[Trends in the prevalence of schistosomiasis in Anhui Province from 2004 to 2020 based on Joinpoint regression analysis].

OBJECTIVE: To investigate the changing trends in the prevalence of schistosomiasis in Anhui Province from 2004 to 2020, so as to provide the evidence for formulating the schistosomiasis elimination strategy in the province. METHODS: The epidemiological data of schistosomiasis in Anhui Province from 2004 to 2020 were collected, and the trends in the endemic status of schistosomiasis were analyzed using a Joinpoint regression model. The trends in the prevalence of Schistosoma japonicum infections in humans, bovines and Oncomelania hupensis were measured in Anhui Province from 2004 to 2020 using average annual percent change (AAPC), and the correlations among the changing trends in the prevalence of S. japonicum infections in humans, bovines and O. hupensis snail status were evaluated using Pearson correlation analysis. RESULTS: The prevalence of S.japonicum human infections continued to decline in Anhui Province from 2004 to 2020, with an annual mean decline of 14.8% [AAPC = -14.8%, 95% confidential interval (CI): (-18.9%, -10.5%), P < 0.01]. The prevalence of S. japonicum infections continued to decline in bovines in Anhui Province from 2004 to 2015 [AAPC = -31.3%, 95%CI: (-35.1%, -27.2%), P < 0.01], and was 0 for 5 successive years from 2016 to 2020. During the period from 2004 to 2020, there was an annual mean decline of 0.7% in areas of snail habitats [AAPC = -0.7%, 95%CI: (-1.2%, 0.3%), P < 0.05] and an annual mean decline of 9.2% in the density of living snails [AAPC = -9.2%, 95%CI: (-18.3%, 1.0%), P = 0.08] in Anhui Province from 2004 to 2020, and an annual mean decline of 35.6% was found in the density of S. japonicum-infected snails [AAPC = -35.6%, 95%CI: (-49.2%, -18.3%), P < 0.01] from 2004 to 2012, with no infected snails detected in Anhui Province from 2013 to 2020. There were significant correlations in the prevalence of S. japonicum infections between humans and bovines (r = 0.959, P < 0.01), between the prevalence of S. japonicum human infections and the density of S. japonicum-infected snails (r = 0.823, P < 0.01) and between the prevalence of S. japonicum infections in bovines and the density of S. japonicum-infected snails (r = 0.902, P < 0.01). CONCLUSIONS: The prevalence of S. japonicum infections appeared a decline in humans, bovines and O. hupensis in Anhui Province from 2004 to 2020, and significant correlations were found among the changing trends in the prevalence of S. japonicum human infections, the prevalence of S. japonicum bovine infections and the density of S. japonicum-infected O. hupensis snails. Because of a minor decline in the area of snail habitats and widespread distribution of O. hupensis, however, there is still a risk of schistosomiasis transmission, and precision control for schistosomiasis remains to be reinforced in Anhui Province.

[Investigation on prevalence of Schistosoma japonicum infections in wild mice in Shitai County, Anhui Province, 2018].

OBJECTIVE: To investigate the prevalence of Schistosoma japonicum infection in wild mice in Shitai County, Anhui Province, so as to provide insights into precise control of the source of S. japonicum infections. METHODS: Wild mice were captured using the trapping method for three successive nights at snail-infested settings from Jitan Village of Jitan Township, and Shiquan Village and Xibai Village of Dingxiang Township, Shitai County, Anhui Province in June and October, 2018. All trapped wild mice were sacrificed and liver and mesenteric vein specimens were collected for detection of S. japonicum eggs using microscopy, while the fecal samples in mouse intestines were collected for identification of S. japonicum infections using Kato-Katz technique. In addition, the population density of trapped wild mice was estimated and the prevalence of S. japonicum infection was calculated in trapped wild mice. RESULTS: A total of 376 wild mice were trapped from three villages in Shitai County. The population density of trapped wild mice was 9.1% (376/4 124), and the prevalence of S. japonicum infection was 24.2% (91/376) in trapped wild mice. The highest prevalence of S. japonicum infection was detected in Shiquan Village of Dingxiang Township (30.1%), and the lowest prevalence was seen in Xibai Village of Dingxiang Township; however, there was no significant difference in the prevalence of S. japonicum infection in trapped wild mice among three villages (χ2= 4.111, P > 0.05). In addition, there was no significant difference in the prevalence of S. japonicum infection in wild mice captured between on June (26.8%, 34/127) and October (22.9%, 57/249) (χ2 = 0.690, P = 0.406). The trapped wild mice included 6 species, including Rattus norvegicus, Niviventer niviventer, R. losea, Apodemus agrarius, Mus musculus and N. coning, and the two highest prevalence of S. japonicum infection was detected in R. losea (34.9%, 22/63) and R. norvegicus (31.2%, 44/141). CONCLUSIONS: The prevalence of S. japonicum infections is high in wild mice in Shitai County, and there is a natural focus of schistosomiasis transmission in Shitai County.

