Suspension rheology is of widespread importance to industry and research. The rheology of spherical silica particle suspensions with different particle volume fractions and particle size distribution ...under different shear rates has been determined experimentally. Furthermore, the volume fraction at random close packing (
φ
rcp
) was introduced as the parameter of the initial relative viscosity model. In addition, suspension relative viscosity model including particle volume fraction, particle size distribution, and shear rate was obtained. The results showed that as the particle volume fraction increased, the shear thinning effect of the suspensions became more apparent. The relative viscosity decreased as the shear rate increased, and the decrease rate increased as the suspension particle volume fraction increased. As the range of particle size distribution increased, the relative viscosity of the suspensions decreased significantly, and the relative viscosity of the suspensions was independent of particle size in a certain range. The prediction of the suspension relative viscosity model proposed in this paper had a high degree of matching with the experimental data, effectively predicting the rheology of concentrated suspensions.
Remote transmission: In the presence of chiral amines, 2,4‐dienones are activated toward the attack of a nucleophile at the δ position, a mode of activation that is termed vinylogous iminium ion ...catalysis. Specifically, the 1,6 addition of alkyl thiols to β‐substituted cyclic dienones was catalyzed by a cinchona‐based primary amine; the reaction was highly stereoselective and displayed high selectivity for reaction at the δ position.
Purpose Most of current studies have explored the impact of entrepreneurial culture on entrepreneurial intentions in specific region rather than cross-cultural regions; in addition, these studies ...have looked more at entrepreneurial role models as part of the environmental factors that influence individuals’ entrepreneurial intentions (Lafuente et al. , 2007), rather than viewing environmental factors as independent variables. Furthermore, less research exists to hypothesize and validate the mechanism of this process, even if some studies have already shown the similar ideas. To fill the aforementioned research gap in this area, based on new institutional theory and social cognitive career theory, this paper aims to explore the influence of entrepreneurial role models on entrepreneurial intentions in different cultural contexts by introducing two independent national-level factors, collectivism and media publicity, and subsequently examines the mediating role of self-efficacy. Design/methodology/approach Two major international databases, Adult Population Survey Global Entrepreneurship Monitor (APS GEM) 2017 and Global Leadership and Organizational Behavior Effectiveness (GLOBE), were used as data sources for this paper. In total, the authors obtained data from 174,128 respondents in the APS GEM 2017 database. Because there is a national-level variable, collectivism, which was collected by the GLOBE, the authors excluded 50,046 participants because their countries did not score collectivism in this database. After screening, 124,082 valid observations from 35 countries were obtained. In this study, hierarchical linear modeling (HLM) was used as the method and HLM 6.08 was adopted for data analysis. According to the purpose of the study, the following four different models will be tested in turn using the HLM, which include the null model, random coefficients regression model, intercepts as outcomes model and slopes as outcomes model. Findings Some previous studies have shown that entrepreneurial role models have a positive impact on individuals' entrepreneurial intentions, however, the exploration of this effect and its mechanisms in different cultural contexts is lacking (Abbasianchavari and Moritz, 2021). In response, based on a cross-level and cross-national survey, this paper advances the original literature by introducing two cultural dimensions, collectivism and media publicity. The current results suggest that the positive influence of entrepreneurial role models on individuals’ entrepreneurial intentions is somewhat generalized and that self-efficacy plays a mediating role. Moreover, collectivism and media publicity can negatively and positively moderate the effects of entrepreneurial role models on self-efficacy and entrepreneurial intentions, respectively. The findings provide some theoretical support for the role of cultural context in the formation of entrepreneurial intentions, which can help countries with diverse cultures to develop differentiated entrepreneurial role model advocacy strategies to better facilitate the emergence of potential entrepreneurs and advance their subsequent entrepreneurial activities. Research limitations/implications First, because this study assumes that entrepreneurial role models are templates that can inspire potential entrepreneurs and provide them with entrepreneurial approaches (Laviolette et al. , 2012), which has a certain positive bias, it may mean that the findings of this paper are not applicable to all scenarios, as role models are usually classified by