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Honghua (Carthami flos) and Xihonghua (Croci stigma) have been used in anti-COVID-19 as Traditional Chinese Medicine, but the mechanism is unclear. In this study, we applied network pharmacology by analysis of active compounds and compound-targets networks, enzyme kinetics assay, signaling pathway analysis and investigated the potential mechanisms of anti-COVID-19. We found that both herbs act on signaling including kinases, response to inflammation and virus. Moreover, crocin likely has an antiviral effect due to its high affinity towards the human ACE2 receptor by simulation. The extract of Honghua and Xihonghua exhibited nanozyme/herbzyme activity of alkaline phosphatase, with distinct fluorescence. Thus, our data suggest the great potential of Honghua in the development of anti-COVID-19 agents.

Purpose This paper aims to put forth a model that accounts for the effect of servant leadership on employee creativity from a social identity perspective. Specifically, this paper aims to examine team identification as the mediating mechanism by which servant leadership influence employee creativity. This paper also intends to investigate the moderating influences of horizontal and vertical collectivism on the effectiveness of servant leadership on follower team identification. Design/methodology/approach Servant leadership, team identification, collectivism (consisted of horizontal and vertical collectivism) and employee creativity were assessed in an empirical study based on a sample of 451 employees from 11 banks in China. Findings Drawing on social identity theory, this study found that follower team identification partially mediates the relationship between servant leadership and employee creativity. In addition, results showed that horizontal collectivism moderates the relationship between servant leadership and follower team identification; the relationship was more positive when horizontal collectivism was high, rather than low; vertical collectivism also moderates the relationship between servant leadership and follower team identification; the relationship was more positive when vertical collectivism was low, rather than high. However, results of this study indicated that the moderated mediation effects of team identification on the relationship between servant leadership and employee creativity are nonsignificant. Practical implications First, this research affirmed the need to promote servant leadership in employment settings. Second, managers’ understandings of the instrumental role of servant leadership in showing interpersonal acceptance, offering encouragement and support and expressing trust would prove to be valuable because it could enhance employee creativity. Finally, the findings from this study should help managers gain a better understanding of the contextual factors. Originality/value The first contribution of the current study was to identify team identification as an important psychological process that can link servant leadership to employee creativity. Another important contribution of the current research was the identification of the boundary conditions (e.g. horizontal and vertical collectivism).

Driven by a bright prospect for rapid, portable and cost-effective point-of-care testing, an assembled Pasteur pipette device to integrate nucleic acid extraction, amplification and detection was developed to detect B. cereus in a sample-to-answer format. Denaturation Bubble-mediated Strand Exchange Amplification (SEA) was chosen to perform isothermal amplification because it requires only a pair of primers and one Bst DNA polymerase. The established SEA can detect as low as 1.0 × 10−13 M genomic DNA of B. cereus, which was comparable with the previously reported method for B. cereus detection. The assembled Pasteur pipette allows sample-to-answer diagnostic in a simple, low-cost, portable, and disposable format. The inherent function of Pasteur pipette enables direct liquid handling without the need of extra pipettes, syringes or pumps. Visual readout was achieved by using a pH sensitive dye, further simplifying result judgment process. The detection limit for B. cereus is 1.0 × 104 CFU/mL in pure cultures, while the detection limit in artificially contaminated milk is 1.0 × 105 CFU/mL without enrichment and 1.0 × 100 CFU/mL following 12 h enrichment. Considering that typical cell counts in food samples associated to food poisoning are 1.0 × 105 to 1.0 × 108 CFU per gram/milliliter B. cereus, our Pasteur pipette is enough sensitive for answer-to-sample diagnosis of B. cereus even directly from foods without enrichment. The whole diagnostic procedure could be completed within 50 min, dramatically decreasing the detection time. In a word, the assembled Pasteur pipette device, combined with a homemade metal bath, possesses great potential for sample-to-answer application in resource-limited settings.

As meat adulteration issue is becoming increasingly prominent worldwide, it is crucial to realize on-site detection with simple equipment. Conventional nucleic acid amplification methods are reliable but the requirement of complex equipment, skilled technicians and long operation time limit their on-site use. Here, a simple denaturation bubble-mediated strand exchange amplification method (SEA) requiring only a pair of primers and one polymerase was first reported for identifying adulteration of pork source by targeting the specie-specific mitochondrial DNA sequence. The SEA method displayed good specificity for pork and could detect as low as 30 pg/μL pork DNA. In binary mixtures, the SEA method could detect 1% pork meat total DNA by both colorimetric and fluorescence determination, fulfilling the requirement of artificial meat adulteration. Excitedly, the whole detection process could be finished within 1 h by coupling with fast tissue DNA extraction method, only requiring a simple heating block. Therefore, with simplicity and rapidity, SEA method will be suitable for on-site meat species identification.

