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Background Although programmed cell death‐ligand 1 (PD‐L1) plays a well‐known function in immune checkpoint response by interacting with programmed cell death‐1 (PD‐1), the cell‐intrinsic role of PD‐L1 in tumors is still unclear. Here, we explored the molecular regulatory mechanism of PD‐L1 in the progression and metastasis of ovarian cancer. Methods Immunohistochemistry of benign tissues and ovarian cancer samples was performed, followed by migration, invasion, and angiogenesis assays in PD‐L1‐knockdown ovarian cancer cells. Immunoprecipitation, mass spectrometry, and chromatin immunoprecipitation were conducted along with zebrafish and mouse experiments to explore the specific functions and mechanisms of PD‐L1 in ovarian cancer. Results Our results showed that PD‐L1 induced angiogenesis, which further promoted cell migration and invasion in vitro and in vivo of ovarian cancer. Mechanistically, PD‐L1 was identified to directly interact with vascular endothelial growth factor receptor‐2 (VEGFR2) and then activated the FAK/AKT pathway, which further induced angiogenesis and tumor progression, leading to poor prognosis of ovarian cancer patients. Meanwhile, PD‐L1 was found to be regulated by the oncogenic transcription factor c‐JUN at the transcriptional level, which enhanced the expression of PD‐L1 in ovarian cancer. Furthermore, we demonstrated that PD‐L1 inhibitor durvalumab, combined with the antiangiogenic drug, apatinib, could enhance the effect of anti‐angiogenesis and the inhibition of cell migration and invasion. Conclusion Our results demonstrated that PD‐L1 promoted the angiogenesis and metastasis of ovarian cancer by participating in the c‐JUN/VEGFR2 signaling axis, suggesting that the combination of PD‐L1 inhibitor and antiangiogenic drugs may be considered as a potential therapeutic approach for ovarian cancer patients., This manuscript demonstrated that PD‐L1 promoted the angiogenesis and metastasis of ovarian cancer by participating in the c‐JUN/VEGFR2 signaling axis, and suggested that the combination of PD‐L1 inhibitor and antiangiogenic drugs may be considered as a potential therapeutic approach for ovarian cancer patients.

Rationale: Cisplatin derivatives are first-line chemotherapeutic agents for epithelial ovarian cancer. However, chemoresistance remains a major hurdle for successful therapy and the underlying molecular mechanisms are poorly understood at present. Methods: RNA sequencing of organoids (PDO) established from cisplatin-sensitive and -resistant ovarian cancer tissue samples was performed. Glucose metabolism, cell senescence, and chemosensitivity properties were subsequently examined. Immunoprecipitation, mass spectrometry, Fӧrster resonance energy transfer-fluorescence lifetime imaging (FRET-FLIM), luciferase reporter assay, ChIP and animal experiments were conducted to gain insights into the specific functions and mechanisms of action of the serine/threonine kinase, Aurora-A, in ovarian cancer. Results: Aurora-A levels were significantly enhanced in cisplatin-resistant PDO. Furthermore, Aurora-A promoted chemoresistance through suppression of cell senescence and induction of glucose metabolism in ovarian cancer organoids and cells. Mechanistically, Aurora-A bound directly to the transcription factor sex determining region Y-box 8 (SOX8) and phosphorylated the Ser327 site, in turn, regulating genes related to cell senescence and glycolysis, including hTERT, P16, LDHA and HK2, through enhancement of forkhead-box k1 (FOXK1) expression. Conclusions: Aurora-A regulates cell senescence and glucose metabolism to induce cisplatin resistance by participating in the SOX8/FOXK1 signaling axis in ovarian cancer. Our collective findings highlight a novel mechanism of cisplatin resistance and present potential therapeutic targets to overcome chemoresistance in ovarian cancer.

Gelatin is a natural biological macromolecule derived from the collagen in the connective tissue of the skin, bone and other tissues. It has been widely used in medicine, food and industrial production and other fields for easy molding, excellent compatibility and biodegradability. However, physical and chemical disadvantages impede its further application, seriously. Therefore, modification of the gelatin films becomes more and more important. In this study, the gelatin/nanocrystalline cellulose (NCC) composite films were prepared by casting method with 4% glycerol as plasticizer. The effect of NCC on the properties of the composite films was investigated by the characterization of its morphology and mechanical, thermal, and optical properties and water adsorption. The results showed that mechanical, thermal stability and water absorption properties of the gelatin/NCC composite film were obviously improved. The composite films showed the highest tensile strength (13.56 ± 0.25 MPa) when the mass concentration of NCC was 0.6%. Adding NCC to gelatin benefited the thermal stability of composite films. The gelatin/NCC composite film of 0.4% NCC had the highest melting transition temperature (138.9 °C). The composite films exhibited the lower water absorption (271.1%) when mass concentration of NCC was 1.0%. Thus, these results indicated that NCC could affect the properties of gelatin-based composite films, and showed it has potential for application in food packing.

