[Application progress of home self-sampling for human papillomavirus and human immunodeficiency virus testing].

Self-sampling is a method by which the subject collects the own specimens for disease detection. It has the advantages of strong privacy, convenient and simple operation, free time and place, etc. It can improve the compliance of people in remote areas, affected by traditional concepts, limited by working hours and underdeveloped transportation and medical treatment to participate in disease detection and screening. With the development of "Internet+health care" and "Internet+nursing service", home-based self-sampling testing will become a developing situation for disease detection and screening. Human immunodeficiency virus and Human papillomavirus infection bring a heavy burden to individuals and society. In the absence of effective and widespread primary prevention, secondary prevention, namely "early detection, early diagnosis and early treatment" is an effective measure to control the adverse consequences. At present, there are many researches on HPV and HIV self-sampling test, whose test results are highly reliable and highly accepted in the population, and is of great significance for improving the coverage rate of cervical cancer screening and the diagnosis rate of HIV carriers.

Cyclic Deformation in Metallic Glasses.

Despite the utmost importance and decades of experimental studies on fatigue in metallic glasses (MGs), there has been so far little or no atomic-level understanding of the mechanisms involved. Here we perform molecular dynamics simulations of tension-compression fatigue in Cu50Zr50 MGs under strain-controlled cyclic loading. It is shown that the shear band (SB) initiation under cyclic loading is distinctly different from that under monotonic loading. Under cyclic loading, SB initiation takes place when aggregates of shear transformation zones (STZs) accumulating at the MG surface reach a critical size comparable to the SB width, and the accumulation of STZs follows a power law with rate depending on the applied strain. It is further shown that almost the entire fatigue life of nanoscale MGs under low cycle fatigue is spent in the SB-initiation stage, similar to that of crystalline materials. Furthermore, a qualitative investigation of the effect of cycling frequency on the fatigue behavior of MGs suggests that higher cycling frequency leads to more cycles to failure. The present study sheds light on the fundamental fatigue mechanisms of MGs that could be useful in developing strategies for their engineering applications.

Preparation and mechanical property of poly(ε-caprolactone)-matrix composites containing nano-apatite fillers modified by silane coupling agents.

This study aims to improve the tensile strength and elastic modulus of nano-apatite/poly(ε-caprolactone) composites by silane-modification of the nano-apatite fillers. Three silane coupling agents were used to modify the surfaces of nano-apatite particles and composites of silanized apatite and PCL were prepared by a technique incorporating solvent dispersion, melting-blend and hot-pressing. The results showed that the silane coupling agents successfully modified the surfaces of nano-apatite fillers, and the crystallization temperatures of the silanized apatite/PCL composites were the higher than that of the non-silanized control material, although the melting temperature of the composites remained almost unaffected by silanization. The ultimate tensile strength and elastic modulus of the silanized composites reached 22.60 MPa and 1.76 GPa, as a result of the improved interfacial bonding and uniform dispersion of nano-apatite fillers. This study shows that the processing technique and silanization of nano-apatite particles can effectively improve the tensile strength and elastic modulus of nano-apatite/PCL composites.

Altered expression of estrogen receptor alpha and beta in advanced gastric adenocarcinoma: correlation with prothymosin alpha and clinicopathological parameters.

AIMS: We aimed to investigate the sources of estrogen receptor alpha (ERalpha), estrogen receptor beta (ERbeta) and estimate the value of both ER subtypes in gastric adenocarcinoma and analyze the possible relationship of prothymosin alpha (ProTalpha) to ERs. METHODS: ERs at the mRNA and protein levels in matched advanced gastric adenocarcinomas and surrounding non-cancerous tissues were examined by using reverse transcription-polymerase chain reaction and immunohistochemical (IHC) methods. Cell proliferation related protein ProTalpha was also detected in IHC. The immunoreactive signal, corresponding to the proteins expression level, was quantitatively analyzed. RESULTS: Both ERalpha and ERbeta mRNAs were detected in most of the cancer and matched normal tissues analyzed. At the protein level, the percentage of ERalpha and ERbeta positive cases changed. ERalpha immunoreactivity was only detected in poorly differentiated adenocarcinoma and ERalpha positive expression correlated with depth of invasion of the tumors. Compared with non-cancerous tissues, gastric tumors showed decreased ERbeta expression and lost ERbeta. Altered ERbeta in gastric adenocarcinoma correlated with decreased differentiation. And the tumors involved lymph node metastasis showed significantly lower expression level of ERbeta. ProTalpha in ERbeta-positive tumors showed higher expression than that in lost ERbeta tumors. CONCLUSIONS: Altered expression of ERalpha and ERbeta in tumors compared with corresponding normal gastric tissues was more common in poorly differentiated adenocarcinomas and related to malignant properties, such as lymph node metastasis. Decreased ERbeta and increased ProTalpha expression in advanced gastric adenocarcinoma indicated that ERbeta may play an anti-proliferation role which is opposed to the role of ProTalpha in gastric epithelium.