Bursaphelenchus xylophilus (B. xylophilus) is one of the most important causal agents of infectious diseases in forest pathology. Obviously, the rapid detection of B. xylophilus is an urgent need for its prevention and cure. We have developed a detection method of B. xylophilus by strand exchange amplification (SEA). This method could detect 105 copies of genomic DNA of B. xylophilus, and it was sufficiently sensitive to detect a single nematode as short as 40 min. Moreover, because the amplification result could be visualized by the naked eyes, the only equipment required throughout the process was a simple isothermal block. Therefore, our method would be a potential for developing on-site detection of B. xylophilus to prevent and control its spread.

M. pneumoniae infection is often ignored due to its similar clinical symptom with respiratory tract infections caused by bacteria or viruses, and thus leading to misdiagnosis and delayed treatment. It is critical to develop a rapid, sensitive and specific diagnosis method. Denaturation Bubble-mediated Strand Exchange Amplification (SEA) was established, which is an isothermal method with only a primer pair and one Bst DNA polymerase. Notably, colorimetric SEA assay was developed with simple visual readout, making instrument-independent in detection step. The method could detect as low as 1.0 × 104 copies/mL genomic DNA within 60 min. Considering that more than 80% infected patients have 1.0 × 105−1.0 × 107 copies/mL M. pneumonia DNA, SEA is available for the practical diagnosis of M. pneumoniae in clinical specimens. Through comparing 224 sputum specimens, excellent performance of SEA assay with 90.48% sensitivity and 100% specificity relative to real-time PCR was observed. Compared with LAMP, a comparable sensitivity and low false positive rate was observed for SEA method. Therefore, SEA is a promising method for detecting M. pneumoniae directly from clinical specimens, which is especially suitable for point-of-care testing in primary care facilities and resource-limited settings with minimal equipment and technological expertises.

There is growing concern that farmland transfers lead to less agricultural investment, which may adversely affect agricultural productivity growth in China. Prior research has primarily focused on the differences between owned cultivated land and rented plots, but little is known about how farmland transfers between relatives, which are popular in rural China, specifically affect agricultural investment. In this paper, we present a conceptual framework of transaction cost economics to compare different contracting strategies in China's farmland rental markets. As farmland rental markets in China are immature, land transfer between relatives establishes bilateral governance, which has the advantage of addressing the opportunistic activities of both parties and can ultimately increase investment by tenants. Based on data from two waves of household surveys, we empirically examine the impact of bilateral governance on the application of organic fertilizer, an indicator for agricultural investment. Our findings show that apart from economic factors, kinship is important to the functioning of farmland rental markets in rural areas.

Rapid detection of single-nucleotide mutations (SNMs) has played a vital role for point-of-care testing. We herein first introduced accelerated thermal cycling into conventional allele-specific qPCR (AS-qPCR), named accelerated cycling PCR (AC-PCR) to achieve rapid and sensitive detection of SNM. It could simultaneously detect 10 copies of H. pylori DNA and identify its clarithromycin-resistance genotype within 30 min, and showed 100-fold enhanced specificity than AS-qPCR. Therefore, AC-PCR shows great potential in clinical diagnosis for drug-resistance mutation or genotyping analysis.

The detection of acetone in the gaseous form in exhaled breath using an integrated sensor can provide an effective tool for disease diagnostics as acetone is a marker for monitoring human metabolism. An on-chip acetone gas sensor based on the principle of Mach-Zehnder interferometer is proposed and demonstrated. The sensing arm of the device is activated with a composite film of polyethyleneimine and amido-graphene oxide as the gas-sensitive adsorption layer. The composite film demonstrates good selectivity to acetone gas, can be used repeatedly, and is stable in long-term use. Room temperature operation has been demonstrated for the sensor with high sensitivity under a 20 ppm acetone environment. The detection limit can reach 0.76 ppm, making it feasible to be used for the clinical diagnosis of diabetes and the prognosis of heart failure.

Elevated levels of alkaline phosphatase (ALP) are associated with bone metastasis, liver cancer, prostate cancer, breast cancer, and many other diseases or stem cell marker. It is therefore of great significance to quantitatively detect the ALP levels by a rapid, highly sensitive, and easy-to-use strip paper test. In the present work, we discovered an enhancement of ALP activity upon the addition of cauliflower-derived carbon dots (CFCDs), which can be applied as a sensor for ALP. The mixed ALP and CFCDs exhibited a typical Michaelis Menten mechanism with increased Vmax and reduced Km compared to ALP alone. High-Resolution Atomic Force Microscopy (HR-AFM) reveals the dimensions of ALP, the CFCDs, and the phosphatase substrate para-nitrophenyl phosphate (pNPP), as well as the potential interactions among them. The role of the CFCDs was identified as the addition of reaction centers to ALP; in other words, a competitive activator. Besides the improved kinetics, the yield of dephosphorylated product was also increased by at least twice upon the addition of CFCDs. Taking advantage of this effect, a portable CFCD-based paper strip assay was developed to achieve sensitive detection of abnormally elevated ALP levels and visualization of cancer stem cells or proteins by phosphatase-conjugated antibodies. Our findings show great promise for disease diagnosis and bioassays related to ALP enhancement that may be used for protein or cell detection.