Exposure to Polycyclic aromatic hydrocarbons (PAHs) has been associated with inflammatory responses. Fractional exhaled nitric oxide (FeNO) and exhaled carbon monoxide (eCO) are both important inflammatory mediators especially in airways. However, few studies have investigated associations of PAH exposures with FeNO or eCO. Therefore, we aimed to quantify the associations of urinary PAH metabolites with FeNO and eCO levels, and investigate their potential effect modifiers by linear mixed models among 4133 participants from the Wuhan-Zhuhai cohort in China. We further performed stratified analyses to estimate effect modification. We found significant associations of increased urinary PAH metabolites with elevated eCO and FeNO. Among all participants, each 1% increase of 1-hydroxynaphthalene, 2-hydroxynaphthalene, 2-hydroxyfluorene, 4-hydroxyphenanthrene, 3-hydroxyphenanthrene, and total PAH metabolites was significantly associated with a 12.6% (95% confidence interval: 9.3%, 15.9%), 9.7% (6.5%, 12.9%), 7.5% (4.1%, 10.9%), 3.2% (0.2%, 6.2%), 2.7% (0.1%, 5.3%), and 6.5% (2.7%, 10.4%) increased eCO level, respectively; while each 1% increase of urinary 1-hydroxynaphthalene, 9-hydroxyphenanthrene, 3-hydroxyphenanthrene, and 2-hydroxyphenanthrene was associated with a -3.0% (-5.8%, -0.2%), 2.9% (0.3%, 5.6%), 3.2% (1.0%, 5.4%), and 4.5% (2.2%, 6.9%) change of FeNO level, respectively. Positive associations between certain urinary PAH metabolites and eCO were observed among both ever-smokers and non-smokers, and the associations were stronger among ever-smokers than that among non-smokers. Increased urinary PAH metabolites were associated with decreased FeNO among ever-smokers and elevated FeNO levels among non-smokers. Our findings suggest that PAH exposures may impair airway through inducing inflammatory response, especially among ever-smokers.

Background Inflammation may play an important role in the association between exposure to polycyclic aromatic hydrocarbons (PAHs) and atherosclerotic cardiovascular disease (ASCVD) risk. However, the underlying mechanisms remain unclear. Objectives To investigate the association of PAHs exposure with ASCVD risk and effects of mean platelet volume (MPV) or Club cell secretory protein (CC16) on the association. Methods A total of 2022 subjects (689 men and 1333 women) were drawn from the baseline Wuhan residents of the Wuhan-Zhuhai Cohort study. Data on demography and the physical examination were obtained from each participant. Urinary monohydroxy PAH metabolites (OH-PAHs) levels were measured by a gas chromatography-mass spectrometry. We estimated the association between each OH-PAHs and the 10-year ASCVD risk or coronary heart disease (CHD) risk using logistic regression models, and further analyze the mediating effect of MPV or plasma CC16 on the association by using structural equation modeling. Results The results of multiple logistic regression models showed that some OH-PAHs were positively associated with ASCVD risk but not CHD risk, including 2-hydroxyfluoren (β = 1.761; 95% CI: 1.194–2.597), 9-hydroxyfluoren (β = 1.470; 95% CI: 1.139–1.898), 1-hydroxyphenanthrene (β = 1.480; 95% CI: 1.008–2.175) and ΣOH-PAHs levels (β = 1.699; 95% CI: 1.151–2.507). The analysis of structural equation modeling shows that increased MPV and increased plasma CC16 levels contributed 13.6% and 15.1%, respectively, to the association between PAHs exposure and the 10-year ASCVD risk (p Conclusions Exposure to PAHs may increase the risk of atherosclerosis, which was partially mediated by MPV or CC16.