[Endemic situation of schistosomiasis in national surveillance sites of Anhui Province from 2015 to 2018].

OBJECTIVE: To analyze the endemic situation of schistosomiasis in national surveillance sites of Anhui Province from 2015 to 2018, so as to provide scientific evidence for schistosomiasis control and prevention in Anhui Province. METHODS: According to the National Schistosomiasis Surveillance Programme (2014 version), a total of 51 national schistosomiasis surveillance sites were assigned in Anhui Province in 2015, and Schistosoma japonicum infections in humans and livestock and snail distribution were monitored from 2015 to 2018. RESULTS: A total of 89 638 local residents and 42 609 mobile populations received serological screening of schistosomiasis in 51 national surveillance sites of Anhui Province from 2015 to 2018, and the sero-prevalence of S. japonicum infections was 1.41% to 3.69% in local residents and 0.84% to 2.13% in mobile populations, respectively. There were 5 egg-positive local residents and 1 egg-positive mobile populations detected in 2015, with occupations of farmers and fishermen. There were 6 405 livestock detected for S. japonicum infections, and no egg-positives were identified. Among an area of 12 661 hm2 surveyed in the national schistosomiasis surveillance sites of Anhui Province from 2015 to 2018, the areas of snail habitats were 2 461.27 to 2 628.96 hm2, andthemeandensityoflivingsnailswas 0.3757 to 0.4330 snails/0.1 m2, with no S. japonicum infections identified in snails. CONCLUSIONS: The endemic situation of schistosomiasis is at a low level in Anhui Province; however, the risk of schistosomiasis transmission remains in local regions of the province. The construction of the surveillance-responsesystemshouldbereinforcedtoconsolidatetheachievementsofschistosomiasis control in Anhui Province.

[Role and clinical significance of coagulation and inflammatory factors in moderate and severe ovarian endometriosis].

Objective: To determine the levels of coagulation and inflammatory factors in women with moderate and severe ovarian endometriosis so as to investigate the possible role of coagulation and inflammatory factors in the pathogenesis, diagnosis and treatment of this disease. Methods: From June 2015 and June 2017, clinical data of 366 patients with pathologically diagnosed moderate and severe ovarian endometriosis (case group) and 244 patients with pathologically diagnosed benign ovarian cysts (control group) in Women's Hospital of Zhejiang University School of Medicine were retrospectively analyzed. The levels of coagulation indicators, inflammatory factors and serum tumor markers were measured. Then, the values of these indicators in diagnosis of endometriosis were analyzed. Results: (1) The levels of plasma prothrombin time (PT) and thrombin time (TT) in patients with ovarian endometriosis [median: 12.8 s (range: 12.4-13.2 s) and 15.5 s (range: 15.1-15.9 s), respectively] were significantly shorter than those with benign ovarian cysts [median: 13.0 s (range: 12.5-13.4 s) and 15.7 s (range: 15.3-16.1 s), respectively; allP<0.01]. The levels of plasma fibrinogen (FIB) and D-dimer [D-D; median: 3.1 g/L (range: 2.8-3.5 g/L) and 0.9 mg/L (range: 0.6-2.1 mg/L) , respectively] in patients with ovarian endometriosis were significantly higher than those with benign ovarian cysts [median: 2.8 g/L (range: 2.6-3.2 g/L) and 0.6 mg/L (range: 0.4-1.2 mg/L), respectively; P=0.000]. Moreover, neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio [PLR; median: 2.3 (range: 1.8-3.1) and 144 (range: 113-179), respectively] in patients with ovarian endometriosis were significantly higher than those with benign ovarian cysts [median: 2.1 (range: 1.6-2.8) and 128 (range: 104-165), respectively; P<0.01]. Furthermore, in patients with ovarian endometriosis, the levels of PT were significantly shorter in stage Ⅳ endometriosis than that in stage Ⅲ endometriosis (P<0.05). The levels of FIB and PLR in patients with stage Ⅳ endometriosis were significantly higher than those in patients with stage Ⅲ endometriosis (P<0.01) . (2) The cut-off value of CA(125) was 27.2 kU/L with a sensitivity of 83.6%, the cut-off value of FIB was 3.1 g/L with a sensitivity of 53.2%, while the sensitivity of combination index (FIB×CA(125)) was 84.9%. Conclusion: The abnormality of coagulation and inflammatory factors may be involved in the pathogenesis of moderate and severe ovarian endometriosis, and the detection of coagulation and inflammatory factors may be have important clinical significance for the diagnosis and treatment of moderate and severe ovarian endometriosis.

