Global prevalence and risk factors of Enterocytozoon bieneusi infection in humans: a systematic review and meta-analysis.

Enterocytozoon bieneusi is one of the most important zoonotic pathogens. In this study, we present a systematic review and meta-analysis of the prevalence of human E. bieneusi infection in endemic regions and analyze the various potential risk factors. A total of 75 studies were included. Among 31,644 individuals tested, 2,291 (6.59%) were E. bieneusi-positive. The highest prevalence of E. bieneusi in the male population was 5.50%. The prevalence of E. bieneusi in different age groups was varied, with 10.97% in teenagers. The prevalence of E. bieneusi in asymptomatic patients (6.49%) is significantly lower than that in HIV-infected patients (11.49%), and in patients with diarrheal symptoms (16.45%). Rural areas had a higher rate (7.58%) than urban ones. The prevalence of E. bieneusi in humans was the highest (6.42%) at altitudes <10 m. Moreover, the temperate zone marine climate (13.55%) had the highest prevalence. A total of 69 genotypes of E. bieneusi have been found in humans. This is the first global study regarding E. bieneusi prevalence in humans. Not only people with low immunity (such as the elderly, children, people with HIV, etc.), but also people in Europe in temperate marine climates should exercise caution to prevent infection with E. bieneusi during contact process with animals.

Title: Prévalence mondiale et facteurs de risque de l'infection à Enterocytozoon bieneusi chez l'homme : revue systématique et méta-analyse. Abstract: Enterocytozoon bieneusi est l'un des agents pathogènes zoonotiques les plus importants. Dans cette étude, nous présentons une revue systématique et une méta-analyse de la prévalence de l'infection humaine à E. bieneusi dans les régions endémiques et analysons les différents facteurs de risque potentiels. Au total, 75 études ont été incluses. Parmi 31 644 individus, 2 291 (6,59 %) étaient positifs à E. bieneusi. La prévalence la plus élevée d'E. bieneusi dans la population masculine était de 5,50 %. La prévalence d'E. bieneusi dans différents groupes d'âge variait, avec 10,97 % chez les adolescents. La prévalence d'E. bieneusi chez les patients asymptomatiques (6,49 %) était significativement inférieure à celle des patients VIH (11,49 %) et des patients présentant des symptômes de diarrhée (16,45 %). Les zones rurales avaient un taux plus élevé (7,58 %) que les zones urbaines. La prévalence d'E. bieneusi chez les humains était la plus élevée (6,42 %) à une altitude <10 m. De plus, le climat marin de la zone tempérée (13,55 %) avait la prévalence la plus élevée. Au total, 69 génotypes d'E. bieneusi ont été trouvés chez l'homme. Il s'agit de la première étude mondiale concernant la prévalence d'E. bieneusi chez l'homme. Non seulement les personnes ayant une faible immunité (telles que les personnes âgées, les enfants, les patients atteints du VIH, etc.), mais également les personnes vivant en Europe dans un climat marin tempéré doivent veiller à prévenir l'infection par E. bieneusi lors du contact avec des animaux.

Meta-analysis of the global prevalence and risk factors of Enterocytozoon bieneusi infection in pigs from 1999 to 2021.

Enterocytozoon bieneusi (E. bieneusi), which is one of the most common microsporidia, has been identified as an important obligate intracellular pathogen that commonly colonizes in a variety of animal species and humans worldwide, including humans. In this study, the statistical analyses of E. bieneusi infection and prevalence were performed to clarify the relationship between different genotypes in different countries. The databases Chinese National Knowledge Infrastructure (CNKI), VIP Chinese Journal Database, Wanfang Data, PubMed, Web of Science and ScienceDirect were used for data collection. The research data were subjected to subgroup, univariate regression, and correlation, to reveal factors related to the high prevalence of E. bieneusi. A total of, 34 of the 498 articles published before April 2022 met the inclusion criteria. The global prevalence of E. bieneusi in pigs was 37.69% (5175/12672). The prevalence of E. bieneusi in nursery pigs was 58.87% (588/946). In developing countries and Asia, the highest prevalence of E. bieneusi in pigs were 37.62% (4752/11645) and 40.14% (4715/11345), respectively. Moreover, humans and pigs have been found to be infected with the same genotype of E. bieneusi in some cases, as evidenced by the consolidation of genotype information. The results showed that pigs are susceptible to E. bieneusi during the nursery period. The prevalence of E. bieneusi is high in developing countries, and its genotype prevalence varies in each country. Thus, it is essential to strengthen the health inspection of vulnerable groups and customs quarantine inspection.