scholars into positive and negative ones. The effect of different types of role models on entrepreneurial intention in a cross-cultural context will be considered as one of the future research directions. Second, in the measurement of country-level variables, this paper assumes that the degree of media publicity and collectivism are homogeneous within a country and does not take into account the differences in these two variables across regions within the same country. Future research is expected to use more granular designs to explore, for example, the effect of entrepreneurial role models on entrepreneurial intentions based on regional differences in media publicity and collectivism, rather than national differences. Third, due to the cross-sectional research design used in this paper, the dynamic influence of entrepreneurial role models in the entrepreneurial process was not included in the analysis. In addition, the focus of this study is only on entrepreneurial intention, which is separated from the subsequent entrepreneurial behavior of entrepreneurs. Therefore, the longitudinal study design that explores the dynamic influence of role models in entrepreneurial process should receive more attention. Practical implications First, enhancing the exposure of entrepreneurial role models is necessary because the authors found that entrepreneurial role models can positively promote entrepreneurial intentions, whereas self-efficacy plays a mediating role. For example, it is advised for the society to publish entrepreneurs' autobiographies, open entrepreneurial forums, create entrepreneurial interview columns, etc. In these books and activities, detailed descriptions of successful entrepreneurs' methods and skills are highly needed, as these can help potential entrepreneurs to better understand the entrepreneurial process, thus improving their self-efficacy and facilitating their entrepreneurial activities (Zhao et al. , 2005). It is necessary to note here that matching the characteristics of entrepreneurial role models and potential entrepreneurs cannot be ignored, as similar characteristics could facilitate the desire of potential entrepreneurs to become more like entrepreneurial role models (Hoffner and Buchanan, 2005).These similar characteristics encompass both demographic characteristics, such as gender, race and age (Garcia, 2017; Harwood, 1999; Jose, 1989), and personal characteristics, such as goal embodiment and educational background (Bosma et al. , 2012; Morgenroth et al. , 2015). Moreover, the authors believe that the media's promotion of entrepreneurial role models and entrepreneurial activities needs to be enhanced, for example, by incorporating entrepreneurship education in television programs, allowing youth to meet face-to-face with successful entrepreneurs, and developing entrepreneurship lectures or interview programs. Social implications At the same time, role models should be presented differently in diverse cultural contexts. For example, in countries with a strong collectivist orientation, the media should include collectivist messages when promoting entrepreneurial role models, such as his cooperation with the government, family and friends, which is in line with collectivist values, so that potential entrepreneurs in a collectivist context may perceive more similarity to role models and thus increase their entrepreneurial intentions (Morris et al. , 1994); On the contrary, in countries with low collectivist tendencies, the media can appropriately carry an element of individualism when promoting entrepreneurial role models, for example, by telling how entrepreneurs succeed on their own strength and superior abilities, which is in accordance with the values of individualism. Based on the same logic, potential entrepreneurs in the context of individualism may thus generate more entrepreneurial intentions (Morris et al. , 1994). Originality/value First, building on previous studies that explored the relationship between entrepreneurial role models and individuals’ entrepreneurial intentions (Stupacher et al. , 2017), the authors further validated the moderating role of two national-level situational factors, collectivism and media advocacy, in this process, which echoes Abbasianchavari and Moritz (2021) that exploring the effects of entrepreneurial role models on entrepreneurial intentions in different cultural context is an essential topic for the future research. Second, the authors demonstrated that self-efficacy can mediate the relationship between entrepreneurial role models and entrepreneurial intentions and that this finding is generalizable. This responds to the hypothesis presented by Morgenroth et al. (2015) that role models, who are served as behavioral templates, can facilitate the generation of goals and behavioral intentions by increasing role aspirates’ self-efficacy, as it enhances their perceived accessibility to goals. Another contribution is that the authors found a possible explanation that the interaction of collectivism and media publicity with entrepreneurial role models may influence individuals' entrepreneurial intentions by affecting their self-efficacy, which unifies the new institutional theory and social cognition career theory.
