A long non-coding RNA functions as a competitive endogenous RNA to modulate TaNAC018 by acting as a decoy for tae-miR6206.

Increasing evidence indicates a strong correlation between the deposition of cuticular waxes and drought tolerance. However, the precise regulatory mechanism remains elusive. Here, we conducted a comprehensive transcriptome analysis of two wheat (Triticum aestivum) near-isogenic lines, the glaucous line G-JM38 rich in cuticular waxes and the non-glaucous line NG-JM31. We identified 85,143 protein-coding mRNAs, 4,485 lncRNAs, and 1,130 miRNAs. Using the lncRNA-miRNA-mRNA network and endogenous target mimic (eTM) prediction, we discovered that lncRNA35557 acted as an eTM for the miRNA tae-miR6206, effectively preventing tae-miR6206 from cleaving the NAC transcription factor gene TaNAC018. This lncRNA-miRNA interaction led to higher transcript abundance for TaNAC018 and enhanced drought-stress tolerance. Additionally, treatment with mannitol and abscisic acid (ABA) each influenced the levels of tae-miR6206, lncRNA35557, and TaNAC018 transcript. The ectopic expression of TaNAC018 in Arabidopsis also improved tolerance toward mannitol and ABA treatment, whereas knocking down TaNAC018 transcript levels via virus-induced gene silencing in wheat rendered seedlings more sensitive to mannitol stress. Our results indicate that lncRNA35557 functions as a competing endogenous RNA to modulate TaNAC018 expression by acting as a decoy target for tae-miR6206 in glaucous wheat, suggesting that non-coding RNA has important roles in the regulatory mechanisms responsible for wheat stress tolerance.

Characterization of the powdery mildew resistance locus in wheat breeding line Jimai 809 and its breeding application.

Powdery mildew, caused by Blumeria graminis f. sp. tritici (Bgt), is a severe disease that affects the yield and quality of wheat. Popularization of resistant cultivars in production is the preferred strategy to control this disease. In the present study, the Chinese wheat breeding line Jimai 809 showed excellent agronomic performance and high resistance to powdery mildew at the whole growth stage. To dissect the genetic basis for this resistance, Jimai 809 was crossed with the susceptible wheat cultivar Junda 159 to produce segregation populations. Genetic analysis showed that a single dominant gene, temporarily designated PmJM809, conferred the resistance to different Bgt isolates. PmJM809 was then mapped on the chromosome arm 2BL and flanked by the markers CISSR02g-1 and CIT02g-13 with genetic distances 0.4 and 0.8 cM, respectively, corresponding to a physical interval of 704.12-708.24 Mb. PmJM809 differed from the reported Pm genes on chromosome arm 2BL in origin, resistance spectrum, physical position and/or genetic diversity of the mapping interval, also suggesting PmJM809 was located on a complex interval with multiple resistance genes. To analyze and screen the candidate gene(s) of PmJM809, six genes related to disease resistance in the candidate interval were evaluated their expression patterns using an additional set of wheat samples and time-course analysis post-inoculation of the Bgt isolate E09. As a result, four genes were speculated as the key candidate or regulatory genes. Considering its comprehensive agronomic traits and resistance findings, PmJM809 was expected to be a valuable gene resource in wheat disease resistance breeding. To efficiently transfer PmJM809 into different genetic backgrounds, 13 of 19 closely linked markers were confirmed to be suitable for marker-assisted selection. Using these markers, a series of wheat breeding lines with harmonious disease resistance and agronomic performance were selected from the crosses of Jimai 809 and several susceptible cultivars. Supplementary Information: The online version contains supplementary material available at 10.1007/s11032-024-01467-8.

Proximal femoral tumor resection followed by joint prosthesis replacement: a systematic review and meta-analysis.