The accurate detection of the leaf chlorophyll (Chl) is of substantial importance for the immediate assessment of forest conditions to manage and conserve forest ecosystems. We compared 80% acetone, 95% ethanol, and dimethyl sulfoxide (DMSO) over a range of incubation times (2, 4, 6, 8, 18, 26, and 32 h) to determine the Chl contents of 12 tree species in northeast China. The results showed that to obtain the maximum Chl (a+b) contents for most tree species extracted by 80% acetone and 95% ethanol required a minimum of 18 h, while the incubation periods by DMSO were 2-6 h and 18-32 h to extract 90% of the Chl from the broadleaved and coniferous tree species, respectively. We observed that the amount of Chl extracted with DMSO was significantly higher than that extraction with 80% acetone and 95% ethanol, particularly for conifer species with the exception of Phellodendron amurense, Fraxinus mandshurica, and Tilia amurensis, in which the maximum amount of Chl was extracted with acetone. The DMSO extracted Chl in exhibited the lowest degree of variation among the three solvents. The leaf mass area (LMA), leaf thickness, and diameter of the primary leaf vein were significantly negatively correlated with the Chl a, Chl b, and Chl (a+b) content for the 12 tree species. There were non-significant different slopes or intercepts between the curves for LMA and Chl a, Chl b, or Chl (a+b) at the different incubation times for the same solvent or the different solvents at the certain incubation time (P > 0.05).

Association of exposure to polycyclic aromatic hydrocarbons (PAHs) with increased urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG) formation has been reported in occupational population and children. However, studies on the association between them in general population are limited. A total of 1864 eligible subjects from the baseline Wuhan participants of the Wuhan-Zhuhai Cohort Study (n = 3053) were included in this study, after excluding individuals with certain disease and missing data on urinary monohydroxy PAHs (OH-PAHs) and 8-OHdG levels. Urinary monohydroxy PAHs and 8-OHdG levels were measured by gas chromatography-mass spectrometry and high performance liquid chromatography-electrochemical detection, respectively. Association of urinary OH-PAHs with urinary 8-OHdG was analyzed by multiple linear regression analysis. We found a dose-dependent relationship between urinary PAHs metabolites and urinary 8-OHdG (p 0.05 for all). Furthermore, more evidence for the association of total concentrations of urinary OH-PAHs with 8-OHdG levels were observed in individuals with normal body mass index or central obesity (p 0.01 for all). There was a dose-dependent relationship between urinary OH-PAHs levels and urinary 8-OHdG levels among a general Chinese population. Exposure to background PAHs may have a greater influence on urinary 8-OHdG levels in individuals with central obesity.

Lung function is related to socioeconomic status (SES) and exposure to polycyclic aromatic hydrocarbons (PAHs). However, joint effect of SES and exposure to PAHs on lung function has been largely unknown. We aimed to investigate joint effects of SES and urinary OH-PAHs levels on lung function parameters. This study included 2739 Wuhan participants from the baseline survey of the Wuhan-Zhuhai (WHZH) Cohort Study (n=3053). They completed the questionnaire, physical examination and provided blood and urine samples. Twelve urinary monohydroxy-PAHs metabolites (OH-PAHs) and lung function were measured by gas chromatography-mass spectrometry and digital spirometers, respectively. Individuals with low educational levels and low or high levels of urinary ΣOH-PAHs had a 3.5% (95% CI: -5.4, -1.6%) or 4.2% (95% CI: -6.1, -2.3%) reduction in the ratio of forced expiratory volume in 1s to forced vital capacity (FEV1/FVC), respectively, and those with middle levels of education and high levels of urinary ΣOH-PAHs had a 2.1% (95% CI: -5.4, -1.6%) reduction in the FEV1/FVC ratio, rather than those with high levels of education and low levels of urinary ΣOH-PAHs. Individuals with low levels of education had a -3.0% (95% CI: -4.4, -1.6%) reduction in FEV1/FVC compared with individuals with high levels of education. Urinary OH-PAHs levels were marginally negatively related to FEV1 in all participants (p=0.073). The results indicated that there was a prominent effect of low levels of education and higher exposure to PAHs on lung function decline, indicating that it is a necessary to take measures to promote the education level and reduce exposure to environmental PAHs.