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Background and aims Endophytic bacteria from legume roots and nodules play important roles in regulating plant growth and health. However, little is known about how the endophytic bacteria community changes and how it interacts with each other throughout the plant life cycle. Methods We collected twenty pea cultivars to study the composition and structure of endophytic bacterial community during the whole developmental period using Illumina sequencing of 16S rRNA gene. Results Here we show that the development period significantly affected the structure of root endophytic bacterial community and peas recruit different root microbes during different developmental stages. The complexity of microbial community first increased and then decreased with the growth of pea. Rhizobium began to accumulate in pea seedling roots, and the content peaked at flowering stage and remained at high levels during the mature stage. In the flowering and mature stage, the relative abundance of Pseudomonas increased. Conclusions These findings can deepen the overall understanding of the community structure and interaction network of endophytic bacteria from pea root and nodules, and provide a detail for the establishment of root endophytic bacteria throughout the plant life cycle.

Background Manganese (Mn2+) has been shown to promote type I interferon (IFN) production and activate the cyclic GMP-AMP synthase (cGAS)/Stimulator of Interferon Genes (STING) signaling pathway, suggesting that Mn2+ could be used as an adjuvant for vaccination. Methods In present study, the effects of Mn2+ on vaccination against hepatitis B virus (HBV) were evaluated. We treated mouse hepatocytes and kuppfer cells with Mn2+ with or without adeno-associated virus (AAV)–HBV infection. Expression of IFN-α and IFN-β and activation of TBK1 and IRF3 were monitored. Wild-type and STING-/- mice were treated with Mn2+ and then infected with AAV-HBV. Serum levels of HBV surface antigen (HBsAg), alanine aminotransferase (ALT) activity, IFN-α, and IFN-β were detected. Lymphocyte infiltration in the liver was evaluated. HBsAg-Tg mice were vaccinated with Mn2+ and HBsAg. The serum levels of HBsAg antibody, alanine transaminase activity, and IFN-β were monitored after vaccination. Results Mn2+ promoted IFN-α and IFN-β production in mouse hepatocytes and kuppfer cells. Mn2+ failed to promote IFN-α and IFN-β production in kuppfer cells deficient in STING. Mn2+ promoted activation/phosphorylation of TBK1 and IRF3 during AAV-HBV infection. Mn2+ decreased serum levels of HBsAG, increased serum levels of alanine aminotransferase (ALT), IFN-α and IFN-β, and enhanced lymphocyte infiltration and the percentage of IFN-γ-producing CD8+ T cells in the liver of AAV-HBV-infected mice. In contrast, Mn2+ treatment did not affect serum levels of HBsAG, ALT, IFN-α, or IFN-β in STING-deficient mice. Conclusions Mn2+ promoted HBsAG antibody, ALT, and IFN-β production after HBsAG immunization. Mn2+ promoted type I IFN production in AAV-HBV infection and HBsAG immunization and could be used as an adjuvant for vaccination.

The development of rapid nucleic acid detection methods, which are promising the diagnostic standard of the infectious disease, could expand more options for disease traceability and controllability. Nucleic acid hybridization-based biosensing techniques still encounter limitations in meeting the requirements for rapid detection. Therefore, we proposed a potential-assisted ratiometric electrochemical biosensor for rapid and accurate target DNA detection. This dual-signal analysis system actuated an enzyme-free detection process. The application of an external electric field accelerated molecular dynamics, resulting in highly efficient collision chances. This hybridization process was thus improved from hours to minutes compared with passive hybridization approach. The biosensor not only had a high sensitivity with the detection limit of 12 fM, but also features a robust capability in identifying single-base mismatch. Moreover, the biosensor realized sensitive detection of target DNA in complex biological environments. Overall, this sensing strategy exhibits a promising potential for application in point-of-care testing.

Canine parvovirus 2 (CPV-2) and feline panleukopenia virus (FPLV) often cause acute enteric disease in their hosts. A simple, rapid, and effective method for the on-site detection of these viruses would be useful. We used a denaturation bubble-mediated strand exchange amplification (SEA) method to successfully detect CPV-2 and FPLV in fecal samples. SEA could detect as little as 3.6 pg/μL of CPV-2 and 6.6 pg/μL of FPLV genomic DNA following a 40-min incubation at an isothermal temperature of 61°C. Unlike PCR, SEA does not require complicated equipment, and positive samples produce a color change that can be visualized by the naked eye. Additionally, SEA is simpler than PCR because no extraction is needed, and heating of the fecal sample at 98°C can be performed with a heating block or water bath. This rapid and effective nucleic acid detection platform could be used as a point-of-care test for the detection of CPV-2 and FPLV.