BACKGROUND: This study aimed to determine the prognostic outcome of hip joint replacement after resection of proximal femoral tumors by reviewing original studies. METHODS: Two researchers independently searched PubMed, Embase, Cochrane Library, and Web of Science databases from inception to July 17, 2022. Then, the literature was screened by inclusion criteria. The basic information, primary outcomes, and secondary outcomes were extracted for weighted combined analysis. The quality of the included literature was evaluated using the Newcastle-Ottawa scale. RESULTS: Twenty-four retrospective cohort studies comprising 2081 patients were included. The limb salvage rate was 98%. The survival rates at 1, 2, 3, 4, and 5 years were 80, 72, 65, 64, and 55% for patients with primary tumors and the rate at 1, 2, 3, 4, and 5 years were 44, 25, 17, 14, and 11% for patients with bone metastases, respectively. CONCLUSION: As chemotherapy and radiotherapy treatment progressed, joint reconstruction after proximal femoral tumor resection improved patients' function and quality of life.

Has breeding altered the light environment, photosynthetic apparatus, and photosynthetic capacity of wheat leaves?

Whether photosynthesis has improved with increasing yield in major crops remains controversial. Research in this area has often neglected to account for differences in light intensity experienced by cultivars released in different years. Light intensity is expected to be positively associated with photosynthetic capacity and the resistance of the photosynthetic apparatus to high light but negatively associated with light-utilization efficiency under low light. Here, we analyzed the light environment, photosynthetic activity, and protein components of leaves of 26 winter wheat cultivars released during the past 60 years in China. Over time, light levels on flag leaves significantly decreased due to architectural changes, but photosynthetic rates under high or low light and the resistance of the photosynthetic apparatus to high light remained steady, contrary to expectations. We propose that the difference between the actual and expected trends is due to breeding. Specifically, breeding has optimized photosynthetic performance under high light rather than low light. Moreover, breeding selectivity altered the stoichiometry of several proteins related to dynamic photosynthesis, canopy light distribution, and photoprotection. These results indicate that breeding has significantly altered the photosynthetic mechanism in wheat and its response to the light environment. These changes likely have helped increase wheat yields.

Effects of the different waxy proteins on starch biosynthesis, starch physicochemical properties and Chinese noodle quality in wheat.

Noodles are an important food in Asia. Wheat starch is the most important component in Chinese noodles. Loss of the waxy genes leads to lower activity of starch synthesis enzymes and decreased amylose content that further affects starch properties and noodle quality. To study the effects of different waxy (Wx) protein subunits on starch biosynthesis and processing quality, the high-yielding wheat cultivar Jimai 22 was treated with the mutagen ethyl methane sulfonate (EMS) to produce a population of Wx lines and chosen 7 Wx protein combinations. The amylose content increased but swelling power decreased as the number of Wx proteins increased. Both GBSS activity and gene expression were the lowest for the waxy mutant, followed by the mutants with 1 Wx protein. The combinations of these mutant alleles lead to reductions in both RNA expression and protein levels. Noodles made from materials with 2 Wx protein subunits had the highest score, which agreed with peak viscosity. The influence of the Wx-B1 protein on amylose synthesis and noodle quality was the highest, whereas the influence of Wx-A1 protein was the lowest. Mutants with lower amylose content caused by the absence of 1 subunit, especially the Wx-B1 subunit, had superior noodle quality. Additionally, the identified mutant lines can be used as intermediate materials to improve wheat quality. Supplementary Information: The online version contains supplementary material available at 10.1007/s11032-022-01292-x.

Identification and Evaluation of Wheat-Aegilops bicornis Lines with Resistance to Powdery Mildew and Stripe Rust.

