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In recent years the entry price to tourism attractions, the price of tourism catering and the price of commodities in tourism destinations have been rising continuously in China. This has resulted in dissatisfaction amongst tourists and residents, especially residents living in a tourism city, with rising tourism prices becoming a hot social problem in many areas. However, China has not yet established and released an authoritative tourism price index (TPI) and this means that prices in the tourism sector are just a black box for the government, enterprises, tourists, and residents alike. It is necessary to build a scientific and systematic tourist price index system in China which will be conducive to optimizing the overall allocation of the tourism resources of the country. This will then allow adjustments in the flow of visitors among different destinations, provide basic data for the various levels of government to make economic decisions in relation to the tourism industry, and will be conducive to the establishment of reasonable tourism price structures and the dynamic monitoring of the price of tourism goods and services. Many studies have shown that the consumer price index (CPI) and the TPI cannot be substituted for each other because of differences in their accounting of consumers, places, and goods and services. A completely revised tourism price index system would consist of a basic goods price index, a major goods price index, and a total price index for the industry. At present, given the lack of statistics on tourist price formulation in China, we have no choice but to select a typical basket of goods and services that are generally related to tourism, and calculate its price from those available for other industries. Using this approach we collected relevant network data, then computed the TPI according to the Laspeyres Index formulation. As a test of this model we conducted a simulation test of the TPI of twelve representative tourist cities in China. We found that the TPI in China as calculated in this way stands at a high level, at a monthly index of more than four, which is much higher than the CPI of the same period. We also found that there are great variations among the regions in China, especially that the TPI of a tourist city in developed areas is higher than that of a tourist city in the less developed regions, and that TPI is also strongly affected by seasonal factors. The seasonal factor is mainly due to price changes amongst certain elements of tourism such as transport and food, which then cause the overall travel price to go up. In addition, through correlation analysis, we are able to show that the coefficient of TPI to CPI is 0.85, which clearly demonstrates that TPI affects CPI and inflates it. It is for this reason that increases in tourism prices are censured by the public. This study showed that it is important to open the black box of travel prices. We therefore suggest that governments and NGOs be encouraged to research, compile and publish tourism price indices, especially in order to build a tourism price index system which can reflect the prices found in the main tourist cities, tourist towns and key scenic spots in China. Such a tourism price index system also requires governments and enterprises to strengthen the collection and analysis of accurate price data for tourism goods and services. Only in this way can the interests of tourists, enterprises, and local communities be protected, and the tourism price index be standardized for their guidance. [ABSTRACT FROM AUTHOR]

BackgroundEctopic pregnancy (EP) is a serious complication of assisted reproductive technology (ART). However, there is no acknowledged mathematical model for predicting EP in the ART population. ObjectiveThe goal of the research was to establish a model to tailor treatment for women with a higher risk of EP. MethodsFrom December 2015 to July 2016, we retrospectively included 1703 women whose serum human chorionic gonadotropin (hCG) levels were positive on day 21 (hCG21) after fresh embryo transfer. Multivariable multinomial logistic regression was used to predict EP, intrauterine pregnancy (IUP), and biochemical pregnancy (BCP). ResultsThe variables included in the final predicting model were (hCG21, ratio of hCG21/hCG14, and main cause of infertility). During evaluation of the model, the areas under the receiver operating curve for IUP, EP, and BCP were 0.978, 0.962, and 0.999, respectively, in the training set, and 0.963, 0.942, and 0.996, respectively, in the validation set. The misclassification rates were 0.038 and 0.045, respectively, in the training and validation sets. Our model classified the whole in vitro fertilization/intracytoplasmic sperm injection–embryo transfer population into four groups: first, the low-risk EP group, with incidence of EP of 0.52% (0.23%-1.03%); second, a predicted BCP group, with incidence of EP of 5.79% (1.21%-15.95%); third, a predicted undetermined group, with incidence of EP of 28.32% (21.10%-35.53%), and fourth, a predicted high-risk EP group, with incidence of EP of 64.11% (47.22%-78.81%). ConclusionsWe have established a model to sort the women undergoing ART into four groups according to their incidence of EP in order to reduce the medical resources spent on women with low-risk EP and provide targeted tailor-made treatment for women with a higher risk of EP.

