AIM: To validate and compare the cost of microdose 14C urea breath test (UBT) with histology and rapid urease test for the diagnosis of H Pylori. METHODS: Ninety-four consecutive patients with dyspeptic symptoms under...AIM: To validate and compare the cost of microdose 14C urea breath test (UBT) with histology and rapid urease test for the diagnosis of H Pylori. METHODS: Ninety-four consecutive patients with dyspeptic symptoms undergoing gastroscopy were enrolled. Gastric biopsies were taken for histology and rapid urease test. UBT was performed after gastroscopy by microdose 14C urea capsules. Sensitivity, specificity and accuracy of UBT were calculated and compared with histology and rapid urease test. Cost comparison of these tests was also performed. RESULTS: H pylori was diagnosed by histology and rapid urease test in 66 (70%) and 61 (65%) patients, while 14C UBT detected infection in 63 (67%). Accuracy of UBT was 93% in comparison with histology while its positive and negative predictive values were 97% and 84%, respectively. Comparison of 14C UBT with rapid urease test gives an accuracy of 96%, with positive and negative predictive values of 95% and 97%, respectively. These results were highly reproducible with a Kappa test (P value < 0.001). Cost of histology or rapid urease test with gastroscopy was 110 USD or 95 USD respectively while the cost of UBT was 15 USD. CONCLUSION: Microdose 14C UBT was comparable to histology and rapid urease test. 14C UBT is an economical, self sufficient and suitable test to diagnose active H pylori infection in less developed countries.展开更多
“Little Ice Age”(LIA)was first introduced by Matthes in 1939 with reference to the phenomenon of cirque glacier regrowth during the Holocene.China is located in the Asian monsoon region,and monsoon circulations on e...“Little Ice Age”(LIA)was first introduced by Matthes in 1939 with reference to the phenomenon of cirque glacier regrowth during the Holocene.China is located in the Asian monsoon region,and monsoon circulations on ecological environment have a variety of effects on ecological environment during the LIA.However,existing research has little documented on environmental changes based on pollen during the LIA.A 100-cm-deep section of drilling was collected at the Kanas wetland,northern Altay.By using the data of pollen and^14C,we obtained vegetation types from the study area,which will providenew evidence of“Little Ice Age”in the Altay area.展开更多
Hot springs are natural exposed points of the hydrothermal system. The hydrogeochemistry of hot springs can be used to interpret the formation of the hydrothermal system; and the ^(14)C dating can be used to evaluate ...Hot springs are natural exposed points of the hydrothermal system. The hydrogeochemistry of hot springs can be used to interpret the formation of the hydrothermal system; and the ^(14)C dating can be used to evaluate the renewability of the hydrothermal system. The hot springs exposed from fault zones in western Guangdong are classified as granite fissure water and clastic rock fissure water, which are sampled and tested. The results of water chemistry analysis show that hot spring water is mainly HCO_3-Na type in the beginning, while the mixing of seawater leads to the increase of Cl^-. Hydrogen and oxygen isotopes indicate that these hot springs mainly come from atmospheric precipitation, and water-rock interactions produce oxygen isotope exchange reactions, where a significant "oxygen drift" phenomenon can be observed. The relationship between δ^(13)C and HCO_3^- indicates that there is a deep source of CO_2 "dead carbon" in hot spring water. This systematic error is not considered in the existing ^(14)C dating correction models. The ^(14)C age of the deep source "dead carbon" correction proposed in this paper is close to the ^(14)C age of the reverse chemical simulation correction, the Gonfiantinie model, and the Mook model. The deep source "dead carbon" correction method can improve the systematic error. Therefore, the ^(14)C age corrected by the deep source "dead carbon" may be more representative in terms of the actual age of geothermal water.展开更多
Identification and enumeration of both dendritic Ia^+ epi-dermal cells (Ia^+DECs) and dendritic Thy-1^+ epidermalcells (Thy-1^+DECa) from various parts of the body wereexamined by using epidermal sheets of C3H/He inbr...Identification and enumeration of both dendritic Ia^+ epi-dermal cells (Ia^+DECs) and dendritic Thy-1^+ epidermalcells (Thy-1^+DECa) from various parts of the body wereexamined by using epidermal sheets of C3H/He inbred miceof different age groups and indirect immunofluorescent tech-nique. A significant decline of both Ia^+DECs and Thy-1^+DECs in the mice of the aged group was demonstrated anddifferent densities and different distribution patterns betweenIa^+DECs and Thy-1^+DECs were obserged. These findingsmay imply that the decline of both Ia^+DECs and Thy-1^+DECs in the aged group may reflect the alterations of im-mune response in aging.展开更多
