Sensitive and rapid detection of tetrodotoxin based on gold nanoflower-and latex microsphere-labeled monoclonal antibodies.

Tetrodotoxin (TTX) could result in serious diseases due to its extremely high neurotoxicity. Thus, it is of great importance to measure TTX for food safety. In this study, an anti-TTX monoclonal antibody with good specificity and high affinity was used to develop the immunochromatographic test strips (ICTS). Gold nanoflower (AuNF) with multiple branches and latex microsphere (LM) with large particle size as signal reporters were employed for improving the sensitivity of test strips. Both AuNF and LM probes are stable, and the developed ICTS were specific to TTX, demonstrating no cross-reactivity with other marine toxins. The linear range of AuNF- and LM-based strips for TTX was 9.49-330.98 ng/mL and 5.40-443.19 ng/mL, respectively. The limit of detection (LOD) of AuNF- and LM-based strips was determined to be 9.49 ng/mL and 5.40 ng/mL, respectively. In summary, the developed ICTS based on AuNF and LM signal probes displayed enhancement of sensitivity and provided rapid and specific detection of TTX.

Impact of the COVID-19 epidemic on medical product imports from china from outbreak to stabilization: Monthly panel data regression and instrumental variable test.

This study conduct regressions of panal data with OLS and test with IV, empirically examines the COVID-19 epidemic's impact on the import of medical products from China from the perspective of the importing countries, exporting country, and other trading partners, and analyzes the inter-temporal impact across different product categories. The empirical results reveal that, in importing countries, the COVID-19 epidemic increased the import of medical products from China. In China, as an exporting country, the epidemic inhibited the export of medical products; by contrast, for other trading partners, it promoted the import of medical products from China. Among them, key medical products were most affected by the epidemic, followed by general medical products and medical equipment. However, the effect was generally found to wane after the outbreak period. Additionally, we focus on how political relations shape China's medical product export pattern and how the Chinese government is using trade means to improve external relations. In the post-COVID-19 era, countries should prioritize the stability of supply chains for key medical products and actively engage in international cooperation on health governance to further combat the epidemic.

Development of sensitive and portable immunosensors based on signal amplification probes for monitoring the mercury(II) ions.

Mercury ion (Hg2+) as a major environmental pollutant threatens human health even at very low concentrations, so it is essential to monitor mercury residues in food. In this study, Hg2+ was conjugated with protein carrier using 1-(4-Isothiocyanobenzyl) ethylenediamine N, N, N', N'-tetraacetic acid (ITCBE) as a bifunctional chelator. 7A1 monoclonal antibody (mAb) against Hg2+-ITCBE with high affinity (7.3 × 109 L/moL) and good specificity was obtained by cell fusion technology and performed to establish immunosensors. Immunochromatographic test strip using colloidal gold nanoparticles (AuNP with an average diameter of 18 nm) as signal reporter showed low sensitivity. Signal amplification probes including larger multi-branched gold nanoflowers (AuNF) and latex microspheres (LM) were employed to enhance the sensitivity of immunosensors. The visible limit of detection (vLOD) of the AuNF- and LM-based strip were determined to be 50 ng/mL and 25 ng/mL respectively, showing more sensitive than that of AuNP-based strip (200 ng/mL). Quantitative analysis showed that AuNF-based strip exhibited lower quantitative limit of detection (qLOD) (0.44 ng/mL) which was 20-fold lower than that of AuNP-based strip (8.92 ng/mL) for determination of Hg2+, and LM-based strip (0.49 ng/mL) was 18 times as sensitive as AuNP-based strip. In summary, the developed immunosensors using AuNF and LM as signal amplification probes exhibited excellent sensitivity and provided portable, on-site detection for Hg2+.

Preparation of Monoclonal Antibody against Deoxynivalenol and Development of Immunoassays.