Global prevalence and risk factors of Cryptosporidium infection in Equus: A systematic review and meta-analysis.

Intoduction: Cryptosporidiosis is a zoonotic disease caused by Cryptosporidium infection with the main symptom of diarrhea. The present study performed a metaanalysis to determine the global prevalence of Cryptosporidium in Equus animals. Methods: Data collection was carried out using Chinese National Knowledge Infrastructure (CNKI), VIP Chinese journal database (VIP), WanFang Data, PubMed, and ScienceDirect databases, with 35 articles published before 2021 being included in this systematic analysis. This study analyzed the research data through subgroup analysis and univariate regression analysis to reveal the factors leading to high prevalence. We applied a random effects model (REM) to the metadata. Results: The total prevalence rate of Cryptosporidium in Equus was estimated to be 7.59% from the selected articles. The prevalence of Cryptosporidium in female Equus was 2.60%. The prevalence of Cryptosporidium in Equus under 1-year-old was 11.06%, which was higher than that of Equus over 1-year-old (2.52%). In the experimental method groups, the positive rate detected by microscopy was the highest (10.52%). The highest Cryptosporidium prevalence was found in scale breeding Equus (7.86%). The horses had the lowest Cryptosporidium prevalence (7.32%) among host groups. C. muris was the most frequently detected genotype in the samples (53.55%). In the groups of geographical factors, the prevalence rate of Cryptosporidium in Equus was higher in regions with low altitude (6.88%), rainy (15.63%), humid (22.69%), and tropical climates (16.46%). Discussion: The search strategy use of five databases might have caused the omission of some researches. This metaanalysis systematically presented the global prevalence and potential risk factors of Cryptosporidium infection in Equus. The farmers should strengthen the management of young and female Equus animals, improve water filtration systems, reduce stocking densities, and harmless treatment of livestock manure.

Trafficked Malayan pangolins contain viral pathogens of humans.

Pangolins are the most trafficked wild animal in the world according to the World Wildlife Fund. The discovery of SARS-CoV-2-related coronaviruses in Malayan pangolins has piqued interest in the viromes of these wild, scaly-skinned mammals. We sequenced the viromes of 161 pangolins that were smuggled into China and assembled 28 vertebrate-associated viruses, 21 of which have not been previously reported in vertebrates. We named 16 members of Hunnivirus, Pestivirus and Copiparvovirus pangolin-associated viruses. We report that the L-protein has been lost from all hunniviruses identified in pangolins. Sequences of four human-associated viruses were detected in pangolin viromes, including respiratory syncytial virus, Orthopneumovirus, Rotavirus A and Mammalian orthoreovirus. The genomic sequences of five mammal-associated and three tick-associated viruses were also present. Notably, a coronavirus related to HKU4-CoV, which was originally found in bats, was identified. The presence of these viruses in smuggled pangolins identifies these mammals as a potential source of emergent pathogenic viruses.

Natural infection of pangolins with human respiratory syncytial viruses.

Respiratory syncytial virus (RSV) is an enveloped non-segmented negative sense RNA virus that belongs to Orthopneumovirus genus of the Pneumoviridae family in the order Mononegavirales. The virus is the leading cause of severe respiratory disease in children under two years of age and is responsible for substantial disease burden in infants and elder people in both developed and developing countries1,2. RSV is only known to circulate among humans, though it was first isolated from chimpanzees3. The virus can experimentally infect mice, rats, cotton rats, ferrets, and hamsters, but does not naturally circulate in these animal populations4. We found that Malayan pangolins (Manis javanica) were naturally infected with RSVs that have 99.4-99.8% genomic identity with strains circulating in humans. Phylogenetic analyses revealed that five RSVs in pangolins were RSV-A ON1 and seven were RSV-B BA genotypes, both of which are currently prevalent in humans worldwide. These findings suggest that humans might transmit their viruses to endangered wildlife.