A novel colorimetric and fluorescent chemosensor MQS-Si with intramolecular charge transfer character has been designed and synthesized. The chemosensor shows exclusively "off-on" fluorescence response toward F

Supplemental material, Supplemental_material for Detection of canine parvovirus and feline panleukopenia virus in fecal samples by strand exchange amplification by Mengmeng Liu, Mengzhe Li, Cuiping Ma and Chao Shi in Journal of Veterinary Diagnostic Investigation

The Beijing-Tianjin-Hebei (BTH) region in China suffers from heavy air pollution, especially in heating period. SO2 and NO2 are two of the key primary gaseous pollutants emitted by coal burning. The increase in air pollution caused by heating in the south-central part of the BTH region is higher than that in the northern part. And the distribution of SO2 and NO2 increment has significant differences. In this work, SO2 and NO2 emissions over the BTH region are determined using an adaptive “nudging” constrained method and a variational processing technique based on Ozone Monitoring Instrument (OMI) satellite data and surface measurement data collected in 2015. The application of the method can provide reliable, up-to-date and high-resolution mapping of sources of SO2 and NO2 emissions. These SO2 and NO2 emissions reflect the spatial differences in point and area sources in urban agglomerations and rural areas under different meteorological conditions during the non-heating and heating seasons. The intensity and influence of SO2 and NO2 emissions, particularly those of SO2, are significantly greater during the heating season than those during the non-heating season. Winter increases in SO2 emissions in the northern areas of the BTH region are larger than those in the southern part. In addition, significant increases in SO2 emissions occur mainly in suburban and rural areas, while those of NO2 emissions mainly occur in urban agglomerations. In the major urban areas, where coal has been replaced by natural gas or electric power for heating, winter heating causes much smaller increases in SO2 emissions than in other areas. The large amounts of bulk coal consumption in the suburban and rural areas could cause significant regional air pollution. Clear increases in SO2 and NO2 emissions in winter occur along a belt from southern Beijing to Langfang, Baoding, Shijiazhuang and Xingtai, which is consistent with a special “quasi-steady” air pollutant transport belt in the region. All above results show that the adaptive “nudging” constrained emission method could be an effective tool for air pollution control during certain seasons.

This paper presents a simulation study on the methane–air mixture explosions through using the eddy-dissipation concept (EDC) model in FLUENT. The aims are to investigate the structure effects of methane–air mixture explosions in a spherical vessel, cylindrical vessel and different systems of cylindrical vessels connected with pipe. Meanwhile, in order to study the characteristics of methane-air mixture explosions in the linked vessels, changes of flame temperature and airflow velocity in the linked vessels are simulated and analyzed. The results suggest that the effect of structural changes of a single vessel on the gas explosion intensity is clear, and the explosion intensity of a spherical vessel is greater than that of a cylindrical vessel. The simulation results of different structural forms of a cylindrical vessel connected with pipelines show that the time to reach the peak value of explosion pressure is the shortest in the linked vessels, and the explosion pressure rising rate is highest at the vessel’s center. For the linked vessels, after ignition, the airflow ahead of the flame propagates to the secondary vessel, and the maximum airflow velocity of every monitoring point in the linked vessels increases. The detonation occurs when the flame propagates to the secondary vessel, which leads to a severe secondary explosion in the secondary vessel. The studies can provide an important reference for the safe design of industrial vessels.

Purpose The purpose of this paper is to focus on the cultural cognition of Chinese Zhong-yong thinking, which is deeply rooted in Chinese Confucius culture, and to examine how entrepreneurs’ Zhong-yong thinking is related to new venture performance through guanxi network, and also examine how environmental turbulence affects the influencing mechanism. Design/methodology/approach This paper follows an empirical design. Data are collected from a survey administered to entrepreneurs in new ventures of China. Regression analysis is used to test the hypothesis. Findings Results show that entrepreneurs’ Zhong-yong thinking is positively related to guanxi and new venture performance, and guanxi mediates the relationship between entrepreneurs’ Zhong-yong thinking and new venture performance. In addition, environmental turbulence moderates the relationship between entrepreneurs’ Zhong-yong thinking and guanxi such that the relationship is stronger under higher technological turbulence or lower market turbulence. Research limitations/implications This research uses cross-sectional data, so causal conclusions cannot be made. In addition, more moderators should be considered. Practical implications The present study enriches the understanding of how entrepreneurs’ Zhong-yong thinking affects new ventures, which helps entrepreneur understand how to strategize according to external environment and develop what kind of cognitive style to deal with complex situation of their own venture. Originality/value This study is a pioneer in exploring non-Western cognitive style–Zhong-yong thinking in entrepreneurial context. It not only enriches the understanding of how Chinese wisdom affects organizational strategy and organizational performance but also advances the cognition research in the field of entrepreneurship.