Fusarium toxins are the largest group of mycotoxins, which contain more than 140 known secondary metabolites of fungi. Deoxynivalenol (DON) is one of the most important compounds of this class due to its high toxicity and its potential to harm mankind and animals and a widespread contaminant of agricultural commodities, such as wheat, corn, barley, oats, bread, and biscuits. Herein, a hybridoma cell 8G2 secreting mAb against DON was produced by fusing the splenocytes with a tumor cell line Sp2/0. The obtained mAb had a high affinity (2.39 × 109 L/mol) to DON. An indirect competitive Enzyme-Linked Immunosorbent Assay (ic-ELISA) showed that the linear range for DON detection was 3.125-25 µg/mL, and the minimum inhibitory concentration (IC50) was 18.125 µg/mL with a limit of detection (LOD) of 7.875 µg/mL. A colloidal gold nanoparticle (AuNP) with 20 nm in diameter was synthesized for on-site detection of DON within 10 min with vLOD of 20 µg/mL. To improve the limit of detection, the gold nanoflower (AuNF) with a larger size (75 nm) was used to develop the AuNF-based strip with vLOD of 6.67 µg/mL. Compared to the vLOD of a convectional AuNP-based strip, the AuNF-based strip was three times lower. Herein, three immunoassay methods (ic-ELISA and AuNP/AuNF-based strips) were successfully developed, and these methods could be applied for the DON detection in agricultural products.

The Nexuses Between Social Media Marketing Activities and Consumers' Engagement Behaviour: A Two-Wave Time-Lagged Study.

This study examined how social media marketing activities (SMMA) influence consumers' engagement behaviour in developing countries. Based on the stimulus-organism-response theory, we examined the effect of SMMA on consumers' engagement intention and further investigated the moderating effect of social media sales intensity. The study employed a time-lagged design with two waves to confirm the hypothesised framework. The study findings showed that SMMA positively influence consumers' engagement intention and engagement behaviour. In addition, social media sales intensity strengthens the link between engagement intention and engagement behaviour. This study adds to the literature on social media and discusses its practical implications.

Monitoring the CO2 Emission Trajectory and Reduction Effects by ETS and Its Market Performances for Pre- and Post-pandemic China.

The COVID-19 pandemic has caused great shocks on economic activities and carbon emissions. This paper aims to monitor the CO2 emission trajectory in China before and after the pandemic outbreak, and analyze the emission reduction effects by ETS and its market performances, which are important determinants underlying the trajectory and key drivers for emission reductions. We firstly find out a rather consistent trajectory of CO2 emissions in pre- and post-pandemic China over a 2-year time horizon, using the near-real-time datasets of daily CO2 emissions by Carbon Monitor and applying the Cox-Stuart trend test and mean equality test. We then examine the emission reduction effects by China's carbon ETS and its pilot market performances, using the methodologies of DID and PSM-DID as well as pre-pandemic region-level emission datasets by CEADs. Furthermore, it's found that the ETS pilot markets, which are immature with defects, have been performing more vulnerably in terms of liquidity and transaction continuity under pandemic shocks, thus undermining the emission reduction effects by ETS. These findings are providing insights into further mechanism design of the carbon ETS to the end of steady emission reductions even under shocks for post-pandemic China. It's of particular importance now that the nationwide market has been launched and needs to be enhanced based on lessons learned.

Do Overweight People Have Worse Cognitive Flexibility? Cues-Triggered Food Craving May Have a Greater Impact.

BACKGROUND: Overweight people have been revealed to have poor cognitive flexibility. Cognitive flexibility reflects proactive and reactive control abilities. However, the impairment had not been explicitly positioned at the cognitive stage. Therefore, this study provides increased support for impairment of cognitive flexibility due to overweight. METHOD: The study included 34 overweight and 35 normal-weight participants. They were required to complete the food and flower target AX-continuous performance test (AX-CPT), including the resting-state fMRI and cue-triggered food craving subscales. We compared the performance difference between the two tasks. Furthermore, we investigated whether the cue-triggered food cravings and the corresponding brain regions mediated the effect of overweight on the two control mechanisms. RESULT: Significant differences were found only in the food target AX-CPT task, where overweight participants performed worse. Cue-triggered food cravings mediated this relationship. Additionally, we found that the brain regions associated with cue-triggered food cravings (bilateral SFG) can completely mediate the relationship between BMI and the z-value of the fat mass index and sensitivity to proactive control. CONCLUSION: In the food target task, overweight participants performed worse in both control mechanisms. Moreover, we also revealed the potential mechanism by which being overweight might affect the two control mechanisms through cue-triggered food cravings.

Investigating the Impact of the External Environment and Benchmark Characteristics on the China-Pakistan Economic Corridor's Construction: A COVID-19 Perspective.