Long-term hygroscopic dimensional changes of core buildup materials in deionized water and artificial saliva.

The dimensional stability of core buildup materials plays an important role in clinical application. In this study, hygroscopic dimensional changes of four commercial core buildup materials were investigated in deionized water and artificial saliva for up to 150 days. Specimens were made within a customized cylindrical mold. The initial mass and the apparent mass in liquids were measured. All the tested materials showed hygroscopic expansion after a 150-days immersion time. Hygroscopic expansion of these four materials can partly compensate for the polymerization shrinkage. SDR showed the lowest hygroscopic expansion of the four tested materials when immersed in deionized water and artificial saliva. PC showed the highest hygroscopic expansion in deionized water, while LC showed the highest hygroscopic expansion in artificial saliva. In the case of different immersion solvents, osmotic pressure should be considered. For hygroscopic dimensional changes, the hydrophilicity of monomers and changes of intermolecular forces may be crucial factors.

[Dynamic Assessment of PM2.5 Health Damage Value in China from 2015 to 2018].

With the development of industrialization and urbanization in China, there are many environmental problems especially air pollution, which has serious impacts on the sustainable development of economy, ecological environment and public health. Since 2013, a series of environmental protection laws and regulations, and industrial and energy policies have been successively implemented, including Action Plan for Air Pollution Control, and Three-Year Action Plan to Win the Blue Sky Defense War etc. The air quality of the whole country has been improved. In order to evaluate the dynamic changes of environmental health benefits from air pollution control in China, this paper estimates the health effects and health economic losses caused by PM2.5 pollution, and makes a comparative analysis among different regions and cities based on the data of 297 cities at prefecture level and above in China from 2015 to 2018. The results show that, due to sharp decline of ρ(PM2.5), the population exposed to ρ(PM2.5)>35 µg·m-3 decreased year by year, and the proportion of the total population decreased from 80.88% to 62.32%. The total number of all kinds of health endpoints decreased from 33.23 million to 15.91 million, health economic loss decreased from 1579.04 billion yuan to 838.42 billion yuan, the proportion of healthy economic loss in GDP dropped from 2.31% to 0.99%. Among the six regions, the index values of Beijing, Tianjin, Hebei, and surrounding areas, and Chengyu areas have declined year by year. However, Fenwei Plain areas, Yangtze River Delta areas, Pearl River Delta areas, and the middle reaches of the Yangtze River show a complex trend of increasing in some years and decreasing later. However, the situation of Fenwei Plain is still more serious than other areas, and the ρ(PM2.5) is next to Beijing, Tianjin, Hebei and surrounding areas. ρ(PM2.5) of all 11 cities still exceed 35 µg·m-3 in 2018. Compared with 2015, the number of early deaths decreased by 1500, but the total number of all kinds of health endpoints increased by 18900. The health economic loss is 80.711 billion yuan, an increase of 10.714 billion yuan than that in 2015. The proportion of health economic loss in GDP is 3.16%, which is 0.25% lower than that in 2015. The per capita health economic loss is 182.67 yuan higher than that in 2015. In terms of cities, from 2015 to 2018, ρ(PM2.5) in 228 cities decreased with varying degrees. Among which, Dezhou and Baoding dropped the most, only 10 cities saw ρ(PM2.5) rise. 14 cities saw an increase in the number of healthy endpoints, and 11 cities saw an increase in the proportion of healthy economic loss to GDP. Although the index values of Baoding, Xingtai, Handan, and other cities have declined year by year, they still rank top 10 every year. The index value of Xi'an, Xianyang, Linfen, and other cities in 2018 is more than that in 2015. The research shows that the environmental health benefits of air pollution control are significant in China, but it is still necessary to further strengthen regional joint prevention and control, as well as one city one policy.

[Health Effects of PM2.5 Based on Bacterial Toxicity Test and Transcriptional Analysis in Lungs of Mice].