The effect of the major components of Salvia Miltiorrhiza Bunge on bone marrow cells.

Salvia Miltiorrhiza Bunge (SMB), a traditional Chinese medicinal herb, has been alleged to support bone healing. However, the effects of the isolated major components of SMB on osseous cells and their corresponding effective doses are still unclear. In the present study, the effects of three components of SMB, including tanshinone IIA (Ts), salvianolic acid B (salB) and protocatechuic aldehyde (Pca), on mesenchymal bone marrow cells with the potential for osteoblastic differentiation were investigated. Various concentrations of Ts, salB and Pca were added to a rat bone marrow cell culture. The total metabolic activity and differentiation of bone marrow cells were evaluated by a metabolic assay and alkaline phosphatase (ALP) activity, respectively. The morphology and number of cells was observed by phase contrast microscopy and fluorescent microscopy after propidium iodide staining, respectively. Ts suppressed the growth and differentiation of bone precursor cells. SalB exhibited a biphasic effect: the high concentration of 160 microg/mL significantly depressed the population of bone marrow cells, however, lower concentrations (3-80 microg/mL) enhanced the total metabolic activity and their ALP expression. Pca suppressed the bone marrow cell population in a dose-dependent manner. Therefore, SalB has the potential to ameliorate bone healing by stimulating both the total metabolic activity and ALP activity of osteoblastic cells. Aqueous extracts, which preferably contain salB over Pca and are free of Ts therefore are recommended for bone formation.

Insights Into the Evolution of Chemoreceptor Genes Superfamily in Tyrophagus putrescentiae (Acari: Acaridae).

All living organisms, including animals, plants, fungi, and bacteria, use the olfactory system to recognize chemicals or pheromone from their environment. Insects detect a volatile substance using odorant receptors (ORs) or gustatory receptors (GRs) and ionotropic receptors (IRs). The gene families of the olfactory system in Acari are still not clear. In this study, we identified seven ORs, one GR, and five IRs from the transcriptome of the storage mite, Tyrophagus putrescentiae Schrank. No olfactory coreceptor was found in this transcriptome. Phylogenetic analysis of these gene families with other Arthropoda species revealed the conservation of carbon dioxide receptors in all tested flying insects and T. putrescentiae Most of these ORs and GRs were unique to three mosquitoes (Anopheles gambiae Giles, Culex quinquefasciatus Say, and Aedes aegypti L.), Ixodes scapularis Say and Pediculus humanus L., indicating their involvement in specific aspects of both gustatory and olfactory perception. Some clades contained receptors obtained from all tested insect vector species, indicating a degree of conservation among some vector-dependent OR lineages. IRs family was a highly dynamic and independent original of the chemoreceptor genes subfamily. Our findings would make it possible for future research on the chemosensory recognition mechanism in Acari.

Temperature-Dependent Development and Reproductive Traits of Tyrophagus putrescentiae (Sarcoptiformes: Acaridae) Reared on Different Edible Mushrooms.