The economic stability of a country, such as Pakistan is dependent on the construction of mega-projects, such as the China-Pakistan Economic Corridor (CPEC). However, certain external factors and project characteristics may delay the construction of infrastructure projects; scholars have not investigated the development of CPEC from this perspective. In addition, the COVID-19 outbreak has hindered CPEC initiatives. This analysis will examine the effect of external environment factors on CPEC, and benchmark the project's effects on economic stability through CPEC's development by incorporating 523 samples obtained from employees of various CPEC projects. Structural equation modeling was used to analyze all hypotheses proposed here on AMOS 21.0 tools. According to the findings of this study, the CPEC external environment and project benchmark characteristics have a negative effect on the construction of CPEC development. Furthermore, the development of CPEC is found to have a significant effect on economic stability. However, fear of COVID-19 has weakened the relationship between CPEC development and economic stability. Finally, we also discuss the implications and limitations of the study.

The Impact of COVID-19 Epidemic on the Development of the Digital Economy of China-Based on the Data of 31 Provinces in China.

This study investigates the impact of coronavirus disease 2019 (COVID-19) on economic development of China by measuring the HP financial index as an alternative variable of the digital economy. This study shows that economy of China developed further with the dissemination of COVID-19. Furthermore, the digital economy increased the level of economic development more prominently at the onset of COVID-19 pandemic. Moreover, an analysis of regional heterogeneity reveals that the eastern region maintained economic stability through its digital economy during COVID-19, while the central region improved its digital economy during COVID-19 pandemic. Although the economically underdeveloped western region has not suffered too seriously from COVID-19 pandemic, considering the sustained impact of disease and the uncertainty of its transmission speed, the region should vigorously develop its digital economy to manage public risk.

An evaluation of the impact of natural ecotourism on environmental pollution.

The existing models that measure the environmental pollution impact of ecotourism suffer from the problems of low success rate and poor accuracy. We propose a new model to evaluate the environmental pollution impact better. Environmental pollution data are first obtained from the scenic areas of ecotourism. Then, based on the primary parameters of scenic spots, pollution coefficients are determined, and conversion data are used to construct a model to evaluate the pollution impact of ecotourism on scenic spots. Based on the analysis of carbon emission amounts, the monetary value of environmental pollution is determined. Experimental results are provided to show that our proposed model performs better than the existing models.

Single nucleotide polymorphisms in DNA repair genes and risk of cervical cancer: A case-control study.

In this report, we describe a case control study in a Chinese population aimed at identifying possible associations between susceptibility to cervical cancer and single nucleotide polymorphisms in XRCC1 194C>T, XRCC1 280G>A, XRCC1 399G>A, ERCC2 751A>C, ERCC2 156C>A, ERCC1 118C>T, PARP1 762T>C, RAD51 135G>C and HER2 655A>G. The cases comprised 154 patients: 80 cervical squamous cell carcinomas (SCCs), 2 adenocarcinomas and 72 cervical intraepithelial neoplasias (CINs). A total of 177 healthy women were recruited as the controls. A significant association was found between ERCC1 118C>T and SCC in the additive genetic model [odds ratio (OR)=1.711; 95% confidence interval (CI), 1.089-2.880; p=0.021] and the dominant genetic model (OR=1.947; 95% CI, 1.056-3.590; p=0.033). Among women with a smoking family member, ERCC1 118C>T increased SCC risk in the additive model (OR=2.800; 95% CI, 1.314-5.968; p=0.008). For women who had first intercourse before 22 years of age, XRCC1 280G>A was found to act as a protective factor for SCC under the additive model (OR=0.228; 95% CI, 0.058-0.900; p=0.035), while RAD51 135G>C was a risk factor for CIN (OR=4.246; 95% CI, 1.335-13.502; p=0.014). For women who had first intercourse after 22 years of age, the additive genetic model showed RAD51 135G>C (OR=0.359; 95% CI, 0.138-0.934; p=0.036) and HER2 655A>G (OR=0.309; 95% CI, 0.098-0.972; p=0.045) to be protective factors for SCC. XRCC1 399G>A increased CIN risk among women who first gave birth before the age of 22 in the additive genetic model (OR=4.459; 95% CI, 1.139-17.453; p=0.032). For those who first gave birth after age 22, ERCC1 118C>T was found to be a risk factor for SCC in the additive genetic model (OR=1.884; 95% CI, 1.088-3.264; p=0.024). A significant interaction was observed between RAD51 135G>C and age at first intercourse (p(interaction)=0.033 for SCC, p(interaction)=0.021 for CIN), as well with sexual partner number (p(interaction)=0.001 for SCC). The interaction between HER2 655A>G and age at first intercourse, ERCC2 156C>A and family smoking status and XRCC1 280G>A and alcohol consumption were significant, with p(interaction)=0.023 for SCC, p(interaction)=0.021 for CIN and p(interaction)=0.025 for SCC, respectively.