Although epidemiology and toxicology studies have demonstrated that exposure to ambient air particles could result in a variety of lung diseases, but the pulmonary toxicological mechanism remains obscure. In this study, the toxicity of PM2.5 particles in different concentrations was investigated by toxicological methods, including the luminescent bacteria acute toxicity test and genotoxicity performed by SOS chromogenic reaction. The results indicated that, the acute toxicity and genotoxicity were low and negative, respectively. In addition, rats were treated with PM2.5 suspension through intratracheal instillation, and the pathologic changes and expression of different genes in their lungs were carried out. We found that PM2.5 exposure resulted in fibrotic changes and inflammation in the lung with the increase in PM2.5 concentration. Pathway analysis indicated that PM2.5 can induce pulmonary toxicity through disturbing the function of ribosomal protein, fatty acids, and cholesterol metabolism, suggesting an inflammatory reaction in the lung is caused by genetic damage and is irreversible. A gene ontology analysis revealed that abnormal expression of related genes in the immune response could be the specific pathway of lung inflammation. These findings improve our understanding of the toxicological pathway and mechanism of PM2.5 exposure.

[An Assessment of PM2.5-Related Health Risks and Associated Economic Losses in Chinese Cities].

It is important to carry out research on health risks and associated economic losses caused by air pollution using a large sample city in order to control air pollution and improve public health literacy. Using environmental health risk and environmental value assessment methods, the health risks of PM2.5 pollution in 2015, as well as the corresponding economic losses, were estimated in this study using the environmental monitoring data of 62 key cities as samples. The results show that significant impacts due to PM2.5 pollution occurred in 2015, including about 125.1[95% confidence interval (CI):33.29-205.90] thousand premature deaths and 10.10 (95% CI:4.70-15.02) million cases of illness, hospital admissions, and outpatients, which accounted for 3.53% (95% CI:1.64%-5.26%) of the total urban population. The total economic loss associated with the health risks was approximately 570.6 (95% CI:193.08-874.21) billion yuan, which accounts for 1.53% (95% CI:0.52%-2.35%) of the total GDP in 2015. The per capita loss was 1970 (95% CI:667-3018) yuan for these cities. Among the four major urban agglomerations of Beijing-Tianjin-Hebei, the Yangtze River Delta, the Pearl River Delta, and Northeast China, Beijing-Tianjin-Hebei has the highest health risks, associated economic losses, the proportion of associated economic losses to GDP, and associated economic loss per capita because of its high concentration of PM2.5 and dense population than other three urban agglomerations. Among the three economic areas of Eastern, Central, and Western China, the health risks and associated economic losses were highest in the former. However, economic loss per capita did not differ greatly in the three economic areas. The difference in economic losses was very small between South and North China. However, the proportion of economic loss to GDP and per capita loss were much higher in the North than in the South. As to specific cities, the problems of health risks and economic losses were outstanding in Baoding, Zhengzhou, Jinan, and Beijing, which have higher PM2.5 concentrations.

Ovarian Damages Produced by Aerosolized Fine Particulate Matter (PM2.5) Pollution in Mice: Possible Protective Medications and Mechanisms.

BACKGROUND: Ambient aerosol fine particulate matter (PM2.5) is associated with male reproductive toxicity in experiments and may have adverse effects in the female. However, studies evaluating the protective effects and precise mechanisms of aspirin, Vitamin C, Vitamin E, or ozone against toxic effects of PM2.5are sparse. This study was conducted to investigate the possible protective effects and mechanisms of aspirin, Vitamin C, Vitamin E, or ozone on fertility in female mice treated with PM2.5. METHODS: Eighty-four ICR mice were divided into six groups: control group, PM2.5group, PM2.5 + aspirin group, PM2.5 + Vitamin C group, PM2.5 + Vitamin E group, and PM2.5 + ozone group. PM2.5was given by intratracheal instillation every 2 days for 3 weeks. Aspirin, Vitamin C, and Vitamin E were given once a day by oral gavage for 3 weeks, and ozone was administered by intraperitoneal injection once a day for 3 weeks. The levels of anti-Müllerian hormone (AMH), interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), and 8-hydroxy-2'-deoxyguanosine (8-OHdG) were measured using enzyme-linked immunosorbent assay. Western blotting analysis was used to analyze the expressions of Bcl-2, Bax, and caspase-3 in ovaries. Changes in histological structure were examined by light microscope and electron microscopy was used to detect ultramicrostructure. RESULTS: The results demonstrated that PM2.5 decreased AMH levels (P < 0.001); however, aspirin (P < 0.001), Vitamin C (P < 0.001), Vitamin E (P = 0.001), and ozone (P = 0.002) alleviated the decrease. Changes of IL-6, TNF-α, 8-OHdG, Bax/Bcl-2, and caspase-3 in PM2.5group were increased compared to control group (P < 0.001), while in PM2.5 + aspirin, PM2.5 + Vitamin C, PM2.5 + Vitamin E, and PM2.5 + ozone groups, they were statistically decreased compared to PM2.5group (P < 0.001 or P< 0.05). CONCLUSIONS: PM2.5cause the damage of ovaries, and aspirin, Vitamin C, Vitamin E, and ozone antagonizes the damage. The protective mechanism is probably due to its ability to blunt the inflammatory and oxidative stress caused by PM2.5, which subsequently suppressing the expression of apoptotic regulatory protein and reducing the incidence of ovary apoptosis.