China is the largest producer, consumer, and exporter of mushrooms in the world. The storage mite, Tyrophagus putrescentiae Schrank, is one of the most important arthropod pests in mushroom cultivation. This study investigated the development and reproductive traits of this mite reared on four mushroom species: Agaricus bisporus Lange, Pleurotus ostreatus Kumm, Auricularia polytricha (Mont.) Sacc., and Flammulina velutipes (Fr.) Sing., at seven constant temperatures ranging from 16 to 34 °C at 80% relative humidity. Development time for the immature stages decreased with increasing temperature, and was also significantly affected by mushroom species. The shortest immature developmental period (7.0 ± 0.2 d) was observed at 31 °C when reared on F. velutipes, while the longest development was at 16 °C (36.0 ± 0.3 d) reared on P. ostreatus. The effects of temperature and mushroom hosts on the development, female longevity, and reproduction were also significant. The lower threshold temperatures from egg-to-adult for the four mushroom species were 11.97, 12.02, 10.80, and 11.57 °C, for A. bisporus, P. ostreatus, Au. polytricha, and F. velutipes, and the thermal constants were 133.3, 136.8, 165.2, and 135.9 degree days (°C d), for the same mushroom species, respectively. Life table parameters at 25 °C were estimated as follows: net reproductive rates (R0), 59.16, 28.94, 42.62, and 62.93, and intrinsic rate of natural increase (rm), 0.24, 0.13, 0.17, and 0.24, respectively. These results suggest that these mushrooms are suitable hosts for T. putrescentiae, and the storage mite may be able to adapt to higher temperatures.

Characterization of titanium surfaces with calcium and phosphate and osteoblast adhesion.

The titanium surfaces containing calcium, phosphate ions and the carbonate apatite were characterized. The effect of surface chemistry on the initial rabbit osteoblast response on these surfaces was investigated. The cell count and alkaline phosphatase (ALP) specific activity assay were used for biochemical analyses. Scanning electron microscopy was used for morphology observation and in particular X-ray photoelectron spectroscopy (XPS) for surface chemistry characterization. The number of cells adhering to the apatite coating surface was the maximum, the number of cells on the surface containing calcium without phosphate ions was higher than that containing phosphate without calcium, and the number on the unmodified titanium surface was the least. The osteoblasts cultured on the apatite surface exhibited the highest ALP specific activity, next were the ones on the surface containing solely calcium, the lowest were on the unmodified titanium surface. On the substrate surfaces removed of adhered cells, the order of nitrogen amounts detected by XPS was consistent with ones of ALP specific activity and cell number, except for the unmodified titanium surface. For the substrate surfaces removed of adhered osteoblasts, XPS analysis showed that calcium and phosphorous amounts decreased during cell adhesion. After cell culture the Ca2p binding energy (BE) values for apatite coating and the surface containing solely calcium were similar to those of the two surfaces adsorbed bovine serum albumin (BSA). The P2p BE values for the surfaces containing phosphate ions, including the apatite coating and the surface containing solely phosphate ions, showed the same change. But after cell culture the decrease of the P2p BE value for the coating surface was larger than the one for the surface containing solely phosphate ions. Considering the bovine serum albumin adsorption on the same samples, these results indicated that calcium ions on titanium surfaces play a more important role than phosphate ions in initial interactions among culture medium, osteoblasts and titanium surfaces. On the apatite coating surface, calcium ions are active sites for osteoblast adhesion, while calcium and phosphate ions co-exist on titanium surfaces, the former promotes the osteoblast adhesion onto the phosphate sites on titanium surfaces. The cell adhesion was a complicated biological and chemical process relating to surface several elements similar to protein adsorption.

Characterization of surface oxide films on titanium and adhesion of osteoblast.

The relationship between surface characteristics of titanium and initial interactions of titanium-osteoblasts was investigated. Titanium plates were heat-treated in different oxidation atmospheres. The third passage rabbit osteoblasts were cultured on the titanium plates for 24h. After the heat-treatment, the crystal structure of the surface oxide films on titanium was identified using X-ray diffractometer and X-ray photoelectron spectroscopy (XPS). The surface roughness of titanium was measured with a profilometer. The surface energy was obtained by measurement of contact angles and calculation with Owens-Wendt-Kaeble's equation. The amount of surface hydroxyl (OH)(s) groups was examined using XPS. The change of binding energy of the some elements on the substrate surface suggested that the interactions between the cells and the titanium involved chemical reactions. The greater surface roughness, higher surface energy and more surface hydroxyl groups resulted in greater numbers of adhered osteoblasts and higher cell activity. Compared to the acidic hydroxyl (OH)(a) groups in (OH)(s) groups and the dispersion component of the total surface energy, the basic hydroxyl (OH)(b) groups and the polar component play more important roles in the osteoblast-titanium interaction.