Background In duplex real time quantitative PCR (qPCR), there are several factors affecting the sensitivity of duplex qPCR, such as sharing primer, quantity of the internal control (IC) gene, and the primer dimer (PD). The aim of the study is to find out the relationship of interference among templates with different primer pairs, the internal control gene, and the PD in duplex PCR. Methods We designed and synthesized plasmids with partial same sequence and different types of primers include central-homo primer pair, ordinary primer pair, and complementary primer pair. Then we compared the amplification efficiencies of different kinds of primer pairs. Besides, we adjusted the amount of IC plasmid and IC primer to find out the key factor that influences the sensitivity of the target template. Results The concentration ratios of two plasmids showed interference in sharing the universal primer pair, sharing one forward primer, and sharing no primer were 50:1, 200:1 and 500:1, respectively. The amplification efficiency of the ordinary primer pair was higher than that of the universal primer pair for the plasmid. Sensitivity of the duplex qPCR remained unchanged when the amount of PDs increased, but it declined rapidly when the quantity of the IC increased. Conclusions IC is the major factor influencing the sensitivity of the duplex qPCR and it would be better to use one universal primer for IC and target template to achieve minimum interference.

Exposure to polycyclic aromatic hydrocarbons (PAHs) has been associated with adverse effects on the respiratory system. However, the association between internal levels of PAH metabolites and lung function levels remains unclear.We investigated the relationships between urinary PAH metabolite concentrations and lung function levels in a general Chinese population.Lung function and 12 urinary PAH metabolites were measured in 2,747 participants from the Wuhan-Zhuhai cohort in China. Associations between urinary PAH metabolites and lung function were analyzed by linear mixed models. We also investigated associations among urinary PAH metabolite concentrations, traffic exposure time, and dietary PAH exposure.We found significant associations between increased levels of urinary PAH metabolites and reduced lung function. Each 1-U increase in log-transformed levels of 2-hydroxynaphthalene, 9-hydroxyfluorene, 2-hydroxyfluorene, 4-hydroxyphenanthrene, 9-hydroxyphenanthrene, 3-hydroxyphenanthrene, 1-hydroxyphenanthrene, 2-hydroxyphenanthrene, 1-hydroxypyrene, or total urinary PAH metabolites was associated with a 23.79-, 19.36-, 41.76-, 36.87-, 33.47-, 27.37-, 39.53-, 34.35-, 25.03-, or 37.13-ml reduction in FEV1, respectively (all P 0.05). Each 1-U increase in 2-hydroxynaphthalene, 2-hydroxyfluorene, 4-hydroxyphenanthrene, 1-hydroxyphenanthrene, 2-hydroxyphenanthrene, or total urinary PAH metabolites was associated with a 24.39-, 33.90-, 27.15-, 28.56-, 27.46-, or 27.99-ml reduction in FVC, respectively (all P 0.05). The total urinary PAH metabolites concentration was positively associated with both traffic exposure time and dietary PAH exposure among nonsmokers.Total and specific urinary PAH metabolites were associated with lung function reduction in a general Chinese population. Further studies are needed to investigate the potential mechanism by which PAHs induces lung function reduction.

Properties of gelatin composite films（with 4% glycerol as plasticizer）with different mass concentrations of microfibrillated cellulose (MFC) (0.2-1.0%) were investigated. The prepared composite films with 1.0 % MFC showed the highest tensile strength (12.32 MPa) with the lowest water absorption rate (391.1 %). The composite films can be dissolved in hot water of 95°C in less than 5 minutes. However, the addition of MFC had insignificant effect on the heat shrinkage and light transmittance of the resultant composite films.

Stellera chamaejasme ，widely distributed on the Qinghai-Tibet Plateau， is a poisonous plant causing serious harm to grassland. Activated carbons have been prepared from the roots of Stellera chamaejasme via phosphoric acid and zinc chloride activation at500 °C for 60 min with an impregnation ratio of 3:1. Yield (25.1% -27.6%), ash (4.5%-4.9%), methylene blue ( 195.0 mg/g-254.5 mg/g), iodine value (720.4 mg/g- 810.5 mg/g), specific surface area (1023.3 m 2 /g-1216.7 m 2 /g), specific pore volume (2.13 cm 3 /g-2.26 cm 3 /g), mesopore volume (1.30 cm 3 /g-1.59 cm 3 /g) and average pore size (5.88nm-7.45 nm) of the products were determined. The results from both the zinc chloride and phosphoric acid activation processes showed that the activated carbons of S. chamaejasme roots exhibit a characterization of natural developed mesopores.

