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Alliances are essential for high-tech startups that are seeking resources and preparing for future expansion. This study examines how the attributes of high-tech startups' early-stage inventions influence the likelihood of forming alliances. Specifically, we explore the impact of technological novelty and economic scope of inventions on alliance formation. Using a sample of 408 healthcare startups, we empirically demonstrate that technological novelty has a negative impact on alliance formation, whereas economic scope has a positive impact. We also find that the engagement of corporate venture capitalists can mitigate the negative impact of technological novelty on high-tech startups' alliance formation. [ABSTRACT FROM AUTHOR]

This study investigates the influence of ascribed and achieved political connections on corporate strategies of incremental versus radical innovation. The corporate political strategy literature maintains that while politically connected firms have access to resources controlled by the government, they also have an obligation to reciprocate for this access by fulfilling government expectations. We integrate an institutional perspective with the political strategy literature to develop the argument that ascribed political connections enhance incremental innovation because firms with these connections will tend to innovate just enough to meet government expectations. In contrast, firms with achieved political connections will tend to prefer radical innovation because these innovations help them to maintain their relationships with the government and expand their competitive advantage in the market. Furthermore, we propose that these effects depend on firms' innovation orientation, captured by the firms' technological capability, industry characteristics, and the innovation context of their geographical region. Our predictions are largely supported by analysis of a panel dataset of privately controlled, publicly listed Chinese firms during the period 2008 to 2018. Our findings reveal that the positive effect of ascribed political connections on incremental innovation is less salient when a firm has stronger technological capability, or when a firm operates in a high‐tech industry or a region with a strong innovative climate. Conversely, the positive influence of achieved political connections on radical innovation is stronger when a firm has stronger technological capability, or when a firm competes in a high‐tech industry or is located in a region with a strong innovative climate. We also discuss the important implications for firms and the government. [ABSTRACT FROM AUTHOR]

Temperature compensation is the main measure to solve the problem that the detection accuracy of non-dispersive infrared CO2 gas sensor is affected by temperature. As the measurement accuracy of the non-dispersive infrared CO2 gas sensor is easily affected by the ambient temperature, this article analyzes the reasons why the sensor is affected by temperature, and proposes a temperature compensation method that integrates the Whale Algorithm (WOA) and BP neural network. The whale algorithm is used to optimize the weights and thresholds of the BP neural network to build a temperature compensation model for the non-dispersive infrared CO2 gas sensor and compare the superiority with the traditional BP neural network model and particle swarm optimization (PSO) BP neural network model. The experimental results show that the temperature compensation model error of WOA-BP algorithm is lower than 30 ppm, and the average absolute error percentage is 3.86%, which is far better than BP neural network and PSO-BP neural network, and effectively reduces the influence of temperature on the accuracy of the sensor. [ABSTRACT FROM AUTHOR]

Droop control is widely used in multi-terminal flexible DC (VSC-MTDC) transmission systems by virtue of the advantage of multi-station cooperative unbalanced power dissipation, however, the essence of the droop control strategy is to change the DC current to realize the unbalanced power dissipation, and the resulting DC voltage deviation will affect the normal operation of the system. Firstly, this paper theoretically analyses the working characteristics of the conventional droop control and proposes a control method to realize the quasi-differential-free regulation of DC voltage by translating the droop curve. Second, according to the power margin of the converter station, the feedforward compensation amount of each converter station is reasonably set to avoid the power impact on the converter station. Finally, for the problem that the actual value of DC voltage still deviates from the rated value, a control strategy containing secondary regulation of DC voltage is proposed to further restore the DC voltage to the initial value on the basis of ensuring the effect of power regulation, which improves the stability of the operation of the VSC-MTDC system. The final simulation results verify the effectiveness of the proposed method. [ABSTRACT FROM AUTHOR]