Wheat pathogens, especially those causing powdery mildew and stripe rust, seriously threaten yield worldwide. Utilizing newly identified disease resistance genes from wheat relatives is an effective strategy to minimize disease damage. In this study, chromosome-specific molecular markers for the 3Sb and 7Sb chromosomes of Aegilops bicornis were developed using PCR-based landmark unique gene primers for screening wheat-A. bicornis progenies. Fluorescence in situ hybridization (FISH) was performed to further identify wheat-A. bicornis progenies using oligonucleotides probes Oligo-pSc119.2-1, Oligo-pTa535-1, and Oligo-(GAA)8. After establishing A. bicornis 3Sb and 7Sb chromosome-specific FISH markers, Holdfast (common wheat)-A. bicornis 3Sb addition, 7Sb addition, 3Sb(3A) substitution, 3Sb(3B) substitution, 3Sb(3D) substitution, 7Sb(7A) substitution, and 7Sb(7B) substitution lines were identified by the molecular and cytological markers. Stripe rust and powdery mildew resistance, along with agronomic traits, were investigated to evaluate the breeding potential of these lines. Holdfast and Holdfast-A. bicornis progenies were all highly resistant to stripe rust, indicating that the stripe rust resistance might derive from Holdfast. However, Holdfast-A. bicornis 3Sb addition, 3Sb(3A) substitution, 3Sb(3B) substitution, and 3Sb(3D) substitution lines showed high resistance to powdery mildew while Holdfast was highly susceptible, indicating that chromosome 3Sb of A. bicornis carries previously unknown powdery mildew resistance gene(s). Additionally, the transfer of the 3Sb chromosome from A. bicornis to wheat significantly increased tiller number, but chromosome 7Sb has a negative effect on agronomic traits. Therefore, wheat germplasm containing A. bicornis chromosome 3Sb has potential to contribute to improving powdery mildew resistance and tiller number during wheat breeding.

Autonomic Behaviors in Lipase-Active Oil Droplets.

Developing self-fueled micro-reactor droplets with programmable autonomic behaviors provides a step towards smart liquid dispersions comprising motile microscale objects. Herein, we prepare aqueous suspensions of lipase-coated oil globules comprising a mixture of a triglyceride substrate (tributyrin, 1,2,3-tributylglycerol) and a low-density oil (polydimethylsiloxane, PDMS) and describe a range of active behaviors based on controlled enzyme-mediated consumption of individual droplets under non-equilibrium conditions. Encapsulation of the lipase-coated lipid/PDMS droplets into a model protocell as energy-rich sub-compartments is demonstrated as an internalized mechanism for activating protocell buoyancy. Taken together, our results highlight opportunities for the regulation of autonomic behavior in enzyme-powered oil droplets and provide a new platform for increasing the functionality and energization of synthetic protocells.

The influence of environmental factors on clinical pathological changes of patients with immunoglobulin A nephropathy from different areas of China.

OBJECTIVES: The effects of regional characteristics of IgAN patients in different areas of China were investigated. METHODS: Patients who were identified to have primary IgAN by renal biopsy diagnosis were recruited both from Shaanxi province hospital of traditional Chinese medicine and Guangdong province hospital of traditional Chinese medicine. Besides renal histopathology data, a number of clinical and laboratory data were collected. RESULTS: It was shown that the frequency of the patients with no mucosal infection in the urinary tract was higher in the Guangzhou group, while the frequencies of upper respiratory tract and biliary infections were lower when compared with those in the Xi'an group. Serum uric acid, alexin C3, creatinine and serum cholesterol concentrations were increased in the Guangzhou group, while triglyceride, glomerular filtration rate, and urine red blood cell count level decreased. IgA + IgM + C3 and IgA + IgG + IgM + C3 were found in most patients of the Xi'an group, whereas IgA + C3, IgA + IgM + C3 and IgA were more frequent in the Guangzhou group. CONCLUSION: It was found that differential environment, life habits and patterns in the two investigated areas obviously may influence the variable characteristics of IgAN patients.

Atomic Force Microscopy Sidewall Imaging with a Quartz Tuning Fork Force Sensor.

