•We examine how region-specific institutions moderate the relationship between academic collaborations and innovation performance.•There are significant within-country variations in IPR enforcement, ...international openness and quality of universities and research institutes.•IPR enforcement, international openness and the quality of universities and research institutes increase the effects of academic collaborations on innovation performance.
Although prior research has highlighted the importance of academic collaborations in enhancing firms’ innovation performance, it has largely focused on developed countries. As a result, how academic collaborations influence innovation in emerging countries, which differ fundamentally from developed countries in their institutional environment, remains unclear. We contribute to this literature by examining how collaborations with universities and research institutes influence the ability of Chinese emerging market enterprises (EMEs) to develop innovations. Our analysis challenges the assumption of institutional homogeneity within a given country, showing that institutions evolve in different ways across sub-national Chinese regions. This uneven institutional evolution affects the enforcement of intellectual property rights (IPRs), the level of international openness, the quality of universities and research institutes across regions and thus the degree to which Chinese EMEs benefit from academic collaborations. Our findings reveal that sub-national institutional variations have a profound impact on the relationship between academic collaborations and firms’ innovation performance, illustrate that some established assumptions are not valid in emerging countries, such as China, and offer insights into how EMEs can enhance their innovation performance.
Aluminum (Al) and copper (Cu) have been widely used in many industrial fields thanks to their good plasticity, high thermal conductivity and excellent electrical conductivity. An effective joining of ...dissimilar Al and Cu materials can make full use of the special characteristics of these two metals. Friction stir spot welding (FSSW), as an efficient solid-state welding method suitable for joining of dissimilar metal materials, has great prospects in future industrial applications. In this paper, the FSSW studies on Al-Cu dissimilar materials are reviewed. The research progress and current status of Al-Cu FSSW are reviewed with respect to tool features, macroscopic characteristics of welded joints, microstructures, defects in welds and mechanical properties of joints. In addition, some suggestions on further study are put forward in order to promote the development and progress of Al-Cu FSSW studies in several respects: material flow, thermal history, addition of intermediate layer, auxiliary methods and functionalization of Al-Cu FSSW joint.
China is an important centre of diversity for Prunus persica. In the present study, 17 Chinese peach cultivars were evaluated for phenolic content and antioxidant activity. Neochlorogenic acid ...(NCHA), chlorogenic acid (CHA), procyanidin B1 (B1), catechin (CAT), cyanidin-3-O-glucoside (C3G), quercetin-3-O-galactoside (Q3GAL), quercetin-3-O-glucoside (Q3GLU), quercetin-3-O-rutinoside (Q3R), and kaempferol-3-O-rutinoside (K3R) were identified and quantified. CHA and CAT were the predominant components in both the peel and pulp of this fruit. In general, peel extracts showed higher antioxidant activities than the pulp counterparts, consistent with the observed higher phenolic content. The melting peach cultivar "Xinyu" showed the highest antioxidant potency composite (APC) index. The principal component analysis (PCA) of peel phenolics showed a clear distinction between the melting peach and nectarine. Overall, peach cultivars rich in hydroxycinnamates and flavan-3-ols showed relatively higher antioxidant activities and might be excellent sources of phytochemicals and natural antioxidants.
•19 PACs and 37 other phenolic compounds were quantified in fruits of 217 peach accessions.•Most quantified phenolics showed a vast diversity between tested peach accessions.•PACs and other phenolics ...are affected by peach origins, fruit maturing periods, and fruit types.•Peaches with medium astringency had higher levels of PAC and phenolic acid than those without.
Peach fruits are rich in phenolic compounds and have considerable health benefits. In this study, 19 proanthocyanidins (PACs) and 37 other phenolic compounds are identified and evaluated in the mature fruits of 217 peach accessions using LC-QTRAP-MS/MS and LC-QTOF-MS analyses. Total PAC quantities ranged from 18.93 to 697.52 μg/g fresh weight with a variance of 36.8-fold, and accounted for 11.2 % − 85.6 % of total phenolics content. Kaempferol-3-O-rutinoside (0.001–0.968 μg/g), isorhamnetin-3-O-rutinoside (0.001–0.300 μg/g), taxifolin (0.006–0.078 μg/g), luteoloside (0.002–0.068 μg/g), prunin (0.043–33.333 μg/g), phlorizin (0.018–1.100 μg/g), and trans-piceid (0.013–0.472 μg/g) were also highly diverse. The fruit ripening period, breeding background and fruit type significantly influenced the PACs and phenolic glycosides. This study presents a complete profile of PACs and other major phenolics in 217 peach germplasms, and is expected to aid future peach breeding procedures targeted at producing plants rich in specific phenolics.