The technological novelty of inventions signals economic potential while simultaneously indicating considerable technological and market risks. We speculate that unlike early-stage venture capital (VC) investors, late-stage public investors will interpret technological novelty as a signal of high risks. Consequently, they will hesitate to promptly invest in high-tech start-ups with such inventions, thereby slowing the initial public offering speed of the start-ups. Based on a sample of 408 VC-backed healthcare start-ups founded between 1990 and 2010, we find support for our hypothesis. We also find that the negative effect of technological novelty of inventions can be relieved when the technology is characterised by conventionality, when the founder is also the inventor, or when the start-up is backed by premium VC investors. [ABSTRACT FROM AUTHOR]

Objective: Periostin is important for the maintenance of periodontal tissue, but its role in periodontitis is controversial. This research investigated the effect of periostin in periodontitis and the underlying mechanism. Design: Mouse periodontitis models in vivo and inflammation model in vitro which were induced by Porphyromonas gingivalis lipopolysaccharide were established to evaluate periostin expression. Human periodontal ligament fibroblasts (PDLFs) were treated with lipopolysaccharide and N‐acetylcysteine, fluorescence staining, flow cytometry, Western blot, and qRT‐PCR were used to detect reactive oxygen species (ROS), periostin expression, and apoptosis‐related makers. The periostin gene was successfully transfected into PDLFs to verify the effect of periostin on apoptosis. Then, the Nrf2 inhibitor was added to clarify the mechanism. Results: Periostin expression decreased in the periodontal ligaments of mouse periodontitis models and lipopolysaccharide‐induced PDLFs. Lipopolysaccharide promoted the activation of ROS and apoptosis in PDLFs, whereas N‐acetylcysteine reversed this condition. Overexpression of periostin suppressed apoptosis of PDLFs and reversed the inhibitory effect of lipopolysaccharide on nuclear Nrf2 expression. Moreover, the Nrf2 inhibitor attenuated the protective effect of periostin on lipopolysaccharide‐induced apoptosis. Conclusions: Lipopolysaccharide induced apoptosis in PDLFs by inhibiting periostin expression and thus Nrf2/HO‐1 pathway, indicating that periostin could be a potential therapeutic target for periodontitis. [ABSTRACT FROM AUTHOR]

In order to solve the problem that the voltage source converter based multi-terminal direct current (VSC-MTDC) system cannot provide inertia and participate in frequency modulation after connecting to the AC power grid under the traditional control strategy, an adaptive control strategy based on virtual inertia is proposed. First, the relationship between AC frequency and DC voltage was established by a virtual inertia control, allowing the VSC-MTDC system to provide inertia to the AC side. Second, to address the limited inertia coefficient selection due to DC voltage deviation, an adaptive control was adopted. When the DC voltage deviation is small, the inertia coefficient is increased to obtain a better inertial response; on the contrary, the inertia coefficient is reduced to prevent the DC voltage from exceeding the limit. Finally, to solve the problem of insufficient flexibility of the fixed droop coefficient, this paper introduces the power margin of a VSC-station into the droop coefficient to dynamically adjust the distribution ratio of unbalanced power and reduce the DC voltage deviation. The three-terminal VSC-MTDC system was modelled on the PSCAD/EMTDC simulation platform, and the superiority of the control strategy was highlighted in this paper by comparing it with conventional droop control and a fixed virtual inertia coefficient. [ABSTRACT FROM AUTHOR]

Reverse innovation (RI) patents, which apply to intellectual property that is created in an emerging country but patented in a developed country, are better representatives of innovation value than domestic patents in emerging economies. We argue that RI patents contribute to firm value by proxying for the private value of innovation, generating product market value, and signalling firms' capabilities. Using a sample of Chinese‐listed companies, we find RI patents positively relate to firms' short‐ and long‐term market value. This effect is stronger for firms with high innovative intensity and managerial ability. We also explore the mechanisms behind the relationship between RI and firm value. We demonstrate that, in addition to the domestic patent functions of creating value and capturing innovation rent, RI patents can further leverage firm value by signalling firm quality to customers and investors in developed markets, a function that is unique to RI patents. [ABSTRACT FROM AUTHOR]