Evaluation of the expression of collagen type I in porous calcium phosphate ceramics implanted in an extra-osseous site.

The aim of the present study is to demonstrate the newly formed tissue in calcium phosphate (Ca/P) ceramics after extra-osseous implantation by histological and immunohistochemistry (IHC) methods. Synthesis porous Ca/P ceramics without adding any growth factor and living cell were implanted in the dorsal muscle of dogs for 1 and 2 months. Undecalcified and decalcified sections were stained by hematoxylin and eosin (H&E), and IHC, respectively. The histological results showed the beginning of osteogenesis and angiogenesis after being implanted for 1 month and the obvious new bone formation after being implanted for 2 months. IHC were conducted via the avidin-biotin peroxidase complex (ABC) method and the primary antibody was collagen type I. IHC results indicated that collagen type I was expressed within osteoblast-like cells and newly formed bone-like tissue in Ca/P ceramics after 1 month, and in the mineralized matrix of newly formed bone and osteoblasts, some osteocytes and some lacunae after 2 months. No cartilage and chondrocytes were observed in the histological and IHC-stained sections. Evidence of intramembranous osteogenesis was confirmed.

Comparison of DNA adduct induction in vitro by PAHs and nitro-pahs in freshly isolated rat hepatocytes.

Polycyclic aromatic hydrocarbons (PAHs) and nitro-PAHs have been identified widely in occupational and environmental pollution, such as diesel engine emissions and other combustion products. In most cases, hepatic biotransformation is involved in converting these chemicals to their carcinogenic metabolites. It has been demonstrated that isolated hepatocytes possess substantial amounts of the enzymes responsible for metabolizing xenobiotics and are therefore a convenient model for studying chemicals that require activation to exert their carcinogenic effects. In this study, rat hepatocytes were isolated by collagenase digestion and then exposed to benzo[a]pyrene (B) [a]P), benzo[a]anthracene (B[a]A), 1-nitropyrene (1-NP) and 1,6-dinitropyrene (1,6-DNP) at different doses and/or times so that DNA adducts levels, as measured with the (32)P-postlabelling technique, could be compared. Each of the four compounds tested induced significant increases of total DNA adducts with clear dose-related responses. One or more individual adducts were identified as major adducts for each compound. Time-related increases of DNA adducts were also observed from 1 to 4 hr of incubation. Greater amounts of DNA adducts were induced by B[a]P or 1,6-DNP than by B[a]A or 1-NP, with potency being in the order 1,6-DNP > B[a]P > 1-NP B[a]A. These results demonstrate that freshly isolated hepatocytes can be used as an effective in vitro system for the detection of DNA adducts using (32)P-postlabelling, and have shown 1,6-DNP to be the most potent of the tested constituents of diesel emissions.

A study of the pesticide fenthion: toxicity, mutagenicity, and influence on tissue enzymes.

In this paper results of acute toxicity (oral and dermal), cumulative toxicity, subchronic toxicity, and conjunctiva irritation tests are reported. The mutagenic effects of fenthion, using SCE (in vivo) and UDS (in vitro) as indicators, were also tested. Histochemical changes in enzyme activities (including AChE, ATPase, and AKP) in tissues were observed. The results showed that the acute toxicity of fenthion belongs to highly toxic category. The highly cumulative effect of fenthion was also observed. The subchronic toxicity test, however, did not reveal any abnormal effects except the inhibition of ChE activity in plasma. The dose and ChE activity relationship equation was Y = 0.82x + 4.71. The SCE and UDS tests revealed no mutagenic potential. In histochemical experiments we found that AChE activity in tissues was markedly inhibited. AKP and ATPase activities at the cortex renis were increased in the treated rats.

Microstructure and self-sharpening of the magnetite cap in chiton tooth.

The magnetite cap of chiton tooth (Acanthochiton rubrolineatus) was studied with SEM. Three microstructurally distinct regions were recognized: Region I, close to the anterior surface of the cusp and composed of thick rod microstructure units; Region III, close to the posterior surface and composed of fine fibers; and Region II, sandwiched between Regions I and II and composed of thin sheets. The microstructure units in the three regions constitute a continuous and integrated architecture component. The hardness of Regions I and II was measured to be Hv270 and Hv490, respectively. Based on these microstructure observation and hardness data, the abrasive behavior and microstructural mechanism of self-sharpening of the chiton tooth were discussed in the paper. The self-sharpening was attributed to the combined effect of the hardness and the texture orientation of the microstructure units in Regions I and II.

