In recent years (2007 to 2011), although the overall number of rabies cases in China has decreased, there is evidence of emerging or re-emerging cases in regions without previous rabies cases or with low incidence of ...In recent years (2007 to 2011), although the overall number of rabies cases in China has decreased, there is evidence of emerging or re-emerging cases in regions without previous rabies cases or with low incidence of rabies. To investigate the origin and the factors affecting the spread of rabies in China, specimens were collected from 2007 to 2011 from provinces with emerging and re-emerging cases and tested for the presence of the rabies virus. Positive specimens were combined with sequences from GenBank to perform comparisons of homology and functional sites, and to carry out phylogenetic analyses. Out of these regions, five provinces had 9 positive specimens from canine and cattle, and 34 canine or human specimens were obtained from previously high-incidence provinces. Complete sequences of G gene were obtained for these samples. Homology of the sequences of these 43 specimens was 87%-100% at the nucleotide level and 93.7% -100% at the amino acid level. These G gene sequences were combined with reference sequence from GenBank and used to construct a phylogenetic tree. The results showed that 43 specimens were all assigned to China clade I and clade II, with all specimens from emerging and re-emerging areas placed within clade I. Specimens isolated from Shanxi and Inner Mongolia in 2011 were distinct from previously-isolated local strains and had closer homology to strains from Hebei, Beijing and Tianjin whereas new isolates from Shanghai were tightly clustered with strains isolated in the 1990s. Finally, Shaanxi isolates were clustered with strains from adjacent Sichuan. Our results suggest that the rabies cases in emerging and re-emerging areas in China in the last 5 years are a consequence of the epidemic spreading from of neighboring provinces and regions experiencing a serious epidemic of rabies.展开更多
AIM: To evaluate the role of preoperative angiography inthe diagnosis and treatment of colorectal cancer.METHODS: The authors performed selective arterialcannulation by Seldinger's method in 47 patients to locatet...AIM: To evaluate the role of preoperative angiography inthe diagnosis and treatment of colorectal cancer.METHODS: The authors performed selective arterialcannulation by Seldinger's method in 47 patients to locatethe primary cancer and to diagnose metastasis to the liver.Each patient was then given intra-arterial regionalchemotherapy, and received 5-fluorouracil (5-Fu, 1 000 mg),mitomycin C (MMC, 20 mg), and cisplatinum (CDDP, 80 mg).RESULTS: The location and shape of each tumor wereobserved, including metastatic tumors in the liver, in 42 ofthe 47 (89.4 %) patients. The site of the primary tumor wasdifficult to identify in 5 cases because the patients had arecurrence of cancer. Arterial chemotherapy was performedsuccessfully in all patients. The authors recorded no partialor significant morbidity resulted from angiography. The onlyincident was bleeding from the artery puncture site in onepatient, which was successfully stopped by generalmedication.CONCLUSION: Preoperative selective arterial angiographycan help the diagnosis and locate primary tumors and todetect liver metastasis. At the same time, regional arterialchemotherapy can be an important form of preoperativetherapy.展开更多
With rapid progressive application of TiO2 thin films, magnetron sputtering becomes a very interesting method to prepare such multi-functional thin films. This paper focuses on influences of various deposition process...With rapid progressive application of TiO2 thin films, magnetron sputtering becomes a very interesting method to prepare such multi-functional thin films. This paper focuses on influences of various deposition processes and deposition rate on the structures and properties of TiO2 thin films. Anatase, rutile or amorphous TiO2 films with various crystalline structures and different photocatalytic, optical and electrical properties can be produced by varying sputtering gases, substrate temperature, annealing process, deposition rate and the characteristics of magnetron sputtering. This may in turn affect the functions of TiO2 films in many applications. Furthermore, TiO2-based composites films can overcome many limitations and improve the properties of TiO2 films.展开更多