Quantification for total demethylation potential of environmental samples utilizing the EGFP reporter gene.

The demethylation potential of pollutants is arguably an innate component of their toxicity in environmental samples. A method was developed for determining the total demethylation potential of food samples (TDQ). The demethylation epigenetic toxicity was determined using the Hep G2 cell line transfected with pEGFP-C3 plasmids containing a methylated promoter of the EGFP reporter gene. The total demethylation potential of the sample extracts (the 5-AZA-CdR demethylation toxic equivalency) can be quantified within one week by using a standard curve of the 5-AZA-CdR demethylation agent. To explore the applicability of TDQ for environmental samples, 17 groundwater samples were collected from heavy polluted Kuihe river and the total demethylation potentials of the sample extracts were measured successfully. Meaningful demethylation toxic equivalencies ranging from 0.00050 to 0.01747µM were found in all groundwater sample extracts. Among 19 kinds of inorganic substance, As and Cd played important roles for individual contribution to the total demethylation epigenetic toxicity. The TDQ assay is reliable and fast for quantifying the DNA demethylation potential of environmental sample extracts, which may improve epigenetic toxicity evaluations for human risk assessment, and the consistent consuming of groundwater alongside the Kuihe river pose unexpected epigenetic health risk to the local residents.

[Improving the temperature robustness of the DOAS based on two-dimensional correlation spectroscopy technology].

The accuracy of the measurement results will be influenced by the ambient temperature in the real-time monitoring based on Differential Optical Absorption Spectroscopy (DOAS). A novel method to improve the temperature robustness of DOAS technology is adopted by two-dimensional correlation spectroscopy technology. Two-dimensional correlation is used to analyse the SO2 absorption cross section at different temperatures. The diagonal slices of synchronization correlation spectroscopy which come from dynamic absorption cross section are obtained. The wavelength 300.5-310 nm is used as the preferred inversion wavelength range based on the slices. The field measurement results and reference value are compared. Results show that the 24-hour average measurement error is 22.5% at 290-310 nm and that at 300.5-310 nm is 9.9%. The correlation coefficients are 0.9496 and 0.7808, respectively. Two-dimensional correlation DOAS technology can be applied to enhance the robustness of temperature, and to improve the accuracy of the measurement results.

The relationship between cyclic hygroscopic dimensional changes and water sorption/desorption of self-adhering and new resin-matrix composites.

OBJECTIVES: This study evaluated the relationship between mass changes and hygroscopic dimensional changes during water sorption/desorption cycles in new resin composites. METHODS: A silorane posterior composite (Filtek(®) Silorane, FS), two micro-fine hybrid composites (GC Gradia Direct Anterior, GDA; GC Gradia Direct Posterior, GDP), a universal composite (GC Kalore, GCK), and a self-adhering flowable composite (Vertise(®) Flow, VF) were evaluated. 25 (n=5) disk specimens (15mm×2mm) were prepared according to ISO 4049. Water sorption was measured gravimetrically. Hygroscopic expansions were measured by a laser micrometer regularly during 150 d water storage and 40 d recondition periods, all at 37°C. Data were analyzed by repeated measures ANOVA, one-way ANOVA and Tukey's post hoc test (p<0.05). RESULTS: Mass changes after 150 d water immersion ranged from 0.68% (±0.02) for FS to 2.83% (±0.11) for VF and the corresponding hygroscopic expansions were from 0.74% (±0.05) for FS to 4.79% (±0.18) for VF. The differences were significant for all materials (p<0.001), except mass changes between GCK and GDP, as well as hygroscopic changes between GCK and GDA. The relationship between hygroscopic expansions and mass changes was initially non-linear and then tended toward linear behavior. But at the late stage of water sorption the hygroscopic expansion of GCK and VF was slightly sigmoidal with respect to their mass changes. SIGNIFICANCE: Relationships between hygroscopic expansion and mass change were determined for some diverse resin-matrix composites. The initial non-linearity for all materials suggests a lower expansion rate due to occupancy of internal free volume by water ingress. The silorane composite FS showed statistically the lowest mass change and hygroscopic dimensional change.