This study presents the chemical compositional analysis of cow manure in terms of holocellulose (35.97%), lignin (19.02%), and ash (17.47%). Activated carbons (of specific surface area 114 to 893 m2/g, iodine value 219 to 718 mg/g, methylene blue adsorption value 40.5 to 501 mg/g, and ash 16.17% to 22.3%) were prepared from cow manure by using various activator compounds such as potassium carbonate. The results showed that the activation effect of potassium carbonate and zinc chloride was better under the given conditions. The main ash found in the activated carbons was silica, which was reduced to about 3% by washing with sodium hydroxide solution. The prepared activated carbons were used to treat the wastewater from the cow farm and for the pollutant removal that effectively met the discharge standard requirements. These results indicated that the production of activated carbons from cow manure is a promising method for the cleaner production in intensive dairy farms.

Cellulosic pulps were prepared from Achnatherum inebrians straw using soda, soda anthraquinone (soda-AQ), and Kraft pulping processes. The main chemical compositions in A. inebrians straw are 70.5% holocellulose, 41.6% alpha-cellulose, and 18.2% lignin, similar to those in other non-wood materials. The conditions of a liquid/solid ratio of 4.5:1, a time-to-maximum temperature of 100 min, a maximum temperature of 165 °C and a time-at-maximum temperature of 40 min were used in all pulping processes. The results showed that the pulp yield was 35.12–37.01%, the kappa number was 13.23–17.67, drainage index was 19–21 °SR and the viscosity of pulps was 846–898 mL/g. Tear index, tensile index, burst index and brightness of the paper were 5.27–5.83 mN m2/g, 16.58–18.11 mN/g, 1.76–2.37 kPa m2/g and 40.7–43.1% ISO respectively. It is indicated that A. inebrians straw can be used as an alternative raw material for pulping.

Chemical constituents of naturally decayed Qinghai spruce branches were analyzed in terms of holocellulose, lignin, and pentosan. The holocellulose content declined from 57.98% to 35.29% in one year. The rate of change may be related to weather conditions, i.e., the rate of variation was higher when the temperature was high and rainfall was abundant. The changes in lignin and pentosan relative content were completely different from holocellulose; they increased first and then decreased during the decay period. Compared with fresh raw materials, pentosan content (from 14.44% to 25.9%) was increased by 79.4% after four months decay. The highest yield of furfural (10.2%) prepared by a two-stage method from decayed Qinghai spruce branches was similar to the reported yield from corncobs.

Previous studies have reported an association of exposure to polycyclic aromatic hydrocarbons (PAHs) with lung function decline or cardiovascular diseases, or reduced lung function with 10-year cardiovascular (CV) risk. We analyzed risk factors for the 10-year Framingham CV risk using multiple logistic regression, and examined the mediational effect of reduced lung function on the association between exposure to PAHs and FRS using the post-exploratory structural equation modeling. Participants (n = 2268) were drawn from the Wuhan residents at baseline from the Wuhan-Zhuhai Cohort Study. They completed the physical examination, measurements of lung function and urinary monohydroxylated-PAHs (OH-PAHs). In all individuals, we found a dose-response relationship of PAHs exposure, forced expiratory volume in 1 s (FEV1) or forced vital capacity (FVC) with the 10-year CV risk. The proportions of FEV1 and FVC mediation effects in association of PAH exposure with the10-year CV risk were 35% and 24%, respectively. The findings indicated that PAHs exposure or reduced lung function increased the 10-year CV risk. Impaired lung function may partly contribute to increase in the 10-year CV risk regarding exposure to PAHs.

Some studies have shown an association between obesity or exposure to polycyclic aromatic hydrocarbons (PAHs) and the risk of diabetes. This study aimed to investigate the interaction of obesity and urinary monohydroxy-PAHs (OH-PAHs) on diabetes. Individuals (n = 2716) were drawn from the baseline survey of the Wuhan-Zhuhai Cohort Study. They completed the physical examination, measurements of lung function, biochemical indices and urinary OH-PAHs levels. Additive effect of obesity and urinary ΣOH-PAHs levels on diabetes was assessed by calculating the relative excess risk due to interaction (RERI) and the attributable proportion (AP) due to interaction. Several urinary OH-PAHs were positively associated with diabetes in individuals with central obesity or normal weight (p 0.05 for all). Among individuals with poor lung function, the RERI between urinary ΣOH-PAHs and waist circumstance (WC, RERI: 0.866, 95% CI: -0.431, 2.164, p = 0.192) or waist-to-height ratio (WHtR, RERI: 1.091, 95% CI: -0.124, 2.305, p = 0.078) was found; the AP due to the interaction between urinary ΣOH-PAHs and WC or WHtR was 0.383 (95% CI: -0.07, 0.80, p = 0.086) or 0.465 (95% CI: 0.019, 0.912, p = 0.04). The results indicated that central obesity may enhance the effect of exposure to background PAHs on diabetes in individuals with poor lung function.