Direct Growth of Al2O3 on Black Phosphorus by Plasma-Enhanced Atomic Layer Deposition.

Growing high-quality and uniform dielectric on black phosphorus is challenging since it is easy to react with O2 or H2O in ambient. In this work, we have directly grown Al2O3 on BP using plasma-enhanced atomic layer deposition (PEALD). The surface roughness of BP with covered Al2O3 film can reduce significantly, which is due to the removal of oxidized bubble in BP surface by oxygen plasma. It was also found there is an interfacial layer of PO x in between amorphous Al2O3 film and crystallized BP, which is verified by both X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM) measurements. By increasing temperature, the PO x can be converted into fully oxidized P2O5.

[The relationship between myocardial bridge in mural coronary artery segment and coronary atherosclerosis].

Objective: The myocardial bridging (MB) prevalence, anatomic characteristics of MB, and the relationship between characteristics of MB in mural coronary artery segment and coronary atherosclerosis were analyzed. Methods: In this perspective nonrandomized controlled study, a total of 1 132 patients who admitted to our hospital for suspected or known coronary artery disease from January 2012 to June 2013 were enrolled. All patients underwent dual-source 64-slice spiral CT coronary angiography. The general patient characteristics including gender, age, history of hypertension, diabetes, hyperlipidemia and smoking, serum level of total cholesterol (TC) and LDL-C were recorded. The length, depth and the degree of compression of myocardial bridge in systolic or diastolic phase were also analyzed in patients with MB. The relationship between MB and coronary atherosclerosis, the characteristics of MB and coronary atherosclerosis were analyzed by Spearman correlation analysis, univariate logistic regression analysis, variate logistic regression analysis and linear regression analysis. Results: Myocardial bridging was detected in 330 out of 1 132 patients, and MB was mostly located in the mural coronary artery (329/330) and at the mid-distal segment of the left anterior descending artery (LAD). Average MB length was 20.1 mm (3.3-95.5 mm) and the average depth was 2.13 mm (0.24-12.40 mm). There were 140 patients with intramyocardial MB (42.6%) and 189 patients with superficial MB (57.4%). Myocardial bridging was an independent protective factor of coronary atherosclerosis (OR=0.361, P=0.000) and the proximal segment of MB was more susceptible to atherosclerosis compared to the distal segment of MB (P=0.000). Multivariate analysis revealed that age, hypertension and the degree of compression of myocardial bridge in diastolic phase were independent factors related to the atherosclerosis (odds ratio: 1.064, 2.186 and 1.049 respectively, P value: 0.000, 0.002 and 0.000). The depth of MB was significantly correlated with systolic or diastolic narrowing(OR: 4.227, 3.398 and P value: 0.000, 0.001). Conclusions: The prevalence of myocardial bridging is 29% in this patient cohort. The proximal segment of myocardial bridging in mural coronary artery is more susceptible to atherosclerosis. In addition, the depth of myocardial bridging and the degree of compression of myocardial bridge in diastolic phase are the independent factors related to atherosclerosis.

Electroless fabrication and supercapacitor performance of CNT@NiO-nanosheet composite nanotubes.