Uncertainty is a common and critical problem for planning the capacity and operation of integrated energy systems (IESs). This study evaluates the effects of uncertainties on the capacity and operation of an IES. To this aim, system planning and operation with uncertainties are optimized by a two-stage stochastic programming model and compared with a referencing deterministic case. Specifically, the uncertainties of photovoltaic (PV) generation and energy demand are investigated. Regarding system capacity, a larger energy storage capacity is needed to accommodate a higher uncertainty. The superimposed uncertainties have a higher effect on system capacity than the sum of the effect of each uncertainty. The uncertainty of energy demand has a higher impact than the uncertainty of PV generation. Regarding system operation, the increase in operation cost is smaller than the increase in investment cost and total cost. In addition, the average flexibility provided by the energy storage increases with uncertainty and uncertainties affect the change rate for power charging/discharging of the electric energy storage. Regarding the effect on the grid, the uncertainties increase not only the magnitude of ramping-rate, but also the frequency of power-dispatch.

The outbreak of COVID-19 makes epidemic prevention and control become a growing global concern. Nucleic acid amplification testing (NAAT) can realize early and rapid detection of targets, thus it is considered as an ideal approach for detecting pathogens of severe acute infectious diseases. Rapid acquisition of high-quality target nucleic acid is the prerequisite to ensure the efficiency and accuracy of NAAT. Herein, we proposed a simple system in which magnetic nanoparticles (MNPs) based nucleic acid extraction was carried out in a plastic Pasteur pipette. Different from traditional approaches, this proposed system could be finished in 15 min without the supports of any electrical instruments. Furthermore, this system was superior to traditional MNPs based extraction methods in the aspects of rapid extraction and enhancing the sensitivity of a NAAT method, accelerated denaturation bubbles mediated strand exchange amplification (ASEA), to the pathogens from various artificial samples. Finally, this Pasteur pipette system was utilized for pathogen detection in actual samples of throat swabs, cervical swabs and gastric mucosa, the diagnosis results of which were identical with that provided by hospital. This rapid, easy-performing and efficiency extraction method ensures the applications of the NAAT in pathogen detection in regions with restricted resources., Graphical abstract Image 1

Bacterial foodborne diseases have become a growing global health concern, and nucleic acid-based analysis is considered as a promising approach for rapid identification of foodborne pathogens. Accordingly, nucleic acid isolation becomes the prerequisite first step for subsequent bioanalysis. However, current nucleic acid extraction suffers from operation time delayed, amplification inhibited by chemicals, or bulky instruments required. Here, we presented an ultrafast bacterial cell lysis induced by corona discharge within 40 s and combined it with loop-mediated isothermal amplification (LAMP) for the first time to achieve rapid and convenient detection of foodborne pathogens. Firstly, the viability and morphological changes revealed that corona discharge could destabilize bacterial cell envelope and eliminate more than 90% of Salmonella enterica (S. enterica) or Staphylococcus aureus (S. aureus) within 40 s. More surprisingly, more DNA were released from 100-103 CFU of electrical lysed S. enterica than equivalent thermal lysed ones, manifesting advantages of corona discharge on shorter preparation time and greater yields of DNA. Furthermore, the advantages of this ultrafast bacterial cell lysis were leveraged when collaborating with colorimetric LAMP. After conducting colorimetric LAMP in a water bath at 63 °C for 1 h, we could visually detect released DNA from 100 CFU of electrical lysed S. enterica and 103 CFU of electrical lysed S. aureus, respectively. Finally, we validated the applicability of the electrical lysis combined with LAMP reaction to detect (viable) S. enterica and S. aureus in artificially spiked pork samples. Therefore, we provided a rapid and convenient bioanalysis platform integrating an ultrafast electrical lysis and LAMP detection, opening up its extensive applications for versatile pathogens in resource-limited settings.

A novel colorimetric and fluorescent chemosensor MQS-Si with intramolecular charge transfer character has been designed and synthesized. The chemosensor shows exclusively “off-on” fluorescence response toward F- at 620 nm in HEPES (pH 7.4): DMSO solution (7:3, v/v), which is attributed to the specific cleavage of Si-O bond. The ultrasensitive detection limit for F- in the fluorescence measurement is down to 30 nM. Application of the chemosensor has been demonstrated by selective detection of F- in drinking water, urine and serum samples and fluorescence imaging of F- in living cells and zebrafish, which proves that MQS-Si has a promising application in vitro and in vivo detection of F- and may be utilized for the diagnosis of fluorosis and esteofluorosis.