Sidewall roughness measurement is becoming increasingly important in the micro-electromechanical systems and nanoelectronics devices. Atomic force microscopy (AFM) is an emerging technique for sidewall scanning and roughness measurement due to its high resolution, three-dimensional imaging capability and high accuracy. We report an AFM sidewall imaging method with a quartz tuning fork (QTF) force sensor. A self sensing and actuating force sensor is fabricated by microassembling a commercial AFM cantilever (tip apex radius ≤10 nm) to a QTF. The attached lightweight cantilever allows high-sensitivity force detection (7.4% Q factor reduction) and sidewall imaging with high lateral resolution. Owing to its unique configuration, the tip of the sensor can detect sidewall surface orthogonally during imaging, which reduces lateral friction. In experiments, sidewalls of a micro-electro-mechanical system (MEMS) structure fabricated by deep reactive ion etching process and a standard step grating are scanned and the sidewall roughness, line edge roughness and sidewall angles are measured.

Multiparametric Kelvin Probe Force Microscopy for the Simultaneous Mapping of Surface Potential and Nanomechanical Properties.

We report high-resolution multiparametric kelvin probe force microscopy (MP-KPFM) measurements for the simultaneous quantitative mapping of the contact potential difference (CPD) and nanomechanical properties of the sample in single-pass mode. This method combines functionalities of the force-distance-based atomic force microscopy and amplitude-modulation (AM) KPFM to perform measurements in single-pass mode. During the tip-sample approach-and-retract cycle, nanomechanical measurements are performed for the retract part of nanoindentation, and the CPD is measured by the lifted probe with a constant tip-sample distance. We compare the performance of the proposed method with the conventional KPFMs by mapping the CPD of multilayer graphene deposited on n-doped silicon, and the results demonstrate that MP-KPFM has comparable performance to AM-KPFM. In addition, the experimental results of a custom-fabricated polymer grating with heterogeneous surfaces validate the multiparametric imaging capability of the MP-KPFM. This method can have potential applications in finding the inherent link between nanomechanical properties and the surface potential of the materials, such as the quantification of the electromechanical response of the deformed piezoelectric materials.

In Situ Gelation-Induced Death of Cancer Cells Based on Proteinosomes.

Hydrogels are an excellent type of material that can be utilized as a platform for cell culture. However, when a bulky hydrogel forms on the inside of cancer cells, the result would be different. In this study, we demonstrate a method for in situ gelation inside cancer cells that can efficiently induce cell death. Glutathione-responsive proteinosomes with good biocompatibility were prepared as carriers for sodium alginate to be endocytosed by cancer cells, where the chelation between sodium alginate and free calcium ions in the culture medium occurs during the diffusion process. The uptake of the hydrogel-loaded proteinosomes into the cancer cells, and then the triggered release of hydrogel with concomitant aggregation, was well-confirmed by monitoring the change of the Young's modulus of the cells based on AFM force measurements. Accordingly, when a large amount of hydrogel formed in cells, the cell viability would be inhibited by ∼90% by MTT assay at a concentration of 5.0 µM of hydrogel-loaded proteinosomes after 48 h incubation, which clearly proves the feasibility of the demonstrated method for killing cancer cells. Although more details regarding the mechanism of cell death should be conducted in the near future, such a demonstrated method of in situ gelation inside cells provides another choice for killing cancer cells.

Genetic analysis of phytoene synthase 1 (Psy1) gene function and regulation in common wheat.

BACKGROUND: Phytoene synthase 1 (PSY1) is the most important regulatory enzyme in carotenoid biosynthesis, whereas its function is hardly known in common wheat. The aims of the present study were to investigate Psy1 function and genetic regulation using reverse genetics approaches. RESULTS: Transcript levels of Psy1 in RNAi transgenic lines were decreased by 54-76 % and yellow pigment content (YPC) was reduced by 26-35 % compared with controls, confirming the impact of Psy1 on carotenoid accumulation. A series of candidate genes involved in secondary metabolic pathways and core metabolic processes responded to Psy1 down-regulation. The aspartate rich domain (DXXXD) was important for PSY1 function, and conserved nucleotides adjacent to the domain influenced YPC by regulating gene expression, enzyme activity or alternative splicing. Compensatory responses analysis indicated that three Psy1 homoeologs may be coordinately regulated under normal conditions, but separately regulated under stress. The period 14 days post anthesis (DPA) was found to be a key regulation node during grain development. CONCLUSION: The findings define key aspects of flour color regulation in wheat and facilitate the genetic improvement of wheat quality targeting color/nutritional specifications required for specific end products.