Composite nanostructures consisting of porous NiO nanosheets on carbon nanotubes (CNTs) are fabricated using a facile and low-cost electroless plating method. The CNTs, modified by a polymer, are adopted as the template upon which porous Ni nanosheets are grown using electroless plating. This is followed by removal of the polymer layer and oxidation of the Ni by controlled thermal annealing. The effect of reductant concentration on the morphology of the NiO nanosheets is studied. The electrochemical characteristics of the nanostructures are measured using chronopotentiometry. Experimental measurements show that the NiO nanosheet covered CNT composite nanostructures exhibit a relatively high specific capacitance of 1177 F g(-1) at a discharge current density of 2 A g(-1), while retaining 89.2% of its initial capacitance at a current density of 2 A g(-1) after 1000 cycles.

Epidemiological and clinical characteristics of severe fever with thrombocytopenia syndrome (SFTS) in China: an integrated data analysis.

Severe fever with thrombocytopenia syndrome (SFTS) is an emerging infectious disease that was caused by a novel bunyavirus, SFTSV. The study aimed to disclose the epidemiological and clinical characteristics of SFTSV infection in China so far. An integrated clinical database comprising 1920 SFTS patients was constructed by combining first-hand clinical information collected from SFTS sentinel hospitals (n = 1159) and extracted data (n = 761) from published literature. The considered variables comprised clinical manifestations, routine laboratory tests of acute infection, hospitalization duration and disease outcome. SFTSV-IgG data from 19 119 healthy subjects were extracted from the published papers. The key clinical variables, case-fatality rate (CFR) and seroprevalence were estimated by meta-analysis. The most commonly seen clinical manifestations of SFTSV infection were fever, anorexia, myalgia, chill and lymphadenopathy. The major laboratory findings were elevated lactate dehydrogenase, aminotransferase, followed by thrombocytopenia, lymphocytopenia, elevated alanine transaminase and creatine kinase. A CFR of 12·2% was estimated, significantly higher than that obtained from national reporting data, but showing no geographical difference. In our paper, the mortality rate was about 1·9 parts per million. Older age and longer delay to hospitalization were significantly associated with fatal outcome. A pooled seroprevalence of 3·0% was obtained, which increased with age, while comparable for gender. This study represents a clinical characterization on the largest group of SFTS patients up to now. A higher than expected CFR was obtained. A wider spectrum of clinical index was suggested to be used to identify SFTSV infection, while the useful predictor for fatal outcome was found to be restricted.

A cluster of person-to-person transmission cases caused by SFTS virus in Penglai, China.

An emerging infectious disease, severe fever with thrombocytopenia syndrome (SFTS), was identified to be associated with a novel SFTS virus (SFTSV). Transmission of the disease among humans has been described, but clinical impact factors and transmission mechanisms still need further study. An outbreak of person-to-person transmission of SFTS in a cluster of nine patients that occurred in an SFTS endemic area, Penglai County, Shandong province, China, was investigated. We found that the onset date of all eight secondary SFTS patients ranged from 7 to 13 days after exposure to the corpse of the index patient, and clinical incubation time was mostly focused on 9-10 days (n = 6). The two dead patients, including the index patient and one secondary infected patient, presented unusually high levels of viral load (6 × 10(8-9) copies/mL), low levels of platelets count (<55 × 10(9)/L), and significant increase of alanine aminotransferase, aspartate aminotransferase, lactate dehydrogenase, and creatine kinase values in the second week, and died on day 10 or 11 after disease onset. Genetic sequencing revealed 100% homology among virus strains isolated from the index patient and five secondary patients. Risk factors assessment of the person-to-person transmission revealed that the major exposure factor was blood contact without personal protection equipment. Information from this study provided solid references of SFTS incubation time, clinical and laboratory parameters related to SFTS severity and outcome, and biosafety issues for preventing person-to-person transmission or nosocomial infection of SFTSV.

Comparative cell attachment, cytotoxicity and antibacterial activity of radiopaque dicalcium silicate cement and white-coloured mineral trioxide aggregate.