Historical relics of Jurassic sandstones in southwest China have been subjected to weathering damage. Exfoliation, characterized by the detachment of multiple thin stone layers sub-parallel to the ...stone surface, is common in sandstone heritage sites. However, its mechanism of action remains poorly understood. In this study, a conceptual model of exfoliation is drawn from the literature and field investigations. To quantitatively determine the exfoliation mechanism, a range of non-destructive field-based methods (surface hardness, water absorption test, roughness, and amplitude of residual spalling layers) and laboratory analyses (scanning electron microscopy (SEM) and X-ray diffraction (XRD)) are adopted as weathering agents for separated detachments. In addition, the grain and pore sizes of weathering products are analyzed using digital image techniques. The results show that the roughness, water absorption coefficient, and pore size in sandstone surfaces increase from the inner layer to the outer layer, and their hardness and grain size decrease, respectively. The proportions of quartz, dolomite, and illite increases from the interior to the exterior, whereas the proportion of feldspar decreases correspondingly. The residual column strip structure derived from feldspar alteration and a mixed montmorillonite-illite mineral layer can be observed in the SEM images. It can be inferred from surviving environmental analysis that comprehensive actions from solar radiation, acid rain attack and capillary rise lead to sandstone exfoliation. In addition, the alteration of feldspar plays an important role during sandstone exfoliation. The results of this study enhance our understanding of the exfoliation of the Jurassic sandstone of the Chongqing Danzishi rock carvings in China.
•Exfoliation was comprehensive studied and its mechanism was quantitatively revealed.•Roughness, water absorption coefficient and pore size increase from the inner layer to the outer layer, and hardness, grain size and propotion of feldspar decrease correspondingly.•Comprehensive actions from solar radiation, acid rain attack and capillary rise lead to sandstone exfoliation.
To investigate the effects of scleral collagen cross-linking (SXL) using riboflavin and ultraviolet A (UVA) light on the scleral thickness of different regions and expression of matrix ...metalloproteinase 2 (MMP-2) and membrane-type MMP-1 (MT1-MMP) in guinea pigs with lens-induced myopia.
Forty-eight 4-week-old guinea pigs were assigned to three groups (n = 16 per group): SXL group, lens-induced myopia (LIM) group, and control group. The sclera of the right eye of the guinea pig in the SXL group was surgically exposed, riboflavin was dropped on the treatment area for 10 minutes before the 30-minute UVA irradiation. The same surgical procedure was performed in the LIM group without UVA irradiation. The -10.00 D lenses were then placed on the right eyes of guinea pigs in the SXL and LIM groups for six weeks. The control group received no treatment. The left eyes were untreated in all groups. The ocular axial length (AXL) and refraction were measured at 4 weeks and 10 weeks of age. 10-week-old guinea pigs were sacrificed, and the right eyes were enucleated and evenly divided for preparation of hematoxylin and eosin (HE) stained sections, quantitative real-time polymerase chain reaction (qPCR) and western blotting. The scleral thickness of different regions was measured on HE stained sections. The temporal half of the sclera was harvested to measure the expression of MMP-2 and MT1-MMP by qPCR and western blotting.
The AXL was significantly shorter, and the degree of myopic refraction was significantly lower in the SXL group than those in the LIM group at 10 weeks of age. The scleral thickness of the cross-linked area was significantly greater in the SXL group than that of the corresponding area in the LIM group, while the scleral thickness of the untreated nasal side was not significantly different between the SXL group and the LIM group. The expression of MMP-2 and MT1-MMP of the cross-linked sclera was significantly downregulated compared with that of the corresponding area in the LIM group.
Riboflavin/UVA SXL could slow myopia progression and thicken the cross-linked sclera in guinea pigs, which might be related to the downregulation of MMP-2 and MT1-MMP expression during the scleral remodeling process.
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•Both metabolites profile and antioxidant activities were varied among tested 40 peach cultivars.•PLS regression model confirmed key compounds in peach pulp contributing to ...antioxidant activity.•Procyanidins and phloridzin were screened out as antioxidant marker compounds of peaches.