Molecular and Cytogenetic Characterization of a Powdery Mildew-Resistant Wheat-Aegilops mutica Partial Amphiploid and Addition Line.

Aegilops mutica Boiss., a diploid species (2n = 2x = 14, TT), has been rarely studied before. In this research, a hexaploid wheat (cv. Chinese Spring)-Ae. mutica partial amphiploid and a wheat-Ae. mutica addition line were characterized by chromosome karyotyping, FISH using oligonucleotides Oligo-pTa535-1, Oligo-pSc119.2-1, and (GAA)8 as probes, and EST-based molecular markers. The results showed that the partial amphiploid strain consisted of 20 pairs of wheat chromosomes and 7 pairs of Ae. mutica chromosomes, with both wheat 7B chromosomes missing. EST-based molecular marker data suggested that the wheat-Ae. mutica addition line carries the 7T chromosome. Resistance tests indicated that both the partial amphiploid and the 7T addition line were highly resistant to powdery mildew, whereas the wheat control line Chinese Spring was highly susceptible, indicating the presence of a potentially new powdery mildew resistance gene on the Ae. mutica 7T chromosome. The karyotype, FISH patterns, and molecular markers can now be used to identify Ae. mutica chromatin in a wheat background, and the 7T addition could be used as a new powdery mildew resistance source for wheat breeding.

How to mitigate the inhibitory effect of organizational inertia on corporate digital entrepreneurship?

As a novel way for incumbent firms to discover and utilize entrepreneurial opportunities in the digital era, corporate digital entrepreneurship (CDE) is significant for realizing digital transformation through dealing with organizational sclerosis and bureaucratization. Previous studies have identified the variables having positive effects on CDE and put forward practical solutions to promoting CDE. However, the majority of them have ignored the variables having negative effects on CDE and how to mitigate the inhibitory effects. In order to fill the research gap, this study investigates the causal relationship between organizational inertia (OI) and CDE and examines the moderating roles of internal factors such as digital capability (DC) and entrepreneurial culture (EC) as well as external factors such as institutional support (IS) and strategic alliance (SA). Based on multiple linear regression (symmetric) and fuzzy-set qualitative comparative analysis (asymmetric) using survey data from 349 Chinese firms, the results demonstrate that OI has a significant negative effect on CDE. In addition, DC, EC, and SA play negative moderating roles in the relationship between OI and CDE, which means that they could reduce the inhibitory effect derived from OI when incumbent firms implement CDE. Moreover, dividing OI into three dimensions discovers that the moderating roles of DC, EC, and SA present different features. This study enriches the literature on corporate entrepreneurship and provides valuable practical implications for incumbent firms to achieve successful CDE by revealing how to overcome the inertia deeply embedded in organizations.

Genome-wide analysis of hyperosmolality-gated calcium-permeable channel (OSCA) family members and their involvement in various osmotic stresses in Brassica napus.