AIM: To comparatively examine the cell attachment, cytotoxicity, and antibacterial activity of radiopaque dicalcium silicate cement (RDSC) and ProRoot white-coloured mineral trioxide aggregate (WMTA). METHODOLOGY: AlamarBlue was used for real-time and repeated monitoring of MG63 cell attachment on freshly mixed and set cements. The pH changes in the growth medium at different time-points were also measured. Cytotoxicity evaluation was performed according to ISO 10993-5 specifications. The antibacterial activity of the cement specimens was evaluated using Enterococcus faecalis. RESULTS: There were no significant differences (P > 0.05) between the two cements for cell attachment either in the fresh groups or in the set groups at all culture times. Neither freshly mixed group nor set groups had significant pH differences. In the case of cytotoxicity, RDSC was significantly (P < 0.05) superior to WMTA at 12 and 24 h of incubation. RDSC and WMTA possessed similar antimicrobial activity, substantiated by the formation of growth inhibition zones and bacteriostasis ratio in E. faecalis strains. CONCLUSIONS: The cell attachment, cytotoxicity and antibacterial efficacy of RDSC were comparable to those reported for ProRoot WMTA. The results of the current study suggest that this RDSC could be used as a root-end filling material and root sealer.

Physicochemical properties of radiopaque dicalcium silicate cement as a root-end filling material in an acidic environment.

AIM: To investigate the effect of two solutions differing by pH (7.4 and 4.0) on the physicochemical properties of a radiopaque dicalcium silicate cement. METHODOLOGY: The cement was prepared by hand-mixing the dicalcium silicate powder with distilled water in a liquid-to-powder ratio of 0.4 mL g(-1) . A total of 253 cement specimens with dimension of 6 mm (diameter) × 3 mm (height) were used. The morphology, weight loss, porosity and diametral tensile strength of the cement were evaluated after soaking in a solution for different time intervals, in addition to pH changes in the cement-immersed solutions. RESULTS: After soaking in a pH 7.4 solution for 1 day, the particle size of precipitated apatite spherulites on the cement surfaces was greater than that obtained in a pH 4.0 solution. Solution pH did not result in a significant difference (P > 0.05) in diametral tensile strength of cement specimens at the same soaking time-point. On day 30, the sample was associated with a weight loss of 0.8% in a pH 4.0 solution, whereas in a pH 7.4 solution, a weight increase of 0.2% occurred. A greater porosity of the cement soaked in a pH 4.0 was found compared with that in the solution with pH 7.4. Soaking time affected significantly (P < 0.05) the porosity, weight change and strength of the cements in an acidic environment more than at pH 7.4. CONCLUSIONS: High apatite-forming activity and low degradation were the characteristics of a radiopaque dicalcium silicate cement.

Effects of altering the Si/Ca molar ratio of a calcium silicate cement on in vitro cell attachment.

AIM: To examine the effects of altering the Si/Ca molar ratio (6 : 4, 5 : 5, and 4 : 6) of a quick-setting calcium silicate cement on in vitro cell attachment. METHODOLOGY: Working time and setting time of three different calcium silicate cements were measured. Alamar Blue was used for real-time and repeated monitoring of cell attachment and proliferation. The Si and Ca ion concentrations of the cell culture medium in the presence of three different calcium silicate cements seeded with MG63 cells were measured. Kinetic immunofluorescent staining of MG63 cells was performed during cell attachment and spreading. Reverse transcription-polymerase chain reaction was employed to determine gene expression in MG63 cells cultured on the cements. One-way analysis of variance was used to evaluate the significance of the differences between the mean values. RESULTS: The working time (4-7 min) and setting time (17-24 min) of the cements were shortened with an increase in the Ca content of the calcium silicate powders after mixing the powder with water. In contrast, the higher the Si content in the cement, the more the MG63 cells attached to the cement at all culture time-points, accompanying by the formation of more obvious actin stress fibres. Cell proliferation and differentiation increased significantly (P < 0.05) with an increase in the Si content of the calcium silicate cements. Si ion concentration of the culture medium increased significantly (P < 0.05) with increasing cement Si content and culture time-points. CONCLUSIONS: The higher Si content cement enhanced the higher expression of cell attachment, proliferation and differentiation as compared to the lower Si content cement.

Human dental pulp cell responses to new calcium silicate-based endodontic materials.

AIM: To evaluate human dental pulp cell responses to radiopaque dicalcium silicate cement and white-coloured mineral trioxide aggregate (WMTA). METHODOLOGY: Flow cytometry was employed to quantify the phase percentage of pulp cell cycle. Alamar Blue was used for real-time and repeated monitoring of cell proliferation. Reverse transcription-polymerase chain reaction was performed to determine gene expression in pulp cells cultured on the cements. RESULTS: The cells cultured on the radiopaque dicalcium silicate cement had similar S and G2 phases in the cell cycle and proliferation to WMTA at all culture times. In addition, the two materials presented the same evolution with similar values in interleukin-1, inducible nitric oxide synthase, alkaline phosphatase, osteocalcin and bone sialoprotein gene expression at all culture times. CONCLUSIONS: The dental pulp cell responses to radiopaque dicalcium silicate cement were similar to those reported for WMTA in terms of cell cycle, proliferation, immunocompatibility and osteogenic differentiation.