Betaine was used as a common additive to isothermal nucleic acid amplification reactions because of lowering the melting temperature (Tm) of DNA. Herein, we reported a novel finding that betaine was inhibiting the reaction efficiency of isothermal amplification reactions. In this work, we have verified this finding by classical loop-mediated isothermal amplification that the addition of 0.8 M betaine inhibited the efficiency of reaction dropping to approximately 1%. Additionally, we clarified the mechanism of betaine hindering isothermal amplification reactions with a molecular barrier to lower associate rate constant K1 for intermolecular hybridization. This finding would be very significant for studies on the interaction between small molecule substance and DNA, and the development of point-of-care testing because of simplifying reaction system and increasing reaction efficiency.

Nucleic acids have been shown to be versatile molecules and engineered to produce various nanostructures. However, the poor rate of these uncatalyzed nucleic acid reactions has restricted the development and applications. Herein, we reported a novel finding that DNA self-assembly could be nonenzymatically catalyzed by artificial agents with an increasing dissociation rate constant K2. The catalytic role of several artificial agents in DNA self-assembly was verified by real-time fluorescent detection or agarose gel electrophoresis. We found that 20% PEG 200 could significantly catalyze DNA self-assembly and increase the reaction efficiency, such as linear hybridization chain reaction (HCR) and exponential hairpin assembly (EHA). Therefore, we foresee that a fast and efficient DNA self-assembly in structural DNA nanotechnology will be desirable.

This study investigates the mediating role of organizational innovation in the relationship between entrepreneurs’ passion and new venture performance in China. We also examine the moderating role of the Zhong-yong thinking of entrepreneurs in the abovementioned relationship to explore the influencing mechanism of entrepreneurs’ passion in non-Western societies. Results from 154 Chinese new ventures support the positive relationship between entrepreneurs’ passion and new venture performance and the mediating role of organizational innovation. The Zhong-yong thinking of entrepreneurs can also strengthen the relationship between entrepreneurs’ passion and organizational innovation. Finally, the theoretical and practical implications of these findings are discussed.

We developed a novel method to control carryover contamination in loop-mediated isothermal amplification (LAMP) by primer engineering to carry recognition sites for a restriction endonuclease, providing a robust ability to eliminate carryover contaminants.

Motivated by the desire for simple, rapid and highly sensitive DNA detection, we presented a signal-on electrochemical DNA (E-DNA) sensing strategy utilizing cooperative proximity hybridization based on a G-quadruplex (G4) probe labeled with the SH, which could specifically hybridize with its target DNA in homogenous solution. In the presence of target DNA, proximity hybridization was triggered to form a Y-shaped complex and the SH was released from G4 probe stem, companied by chemisorption on the electrode surface through Au-S binding when applied a positive potential, which brought Fc labeled on the signal probe close to the electrode surface. Thus, electrochemical signal dramatically increased, ensuring the highly sensitive “signal-on” assay. Such an E-DNA sensing strategy allows for ultrasensitive DNA detection with a detection limit as low as 2.82 × 10−15 M and a wide linear response from 1.0 × 10−9 to 1.0 × 10−15 M. In addition, the powerful discriminating ability of the mismatched DNA from the perfect matched target DNA was also demonstrated. More importantly, this homogenous proximity hybridization strategy could expand to colorimetric assay by incorporating G4 probe with hemin to form DNAzyme, which could effectively catalyze ABTS to generate a visual color change. Taking the joint advantages of G4 stem-loop probe and homogenous proximity hybridization, this sensing strategy exhibits greatly enhanced sensitivity and excellent specificity, making it a promising strategy for point-of-care testing.

Staphylococcus aureus (S. aureus) contamination in food safety has become a worldwide health problem. In this work, we utilized RNA one-step detection of denaturation bubble-mediated Strand Exchange Amplification (SEA) method to realize the detection of viable foodborne pathogen S. aureus. A pair of S. aureus specific primers were designed for the SEA reaction by targeting hypervariable V2 region of 16S rDNA and the amplification reaction was finished about 1 h. The results of amplification reaction could be observed by the naked eyes with a significant color change from light yellow to red to realize the colorimetric detection of S. aureus. Therefore, there only required an isothermal water bath, which was very popular for areas with limited resources. In real sample testing, although the SEA detection was so time-saving compared with the traditional plating method, the SEA method showed great consistency with the traditional plating method. In view of the above-described advantages, we provided a simple, rapid and equipment-free detection method, which had a great potential on ponit-of-care testing (POCT) application. Our method reported here will also provide a POCT detection platform for other food-borne pathogens in food, even pathogenic bacteria from other fields.