[Air pollutants study by differential optical absorption spectroscopy with transmit-receive fibers].

The differential optical absorption spectroscopy system is presented to monitor air pollutants, such as SO2, NO2, etc. The system employs a reflective telescope to collimate light source and focus absorbed light. A combined transmitting and receiving fiber bundle is set to the focus of a concave mirror. A Xenon lamp works as the light source. The light is coupled into the transmitting fiber, and then collimated by the reflective telescope system. After absorbed by the pollutants, the light is reflected by a pyramid mirror far away the telescope. Then the absorbed light is incident on the concave mirror the second time, and focused on the focal plane again. The receiving fiber induces the light which carries the information of the measured gas into a spectrometer. We can get the concentration of the pollutants by DOAS algorithm. Experimental results show that the proposed method can be adopted to measure some pollutants in air quality monitoring.

Diffusion and concurrent solubility of self-adhering and new resin-matrix composites during water sorption/desorption cycles.

OBJECTIVES: To investigate the kinetic process of water diffusion and mass change in new resin-matrix composites during water sorption/desorption cycles. METHODS: Five new resin-matrix composites were investigated [Filtek(®) Silorane (FS), GC Gradia Direct Anterior (GDA), GC Gradia Direct Posterior (GDP), GC Kalore (GCK), Vertise(®) Flow (VF)]. Five disk-shaped specimens, per material (15.0±0.1) mm diameter by (2.0±0.1) mm, were prepared according to ISO 4049. Each disk was immersed separately in de-ionized water for 150 d and then reconditioned for 75 d; all at (37±1)°C. Mass was measured at different time intervals. Perspex disks were used as control. Data analysis was done by repeated measures ANOVA, one-way ANOVA and Tukey's post hoc test (p<0.05). RESULTS: The water sorption (µg/mm³) after 150 d immersion ranged from 13.51 µg/mm³ (±0.40) for FS to 71.96 µg/mm³ (±0.90) for VF. The solubility ranged up to 16.95 µg/mm³ (±0.79) for VF. A significant mass reduction occurred in VF after the peak value [73.63 µg/mm³ (±0.31)] of water sorption was reached at 42 d. VF had the highest diffusion-coefficient for sorption: 5.23×10⁻9 cm²/s (±0.38) and desorption: 11.72×10⁻9 cm²/s (±0.16). Percentage sorption differences were significant for all materials (p<0.001), except between GCK and GDP. The early correlation between mass change and square root of time was linear. SIGNIFICANCE: Each resin-matrix composite varied in sorption/desorption cycles which may affect clinical service. A concurrent solubility process occurred during sorption of the self-adhering composite VF. The silorane composite FS exhibited minimal sorption.

Hygroscopic dimensional changes of self-adhering and new resin-matrix composites during water sorption/desorption cycles.