Rice black streaked-dwarf virus (RBSDV) disease is recently expanding in southern China and poses a serious threat to rice crops. Few studies related to the genetics and breeding of RBSDV resistance have been reported. We have previously mapped a number of quantitative trait loci (QTLs) for RBSDV resistance by using a recombinant inbred line population of 'Zhenshan 97' (ZS97, susceptible)/'Minghui 63' (MH63, resistant) with natural infection data in two locations. In the present study, we confirmed the presence of a number of resistant QTLs on chromosomes 6, 7, and 9 from MH63 by using the same population in four different locations. We then focused on a major QTL, qRBSDV- 6, on chromosome 6 and introduced it into a highly susceptible japonica rice variety, 'Huaidao 5', using MH63 as the donor via marker-assisted selection, to generate seven backcross inbred lines (BILs). Natural infection and artificial inoculation-based tests revealed that all of the BILs had a significantly higher resistance to RBSDV than the recurrent parent. These results demonstrate that qRBSDV- 6 is a stable major resistance QTL of high breeding value. We also constructed a set of chromosome segment substitution lines (CSSLs) specific to the qRBSDV- 6 region and these used as fine mapping population. Combining the genotypes of CSSLs with the phenotypes from natural infection data in a highly RBSDV epidemic area during two different sowing seasons, we were able to precisely map qRBSDV- 6 to the markers S18 and S23 at a physical distance of 627.6 kb on the Nipponbare reference genome. [ABSTRACT FROM AUTHOR]

Aflatoxin B1 (AFB1), a mycotoxin commonly found in foodstuffs, poses significant health risks when ingested through contaminated food sources. Therefore, it is imperative to devise a safe and efficient method for AFB1 degradation. Graphitic carbon nitride (g-C3N4) stands out as an exceptionally stable, non-toxic, and economical photocatalyst, which is widely used in photocatalysis. In this study, we explored the photocatalytic performance of four g-C3N4 catalysts derived from different precursors (dicyandiamide (D-CN), melamine (M-CN), thiourea (T-CN), and urea (U-CN)) in AFB1 degradation under visible light. Notably, the U-CN catalyst displayed an impressive degradation rate of 93.5% for AFB1 within 30 min, outperforming M-CN (82.5%), T-CN (78.5%), and D-CN (46.2%). This superior performance is attributed to its inherent porous structure, enlarged specific surface area, and reduced electron–hole pairs' recombination rate. Additionally, our investigation identified ˙O2− as the primary active species in AFB1 degradation. Furthermore, we explored the degradation pathway of AFB1 and its associated inactivation mechanism mediated by the U-CN catalyst. This work provides a theoretical foundation for developing highly efficient photocatalysts in AFB1 degradation. [ABSTRACT FROM AUTHOR]

Background: Long-term occupational exposure to cotton dust that contains endotoxin is associated with chronic respiratory symptoms and excessive decline in forced expiratory volume in 1 sec (FEV1), but the mechanisms of endotoxin-related chronic airflow obstruction remain unclear. Objective: In the current study, we examined temporal aspects of the exposure–response relationship between airborne endotoxin exposure, longitudinal change in FEV1, and respiratory symptoms in a cohort of Chinese cotton textile workers. Methods: This prospective cohort study followed 447 cotton textile workers from 1981 to 2006.at approximately 5-year intervals. We used a generalized estimating equations approach to model FEV1 level and respiratory symptoms as a function of past exposure (cumulative exposure up to the start of the most recent 5-year survey interval) and cumulative exposure (within the most recent interval) to endotoxins, after adjusting for other covariates. Models were stratified by active versus retired work status and by years employed before the baseline survey (< 5 and ≥ 5 years). Results and conclusions: Past exposure to endotoxin was associated with reduced FEV1 level among retired cotton workers. Among all cotton workers, past exposure was more strongly associated with reduced FEV1 for those hired < 5 years before baseline than for those who were hired ≥ 5 years after baseline. Recent endotoxin exposure was significantly associated with byssinosis, chronic bronchitis, and chronic cough.

Background: The ubiquitous presence of short tandem repeats (STRs) in virtually all genomes implicates their functional relevance, while a widely-accepted definition of STR is yet to be established. Previous studies majorly focus on relatively longer STRs, while shorter repeats were generally excluded. Herein, we have adopted a more generous criteria to define shorter repeats, which has led to the definition of a much larger number of STRs that lack prior analysis. Using this definition, we analyzed the short repeats in 55 randomly selected segments in 55 randomly selected genomic sequences from a fairly wide range of species covering animals, plants, fungi, protozoa, bacteria, archaea and viruses. Results: Our analysis reveals a high percentage of short repeats in all 55 randomly selected segments, indicating that the universal presence of high-content short repeats could be a common characteristic of genomes across all biological kingdoms. Therefore, it is reasonable to assume a mechanism for continuous production of repeats that can make the replicating process relatively semi-conservative. We have proposed a folded replication slippage model that considers the geometric space of nucleotides and hydrogen bond stability to explain the mechanism more explicitly, with improving the existing straight-line slippage model. The folded slippage model can explain the expansion and contraction of mono- to hexa- nucleotide repeats with proper folding angles. Analysis of external forces in the folding template strands also suggests that expansion exists more commonly than contraction in the short tandem repeats. Conclusion: The folded replication slippage model provides a reasonable explanation for the continuous occurrences of simple sequence repeats in genomes. This model also contributes to the explanation of STR-to-genome evolution and is an alternative model that complements semi-conservative replication. [ABSTRACT FROM AUTHOR]