Amphioxus is an intermediary species bridging invertebrates and vertebrates used to study the development and evolution of species and genes. In this study, the dominant bacterial strain was isolated from tail lesions of cultured amphioxus and designated WW1. Challenge by intramuscular microinjection revealed the 50% lethal dose of WW1 to be 9 x 10(2) bacteria/g amphioxus body weight. Based on 16S rRNA gene sequence, physiological and biochemical characteristics, and species-specific collagenase gene marker, WW1 was identified as Vibrio alginolyticus. To our knowledge, this is the first report on the isolation of V. alginolyticus as pathogen from amphioxus. This study extends the known host range of V. alginolyticus and may provide information helpful in preventing and managing its occurrence in cultured animals.

Here we have developed a novel method of isothermal amplification detection of double-stranded DNA (dsDNA) based on double-stranded fluorescence probe (ds-probe). Target dsDNA repeatedly generated single-stranded DNA (ssDNA) with polymerase and nicking enzyme. The ds-probe as a primer hybridized with ssDNA and extended to its 5′-end. The displaced ssDNA served as a new detection target to initiate above-described reaction. Meanwhile, the extended ds-probe could dynamically dissociate from ssDNA and self-hybridize, converting into a turn-back structure to initiate another amplification reaction. In particular, the ds-probe played a key role in the entire experimental process, which not only was as a primer but also produced the fluorescent signal by an extension and displacement reaction. Our method could detect the pBluescript II KS(+) plasmid with a detection limit of 2.3 amol, and it was also verified to exhibit a high specificity, even one-base mismatch. Overall, it was a true isothermal dsDNA detection strategy with a strongly anti-jamming capacity and one-pot, only requiring one ds-probe, which greatly reduced the cost and the probability of contamination. With its advantages, the approach of dsDNA detection will offer a promising tool in the field of point-of-care testing (POCT).

Isothermal and rapid amplification detection of nucleic acids is an important technology in environmental monitoring, foodborne pathogen detection, and point-of-care clinical diagnostics. Here we have developed a novel method of isothermal signal amplification for single-stranded DNA (ssDNA) detection. The ssDNA target could be used as an initiator, coupled with a double-nicked molecular beacon, to originate amplification cycles, achieving cascade signal amplification. In addition, the method showed good specificity and strong anti-jamming capability. Overall, it is a one-pot and isothermal strand displacement amplification method without the requirement of a stepwise procedure, which greatly simplifies the experimental procedure and decreases the probability of contamination of samples. With its advantages, the method would be very useful to detect nucleic acids in point-of-care or field use.

Here, we introduced the concept of strand exchange amplification (SEA) mediated by denaturation bubbles. Similar to traditional PCR, it only employed a DNA polymerase and a pair of common primers to realize a three-step cycle process, but the entire SEA reaction was performed at a single temperature.

Nucleic acid amplification and testing is routine demand in life science research and analytical chemistry. Polymerase chain reaction (PCR) is a widely employed DNA amplification technique using electrically powered thermal cycling equipment. The advent of isothermal amplification techniques circumvents the limitations of PCR for point-of-care testing (POCT). Here we have developed a novel method of exponential nicking endonuclease-mediated isothermal amplification for double-stranded DNA (dsDNA) detection. The new single-stranded DNA (ssDNA) target generation process occurs at a single temperature with next amplification reaction. The new ssDNA target copies are then exponentially amplified by alternating cycle strand displacement amplification (SDA). Therefore, it is a one-pot and isothermal strand displacement amplification method without the requirement of stepwise procedure, which greatly simplifies experimental procedure and decreases the probability of contamination of samples. With its advantages, it will be a useful tool to detect dsDNA in the field of POCT.

Herein, we have developed a rapid and enzyme-free nucleic acid amplification detection method that combined the exponential self-assembly of four DNA hairpins and the FRET pair Cy3 and Cy5. This strategy was very ingenious and rapid, and could detect nucleic acids at concentrations as low as 10 pM in 15 min in biological fluids.

Hand-powered centrifugal microfluidics combined with isothermal nucleic acid amplification testing (NAAT) have been one of the most promising rapid detection platforms in resource-limited settings. However, current hand-powered centrifuges still suffer from customized instrument-based operation and low rotation rate; and most isothermal NAAT were conducted with complicated reaction systems for DNA detection and required an additional step for RNA detection. Herein, we built a fully hand-powered centrifugal miniaturized NAAT platform inspired by buzzer toys, which embedded sample preparation, strand exchange amplification (SEA) and visual fluorescence detection together. The centrifugal disc was easily fabricated, and operated the mixing in 1 min by simply dragging the looped rope through it with a mean input force of 16.5 N, enabling its rotation rate reach 5000 rpm. In addition, SEA was an ultra-simple one-step DNA or RNA detection method initiated by Bst DNA polymerase and a pair of primers, and thus we took all its merits and integrate it into microfluidic systems firstly. Furthermore, taking Vibrio parahemolyticus as an example, the microfluidic platform achieved DNA or RNA detection within 1 h; and the detection limit of the microchip for artificially spiked oysters was 103 CFU/g without cumbersome sample preparation, and reached to 100 CFU/g after enrichment. Therefore, we provided an ultra-simple and non-instrumental microfluidic platform powered merely by hands, performing general potential in sample-to-answer NAAT for versatile pathogens in remote regions.

