Search

In this paper we perform a systematic literature review of the diverse and somewhat fragmented current state of research on firms’ internationalization and innovation. We analyze 207 key works from 1989 through 2020 and synthesize them into an internationalization process framework that conceptually maps key internationalization-related antecedents and moderators that influence innovation behaviors and outcomes. Through an internationalization process framework, we categorize existing relevant studies into three key stages: (a) the pre-internationalization stage, (b) the internationalization entry stage, and (c) the post-internationalization stage. Furthermore, we review how firms’ various strategic decisions and operations in different stages influence their innovations by elaborating the moderating role of external country/region institutions and firm internal characteristics. Building on this review, we provide suggestions for future research to advance the developments of this domain.

PL Dai,1,2,* XS Du,3,* Y Hou,1,* L Li,1 YX Xia,1 L Wang,1 HX Chen,1 L Chang,1 WH Li1 1Radiotherapy Department, The Third Affiliated Hospital of Kunming Medical University, Kunming, Yunnan 650100, People’s Republic of China; 2Kunming Medical University, Kunming, Yunnan 650100, People’s Republic of China; 3Oncology Department, The Fifth People’s Hospital of Huaian, Jiangsu 223001, People’s Republic of China*These authors contributed equally to this workCorrespondence: L Chang; WH Li Email changli1981@126.com; wenhuili64@aliyun.comIntroduction: The biological changes after irradiation in lung cancer cells are important to reduce recurrence and metastasis of lung cancer. To optimize radiotherapy of lung adenocarcinoma, our study systematically explored the mechanisms of biological behaviors in residual A549 and XWLC-05 cells after irradiation.Methods: Colony formation assay, cell proliferation assay, cell migration assay, flow cytometry, BALB/C-nu mice xenograft models and Western blot of pan-AKT, p-Akt380, p-Akt473, PCNA, DNA-PKCS, KU70, KU80, CD133, CD144, MMP2 and P53 were used in our study to assess biological changes after irradiation with 0, 4 and 8 Gy at 0– 336hr after irradiation in vitro and 20 Gy at transplantation group, irradiated transplantation group, residual tumor 0, 7, 14, 21, and 28 days groups in vivo.Results: The ability of cell proliferation and radiosensitivity of residual XWLC-05 cells was better than A549 cells after radiation in vivo and in vitro. MMP-2 has statistical differences in vitro and in vivo and increased with the migratory ability of cells in vitro. PCNA and P53 have statistical differences in XWLC-05 and A549 cells and the changes of them are similar to the proliferation of residual cells within first 336hr after irradiation in vitro. Pan-AKT increased after irradiation, and residual tumor 21-day group (1.5722) has statistic differences between transplantation group (0.9763, p=0.018) and irradiated transplantation group (0.8455, p=0.006) in vivo. Pan-AKT rose to highest when 21-day after residual tumor reach to 0.5 mm2. MMP2 has statistical differences between transplantation group (0.4619) and residual tumor 14-day group (0.8729, p=0.043). P53 has statistical differences between residual tumor 7-day group (0.6184) and residual tumor 28 days group (1.0394, p=0.007). DNA-PKCS has statistical differences between residual tumor 28 days group (1.1769) and transplantation group (0.2483, p=0.010), irradiated transplantation group (0.1983, p=0.002) and residual tumor 21 days group (0.2017, p=0.003), residual tumor 0 days group (0.5992) and irradiated transplantation group (0.1983, p=0.027) and residual tumor 21 days group (0.2017, p=0.002). KU80 and KU70 have no statistical differences at any time point.Conclusion: Different proteins regulated apoptosis, proliferation and metastasis of lung adenocarcinoma after radiotherapy at different times. MMP-2 might regulate metastasis ability of XWLC-05 and A549 cells in vitro and in vivo. PCNAand P53 may play important roles in proliferation of vitro XWLC-05 and A549 cells within first 336hr after irradiation in vitro. After that, P53 may through PI3K/AKT pathway regulate cell proliferation after irradiation in vitro. DNA-PKCS may play amore important role in DNA damage repair than KU70 and KU80 after 336hr in vitro because it rapidly rose than KU70 and KU80 after irradiation. Different cells have different time rhythm in apoptosis, proliferation and metastasis after radiotherapy. Time rhythm of cells after irradiation should be delivered and more attention should be paid to resist cancer cell proliferation and metastasis.Keywords: lung adenocarcinoma, XWLC-05 cells, biological, radiation