Plant hyperosmolality-gated calcium-permeable channel (OSCA) is a calcium permeable cation channel that responds to hyperosmotic stress and plays a pivotal role in plant growth, development and stress response. Through a genome-wide survey, 41 OSCA genes were identified from the genome of Brassica napus. The OSCA family genes were unevenly distributed over 14 chromosomes of B. napus and phylogenetic analysis separated the OSCA family into four clades. Motif analyses indicated that OSCA proteins in the same clade were highly conserved and the protein conserved motifs shared similar composition patterns. The OSCA promoter regions contained many hormone-related elements and stress response elements. Gene duplication analysis elucidated that WGD/segmental duplication was the main driving force for the expansion of OSCA genes during evolution and these genes mainly underwent purifying selection. RNA-seq and qRT-PCR analysis of different tissues showed that OSCA genes are expressed and function mainly in the root. Among these genes, BnOSCA3.1a and BnOSCA3.1c had relatively high expression levels under osmotic stresses and cold stress and were highly expressed in different tissues. Protein interaction network analysis showed that a total of 5802 proteins might interact with OSCAs in B. napus, while KEGG/GO enrichment analysis indicated that OSCAs and their interacting proteins were mainly involved in plant response to abiotic stress. This systematic analysis of the OSCAs in B. napus identified gene structures, evolutionary features, expression patterns and related biological processes. These findings will facilitate further functional and evolutionary analysis of OSCAs in B. napus for breeding of osmotic-stress-resistant plants.

Single Crystalline Transparent Conducting F, Al, and Ga Co-Doped ZnO Thin Films with High Photoelectrical Performance.

Transparent conductive film (TCF) is a material that integrates electrical conductivity and optical transparency. It is widely used as an electrode material in thin-film solar cells. However, considerable progress is needed to facilitate its high performance and low-cost preparation. In this study, a preparation scheme for AlF3 and GaF3 co-doped ZnO (FAGZO) thin films was designed and implemented by magnetron sputtering (MS). The mutual restraint between the electrical properties and the wide-spectrum transmission performance of ZnO films was resolved. First-principles calculations showed that the doped ZnO system had n-type conductivity and that the most stable structure was the FO-AlZn-GaZn system. The experimental results verified the theoretical predictions. Single crystalline ZnO transparent conducting films (ZnO-TCFs) of high quality were achieved by MS. After rapid thermal annealing (RTA) treatment, the mobility reached 49.6 cm2/V s, and the resistivity decreased to 3.82 × 10-4 Ω cm. The AT was 90% between 380 and 1200 nm. Furthermore, the application of the prepared FAGZO film in perovskite solar cells (PSCs) has been verified. Compared to the reference indium tin oxide film, the PSCs using the FAGZO film showed higher JSC and power conversion efficiency. These results demonstrate that MS combined with anion and cation co-doping provides an effective means of exploring high-quality and high-performance ZnO-TCFs.

Functional analysis of polyphenol oxidase 1 gene in common wheat.

Polyphenol oxidase (PPO) activity is a major cause of the undesirable brown color of wheat-based products. Ppo1, a major gene for PPO activity, was cloned based on sequence homology in previous studies; however, its function and regulation mechanism remain unclear. In this study, the function and genetic regulation of Ppo1 were analyzed using RNA interference (RNAi) and Targeting Induced Local Lesions IN Genomes (TILLING) technology, and superior mutants were identified. Compared with the control, the level of Ppo1 transcript in RNAi transgenic lines was drastically decreased by 15.5%-60.9% during grain development, and PPO activity was significantly reduced by 12.9%-20.4%, confirming the role of Ppo1 in PPO activity. Thirty-two Ppo1 mutants were identified in the ethyl methanesulfonate (EMS)-mutagenized population, including eight missense mutations, 16 synonymous mutations, and eight intron mutations. The expression of Ppo1 was reduced significantly by 6.7%-37.1% and 10.1%-54.4% in mutants M092141 (G311S) and M091098 (G299R), respectively, in which PPO activity was decreased by 29.7% and 28.8%, respectively, indicating that mutation sites of two mutants have important effects on PPO1 function. Sequence and structure analysis revealed that the two sites were highly conserved among 74 plant species, where the frequency of glycine was 94.6% and 100%, respectively, and adjacent to the entrance of the hydrophobic pocket of the active site. The M092141 and M091098 mutants can be used as important germplasms to develop wheat cultivars with low grain PPO activity. This study provided important insights into the molecular mechanism of Ppo1 and the genetic improvement of wheat PPO activity.

[Isolated limb hyperthermic perfusion chemotherapy for melanoma of the extremities].