periodontal ligament stem cells; aging; proliferation; osteogenic differentiation Objective The aim of this study is to investigate the proliferation, differentiation and apoptosis of periodontal ligament stem cells...periodontal ligament stem cells; aging; proliferation; osteogenic differentiation Objective The aim of this study is to investigate the proliferation, differentiation and apoptosis of periodontal ligament stem cells （PDLSC） derived from different aged donors, and to evaluate the effects of aging on the biological characteristics of PDLSC. Methods Periodontal ligament tissues were obtained from 24 surgically extracted human premolars during orthodontics therapy. The specimens were divided into three groups according to the donor’s age. Group A： 18-20 years, group B： 30-35 years, group C： 45-50 years. PDLSC were isolated and cultured using a tissue-block-based enzymolytic method by limiting dilution assay. The colony forming efficiency of PDLSC for three experimental groups was determined. Senescence-Associated β-Galactosidase （SA-β-G） expression in the three groups was examined using β-galactosidase staining working solution. Cell cycle and apoptosis of the PDLSC were examined by the flow cytometry. Alkaline phosphatase （ALP） activity was evaluated by ALP staining. The expression of osteoplastic differentiation related genes Runt-related transcription factor-2 （Runx-2）, Collagen Type 1 （col-1）, and ALP of PDLSC were examined by quantitative real-time RT-PCR. Results The colony forming efficiency of PDLSC in Group A, B and C was 36.67%, 22.67% and 9.33%, respectively, which decreased with donors’ age （P〈0.05）. SA-β-G expression of the senescent PDLSC in group A, B and C were 4.14%, 16.39%, 50.38%, respectively （P〈0.05）. Cells in G2/S phase was 38.73%, 29.88%, 18.25% （P〈0.05）, and the apoptosis rate was 1.57%, 4.56%, 5.84% （P〈0.05）, in group A, B and C respectively. The ALP staining in the three groups decreased with the increase of donors’ ages, and the expression of Runx-2, col-1 and ALP decreased gradually from group A to group C （all P〈0.05）, which indicated the osteogenic differentiation capacity of PDLSC decreased while donor aging. Conclusion Human PDLSC could be successfully isolated from periodontal ligament tissues of different aged donors. However, the proliferation and osteogenic differentiation capacity of PDLSC decreased while donor aging.展开更多
R, 6S)-6-Acetoxyhexadecan-5-olide 1, a natural mosquito attractant pheromone, was synthesized from readily available aldehyde 2 and cyclopentanone 3 using L-proline-catalyzed asymmetric aldol reaction as the key step.
Alnico powders were prepared by gas atomization process. Composition of the Alnico powders was Fe37.1 A18.2Ni17.6-Co26.6 Cu3.3 Ti7.2 (wt pct) which was the same as that of commercially available Alnico magnets. Averag...Alnico powders were prepared by gas atomization process. Composition of the Alnico powders was Fe37.1 A18.2Ni17.6-Co26.6 Cu3.3 Ti7.2 (wt pct) which was the same as that of commercially available Alnico magnets. Averageparticle size of the powders was 119μm. Effects of heat treatment in magnetic field on magnetic properties of thepowders were investigated. The optimum process of heat treatment was found as follows, heated at 870℃ for 1min first, then cooled down to 700℃ at cooling rate 0.3℃/s in magnetic field, and finally aged isothermally for 4 h.Magnetic properties of the Alnico powders were measued and the results were that intrinsic coercivity i_H_c was 1.0kOe and remanence M_r was 36.5 emu/g.展开更多
In this research we presented a non-cyanide plating process of Ni-P alloy coating on Mg alloy AZ91D. By applying a new process flow of electroless nickel plating in which zinc coating is used as transition of Ni-P coa...In this research we presented a non-cyanide plating process of Ni-P alloy coating on Mg alloy AZ91D. By applying a new process flow of electroless nickel plating in which zinc coating is used as transition of Ni-P coating on Mg alloy AZ91D, the process of copper transition coating plated in the cyanides bath can be replaced. A new bath composed of NiSO4 was established by orthogonal test. The results show that zinc transition coating can increase the adhesion and protect the Mg alloy substrate from the bath corrosion. The optimal plating bath composition is NiSO4·6H2O 20 g/L, NaH2PO2·H2O20g/L and C6H8O7·H2O 2.5 g/L, and optimal bath acidity and optimal plating temperature are pH 4.0 and 95℃, respectively. The present process flow is composed of ultrasonic cleaning→alkaline cleaning→acid pickling→activation→double immersing zinc→electroplating zinc→electroless nickel plating→passivation treatment. The present non-cyanide process of electroless nickel plating is harmless to our surroundings and Ni-P coating on Mg alloy AZ91D produced by present process possesses good adhesion and corrosion resistance.展开更多