In this paper, a new angle-of-attack(AOA) guidance law and controller with multi-control surface and reaction control system (RCS) are designed to reduce normal acceleration in sub-orbit re-entry phase. First, the six-degree-of-freedom (6-DOF) nonlinear dynamic model of sub-orbit vehicles established, and the overload characteristics is analyzed under traditional AOA guidance law. Second, an AOA guidance law added height element is proposed to reduce the Normal accelerate peak value during re-entry. Furthermore, an Inverse-PIDA control law and composite control strategy are designed to control multi-aerodynamic surface and RCS. Finally the proposed approach is applied in a sub-orbit vehicle re-entry flight, validation simulation are conducted by using the proposed guidance law and controller with the 6-DOF nonlinear dynamic model , Monte-Carlo statistical analysis shows it can get well control performance with 卤20% aerodynamic elements uncertainty and random wind. 漏 2017, American Institute of Aeronautics and Astronautics Inc, AIAA. All rights reserved.

In the present work we use Raman microscopy to investigate the size effect of spin-phonon coupling in antiferromagnetic Cr2O3 nanoparticles. The peculiarities of the dependency of the phonon wave number on temperature (with a relatively weak peak at 293 cm(-1)) can be attributed to the spin-phonon coupling. The variation with temperature of the spin-phonon mode develops when the antiferromagnetic state is near the ordering temperature of the Cr spins. The observations can be reasonably well interpreted by describing the order parameter. A shift in frequency is caused by a strong spin-phonon interaction in Cr2O3. The obtained s-ph coefficients are found to be consistent with the strain, where raising the strain results in weakening of the s-ph coupling.

The patient was a 40-year-old female with a 5-month history of recurrent painful labial ulcers in December 2013. Investigations by a private physician revealed a negative VDRL (Venereal Disease Research Laboratory) test and vulval swab culture grew commensals only. The ulcers, however, failed to heal following treatment with antibiotics. Vulval biopsy was performed at her first visit and histopathology report revealed only a non-specific ulcer with negative stains for fungus, bacteria, acid-fast bacilli, and herpes simplex virus. Papanicolaou smear showed atypical squamous cells of unknown significance (ASCUS). In the absence of any obvious pathology for the non-healing ulcer, colposcopy was arranged: four ulcers were identified within the vagina, scattered over the right and left vaginal walls (Fig 1). A left lower vulval ulcer measuring 3 cm with slightly raised edges was also seen (Fig 2). Biopsies were taken over the cervix, vaginal, and vulval ulcers. Histopathology of these biopsies confirmed the presence of cervicitis and ulcers, with no evidence of malignancy. Upon systemic review, the patient revealed that she had been suffering from recurrent mouth ulcers and bruising over both shins. Subsequent examination revealed multiple aphthous mouth ulcers, as well as erythema nodosum over both shins. Based on the clinical signs, a diagnosis of Behcet’s disease was made. The patient was commenced on prednisolone, and all ulcers had healed at subsequent follow-up.

This article presents the development of a torsional adaptive tunable vibration absorber using a magnetorheological elastomer for vibration reduction of a powertrain test rig. The magnetorheological elastomer used to develop the adaptive tunable vibration absorber consists of silicone polymer, silicone oil and magnetic particles with the weight percentages of 60%, 20% and 20%, respectively. Experimental testing is conducted to obtain the magnetorheological elastomer's properties, such as Young's modulus and the damping ratio, and effective formulas are derived to facilitate the design of the adaptive tunable vibration absorber. With the derived formulas, a magnetorheological elastomer-based adaptive tunable vibration absorber is designed and manufactured, and experimental testing is also conducted to validate the design. The results of experiments show that the magnetorheological elastomer-based adaptive tunable vibration absorber can work in a frequency range from 10.75 to 16.5 Hz (53% relative change). Both the designed and experimental results of the adaptive tunable vibration absorber's frequencies are in good agreement. A powertrain model is used to validate the magnetorheological elastomer-based adaptive tunable vibration absorber's effectiveness, and the numerical simulations show that the powertrain frequencies are shifted away from the resonant frequency; thus, the powertrain's steady-state vibration can be significantly reduced. This magnetorheological elastomer-based adaptive tunable vibration absorber will be a promising new device for vibration reduction of vehicle powertrains. © The Author(s) 2013.