Parallel pinch is an important grasp method. The end phalanx of the traditional parallel pinch and self-adaptive gripper moves in an arc trajectory, which requires the auxiliary lifting motion of the ...industrial manipulator, which is inconvenient to use. To solve this problem, a novel robot finger is designed and implemented—Hoecken’s finger. In this finger, the Hoecken linkage mechanism is used to realize the straight-line trajectory of the end joint, the differential mechanism set on the surface of the phalanxes is used to realize the shape self-adaptation of the first and second phalanxes, and the parallel four-bar linkage in series is used to realize the attitude keeping, thus comprehensively realizing the underactuated gripper driven by a single motor. After analyzing the grasp force and grasp motion of Hoecken’s fingers, the optimized parameters are obtained, and the Hoecken’s gripper is developed. The experimental results show that the gripper can realize the self-adaptive grasp function of straight parallel pinch, the grasp is stable, and the grasp range is large. It can be applied to more scenes that need to grasp objects.
Porcine circovirus type 3 (PCV3) is an emerging swine pathogen associated with acute porcine dermatitis and nephropathy syndrome (PDNS)-like clinical signs, reproductive failure, and multisystemic ...inflammation. Current evidence shows that PCV3 is spread worldwide, and its high incidence may pose a threat to the global pig industry. Capsid (Cap) protein is the sole structural protein which plays an important role in inducing protective immunity against PCV3 infection. In this study, monoclonal antibodies (mAbs) against Cap protein of PCV3 were produced by the hybridoma technique. Subsequently, 12 serial overlapping peptides (P1 to P12) spanning the entire region of Cap were synthesized to determine the B cell epitope regions using the mAbs. Results from dot-blot and peptide ELISA identified that P3, P9, and P10 were the major B cell antigenic regions. Fine mapping by shorter N- and C-terminal truncated peptides confirmed that the motifs
57
NKPWH
61
,
140
KHSRYFT
146
, and
161
QSLFFF
166
were linear B cell epitopes, which were highly conserved among different PCV3 strains. Interestingly, we found that the motif
140
KHSRYFT
146
was highly conserved in all reported types of PCVs (i.e., PCV1, PCV2, PCV3, and PCV4), except for the substitution (Y → K → R) of the first residue. This is the first research to identify B cell epitopes of PCV3 Cap, and these findings may lead to a better understanding of the antibody–antigen interaction and provide some guidance for PCV3 vaccine design.
Key points
• The recombinant Cap protein of PCV3 was expressed and purified in soluble form.
• PCV3 Cap-specific mAbs prepared in this study had no cross-reactivity with PCV1/PCV2 Cap.
• This is the first report of three conserved linear B cell epitopes on PCV3 Cap.
• The minimal residues of the epitopes were 57–61 aa, 140–146 aa, and 161–166 aa.
Expanding upon the recently developed aminocatalytic asymmetric indole-2,3-quinodimethane strategy, a straightforward synthesis of structurally and stereochemically complex tetrahydrocarbazoles has ...been devised. The chemistry's complexity-generating power was further harnessed by designing a multicatalytic, one-pot Diels-Alder/benzoin reaction sequence to stereoselectively access trans-fused tetracyclic indole-based compounds having four stereogenic centers with very high fidelity.
Angiogenesis, including the growth of new capillary blood vessels from existing ones and the malignant tumors cells formed vasculogenic mimicry, is quite important for the tumor metastasis. ...Anti-angiogenesis is one of the significant therapies in tumor treatment, while the clinical angiogenesis inhibitors usually exhibit endothelial cells dysfunction and drug resistance. Bis(2,3,6-tribromo-4,5-dihydroxybenzyl)ether (BTDE), a marine algae-derived bromophenol compound, has shown various biological activities, however, its anti-angiogenesis function remains unknown. The present study illustrated that BTDE had anti-angiogenesis effect in vitro through inhibiting human umbilical vein endothelial cells migration, invasion, tube formation, and the activity of matrix metalloproteinases 9 (MMP9), and in vivo BTDE also blocked intersegmental vessel formation in zebrafish embryos. Moreover, BTDE inhibited the migration, invasion, and vasculogenic mimicry formation of lung cancer cell A549. All these results indicated that BTDE could be used as a potential candidate in anti-angiogenesis for the treatment of cancer.