OBJECTIVE: To investigate the effect of isolated limb hyperthermic perfusion chemotherapy for melanoma of the extremities. METHODS: Limb isolated hyperthermic perfusion chemotherapy was performed in 41 patients with malignant melanoma of the extremities, and then the primary lesions in 24 patients were removed at 14 - 21 days after chemotherapy. Tumor necrosis was examined by pathology. RESULTS: Among the 41 patients, 40 cases were followed up for 6-113 months, and one was lost. There was no local recurrence in those patients. 29 cases were followed up for more than 3 years, and 26 of them were surviving. Forteen cases were followed up for more than five years, among them 9 cases were surviving. The 3-year and 5-year survival rates of the whole group were 95.0% and 70.0%, respectively. The average reduction of the tumor volume was 55.6% after perfusion. The pathological examination showed that tumor necrosis was 90% - 100% (complete response) in 21 cases (87.5%) and 60% - 89% (partial response) in 3 cases (12.5%). CONCLUSIONS: The isolated limb hyperthermic perfusion chemotherapy is an effective treatment of limb malignant melanoma. It can significantly reduce the local recurrence rate, and improve the 5-year survival rate, prognosis and the quality of life of the patients.

Intelligent Performance Evaluation of Urban Subway PPP Project Based on Deep Neural Network Model.

Neural network refers to an algorithmic mathematical model that imitates the behavioral characteristics of animal neural networks and performs distributed information processing. This kind of network depends on the complexity of the system and needs to adjust the internal node relationship, so as to achieve the purpose of processing information. With the continuous development of the economy, the transportation problem needs to be solved urgently, and the urban subway has emerged at the historic moment. The subway is a fast, large-capacity, electric-driven rail transit built in the city. The advantages of the subway provide conditions for the mitigation of urban traffic, due to the large number of cars, traffic jams, frequent accidents, and serious environmental pollution. In the city center, there are more cars and less space, and the parking lot is not commensurate with the number of cars, making parking difficult. This paper aims to study the intelligent performance evaluation of urban subway PPP projects based on deep neural network models. The subway project has a large investment, a long period, and a wide range, but the development time of the subway in China is relatively short. In order to promote the stable progress of subway projects, it is very necessary to conduct intelligent performance evaluation on subway projects. This paper compares and analyzes the basic characteristics of the PPP model and verifies the applicability and necessity of the PPP model in urban subway transportation projects. Through the investigation of relevant literature, this article puts forward the research content of the social impact assessment of subway projects. The experimental results of this paper show that, from the perspective of whether it is necessary to evaluate the performance of PPP projects, 65% of people think it is very necessary, and 22% think it is more necessary. 3% of people think it is unnecessary, and 10% of people hold an indifferent attitude. These data show that the intelligent performance evaluation of urban subway PPP projects has exploratory significance for urban infrastructure design and construction.

How improvisation drives lean search: The moderating role of entrepreneurial team heterogeneity and environmental uncertainty.

Although lean search is seen as an important action in lean startup, previous studies have less knowledge on how to realize it, especially in the face of traditional plans that cannot cope with sudden changes in the environment. To fill the research gap, this study investigates the effects of improvisation (exploitative, explorative, and ambidextrous improvisation) on lean search. Meanwhile, this research also discusses the moderating effects of entrepreneurial team heterogeneity and the environmental uncertainty to identify the boundary conditions of this relationship. Supported by the cross-sectional data from 203 Chinese startups, the results show that explorative and ambidextrous improvisation are positively associated with lean search. However, the effect of exploitative improvisation on lean search is unsupported. Additionally, technology uncertainty positively moderates the relationship between exploitative improvisation and lean search. Market uncertainty positively moderates the relationship between explorative improvisation and lean search. However, the entrepreneurial team heterogeneity negatively moderates the relationship between ambidextrous improvisation and lean search. These findings contribute to understanding how startups could conduct lean search in a rapidly changing environment, which provides theoretical guidance for improving the success rate of startups.