Peaches (Prunus persica (L.) Batsch) are nutritionally and economically important and they are one of the most popular fruits consumed worldwide. Understanding metabolite-caused bioactivity differences among cultivars is essential for designing a peach with enhanced nutritional traits. In this study, we report an untargeted UPLC-Q-TOF/MS-based metabolomics approach for comprehensively discriminating between peaches with different antioxidant activities. Mature fruit from 40 peach cultivars were distinguished using principal component analysis and orthogonal partial least squares discrimination analysis. Seventeen differential metabolites were tentatively identified between peach cultivars with high and low antioxidant potency composite indices, and eight metabolites, including procyanidin C1, procyanidin trimer isomer 1, procyanidin trimer isomer 2, procyanidin B1, procyanidin B2, procyanidin B3, prunus inhibitor b, and phloridzin, were identified as marker compounds responsible for the discrimination of the cultivars base on potential antioxidant activity. Our study highlights the essence and predictive power of metabolomics for detecting small differences and for identifying potential marker metabolites based on their levels and composition in plants exhibiting varying bioactivities. Overall, the variations in the metabolites in peach pulp reflected the diversity in the peach germplasm, and these eight compounds are good candidate markers for future genetic breeding of peach fruit with enhanced antioxidant activity.
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•The location-controlled cracks were obtained with parallel-hatching scan strategy.•The LAGB generation and cracking are two competing ways to release stress.•The nanopore weakening ...effect on GB strengths was calculated to be nearly 70%.•Geometric effects on crack and microstructure were revealed in multi-wall samples.
Cracking is a critical issue in the additive manufacturing of pure tungsten (W). To eliminate crack formation, it is imperative to gain an in-depth understanding of the underlying mechanisms behind this process. In this study, we systematically investigated the crack behaviors of single tracks, thin walls, and cubes fabricated using powder bed fusion–laser beam (PBF–LB) technology with nonrotational parallel-hatching scanning. The energy framework was employed to elucidate the mechanism of crack formation. The longitudinal cracks appearing in the microstructures of single tracks and the through cracks existing in thin walls and cubes were characterized. Notably, periodic through cracks extended upward across the sample, appearing at every single hatch in unidirectional samples and at every other hatch in bidirectional samples. The horizontal, longitudinal, and transverse cross sections of cubes were studied to clarify the correlation between through crack arrangement and solidification microstructure. Based on a comprehensive analysis of grain boundaries, we proposed a deformation-cracking competition mechanism in PBF–LB tungsten. Geometric effects in the crack and microstructure were also revealed. This study could provide valuable insights into the formation of cracks in PBF–LB tungsten and serve as a foundation for future investigations aimed at eliminating cracks.
In order to fully understand the variation of the fruit alpha-glucosidase inhibitory activity-related phytochemical basis in the Chinese peach
(L.) Batsch, mature fruit from 33 cultivars was used ...for the investigation of fruit phenolic phytochemical attributes, including total phenolics, flavonoids, anthocyanins, and procyanidins, as well as the alpha-glucosidase inhibitory activity in vitro. Alpha-glucosidase inhibitory activity varied significantly among tested peach cultivars and was strongly correlated with total phenolics, total procyanidins, and total flavonoids. Untargeted UPLC-Q-TOF/MS-based metabolomics were used to comprehensively discriminate between peaches with different inhibitory activity on alpha-glucosidase. Principal component analysis (PCA) and orthogonal partial least squares discrimination analysis (OPLS-DA) were used for this process. Twenty-three differential compounds were identified between peach cultivars with high and low alpha-glucosidase inhibitory activity, and nine, including procyanidin C1, procyanidin trimer isomer 1, procyanidin trimer isomer 2, procyanidin B1, procyanidin dimer, epicatechin-epicatechin-epicatechin, phloridzin, kaempferol 3-(2'',6''-di-(E)-p-coumarylglucoside), and luteolin 3'-methyl ether 7-malonylglucoside, were identified as marker compounds responsible for the discrimination. Overall, variations in metabolites in peach pulp reflect the diversity in peach germplasm, and these nine compounds are good candidate markers for future genetic breeding of peach fruit with high alpha-glucosidase inhibitory activity.
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