Atomic-scale interactions at the interface of biopolymer/hydroxyapatite.

Molecular dynamics (MD) simulation was used to study chitosan behaviors on different hydroxyapatite (HA) crystallographic planes at the atomic level. The interaction energy between the chitosan chain and different HA surfaces indicates that the interaction of the chitosan chain and HA(1 0 0) surfaces is stronger than that of HA(0 0 1) and HA(1 1 0) surfaces. The chemical interactions between chitosan and HA were analyzed through the concentration profile and pair correlation function of nitrogen and oxygen atoms in chitosan. The results show that there might be chemical interaction between nitrogen and calcium atoms, and hydrogen bonding between oxygen atoms and hydroxyl groups. This study provides useful information in understanding the interfacial interaction mechanism at the atomistic scale.

Formation and persistence of DNA adducts in different target tissues of rats after multiple administration of benzo[a]pyrene.

Exposure of humans to polycyclic aromatic hydrocarbons is an ongoing concern because of the carcinogenicity of these substances. DNA adducts are being increasingly used as indicators of carcinogen exposure. While considerable experimental evidence exists to support their use there are aspects that require further attention, especially after repeated exposure, which has led to this series of experiments. Male Sprague-Dawley rats were dosed with 10 mg/kg benzo[a]pyrene (B[a]P) i.p., 3 times/week for 2 weeks. At 1, 3, 7, 14, 28 and 56 days after the last treatment liver, lung, spleen and peripheral blood mononuclear cells (PBMNs) were sampled. The DNA adduct levels, as measured by the 32P-postlabelling technique, were significantly increased in all tissues, with lung having the highest levels. At day 14 total DNA adducts in lung, spleen and PBMNs were still > 50% of the level at day 1. The removal of total DNA adducts was found to be fastest in liver > spleen > PBMNs > lung. A consistent correlation of total adducts between the lung and PBMNs was observed. A major adduct, designated adduct 1, was detected in all tissues, while adduct 4 was only found in liver and lung. Adduct 5 was detected only in lung, where it constituted approximately 38-49% of total adducts and persisted at a higher level than either adduct 1 or adduct 4 for the entire post-exposure period. These results indicate that B[a]P induced a significant increase in DNA adduct levels in all tissues tested and that total adducts in PBMNs reflect total lung adduct levels. DNA adducts were still readily detectable 56 days after exposure ceased. Thus the results support the use of PBMNs as surrogates for estimation of B[a]P exposure in lung, the primary target organ, and indicate that samples taken days or weeks after repeated exposure will still yield DNA adducts at detectable levels. The role and significance of adduct 5 deserves further investigation, as it was detected only in the primary target organ for B[a]P-induced cancer.

Individual serum bile acids in apprentice spray painters in association with solvent exposure.

The effects of exposure to solvents on serum bile acids were investigated by comparing a group of apprentice vehicle spray painters (exposed group) with one of apprentice electricians. Apprentice spray painters from the study were subdivided into high- and low-solvent-exposure groups. Concentrations of individual serum bile acids (SBA) were measured and compared with conventional liver function tests (LFTs). Total, free, glycine- and taurine-conjugated SBA were consistently found to be present at higher levels in the spray painters than in the electricians, even at the beginning of the apprenticeship. Total SBA tended to increase in spray painters with increasing years of exposure during the apprenticeship, but this was significant at only one time point. No rises were observed over the sampling period in electricians. The mean values of individual and total SBA concentrations were all found to be higher in the high-exposure group than in the low-exposure group, with some differences reaching statistical significance. None of the routine liver biochemistry parameters was different between spray painters and electricians. gamma-Glutamyl transferase (GGT) was the only enzyme found to be significantly different between the high- and low-exposure groups, but all values were within the normal range. This study suggests that occupational exposure even to low levels of solvent mixtures results in increases in SBA. The increased SBA may be indicative of a subclinical liver dysfunction. Alternatively, they may reflect solvent exposure only, with the raised levels having no pathologic implication or consequence.