Global prevalence of Cryptosporidium spp. in pigs: a systematic review and meta-analysis

Cryptosporidium spp. are significant opportunistic pathogens causing diarrhoea in humans and animals. Pigs are one of the most important potential hosts for Cryptosporidium. We evaluated the prevalence of Cryptosporidium in pigs globally using published information and a random-effects model. In total, 131 datasets from 36 countries were included in the final quantitative analysis. The global prevalence of Cryptosporidium in pigs was 16.3% (8560/64 809; 95% confidence interval [CI] 15.0–17.6%). The highest prevalence of Cryptosporidium in pigs was 40.8% (478/1271) in Africa. Post-weaned pigs had a significantly higher prevalence (25.8%; 2739/11 824) than pre-weaned, fattening and adult pigs. The prevalence of Cryptosporidium was higher in pigs with no diarrhoea (12.2%; 371/3501) than in pigs that had diarrhoea (8.0%; 348/4874). Seven Cryptosporidium species (Cryptosporidium scrofarum, Cryptosporidium suis, Cryptosporidium parvum, Cryptosporidium muris, Cryptosporidium tyzzeri, Cryptosporidium andersoni and Cryptosporidium struthioni) were detected in pigs globally. The proportion of C. scrofarum was 34.3% (1491/4351); the proportion of C. suis was 31.8% (1385/4351) and the proportion of C. parvum was 2.3% (98/4351). The influence of different geographic factors (latitude, longitude, mean yearly temperature, mean yearly relative humidity and mean yearly precipitation) on the infection rate of Cryptosporidium in pigs was also analysed. The results indicate that C. suis is the dominant species in pre-weaned pigs, while C. scrofarum is the dominant species in fattening and adult pigs. The findings highlight the role of pigs as possible potential hosts of zoonotic cryptosporidiosis and the need for additional studies on the prevalence, transmission and control of Cryptosporidium in pigs

A Marked Decline in Taenia solium Taeniasis and Cysticercosis Infections in China: Possible Reasons from the Ecological Determinants Perspective

Taenia solium taeniasis/cysticercosis is an important global food-borne infectious disease transmitted between humans and pigs. According to both national surveys and field investigations, the prevalence of the disease in China has significantly decreased in recent decades. The primary disease control measures are health education and promotion, meat inspection, and chemotherapy. Other factors that influence or fundamentally affect human and pig T. solium taeniasis/cysticercosis have been identified, such as pig farming patterns shift and a revolution in sanitary toilets, which block T. solium transmission routes. Pig farming practices have shifted from backyard to large-scale intensive farming, thus decreasing pig contact with, and consumption of, human excreta. The increased in the use of sanitary toilets has facilitated hygiene by preventing of human excreta from contacting humans, or polluting the environment, feed, or water. The occurrence of human T. solium infections has markedly decreased as a result of these social changes. The objective of this review is to describe the ecological determinants of the cysticercosis decline in China

DNA stretching in the nucleosome facilitates alkylation by an intercalating antitumour agent

DNA stretching in the nucleosome core can cause dramatic structural distortions, which may influence compaction and factor recognition in chromatin. We find that the base pair unstacking arising from stretching-induced extreme minor groove kinking near the nucleosome centre creates a hot spot for intercalation and alkylation by a novel anticancer compound. This may have far reaching implications for how chromatin structure can influence binding of intercalator species and indicates potential for the development of site selective DNA-binding agents that target unique conformational features of the nucleosome

Influence of microwave irradiation on the preparation of novolacs for the shell process

In this paper, the characteristics of the preparation of novolacs for the shell process under microwave irradiation are investigated. Both polymerization and dehydration of the resins under microwave irradiation are compared with those under conventional heating and further analysis is made. The results show that compared with those under conventional heating, the polymerization and dehydration time under microwave irradiation are shortened by 85.2% and 80.7% respectively; On the other hand, the polymerization and dehydration under microwave irradiation lead to a remarkable increase in flow distance of the resins. Furthermore, the polymerization under microwave irradiation leads to reduced cure time, while the dehydration under microwave irradiation causes a slight increase in cure time

Roles of Hydrogen Gas in Plants under Abiotic Stress: Current Knowledge and Perspectives