The incidence of diabetes is increasing rapidly in Chinese population, and it has been postulated that environmental factors may play a role in the etiology of diabetes. Therefore, we aimed to investigate the association between PAHs exposure and risk of diabetes in a community-based population of 2824 participants with completed questionnaires, measurements of biochemical indices, and urinary PAHs metabolites. We found that elevated urinary PAHs metabolites were associated, in a dose-dependent manner, with increased risk of diabetes. Particularly, these associations were more evident in subjects who were female, less than 55 years old, nonsmokers, and normal weight. In addition, there was a modest improvement in diabetes discrimination of prediction models when incorporating certain PAHs metabolites into conventional risk factors (CRF). Overall, our data suggested that there may be a dose-dependent relationship between PAHs metabolites and risk of diabetes among general Chinese population.

Epidemiological studies have suggested associations between polycyclic aromatic hydrocarbons (PAHs) and heart rate variability (HRV). However, the roles of plasma cytokines in these associations are limited. In discovery stage of this study, we used Human Cytokine Antibody Arrays to examine differences in the concentrations of 280 plasma cytokines between 8 coke-oven workers and 16 community residents. We identified 19 cytokines with significant different expression (fold change ≥2 or ≤−2 and q-value p 16% BDNF decreases. Additionally, OH-PAHs were positively associated with activated leukocyte cell adhesion molecule (ALCAM) and C-reactive protein (CRP) (p 20% increases in CRP. We also found significant associations between these cytokines and HRV (p 8% decreases in HRV. Our results indicated PAH exposure was associated with plasma cytokines and higher cytokines were associated with decreased HRV, but additional human and potential mechanistic studies are needed.

Understanding the corrosion behavior of TiB 2p -reinforced aluminum matrix composites is crucial for their development as effective composites. In this work, corrosion characteristics of in situ TiB 2 particulate reinforced Al―Si alloy (A356) composite after T6 treatment are investigated by electrochemical techniques. The electrochemical impedance spectroscopy (EIS) reveals that the protection of nature film for the composites is worse than that for A356 alloy. Polarization experiments testify that the composites are susceptible to corrosion compared with their matrix alloys. Moreover, the corrosion resistance of the composites markedly decreases with increase in the TiB 2 content. The observations of the corrosion morphologies after polarization test show that the corrosion primarily occurs at the interdendritic sites with a large amount of TiB 2 particulates. Corrosion progress continues into the composite inner along the regions of α-A1 dendrite. The poor corrosion resistant properties of the composites are considered primarily due to the galvanic corrosion between noble TiB 2 reinforcements and more active aluminum matrix, as well as the weak protection of the defective nature film on the composite.

In this work, continuous conversion coatings on the surface of in situ TiB2 particulate reinforced A356 composite were formed successfully by cerium surface treatment for the first time. Scanning electron microscope (SEM) analysis showed that the conversion coatings were inhomogeneous and could be divided into two types of regions, namely, fine crack region and noncrack region. Many cerium-rich nano-nodules were uniformly distributed in the whole coatings. Energy dispersive spectroscopy (EDS) analysis testified that the crack coatings mainly covered the interdendritic sites occupied by TiB2 particulates and Si phases. X-ray photoelectron spectroscopy (XPS) analysis indicated that the conversion coatings were composed of CeO2, Ce2O3, Ce(OH)4, Ce(OH)3, and a little amount of Al2O3. The electrochemical polarization tests showed that the cerium-conversion treatment markedly improved the corrosion resistance of in situ TiB2p/A356 composite in chloride environment, and the protection degree of the coatings was superior to that of conventional chromate-conversion coating. According to these results, the formation mechanism of cerium-conversion coatings was discussed. Copyright © 2008 John Wiley & Sons, Ltd.