The ac conductivities of Y2O3 or CaO-stabilized cubic zirconias were obtained from complex impedance measurements in the temperature range from 373 to 473 K. By analyzing the temperature-dependence of the resultant dc...The ac conductivities of Y2O3 or CaO-stabilized cubic zirconias were obtained from complex impedance measurements in the temperature range from 373 to 473 K. By analyzing the temperature-dependence of the resultant dc conductivities, it was shown that the activation energies for conduction are lower than those reported previously for the same materials at high temperatures. Comparing the activation energy data with the theoretically estimated values revealed that there may exist a certain, although very small, amount of free oxygen vacancies in the test samples at low temperatures and the conduction in the test samples is a result of the migration of these free oxygen vacancies.展开更多
A laser flash photolysis study of the reactivity of Cl˙with glyoxal, glyoxal mono- and dibisulfite adducts, 1-hydroxy-2, 2-diol-ethanesulfonate and 1, 2-dihydroxy-1, 2-ethanedi sulfonate in the aqueous phase was ca...A laser flash photolysis study of the reactivity of Cl˙with glyoxal, glyoxal mono- and dibisulfite adducts, 1-hydroxy-2, 2-diol-ethanesulfonate and 1, 2-dihydroxy-1, 2-ethanedi sulfonate in the aqueous phase was carried out. The obtained rate constants can be used for atmospheric modeling.展开更多
To the Editor： The Ebola epidemic has taken almost 7000 lives thus far in Western Africa.[1] China＇s contribution to the control of Ebola has shown China＇s, increasing engagement in global health. After deploying o...To the Editor： The Ebola epidemic has taken almost 7000 lives thus far in Western Africa.[1] China＇s contribution to the control of Ebola has shown China＇s, increasing engagement in global health. After deploying over 260 medical personnel from China Centers for Disease Control （CDC） and hospitals, China decided to send its elite People＇s Liberation Army （PLA） medical team of 163 military medical staffers on November 14, 2014 to Liberia, which is a very significant milestone in China＇s modern engagement in global health because it is the first time for China to send an elite PLA medical team to Africa and to run hospitals on their own.展开更多
基金National Department Public Benefit Research Foundation (201103032)Pathogens Network Monitoring Technology Research (2008ZX10004-008)
文摘In recent years (2007 to 2011), although the overall number of rabies cases in China has decreased, there is evidence of emerging or re-emerging cases in regions without previous rabies cases or with low incidence of rabies. To investigate the origin and the factors affecting the spread of rabies in China, specimens were collected from 2007 to 2011 from provinces with emerging and re-emerging cases and tested for the presence of the rabies virus. Positive specimens were combined with sequences from GenBank to perform comparisons of homology and functional sites, and to carry out phylogenetic analyses. Out of these regions, five provinces had 9 positive specimens from canine and cattle, and 34 canine or human specimens were obtained from previously high-incidence provinces. Complete sequences of G gene were obtained for these samples. Homology of the sequences of these 43 specimens was 87%-100% at the nucleotide level and 93.7% -100% at the amino acid level. These G gene sequences were combined with reference sequence from GenBank and used to construct a phylogenetic tree. The results showed that 43 specimens were all assigned to China clade I and clade II, with all specimens from emerging and re-emerging areas placed within clade I. Specimens isolated from Shanxi and Inner Mongolia in 2011 were distinct from previously-isolated local strains and had closer homology to strains from Hebei, Beijing and Tianjin whereas new isolates from Shanghai were tightly clustered with strains isolated in the 1990s. Finally, Shaanxi isolates were clustered with strains from adjacent Sichuan. Our results suggest that the rabies cases in emerging and re-emerging areas in China in the last 5 years are a consequence of the epidemic spreading from of neighboring provinces and regions experiencing a serious epidemic of rabies.