In order to solve the coordinated optimization problem of distributed generation (DG), on‐load tap changer (OLTC) and capacitor banks, a dynamic reactive power optimization (DRPO) method based on fuzzy time clustering is proposed. In the method, fuzzy time clustering algorithm is used to cluster the static optimal switching sequence of OLTC and capacitor banks. The time decoupling of control variables is realized and it meets the constraints of the maximum switching times. Next, the influencing factors of DG reactive power limit are analysed. Considering the control ability of OLTC, capacitor banks and DG in voltage and reactive power optimization, a coordinated optimization method is proposed. Since the adjustment of OLTC tap position directly affects the voltage and reactive power distribution of the whole line, the switching time and tap position of OLTC are determined based on the static optimization results of each time and fuzzy time clustering algorithm. Then, the switching time of capacitor banks is determined by fuzzy time clustering algorithm. At last, the switching capacity of capacitor banks and DG reactive power are jointly optimized to get the final control scheme. The proposed method demonstrated good performance in the modified IEEE33 node system and two actual power grid examples. [ABSTRACT FROM AUTHOR]

With the development of digital image technology, judging diseases by medical image plays an important role in medical diagnosis. Mammography is the most effective imaging examination method for breast cancer at present. Intelligent segmentation and identification of breast cancer images and judging their size and classification by digital image processing technology can promote the development of clinical medicine. This paper introduces the preprocessing technology of breast cancer pathological image and medical image recognition technology of breast cancer. In order to improve the segmentation accuracy of image processing and optimize, the segmentation recognition ability in digital mammography was improved. Based on the technical basis of pathological image analysis of breast cancer, the architecture of intelligent segmentation and recognition system for breast cancer was constructed, and each functional module of intelligent system was introduced in detail. Based on digital image processing technology, filtering technology is used to reduce dryness and improve the clarity of the image. Public datasets INBreast and DDSM-BCRP were used to verify system's performance, and it was tested on the breast cancer image test set. The experiment shows that the comprehensive performance of the intelligent segmentation and recognition system can realize the segmentation and recognition of breast cancer and has higher accuracy and interpretability, which is helpful to improve the diagnosis of doctors. [ABSTRACT FROM AUTHOR]

Meerwein-Ponndorf-Verley (MPV) reduction has gained much attention due to is mid reaction conditions, and this reaction can be performed without the presence of reductive atmosphere and the reaction conditions of high temperature and high pressure. Solid bases with abundant strong basic sites can be synthesized with metal-organic frameworks (MOFs) as precursors. These MOFs are immobilized with alkane metal nitrides, followed by calcination to produce the desired basic metal oxides. The basic zirconia shows highly efficient catalytic performance in MPV reduction of substrates with the carbonyl group, and benzaldehyde can be completely reduced in 6 hours with a mild reaction temperature (160 °C) in the absence of hydrogen gas. The catalytic efficiency is determined by the amounts of strong basic sites, but not the total amounts of basic sites, and this phenomenon is proved by the contrast experiments with the catalytic test of weak solid bases. Furthermore, the cooperative action between basic and acid sites can also enhance the catalytic performance in MPV reactions. With MOFs as precursors, metal oxide catalysts can be synthesized with well dispersed active sites. [ABSTRACT FROM AUTHOR]

The grid connection of wind farms affects the load flow of a power system and may introduce an unexpected threat to the power system small signal stability. This study presents an application of probabilistic eigenvalue sensitivity indices (PSIs) for optimal allocation of wind farm in a power system. For this purpose, firstly, probabilistic sensitivity indices are used to identify the strongly correlated electromechanical eigenvalues of generators and to facilitate the wind farm site selection. Two different cases are studied, wind farm replacing synchronous generators or being directly added to the power system. Afterwards, the influence of the wind farm location on power system small signal stability is examined. For this purpose, an index is proposed to measure the small signal stability of the system and is used for optimal allocation of the wind farm. Two examples, i.e. a 3‐machine 9‐bus and an 8‐machine 24‐bus power system, with a wind farm integrated based on PSIs are presented to demonstrate the proposed approach by employing the eigenvalue analysis and a dynamic time‐domain simulation. Finally, the results are compared with the traditional optimal allocation of a wind farm for power loss reduction. [ABSTRACT FROM AUTHOR]