Finding efficient photocatalysts is the key to achieving sustainable hydrogen production. In this work, a rational design of Cd2+-doped Zn3In2S6 (ZIS) and a heterojunction structure with g-C3N4 (GCN) was carried out to form a GCN/Cd/ZIS composite. The synergistic effect of Cd2+ doping and heterojunction construction in the photocatalytic hydrogen production process was probed. The results showed that doping Cd2+ modified the bandgap structure of ZIS and improved the photocatalytic activity. The heterojunction construction between Cd/ZIS and GCN also effectively promoted the separation and migration of photogenerated carriers, which significantly improved the hydrogen production performance of the GCN/Cd/ZIS composite. The hydrogen production rate of 15% Cd/ZIS and 5% GCN/Cd/ZIS was 2.45 mmol g−1 h−1, 3.34 mmol g−1 h−1, which was 4.3 and 5.9 times higher than that of ZIS (0.57 mmol g−1 h−1), respectively. This study provides strong evidence that doping and heterojunction construction can synergistically improve photocatalytic activity. [ABSTRACT FROM AUTHOR]

[Display omitted] • The catalysts with ultra-low Pd loading are acquired by co-impregnation method. • Pd-Cu-In 0.25 /Al 2 O 3 exhibits better CO-PROX performance than Pd-Cu/Al 2 O 3. • There is a strong interaction between In 2 O 3 species and Pd-Cu/Al 2 O 3. • The low electron cloud density of Cu+ makes it easier to be oxidized to Cu2+. • Indium species promotes the reoxidation of Pd0 and reduces the formation of PdH x. The impact of Indium (In) doping upon the catalytic performance of Pd-Cu/Al 2 O 3 for carbon monoxide preferential oxidation (CO-PROX) in hydrogen (H 2) rich atmosphere at low temperature has been studied. A series of catalysts with extremely low palladium (Pd) loading (0.06 wt%) are synthesized by the facile co-impregnation method. When the In/copper (Cu) atomic ratio equals 0.25, Pd-Cu-In 0.25 /Al 2 O 3 can keep 40% CO conversion and 100% carbon dioxide (CO 2) selectivity at least 120 min at 30 °C, which is significantly superior to the catalytic performance of Pd-Cu/Al 2 O 3. The elaborate characterization findings reveal that the added In species to Pd-Cu/Al 2 O 3 causes Indium oxide (In 2 O 3) to generate, which produces the interaction of In 2 O 3 with Pd-Cu/Al 2 O 3 , further promoting the dispersion of copper chloride hydroxide (Cu 2 Cl(OH) 3). Moreover, the modification of In facilitates the re-oxidation of Pd0 to Pd+ through reducing the formation of palladium hydride (PdH x) during the CO-PROX reaction. Meanwhile, the addition of In leads to the decrease of Cu+ electron cloud density, making it easier to be oxidized to Cu2+. Collectively, the easy re-oxidation of Pd0 and Cu+ is favorable to fulfill the Wacker cycle between Pd and Cu species, thus improving the catalytic performance for CO-PROX. [ABSTRACT FROM AUTHOR]

Lots of viral genomes were found to contain microsatellites (SSRs) including Ebolavirus , and majority of Ebolavirus microsatellite sites are distributed in protein-coding regions of the genomes. Here, we totally identified 212 reserved microsatellite sites in the protein-coding regions of 213 genomic sequences from five Ebolavirus species. In these reserved microsatellite sites, there is only one significantly conserved microsatellite site among the sample Ebolavirus genomic sequences, and this microsatellite is located at RNA editing site of the GP gene, indicating the selective relevance with RNA editing there. This analysis may help to further explore the biological significance of various microsatellites in Ebolavirus genomes. • We screened out only one conserved coding microsatellite site remained in all of the five species. • A reported RNA editing site of GP is co-located with the only one conserved microsatellite. • The only one conserved microsatellite in coding regions may contribute to RNA editing of GP and the Ebolavirus survival. [ABSTRACT FROM AUTHOR]