文摘AIM: To evaluate the role of preoperative angiography inthe diagnosis and treatment of colorectal cancer.METHODS: The authors performed selective arterialcannulation by Seldinger's method in 47 patients to locatethe primary cancer and to diagnose metastasis to the liver.Each patient was then given intra-arterial regionalchemotherapy, and received 5-fluorouracil (5-Fu, 1 000 mg),mitomycin C (MMC, 20 mg), and cisplatinum (CDDP, 80 mg).RESULTS: The location and shape of each tumor wereobserved, including metastatic tumors in the liver, in 42 ofthe 47 (89.4 %) patients. The site of the primary tumor wasdifficult to identify in 5 cases because the patients had arecurrence of cancer. Arterial chemotherapy was performedsuccessfully in all patients. The authors recorded no partialor significant morbidity resulted from angiography. The onlyincident was bleeding from the artery puncture site in onepatient, which was successfully stopped by generalmedication.CONCLUSION: Preoperative selective arterial angiographycan help the diagnosis and locate primary tumors and todetect liver metastasis. At the same time, regional arterialchemotherapy can be an important form of preoperativetherapy.
文摘With rapid progressive application of TiO2 thin films, magnetron sputtering becomes a very interesting method to prepare such multi-functional thin films. This paper focuses on influences of various deposition processes and deposition rate on the structures and properties of TiO2 thin films. Anatase, rutile or amorphous TiO2 films with various crystalline structures and different photocatalytic, optical and electrical properties can be produced by varying sputtering gases, substrate temperature, annealing process, deposition rate and the characteristics of magnetron sputtering. This may in turn affect the functions of TiO2 films in many applications. Furthermore, TiO2-based composites films can overcome many limitations and improve the properties of TiO2 films.
基金Supported by National Natural Science Foundation of China（51473175）, Science and Technology Nova Plan of Beijing City（Z141107001814101）.
文摘periodontal ligament stem cells; aging; proliferation; osteogenic differentiation Objective The aim of this study is to investigate the proliferation, differentiation and apoptosis of periodontal ligament stem cells （PDLSC） derived from different aged donors, and to evaluate the effects of aging on the biological characteristics of PDLSC. Methods Periodontal ligament tissues were obtained from 24 surgically extracted human premolars during orthodontics therapy. The specimens were divided into three groups according to the donor’s age. Group A： 18-20 years, group B： 30-35 years, group C： 45-50 years. PDLSC were isolated and cultured using a tissue-block-based enzymolytic method by limiting dilution assay. The colony forming efficiency of PDLSC for three experimental groups was determined. Senescence-Associated β-Galactosidase （SA-β-G） expression in the three groups was examined using β-galactosidase staining working solution. Cell cycle and apoptosis of the PDLSC were examined by the flow cytometry. Alkaline phosphatase （ALP） activity was evaluated by ALP staining. The expression of osteoplastic differentiation related genes Runt-related transcription factor-2 （Runx-2）, Collagen Type 1 （col-1）, and ALP of PDLSC were examined by quantitative real-time RT-PCR. Results The colony forming efficiency of PDLSC in Group A, B and C was 36.67%, 22.67% and 9.33%, respectively, which decreased with donors’ age （P〈0.05）. SA-β-G expression of the senescent PDLSC in group A, B and C were 4.14%, 16.39%, 50.38%, respectively （P〈0.05）. Cells in G2/S phase was 38.73%, 29.88%, 18.25% （P〈0.05）, and the apoptosis rate was 1.57%, 4.56%, 5.84% （P〈0.05）, in group A, B and C respectively. The ALP staining in the three groups decreased with the increase of donors’ ages, and the expression of Runx-2, col-1 and ALP decreased gradually from group A to group C （all P〈0.05）, which indicated the osteogenic differentiation capacity of PDLSC decreased while donor aging. Conclusion Human PDLSC could be successfully isolated from periodontal ligament tissues of different aged donors. However, the proliferation and osteogenic differentiation capacity of PDLSC decreased while donor aging.