The following aspects were reviewed: the development status of wind and solar hybrid power generation, the research method on power system low frequency oscillation, the influence of power system small signal stability with integration of wind and solar hybrid power, as well as improving the control strategy of stability of wind and solar hybrid power generation. Therefore, the research direction of the future low frequency oscillation analysis and control could be obtained as follow: the study of the dynamic characteristics of wind turbine and the interaction of traditional power system dynamic characteristic; the influence of wind and solar hybrid system capacity and the corresponding energy storage system on the low frequency oscillation characteristics; the influence factors of wind and solar hybrid power generation system on the damping characteristics of the interconnected systems; the design and parameter optimization of the controller to improve the damping characteristics of the system with integration of wind and solar hybrid power generation. [ABSTRACT FROM AUTHOR]

A novel high‐voltage direct‐current (HVDC) line fault location method based on phase frequency change characteristics is proposed. The idea of the method is the travelling waves for the fault happened on different positions have different phase distortion characteristics, when they spread to the measuring terminal. By using the discrete Fourier analysis, the phase frequency characteristics were obtained. The frequency data of 40 to 60 Hz and the corresponding phase angle ratio data are selected, forming a N × 3 matrix, each row of data represents the relationship between the fault location and phase angle ratio, fitting each row of data, respectively, the mathematical relationship between the fault location and phase angle ratio can be obtained, finally realise DC line fault location by seeking average. Finally, a lot of different faults are simulated and analysed on the PSCAD platform to verify the effectiveness and robustness of the proposed method. [ABSTRACT FROM AUTHOR]

This article describes a new process to manufacture open-cell steel foams. Calcium chloride anhydrous is used as a space holder. By changing the values of the main manufacturing parameters such as volume percentage, and the size and shape of the space holder, we produce different steel foam samples which cover a wide range of solid fraction, pore size, and shape. The effects of space-holder content and sintering condition such as temperature and time on the porosity of steel foam samples are discussed. The microstructure and composition of steel foam samples are observed and analyzed by scanning electron microscope and X-ray diffraction. The compressive curves of steel foams are measured by a universal testing machine. The experiment results show the compressive strength of steel foam samples with porosities between 65% and 85% is in the range of 66.4 ∼ 12.9 MPa. The compressive strength depends mainly on the porosity and pore shape. The absorbed energy per unit volume (W) of steel foams with porosities between 85% and 65% is in range of 6.8 ∼ 31.2 MJ/m3. Under the condition of identical porosity, the absorbed energy per unit volume (W) of steel foam is about three times of aluminum foam. In compression, steel foam specimens show heterogeneous macroscopic deformation. [ABSTRACT FROM PUBLISHER]

This article is an examination of how investors in the corporate bond market in emerging economies react to patents. To empirically explore this question, we constructed a sample of 1862 Chinese corporate bonds issued between 2004 and 2020 and gathered data on Chinese domestic patents, reverse innovation patents, and the validity of patents. The empirical results suggest that domestic patents are the primary source of information for bond investors in China when evaluating corporate innovation and that investors can successfully discern between patents that are valid and those that are not. At the same time, the positive relationship between corporate innovation and bond prices is found to be negatively moderated by credit ratings and state ownership. [ABSTRACT FROM AUTHOR]