OBJECTIVES: To study hygroscopic dimensional changes in new resin-matrix composites during water sorption/desorption cycles. METHODS: Five materials were examined: a self-adhering flowable composite: Vertise® Flow (VF), a universal composite: GC Kalore (GCK), two micro-fine hybrid composites: GC Gradia Direct Anterior (GDA) and GC Gradia Direct Posterior (GDP), and a posterior restorative composite: Filtek® Silorane (FS). Five disk-shaped specimens of each material were prepared (15 mm diameter × 2 mm thickness) according to ISO 4049. The mean diameter of each specimen was measured by a custom-built laser micrometer (to a resolution of 200 nm) periodically over 150d water immersion and 40d recondition periods at (37 ± 1)°C. Perspex controls were used. Data analysis was performed by repeated measures ANOVA, one-way ANOVA and Tukey's post hoc test (p<0.05). RESULTS: Differences in hygroscopic expansion were found for all test materials during sorption, ranging from 0.74% (± 0.05) for FS to 4.82% (± 0.13) for VF. The differences were significant for all materials (p<0.001), except between GCK and GDA. The mathematical relationship between diametral expansion and square root of time was non-linear. VF exhibited significant dehydration shrinkage. SIGNIFICANCE: The silorane composite FS had the lowest hygroscopic expansion. The extent of compensation of polymerization shrinkage by hygroscopic expansion depends on materials, specimen dimensions and time-scale. So the clinical situation must be taken into consideration in the application of these findings.

Bilateral treatment: a strategy for enhancing the mechanical strength of machinable veneers.

OBJECTIVE: To investigate the potential application of bilateral treatment of glazing plus staining in machinable veneer mechanical strength improvement. METHODS: Standard laminate specimens (n=105) were sliced from machinable ceramic blocks and divided into seven batches for further treatments: (1) batch C, standard specimens; (2) batch P, one specimen surface polished; (3) batch F, fired in glaze-firing-program without glaze; (4) batch G, fired with glaze on one surface; (5) batch S, fired with stain on one surface; (6) batch GA, fired with glaze on one surface, then re-fired in stain-firing-program without stain, and (7) batch GS, fired with glaze on one surface then fired with stain on the other side. The flexural strength of all specimens was tested with a three-point-bending test and the results statistically evaluated. Scanning electron microscopy (SEM) was used to analyze fractographs of bilateral treatment specimens. X-ray diffraction (XRD) analysis was performed to evaluate the influence of thermal annealing effect on strength improvement in bilateral treatment. RESULTS: The flexural strength of bilateral treated GS (143.23+/-14.02 MPa) was significantly higher (P<0.05) than unilateral treated G (125.92+/-14.01 MPa) and P (114.48+/-8.45 MPa) and other batches, including C (100.11+/-6.65 MPa), F (99.48+/-8.61 MPa), S (119.28+/-19.34 MPa) and AG (126.65+/-9.83 MPa). SEM imaging showed that no underlying separation between the glaze-matrix or stain-matrix could be found in the fractured GS specimen. No evidence of Bragg diffraction peak broadening could be seen in XRD spectra compared with specimens from batches C and AG. SIGNIFICANCE: To improve machinable laminate strength, a bilateral treatment comprising staining and glazing gave higher strength than unilateral glazing or polishing alone. It was the surface layer effect achieved by glazing and staining, not the thermal annealing effect achieved during glaze and stain sintering, which contributed to the laminate strength improvement.

Source profiles of particulate organic matters emitted from cereal straw burnings.

Cereal straw is one of the most abundant biomass burned in China but its contribution to fine particulates is not adequately understood. In this study, three main kinds of cereal straws were collected from five grain producing areas in China. Fine particulate matters (PM2.5) from the cereal straws subjected to control burnings, both under smoldering and flaming status, were sampled by using a custom made dilution chamber and sampling system in the laboratory. Element carbon (EC) and organic carbon (OC) was analyzed. 141 compounds of organic matters were measured by gas chromatography-mass spectrum (GC-MS). Source profiles of particulate organic matters emitted from cereal straw burnings were obtained. The results indicated that organic matters contribute a large fraction in fine particulate matters. Levoglucosan had the highest contributions with averagely 4.5% in mass of fine particulates and can be considered as the tracer of biomass burnings. Methyloxylated phenols from lignin degradation also had high concentrations in PM2.5, and contained approximately equal amounts of guaiacyl and syringyl compounds. beta-Sitostrol also made up relatively a large fraction of PM2.5 compared with the other sterols (0.18%-0.63% of the total fine particle mass). Normal alkanes, PAHs, fatty acids, as well as normal alkanols had relatively lower concentrations compared with the compounds mentioned above. Carbon preference index (CPI) of normal alkanes and alkanoic acids showed characteristics of biogenic fuel burnings. Burning status significantly influenced the formations of EC and PAHs. The differences between the emission profiles of straw and wood combustions were displayed by the fingerprint compounds, which may be used to identify the contributions between wood and straw burnings in source apportionment researches.