Hyperbaric oxygen preconditioning reduces ischemia-reperfusion injury by inhibition of apoptosis via mitochondrial pathway in rat brain.

This study examined the hypothesis that apoptotic inhibition via mitochondrial pathway was involved in hyperbaric oxygen preconditioning (HBO-PC)-induced neuroprotection on ischemia-reperfusion injury in rat brain. Male Sprague-Dawley rats (250 approximately 280 g, n=144) were divided into control, middle cerebral artery occlusion (MCAO) for 90 min, and HBO-PC plus MCAO groups. HBO-PC was conducted four times by giving 100% oxygen at 2.5 atm absolute (ATA), for 1 h at 12 h intervals for 2 days. At 24 h after the last HBO-PC, MCAO was performed and at 24 h after MCAO, neurological function, brain water content, infarct volume, and cell death were evaluated. Enzymatic activity of capase-3 and -9, and expression of cytochrome c, Bcl-2 and Bax proteins were performed in the samples from hippocampus, ischemic penumbra and core of the brain cortex, respectively. HBO-PC reduced brain edema, decreased infarction volume, and improved neurological recovery. HBO-PC reduced cytoplasm cytochrome c levels, decreased caspase enzyme activity, upregulated the ratio of Bcl-2 and Bax expression, and abated the apoptosis of ischemic tissue. HBO-PC protects brain tissues from ischemia-reperfusion injury by suppressing mitochondrial apoptotic pathways.

A population-based survey of multiple sclerosis in Shanghai, China.

OBJECTIVE: To conduct a large population-based survey on multiple sclerosis (MS) prevalence in Shanghai, China. METHODS: We established a network of physicians, mainly neurologists, for identifying prevalent patients with MS and systematically checked inpatient registers at each hospital in the study area for patients with a diagnosis of MS, neuromyelitis optica, or other demyelinating disorders. MS diagnosis in patients was validated by senior neurologists according to the McDonald criteria. RESULTS: In total, 123 patients with a validated MS diagnosis from the study population, 8.86 million inhabitants with permanent residence in Shanghai, were alive on the prevalence day. The crude MS prevalence rate was 1.39 cases per 100,000 inhabitants (95% CI: 1.16 to 1.66 cases) in the study population in Shanghai. There were 79 female and 44 male patients with MS, a female-to-male ratio of 1.8. Nearly all (96%) of the patients with validated MS had been examined by MRI. CONCLUSION: Multiple sclerosis prevalence in Shanghai is in line with that reported for other Asian populations.

The effect of thermocycling and dentine pre-treatment on the durability of the bond between composite resin and dentine.

The high bond strength between restorative resin and dentine plays an important role in long-term performance of restorations in the oral environment. A variety of treatment techniques have been described to enhance the bond strength of composite resin to dentine. Unfortunately, few studies have reported available bond durability of adhesive resins to dentine. The purpose of this research was to study the shear bond strength of composite resin to dentine pre-treated with phosphoric acid, self-etching agent or Nd:YAP laser irradiation. The durability of bond strength between resin and dentine stored in the artificial saliva thermocycling between 5 and 55 degrees C was also evaluated. The scanning electron microscope was used to assess the treated-dentine surfaces. The mean value of the shear bond strength in the acid-etching group (18.2 +/- 4.9 MPa) was the highest among the three dentine treatments (self-etching system: 12.6 +/-3.0 MPa, Nd:YAP laser: 13.4 +/- 3.3 MPa) prior to thermocycling. After thermocycling, shear strength values of all treated dentines decreased with increasing number of the cycles. When subjected to 3000 thermocycles, the mean bond strengths of these pre-treated samples to composite resin became 9.1 +/- 1.4, 7.8 +/- 1.8, and 8.1 +/- 1.7 MPa for acid-etching, self-etching and laser-irradiation, respectively, with a significant reduction of 38-50%.

Endoglucanase I from the edible straw mushroom, Volvariella volvacea. Purification, characterization, cloning and expression.