• The polypeptide OP 3-4 promoted bone regeneration of mandibular defect. • OP 3-4 improved osteogenic differentiation of bone marrow mesenchymal stem cells. • OP 3-4 promoted osteogenic differentiation by AKT/GSK3β/β-catenin pathway. The aims of this study were to explore: (ⅰ) the effect of the polypeptide OP 3-4 on bone regeneration in vivo ; (ⅱ) the effect of OP 3-4 on osteogenic differentiation of bone marrow mesenchymal stem cells in vitro ; and (ⅲ) the potential mechanism of OP 3-4 in promoting osteogenic differentiation of bone marrow mesenchymal stem cells. 30 Wistar rats (8-week, male) were randomly divided into Control group (n = 5), Hydrogel group (n = 5), and Hydrogel loaded OP 3-4 group (n = 5). Hematoxylin and eosin staining was used to evaluate the level of bone regeneration in mandibular defect. Immunohistochemistry staining was used to evaluate the expression of alkaline phosphatase, runt-related transcription factor 2, and type Ⅰ collagen. Flow cytometry was applied to identify the phenotype of bone marrow mesenchymal stem cells. Furthermore, LY294002, the inhibitor of protein kinase B, was applied to verify the role of OP 3-4 in promoting osteogenic differentiation via protein kinase B/glycogen synthase kinase 3β/β-catenin pathway through western blot. OP 3-4 promoted bone regeneration of rat mandibular defect. The expression of osteogenic differentiation related markers were increased after adding OP 3-4 to bone marrow mesenchymal stem cells. OP 3-4 promoted osteogenic differentiation of bone marrow mesenchymal stem cells via protein kinase B/glycogen synthase kinase 3β/β-catenin pathway. OP 3-4 could promote bone regeneration of mandibular defect and improve osteogenic differentiation through protein kinase B/glycogen synthase kinase 3β/β-catenin pathway. [ABSTRACT FROM AUTHOR]

• Notum expression increased in gingival tissues. • Notum expression increased in periodontal ligament. • Notum inhibited human periodontal ligament stem cell (hPDLSC) osteogenesis. • Notum regulated hPDLSC osteogenesis through Wnt/beta-catentin signaling. The aims of this study were to explore: (ⅰ) the effect of Notum on periodontitis in vivo ; (ⅱ) the effect of Notum on the osteogenic differentiation of human periodontal ligament stem cells (hPDLSCs) in vitro ; and (ⅲ) the potential mechanism of Notum in inhibiting the osteogenic differentiation of hPDLSCs. C57BL/6J mice were randomly assigned into two groups: control group (n = 4) and periodontitis group (n = 4). Immunohistochemical staining was used to evaluate the expression of Notum. In in vitro experiments, Western blot, qRT- PCR and ELISA were used to examine the expression of Notum in a lipopolysaccharide-induced inflammation model. Alkaline phosphatase staining was used to evaluate alkaline phosphatase activity. Western blot and qRT - PCR were used to measure the expression of osteogenic-related markers after adding human recombinant Notum and Notum inhibitor ABC99. In addition, LiCl, an agonist of the Wnt/Beta-catenin signaling pathway, was added to explore using Western blot whether Notum was involved in regulating the osteogenic differentiation of human periodontal ligament stem cells through the Wnt/Beta-catenin signaling pathway. Notum was highly expressed in periodontal tissues of mice and lipopolysaccharide-induced inflammation cell model. The protein and messenger ribonucleic acid levels of hPDLSCs osteogenic markers were reduced after adding human recombinant Notum. However, the inhibitory effect of Notum on the osteogenic differentiation of hPDLSCs could be significantly reversed by adding LiCl. These results demonstrated that Notum inhibited the osteogenic differentiation of hPDLSCs probably via the Wnt/Beta-catenin the downstream signaling pathway. [ABSTRACT FROM AUTHOR]

The well-developed unified power flow controller (UPFC) has demonstrated its capability in providing voltage support and improving power system stability. The objective of this paper is to demonstrate the capability of the UPFC in mitigating oscillations in a wind farm integrated power system by employing eigenvalue analysis and dynamic time-domain simulation approaches. For this purpose, a power oscillation damping controller (PODC) of the UPFC is designed for damping oscillations caused by disturbances in a given interconnected power system, including the change in tie-line power, the changes of wind power outputs, and others. Simulations are carried out for two sample power systems, i.e., a four-machine system and an eight-machine system, for demonstration. Numerous eigenvalue analysis and dynamic time-domain simulation results confirm that the UPFC equipped with the designed PODC can effectively suppress oscillations of power systems under various disturbance scenarios. [ABSTRACT FROM AUTHOR]