Type II phosphatidylinositol 4-kinase beta is a cytosolic and peripheral membrane protein that is recruited to the plasma membrane and activated by Rac-GTP.

Phosphoinositides have a pivotal role as precursors to important second messengers and as bona fide signaling and scaffold targeting molecules. Phosphatidylinositol 4-kinases (PtdIns 4-kinases or PI4Ks) are at the apex of the phosphoinsitide cascade. Sequence analysis revealed that mammalian cells contain two type II PtdIns 4-kinase isoforms, now termed PI4KIIalpha and PI4KIIbeta. PI4KIIalpha was cloned first. It is tightly membrane-associated and behaves as an integral membrane protein. In this study, we cloned PI4KIIbeta and compared the two isoforms by monitoring the distribution of endogenous and overexpressed proteins, their modes of association with membranes, their response to growth factor stimulation or Rac-GTP activation, and their kinetic properties. We find that the two kinases have different properties. PI4KIIbeta is primarily cytosolic, and it associates peripherally with plasma membranes, endoplasmic reticulum, and the Golgi. In contrast, PI4KIIalpha is primarily Golgi-associated. Platelet-derived growth factor promotes PI4KIIbeta recruitment to membrane ruffles. This effect is potentially mediated through Rac; overexpression of the constitutively active RacV12 induces membrane ruffling, increases PI4KIIbeta translocation to the plasma membrane, and stimulates its activity. The dominant-negative RacN17 blocks plasma membrane association and inhibits activity. RacV12 does not boost the catalytic activity of PI4KIIalpha further, probably because it is constitutively membrane-bound and already activated. Membrane recruitment is an important mechanism for PI4KIIbeta activation, because microsome-bound PI4KIIbeta is 16 times more active than cytosolic PI4KIIbeta. Membrane-associated PI4KIIbeta is as active as membrane-associated PI4KIIalpha and has essentially identical kinetic properties. We conclude that PI4KIIalpha and PI4KIIbeta may have partially overlapping, but not identical, functions. PI4KIIbeta is activated strongly by membrane association to stimulate phosphatidylinositol 4,5-bisphosphate synthesis at the plasma membrane. These findings provide new insight into how phosphoinositide cascades are propagated in cells.

Nucleotide Sequence of a 4 730 Base Pairs Region of the Spodoptera litura Nucleopolyhedrovirus Genome.

A 4 730 bp region of the Spodoptera litura Nucleopolyhedrovirus genome EcoRI-E fragment was sequenced, in which the odv-e66 gene and other two ORFs, ORF 1086 and the p34 gene, were found. The SpltNPV odv-e66 gene open reading frame was deduced to be 2 079 bp, encoding a protein of 692 amino acids. Unlike odv-e66 genes of AcMNPV and LsNPV, only one transcriptional initiation conserved sequence ATAAG of the late gene was present upstream of the initial codon ATG of SpltNPV odv-e66 gene, and no poly(A) signal was detected at the 3' end of the gene. Four highly conserved regions homologous to those of LdNPV, LsNPV, AcMNPV, BmNPV, CfNPV and OpNPV were present in the amino acid sequence of SpltNPV ODV-E66 protein, with the putative nuclear targeting signal(NTS) KKIWAEDGR in the fourth conserved region. The ORF upstream of the odv-e66 gene had the same direction of odv-e66 gene, but different reading frame. Besides the CAAT box, the early gene regulatory element ACGT and GC motifs and the transcriptional initiation conserved sequence TTAAG of the late gene were present at the 5' end of this ORF. A putative protein of 289 amino acid residues with Mr. about 34 kD was encoded by the ORF, so that it is named P34 protein. A leucine zipper and a leucine zipper-like structure were found in the C- and N-termini of SpltNPV P34 protein respectively. The functions of those regulatory elements may be of great importance to SpltNPV genome. An 1 086 nt open reading frame (ORF) capable of encoding a 361 amino acids polypeptide was found at the 3' end of the odv-e66 gene and in opposite direction. The ORF 1086 protein shares 44% amino acid sequence homology with AcMNPV ORF 109.