Chronic myelogenous leukemia (CML) is characterized by the constitutive activation of BCR-ABL tyrosine kinase. Imatinib was approved for CML therapy, however, BCR-ABL-dependent drug resistance, ...especially BCR-ABL-T315I mutation, restricts its clinical application. In this study, we reported anthraquinone lactone AS1041, a synthesized derivative of marine natural compound Aspergiolide A, showed anti-leukemia effect in vitro and in vivo by promoting cell senescence. Mechanistic study revealed the pro-senescence effect of AS1041 was dependent on oxidative stress-induced DNA damage, and the resultant activation of P53/P21 and P16INK4a/Rb. Also, AS1041 promoted ubiquitin proteasome system (UPS)-mediated BCR-ABL degradation, which also contributed to AS1041-induced senescence. In vivo, AS1041-induced senescence promoted tumor growth inhibition. In summary, the in vitro and in vivo antitumor effect of AS1041 suggests it can serve as a pro-senescence agent for alternative antileukemia therapy and imatinib-resistant cancer therapy by enhancing cellular oxidative stress and BCR-ABL degradation.
Display omitted
•AS1041 showed anti-leukemia effect in vitro and in vivo.•The anti-leukemia effect of AS1041 was related to senescence induction.•The activation of P53/P21 and P16INK4a/Rb induced by AS1041 contributed senescence.•AS1041-induced proteasomic degradation of BCR-ABL promoted senescence.
Trench cutting re-mixing deep wall method (TRD) is an increasingly common method for building waterproof curtains in deep foundation pits. By combining numerical simulations and field monitoring, ...this study investigated the deformation characteristics of the TRD cement soil mixing wall and soil surrounding the foundation pit. By considering the effect of the discreteness of the TRD cement soil mixing wall’s mechanical properties on the excavation stability under different stratigraphic conditions, the mechanical model of the TRD composite supporting structure was established using FLAC
3D
to simulate the foundation pit excavation process. In addition, field excavation monitoring was performed and compared with simulation results. The results revealed that the lateral deformation of the TRD cement soil mixing wall obtained by simulation was accurate, although the peripheral ground settlement was slightly smaller than the measured value. The maximum lateral deformation of the TRD cement soil mixing wall is positively correlated to the excavation depth. The maximum settlement value of the surface gradually increased as the construction stages progressed. As the distance from the enclosure grew, the settlement value first increased and then decreased. In the same construction stage, the TRD cement soil mixing wall shear stress increased with the depth and was maximum close to the excavation face of each step. Therefore, the design should fully consider the influence of a sudden force change caused by soil excavation on the TRD cement soil mixing wall.
Pseudorabies (PR) is a multi-animal comorbid disease caused by pseudorabies virus (PRV), which are naturally found in pigs. At the end of 2011, the emergence of PRV variant strains in many provinces ...in China had caused huge economic losses to pig farms. Rapid detection diagnosis of pigs infected with the PRV variant helps prevent outbreaks of PR. The immunochromatography test strip with colloidal gold nanoparticles is often used in clinical testing due to its low cost and high throughput.
This study was designed to produce monoclonal antibodies targeting PRV through immunization of mice using the eukaryotic system to express the gE glycoprotein. Subsequently, paired monoclonal antibodies were screened based on their sensitivity and specificity for use in the preparation of test strips.
The strip prepared in this study was highly specific, only PRV was detected, and there was no cross-reactivity with glycoprotein gB, glycoprotein gC, glycoprotein gD, and glycoprotein gE of herpes simplex virus and varicellazoster virus, porcine epidemic diarrhea virus, Senecavirus A, classical swine fever virus, porcine reproductive and respiratory syndrome virus, and porcine parvovirus. Moreover, it demonstrated high sensitivity with a detection limit of 1.336 × 10
copies/μL (the number of viral genome copies per microliter); the coincidence rate with the RT-PCR detection method was 96.4%. The strip developed by our laboratory provides an effective method for monitoring PRV infection and controlling of PR vaccine quality.
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