Eldecalcitol (ED-71) is a new type of vitamin D analog, and vitamin D has been reported to have therapeutic effects in infectious disease, autoimmune disease, and cancer. However, the anti-cancer effect of ED-71 remains unclear. The objective of this study was to explore the anti-cancer effect of ED-71 in human osteosarcoma cells and to identify the related mechanism. The CCK8 assay results showed that ED-71 inhibited MG-63 cell viability in dose and time dependent manners. Cloning and Transwell invasion assays showed that ED-71 inhibited clonal and invasion ability of MG-63 cells. Flow cytometry results showed ED-71 the G2/M cycle arrest rate, apoptosis, and intracellular ROS. Western blot was used to detect cleaved-caspase-3, Bax, Bcl-2, LC3-II/LC3-I, and P62 levels and the mTOR pathway. The increase of LC3-II and P62 indicated that ED-71 induced the formation of autophagosomes and inhibited autophagy flux. Furthermore, ED-71-induced apoptosis was weakened after adding 3-methyladenine and ED-71-induced early autophagy was weakened by caspase-3 inhibitor (Z -VAD-FMK), which indicated the two processes active each other in the presence of ED-71. Furthermore, N-acetylcysteine (NAC) pretreatment reversed the ED-71-treatment outcomes, including increased apoptosis and autophagy and inhibition of the PI3K/Akt/mTOR pathway. In conclusion, our results reveal that ED-71 induced G2/M arrest, apoptosis and autophagy in MG-63 cells by accumulating ROS to suppress the PI3K/Akt/mTOR signaling pathway • ED-71 induced early autophagy and apoptosis in MG-63 cells. • Autophagy induced by ED-71 lead to cell death rather than survival by inducing apoptosis. • Autophagy and apoptosis induced by ED-71 promoted each other. • Autophagy and apoptosis induced by ED-71 were regulated by accumulating ROS to suppress the PI3K/Akt/mTOR signaling pathway. [ABSTRACT FROM AUTHOR]

Aldol condensation between furfural (FA) and MIBK is used to synthesize branched bio-jet-fuel precursors. It remains difficult to design hybrid solid bases to efficiently promote this reaction, because only strong basic sites can activate MIBK. Different basic species were immobilized into zirconia/carbon hybrid supports by thermal decomposition of GO/UiO materials loaded with corresponding alkane (earth) nitrides. Only Cs immobilized zirconia/carbon (CsZC) could efficiently promote this reaction, while counterparts with Li, Mg and Ca species showed little activity over condensation between MIBK and FA. Optimized CsZC showed excellent FA conversion and selectivity towards desired products (88.6% in yields of FMIBK in 6 h at 130 °C). Two indirect proofs were provided to check the influence of basic strength on the catalytic performance, and only Cs samples had enough strong basic sites to accelerate the reaction. After modified with octyl groups, hydrophobic CsZC were reused for 4th cycle while retaining most of its original activity. Functionalization with organosilanes increased the hydrophobicity of the surface, which had dramatical promotion on activity, selectivity, and stability. It was the first time to run recycling experiments for this reaction, to afford the demands for chemical sustainability. Cs immobilized zirconia/carbon hybrid solid bases (CsZC) were synthesized by thermal decomposition of CsNO 3 loaded GO/zirconium MOFs. CsZC could efficiently catalyze aldol condensation of furfural and MIBK to produce bio-jet-fuel precursors, and catalytic stability was greatly promoted by hydrophobic modification of CsZC with octyl groups. Unlabelled Image [ABSTRACT FROM AUTHOR]