Prevalence of human papillomavirus and cervical intraepithelial neoplasia in China: a pooled analysis of 17 population-based studies.

High-risk (HR) human papillomavirus (HPV) prevalence has been shown to correlate well with cervical cancer incidence rates. Our study aimed to estimate the prevalence of HR-HPV and cervical intraepithelial neoplasia (CIN) in China and indirectly informs on the cervical cancer burden in the country. A total of 30,207 women from 17 population-based studies throughout China were included. All women received HPV DNA testing (HC2, Qiagen, Gaithersburg, MD), visual inspection with acetic acid and liquid-based cytology. Women positive for any test received colposcopy-directed or four-quadrant biopsies. A total of 29,579 women had HR-HPV testing results, of whom 28,761 had biopsy confirmed (9,019, 31.4%) or assumed (19,742, 68.6%) final diagnosis. Overall crude HR-HPV prevalence was 17.7%. HR-HPV prevalence was similar in rural and urban areas but showed dips in different age groups: at age 25-29 (11.3%) in rural and at age 35-39 (11.3%) in urban women. In rural and urban women, age-standardized CIN2 prevalence was 1.5% [95% confidence interval (CI): 1.4-1.6%] and 0.7% (95% CI: 0.7-0.8%) and CIN3+ prevalence was 1.2% (95% CI: 1.2-1.3%) and 0.6% (95% CI: 0.5-0.7%), respectively. Prevalence of CIN3+ as a percentage of either all women or HR-HPV-positive women steadily increased with age, peaking in 45- to 49-year-old women. High prevalence of HR-HPV and CIN3+ was detected in both rural and urban China. The steady rise of CIN3+ up to the age group of 45-49 is attributable to lack of lesion removal through screening. Our findings document the inadequacy of current screening in China while indirectly raising the possibility that the cervical cancer burden in China is underreported.

Impact of genital warts on health related quality of life in men and women in mainland China: a multicenter hospital-based cross-sectional study.

BACKGROUND: Information on the health-related quality of life (HRQoL) of patients with genital warts (GW) in populations in mainland China is still limited. The aim of the study was to use a generic instrument to measure the impact of genital warts on HRQoL in men and women in this setting. METHODS: A multi-centre hospital-based cross-sectional study across 18 centers in China was conducted to interview patients using the European quality of life-5 dimension (EQ-5D) instrument; respondents' demographic and clinical data were also collected. RESULTS: A total of 1,358 GW patients (612 men, 746 women) were included in the analysis, with a mean age of 32.0 ± 10.6 years. 56.4% of the patients reported some problems in the dimension of Anxiety/Depression (highest), followed by Pain/Discomfort (24.7%) and Mobility (3.5%). The overall visual analogue scale (VAS) score of the study population was found to be 65.2 ± 22.0, and the EQ-5D index score was found to be 0.843 ± 0.129 using Japanese preference weights (the Chinese preference was unavailable yet). Patients with lower VAS means and EQ-5D index scores were more often female, living in urban area, and suffering multiple GW (all p values < 0.05), but the values did not differ notably by age (p values > 0.05). CONCLUSIONS: The HRQoL of patients with GW was substantially lower, compared to a national representative general population in China (VAS = ~80); the findings of different subgroups are informative for future GW prevention and control efforts.

Knowledge and attitudes about human papillomavirus (HPV) and HPV vaccines among women living in metropolitan and rural regions of China.

Infection with the human papillomavirus (HPV) is one of the most common sexually transmitted infections and causes virtually all cervical cancer globally. The recent development of two safe and clinically effective vaccines against HPV is a promising step towards lowering cervical cancer rates in the future. What Chinese women think about HPV and the vaccines remains unknown. We undertook a population-based survey, which was embedded in a cervical cancer screening project and was designed to assess women's knowledge about HPV and their acceptability to the vaccines. We found that only 15.0% of women in our study reported to have ever heard of HPV, and this knowledge differs by rural (9.3%) and metropolitan areas (21.6%) and also by education. Most (84.6%) participants were willing to be vaccinated if HPV vaccine became available to them. The present study documents ways in which women learn about HPV and indicates the potential barriers and success of introducing HPV vaccine to China.