We isolated an endoglucanase, EG1, from culture fluid of Volvariella volvacea grown on crystalline cellulose by ion-exchange and gel filtration chromatography, and preparative PAGE. EG1 has a molecular mass of 42 kDa as determined by SDS/PAGE and an isoelectric point of 7.7. Enzyme-catalysed hydrolysis of carboxymethyl-cellulose (CM-cellulose) is maximal at pH 7.5 and 55 degrees C. EG1 also hydrolysed phosphoric acid-swollen cellulose and filter paper (at rates of 29% and 6%, respectively, compared with CM-cellulose), but did not hydrolyse crystalline cellulose, cotton, oat spelt xylan, and birchwood xylan. Degenerate primers based on the N-terminal sequences of purified EGI and a protease-generated fragment were used to generate cDNA fragments encoding a portion of the EG1 gene (eg1), and RACE was used to obtain full-length cDNA clones. The cDNA of eg1 contained an ORF of 1167 bp encoding 389 amino acids. The amino-acid sequence from Ala24 to Thr40 corresponded to the N-terminal sequence of the purified protein. The first 23 amino acids are presumed to be a signal peptide. V. volvacea EG1 has been assigned to glycoside hydrolase family 5 according to the classification of glycohydrolases based on amino-acid sequence similarities. Transcripts of eg1 were detected in total RNA from mycelium grown on cellulose but not from mycelium grown on glucose. Cellobiose also induced eg1 expression in 1- to 4-day-old cultures but the signal intensity was lower than that obtained with cellulose. Catabolite repression was observed 24 h after addition of 1% (w/v) glucose, alpha-lactose, beta-lactose, xylose, mannose, sorbose or fructose to medium containing 1% (w/v) crystalline cellulose. Eg1 was expressed at a high level in the yeast, Pichia pastoris, and the catalytic activity of the recombinant EG1 was confirmed.

Structure and immersion behavior of plasma-sprayed apatite-matrix coatings.

The microstructure and properties of a series of plasma-sprayed coatings from sinter-granulated powders fabricated from SiO2, CaO, P2O5 and Na2O-containing HA composite powders on Ti-6Al-4V substrate were reported. The immersion behavior of these coatings in a simulated body fluid (SBF) was also investigated. The results showed that sinter-granulated apatite-matrix powders were irregularly shaped and appeared quite similar. XRD patterns showed that during fabrication of the powders, P2O5 and SiO2 enhanced the decomposition of HA structure, while CaO and Na2O did not. Reasonably high bond strengths (45-50 MPa) were obtained from all coatings. The plasma spray process itself enhanced the decomposition of apatite and chemical reactions among different phases. When immersed in SBF, the intensities of such phases as alpha- and beta-TCP in all coatings decreased with immersion time and an apatite precipitation took place on all coating surfaces. The immersed SiO2- and CaO-containing HA (HSC) coating had the highest rate of apatite precipitation among all coatings. The variations in calcium ion concentration in simulated body fluid indicated that the HSC-immersed solution reached its maximal Ca concentration the earliest, while the HSCP (HA, SiO2, CaO and P2O5)-immersed solution reached its maximum the latest.

Surface reaction of stoichiometric and calcium-deficient hydroxyapatite in simulated body fluid.

In the present study, the immersion behavior of two kinds of sintered HA with different Ca/P ratios in two different extracellular simulated solutions (Tris buffer and Hank's solutions) was investigated and compared. Results indicated that an as-received Ca-deficient HA (FHA) had a lower Ca/P ratio, larger linear shrinkage and higher density than a stoichiometric HA (MHA). When FHA powder was calcined at 900 degrees C, its Ca-deficient apatite structure was unstable and a significant amount of beta-TCP phase was formed. When heated to 1250 degrees C in air, the highly crystalline apatite structure of MHA was still stable without any noticeable decomposition. The FTIR spectra indicated that both immersed MHA and FHA in Hank's solution were gradually covered with a layer of precipitated apatite during immersion. When immersed in Tris buffer solution, neither HA showed significant changes in their FTIR spectra. SEM observation indicated that the precipitation rate on immersed FHA surface was much higher than that on MHA surface when immersed in Hank's solution. The weight loss and pH data confirmed the higher dissolution rate of FHA than MHA in Hank's solution.