基金University Research Council Grant, No. 041F431YC
文摘AIM: To validate and compare the cost of microdose 14C urea breath test (UBT) with histology and rapid urease test for the diagnosis of H Pylori. METHODS: Ninety-four consecutive patients with dyspeptic symptoms undergoing gastroscopy were enrolled. Gastric biopsies were taken for histology and rapid urease test. UBT was performed after gastroscopy by microdose 14C urea capsules. Sensitivity, specificity and accuracy of UBT were calculated and compared with histology and rapid urease test. Cost comparison of these tests was also performed. RESULTS: H pylori was diagnosed by histology and rapid urease test in 66 (70%) and 61 (65%) patients, while 14C UBT detected infection in 63 (67%). Accuracy of UBT was 93% in comparison with histology while its positive and negative predictive values were 97% and 84%, respectively. Comparison of 14C UBT with rapid urease test gives an accuracy of 96%, with positive and negative predictive values of 95% and 97%, respectively. These results were highly reproducible with a Kappa test (P value < 0.001). Cost of histology or rapid urease test with gastroscopy was 110 USD or 95 USD respectively while the cost of UBT was 15 USD. CONCLUSION: Microdose 14C UBT was comparable to histology and rapid urease test. 14C UBT is an economical, self sufficient and suitable test to diagnose active H pylori infection in less developed countries.
基金funded by the National Natural Science Foundation of China(grants No41572331 and 41272386)
文摘“Little Ice Age”(LIA)was first introduced by Matthes in 1939 with reference to the phenomenon of cirque glacier regrowth during the Holocene.China is located in the Asian monsoon region,and monsoon circulations on ecological environment have a variety of effects on ecological environment during the LIA.However,existing research has little documented on environmental changes based on pollen during the LIA.A 100-cm-deep section of drilling was collected at the Kanas wetland,northern Altay.By using the data of pollen and^14C,we obtained vegetation types from the study area,which will providenew evidence of“Little Ice Age”in the Altay area.
基金financially supported jointly by the National Natural Science foundation of China (Grant Nos.40602031,41440027)the China Geological Survey project (Grant No.1212011220014)
文摘Hot springs are natural exposed points of the hydrothermal system. The hydrogeochemistry of hot springs can be used to interpret the formation of the hydrothermal system; and the ^(14)C dating can be used to evaluate the renewability of the hydrothermal system. The hot springs exposed from fault zones in western Guangdong are classified as granite fissure water and clastic rock fissure water, which are sampled and tested. The results of water chemistry analysis show that hot spring water is mainly HCO_3-Na type in the beginning, while the mixing of seawater leads to the increase of Cl^-. Hydrogen and oxygen isotopes indicate that these hot springs mainly come from atmospheric precipitation, and water-rock interactions produce oxygen isotope exchange reactions, where a significant "oxygen drift" phenomenon can be observed. The relationship between δ^(13)C and HCO_3^- indicates that there is a deep source of CO_2 "dead carbon" in hot spring water. This systematic error is not considered in the existing ^(14)C dating correction models. The ^(14)C age of the deep source "dead carbon" correction proposed in this paper is close to the ^(14)C age of the reverse chemical simulation correction, the Gonfiantinie model, and the Mook model. The deep source "dead carbon" correction method can improve the systematic error. Therefore, the ^(14)C age corrected by the deep source "dead carbon" may be more representative in terms of the actual age of geothermal water.
文摘Identification and enumeration of both dendritic Ia^+ epi-dermal cells (Ia^+DECs) and dendritic Thy-1^+ epidermalcells (Thy-1^+DECa) from various parts of the body wereexamined by using epidermal sheets of C3H/He inbred miceof different age groups and indirect immunofluorescent tech-nique. A significant decline of both Ia^+DECs and Thy-1^+DECs in the mice of the aged group was demonstrated anddifferent densities and different distribution patterns betweenIa^+DECs and Thy-1^+DECs were obserged. These findingsmay imply that the decline of both Ia^+DECs and Thy-1^+DECs in the aged group may reflect the alterations of im-mune response in aging.