Denaturation bubble-mediated strand exchange amplification (SEA) is a novel, rapid isothermal nucleic acid amplification has been applied for point-of-care molecular diagnostic in food safety, meat adulteration, forest disease and animal disease. Nevertheless, the absence of specialized strategy for SEA primers design led to long-time of primer screening progress before SEA reaction execution, which would largely increase the time consuming when SEA is utilized for detecting other new targets. In this present work, we investigated the impact of the following primers' attributes on SEA efficiency, including Tm value, 3′ end G/C content, self-complementary and 3′ complementary, according to which we demonstrated that optimal Tm value and reaction temperature were all 61 °C, while 3′-terminal nucleotide should be G/C, as the SEA reaction induced by the primers possessing these attributes exhibited significantly lower threshold time (Tt) value. Moreover, self-complementary and 3′ complementary of primers should be avoided. Besides, we also discussed the consideration priority order of these factors, which was self-complementary and 3′ complementary, Tm value and 3′ end G/C content in turn. Because the SEA primer design strategy is first presented, our work will greatly promote the application of SEA in point-of-care test.

Meat screening plays a significant role in human health and religion. But the identification methods for beef were little reported. In this work, a simple colorimetric method based on denaturation bubble-mediated strand exchange amplification (SEA) was developed for the rapid and sensitive identification of beef. The whole strategy was performed on a portable metal bath and the distinguishable color between positive and negative controls was observed directly by the naked eyes. The feasibility using crude extraction samples by a heating treatment in PBS for 2 min was evaluated in duck spiked by beef. The result demonstrated that the developed method could identify as low as 1% (w/w) beef/duck within 50 min. Meanwhile, the results showed the method had a good repeatability and specificity. Therefore, this assay allows for the rapid, sensitive, specific detection of beef, and can be recommended as an effective, promising strategy for on-site meat identification.

A variety of combinations of leucine-rich repeat (LRR) and immunoglobulin-like (Ig) domains have been found and discovered in invertebrates and vertebrates, but the functions remain largely unexplored. In the present study, a novel LRR and Ig domain-containing protein (LRRIG), CgLRRIG-3, was identified and characterized from oyster Crassostrea gigas. It contained two typical LRR motifs, a LRRNT motif and an Ig domain and PSI-BALST and phylogeny analysis revealed that the sequence of CgLRRIG-3 was most related with leucine-rich repeat neuronal 1 proteins from vertebrate. Its mRNA transcripts were constitutively expressed in muscle, gill, hepatopancreas, mantle, gonad and hemocytes with the highest level in hepatopancreas. The mRNA expression level of CgLRRIG-3 in hemocytes could respond to the stimulations of variety PAMPs including lipopolysaccharide (LPS), peptidoglycan (PGN), glucan (GLU) and polyinosinic-polycytidylic acid (poly I:C). The recombinant proteins exhibited a wide PAMP binding repertoire to four typical PAMPs and could significantly induce the expression of CgTNF-1 and CgIL17-5 as well as increase phagocytosis in primary cultured oyster hemocytes. In hepatopancreas, CgLRRIG-3 was mainly distributed in the basolateral membrane of digestive tubule and the hemocoel sinusoid between the digestive tubules. And in hemocytes, the positive signal was mainly distributed in a special group of granulocytes. These results collectively indicated that CgLRRIG-3 could not only function as an immune effector.

Simple, fast and efficient method for on-site detection of meat adulteration is of increasing demand in low-resource regions. Here, a direct and visual denaturation bubble-mediated strand exchange amplification method (SEA) was developed to detect meat adulteration by targeting the mitochondrial sequence from duck, which required only a heating block. The method allowed detecting as low as 10 pg/μL duck DNA and 0.1% duck meat in binary mixtures, sufficiently meeting the demand of meat adulteration detection. Notably, the method realized instrument-free readout by significant color discrimination of positive and negative results. By coupling with fast DNA release, a direct SEA method was developed and reduced the whole detection time to 1 h, eliminating complex DNA extraction process. The developed method provided a promising strategy with integration of fast sample lysis, miniaturized reaction platform and visual readout for meat adulteration, especially suitable for low resource point-of-care settings.

The Beijing-Tianjin-Hebei (BTH) region in China suffers from heavy air pollution, especially in heating period. SO

A one-step, rapid, and visual method was developed for the detection of RNA viruses and a few copies of the Zika RNA virus were directly detected within 25 min by naked-eye observation. This method will prove to be promising for point-of-care testing in out-of-lab and inconvenient settings.