with lower American Society of Anaesthesiologists score, 2-5 cm tumor located at the lower stomach, and cT1 or cN0 preoperative staging would more likely undergo D1+ lymph node dissection (LND) in uTNM (p < 0.05). Logistic analyses revealed that tumor size > 2 cm and body mass index ≤ 22.72 kg/m2 were independent risk factors of preoperative TNM tumor under-staging in patients with cT1N0M0 staging (p < 0.05). Conclusion Underestimated tumor staging is not rare, which possibly results in inadequate LND and affects the long-term survival for patients undergoing RGGC. D2 LND should be carefully performed in patients who are predisposed to this underestimation.

Add-on Tiotropium in Chinese Patients With Moderate Asthma: A Pooled Subgroup Analysis of MezzoTinA-Asthma 1 and 2

Jiangtao Lin,Huanying Wan,Jian Kang,Qianli Ma,Ping Chen,Meiling Jin,Haoyan Wang,Shuang Liu,Qinglin Hao,Yong Lin,Lin Su,Na Hu 대한천식알레르기학회 2019 Allergy, Asthma & Immunology Research Vol.11 No.4

Purpose: Asthma affects approximately 30 million patients in China; however, tiotropium data for Chinese patients is limited. This study aimed to assess the efficacy and safety of tiotropium in Chinese patients with moderate symptomatic asthma. Methods: A post hoc subgroup analysis was conducted on 430 Chinese patients pooled from two 24-week, replicate phase 3 trials (NCT01172808 and NCT01172821), in which they received once-daily tiotropium 2.5 μg (Tio R2.5) or 5 μg (Tio R5) (n = 106 or 109, respectively), twice-daily salmeterol 50 μg (Sal 50) (n = 110), or placebo (n = 105), while maintaining inhaled corticosteroids (ICS). The co-primary endpoints assessed in week 24 were forced expiratory volume in 1 second (FEV1) peak0–3h response, trough FEV1 response, and responder rate as assessed using the Asthma Control Questionnaire (ACQ). Results: For both FEV1 peak0–3h responses and trough FEV1 responses, the mean treatment differences were greater for Tio R2.5, Tio R5, and Sal 50 compared with placebo at 0.249 L, 0.234 L, and 0.284 L, and 0.172 L, 0.180 L, and 0.164 L, respectively (P< 0.001). The ACQ responder rate in placebo, Tio R2.5, Tio R5, and Sal 50 was 58.7%, 62.3%, 59.3%, and 69.1%, respectively. Furthermore, 11 (2.6%) of 430 patients had serious adverse events (Tio R5, n = 4; Tio R2.5, n = 1; Sal 50, n = 1; and placebo, n = 5). Conclusions: Once-daily tiotropium, as add-on to medium-dose ICS, was effective and well tolerated for Chinese patients with moderate symptomatic asthma, consistent with the main analysis.

Pathologic Response During Chemo-radiotherapy and Variation of Serum VEGF Levels Could Predict Effects of Chemo-Radiotherapy in Patients with Esophageal Cancer

Yu, Jing-Ping,Lu, Wen-Bin,Wang, Jian-Lin,Ni, Xin-Chu,Wang, Jian,Sun, Zhi-Qiang,Sun, Su-Ping Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.3

Background: To investigate the relationship between pathologic tumor response to concurrent chemoradiotherapy and variation of serum VEGF in patients with esophageal cancer. Materials and Methods: Forty six patients with esophageal cancer who were treated with concurrent chemo-radiotherapy were enrolled. Endoscopic and pathologic examination was conducted before and four weeks afterwards. Serum level of VEGF was documented before, four weeks later and after chemo-radiotherapy. The relationship between pathologic response and the variation of serum level of VEGF and its influence on the prognosis were investigated. Results: Serum level of VEGF decreased remarkably during and after chemo-radiotherapy in patients whose pathologic response was severe (F=5.393, 4.587, P(0.05). There were no statistical differences of serum VEGF level before, during and after chemo-radiotherapy for patients whose pathologic response was moderate or mild. There were 18 (85.7%), 7 (53.8%) and 6 patients (50.0%) whose serum VEGF level dropped in the severe, moderate and mild group, respectively, with significant differences among these groups (p=0.046). Two year survival rates of patients with severe, moderate and mild pathologic response were 61.9%, 53.8% and 33.3% respectively, and no statistically difference between severe and mild group regarding OS (p=0.245) was tested. Conclusions: Tumor pathologic response during chemo-radiotherapy and the changes of serum VEGF lever could predict curative effects of chemo-radiotherapy in patients with esophageal cancer.

Expression, Purification, and Biological Characterization of The Amino-Terminal Fragment of Urokinase in Pichia pastoris

( Jian Ping Li ),( Yu Li Lin ),( Hong Qin Zhuang ),( Zi Chun Hua ) 한국미생물 · 생명공학회 2013 Journal of microbiology and biotechnology Vol.23 No.9

Urokinase (uPA) and its receptor (uPAR) play an important role in tumor growth and metastasis. Targeting the excessive activation of this system as well as the proliferation of the tumor vascular endothelial cell would be expected to prevent tumor neovasculature and halt the tumor development. In this regard, the amino-terminal fragment (ATF) of urokinase has been confirmed as effective to inhibit the proliferation, migration, and invasiveness of cancer cells via interrupting the interaction of uPA and uPAR. Previous studies indicated that ATF expressed in Escherichia coli was mainly contained in inclusion bodies and also lacked posttranslational modifications. In this study, the biologically active and soluble ATF was cloned and expressed in Pichia pastoris. The recombinant protein was purified to be homogenous and confirmed to be biologically active. The yield of the active ATF was about 30 mg/l of the P. pastoris culture medium. The recombinant ATF (rATF) could efficiently inhibit angiogenesis, endothelial cell migration, and tumor cell invasion in vitro. Furthermore, it could inhibit in vivo xenograft tumor growth and prolong the survival of tumor-bearing mice significantly by competing with uPA for binding to cell surfaces. Therefore, P. pastoris is a highly efficient and cost-effective expression system for large-scale production of biologically active rATFs for potential therapeutic application.