文摘R, 6S)-6-Acetoxyhexadecan-5-olide 1, a natural mosquito attractant pheromone, was synthesized from readily available aldehyde 2 and cyclopentanone 3 using L-proline-catalyzed asymmetric aldol reaction as the key step.
文摘Alnico powders were prepared by gas atomization process. Composition of the Alnico powders was Fe37.1 A18.2Ni17.6-Co26.6 Cu3.3 Ti7.2 (wt pct) which was the same as that of commercially available Alnico magnets. Averageparticle size of the powders was 119μm. Effects of heat treatment in magnetic field on magnetic properties of thepowders were investigated. The optimum process of heat treatment was found as follows, heated at 870℃ for 1min first, then cooled down to 700℃ at cooling rate 0.3℃/s in magnetic field, and finally aged isothermally for 4 h.Magnetic properties of the Alnico powders were measued and the results were that intrinsic coercivity i_H_c was 1.0kOe and remanence M_r was 36.5 emu/g.
文摘In this research we presented a non-cyanide plating process of Ni-P alloy coating on Mg alloy AZ91D. By applying a new process flow of electroless nickel plating in which zinc coating is used as transition of Ni-P coating on Mg alloy AZ91D, the process of copper transition coating plated in the cyanides bath can be replaced. A new bath composed of NiSO4 was established by orthogonal test. The results show that zinc transition coating can increase the adhesion and protect the Mg alloy substrate from the bath corrosion. The optimal plating bath composition is NiSO4·6H2O 20 g/L, NaH2PO2·H2O20g/L and C6H8O7·H2O 2.5 g/L, and optimal bath acidity and optimal plating temperature are pH 4.0 and 95℃, respectively. The present process flow is composed of ultrasonic cleaning→alkaline cleaning→acid pickling→activation→double immersing zinc→electroplating zinc→electroless nickel plating→passivation treatment. The present non-cyanide process of electroless nickel plating is harmless to our surroundings and Ni-P coating on Mg alloy AZ91D produced by present process possesses good adhesion and corrosion resistance.
基金supported by the State Key Laboratory of New Ceramics and Fine Processing,Tsinghua University,Chinathe supports of K.CWong Education Foundatio,Hong KongChina Postdoctorl Science Foundation
文摘The ac conductivities of Y2O3 or CaO-stabilized cubic zirconias were obtained from complex impedance measurements in the temperature range from 373 to 473 K. By analyzing the temperature-dependence of the resultant dc conductivities, it was shown that the activation energies for conduction are lower than those reported previously for the same materials at high temperatures. Comparing the activation energy data with the theoretically estimated values revealed that there may exist a certain, although very small, amount of free oxygen vacancies in the test samples at low temperatures and the conduction in the test samples is a result of the migration of these free oxygen vacancies.
文摘A laser flash photolysis study of the reactivity of Cl˙with glyoxal, glyoxal mono- and dibisulfite adducts, 1-hydroxy-2, 2-diol-ethanesulfonate and 1, 2-dihydroxy-1, 2-ethanedi sulfonate in the aqueous phase was carried out. The obtained rate constants can be used for atmospheric modeling.
文摘To the Editor： The Ebola epidemic has taken almost 7000 lives thus far in Western Africa.[1] China＇s contribution to the control of Ebola has shown China＇s, increasing engagement in global health. After deploying over 260 medical personnel from China Centers for Disease Control （CDC） and hospitals, China decided to send its elite People＇s Liberation Army （PLA） medical team of 163 military medical staffers on November 14, 2014 to Liberia, which is a very significant milestone in China＇s modern engagement in global health because it is the first time for China to send an elite PLA medical team to Africa and to run hospitals on their own.