Hydrogen gas (H2) is a unique molecular messenger, which is known to be involved in diverse physiological processes in plants, from seed germination to seedling growth to regulation of environmental stresses. In this review, we focus on the role of H2 in plant responses to abiotic stresses, such as temperature, osmotic stress, light, paraquat (PQ)-induced oxidative stresses, and metal stresses. In general, H2 can alleviate environmental stresses by improving the antioxidant defense system, photosynthetic capacity, re-establishing ion homeostasis and glutathione homeostasis, maintaining nutrient element homeostasis, mediating glucose metabolism and flavonoid pathways, regulating heme oxygenase-1 (HO-1) signaling, and interaction between H2 and nitric oxide (NO), carbonic oxide (CO), or plant hormones. In addition, some genes modulated by H2 under abiotic stresses are also discussed. Detailed evidence of molecular mechanisms for H2-mediated particular pathways under abiotic stress, however, is scarce. Further studies regarding the regulatory roles of H2 in modulating abiotic stresses research should focus on the molecular details of the particular pathways that are activated in plants. More research work will improve knowledge concerning possible applications of hydrogen-rich water (HRW) to respond to abiotic stresses with the aim of enhancing crop quality and economic value

Improvement of humidity resistance of water soluble core by precipitation method

Water soluble core has been widely used in manufacturing complex metal components with hollow configurations or internal channels; however, the soluble core can absorb water easily from the air at room temperature. To improve the humidity resistance of the water soluble core and optimize the process parameters applied in manufacturing of the water soluble core, a precipitation method and a two-level-three-full factorial central composite design were used, respectively. The properties of the cores treated by the precipitation method were compared with that without any treatment. Through a systematical study by means of both an environmental scanning electron microscope (ESEM) and an energy dispersive X-ray (EDX) analyzer, the results indicate that the hygroscopicity can be reduced by 20% and the obtained optimal process conditions for three critical control factors affecting the hygroscopicity are 0.2 g·mL-1 calcium chloride concentration, 4% water concentration and 0 min ignition time. The porous surface coated by calcium chloride and the high humidity resistance products generated in the precipitation reaction between calcium chloride and potassium carbonate may contribute to the lower hygroscopicity

Optimization of tensile strength for new type acetone-urea-formaldehyde furan resin using uniform design

In this study, the 24 h tensile strength of new type acetone-urea-formaldehyde furan resin (nitrogen content 3%) was investigated by uniform design optimization. Four independent variables such as acetone : formaldehyde molar ratio (mol/mol), solution pH value, reaction temperature (℃) and reaction time (min) were considered in the experiments. U*13(134) uniform design was employed and the equation of 24 h tensile strength model was obtained after 13 experimentations. The 24 h tensile strength was optimized by applying single factor experiments and stepwise non-linear regression analysis. Minitab (Minitab 15 trial version) and MATLAB (R2010a trial version) were used for data analysis. The t-value and p-value indicate that the major impact factors include the interaction effect of solution pH value and reaction temperature (X2X3), the linear terms of acetone : formaldehyde molar ratio (X1), reaction time (X4) followed by the square effects of acetone/formaldehyde molar ratio (X1X1). The optimized results were achieved with the acetone: formaldehyde molar ratio (mol/mol) at 3:1, solution pH value at 6.0, reaction temperature at 70 ℃, and reaction time at 140 min, respectively. This method can not only significantly reduce the number and cost of the tests, but also provide a good experimental design strategy for the development of furan resin. The investigation shows that the predicted results of 24 h tensile strength are consistent well with the experimental ones

A High Flux Electrochemical Filtration System Based on Electrospun Carbon Nanofiber Membrane for Efficient Tetracycline Degradation

In this work, an electrochemical filter using an electrospun carbon nanofiber membrane (ECNFM) anode fabricated by electrospinning, stabilization and carbonization was developed for the removal of antibiotic tetracycline (TC). ECNFM with 2.5 wt% terephthalic acid (PTA) carbonized at 1000 °C (ECNFM-2.5%-1000) exhibited higher tensile stress (0.75 MPa) and porosity (92.8%), more graphitic structures and lower electron transfer resistance (23.52 Ω). Under the optimal condition of applied voltage 2.0 V, pH 6.1, 0.1 mol L−1 Na2SO4, initial TC concentration 10 ppm and membrane flux 425 LMH, the TC removal efficiency of the electrochemical filter of ECNFM-2.5%-1000 reached 99.8%, and no obvious performance loss was observed after 8 h of continuous operation. The pseudo-first-order reaction rate constant in flow-through mode was 2.28 min−1, which was 10.53 times higher than that in batch mode. Meanwhile, the energy demand for 90% TC removal was only 0.017 kWh m−3. TC could be converted to intermediates with lower developmental toxicity and mutagenicity via the loss of functional groups (-CONH2, -CH3, -OH, -N(CH3)2) and ring opening reaction, which was mainly achieved by direct anodic oxidation. This study highlights the potential of ECNFM-based electrochemical filtration for efficient and economical drinking water purification