AIM:To investigate the relationship between polymorphisms present in the vitamin D receptor(VDR) gene and colorectal cancer risk,a systematic meta-analysis of population-based studies was performed.METHODS:A total of ...AIM:To investigate the relationship between polymorphisms present in the vitamin D receptor(VDR) gene and colorectal cancer risk,a systematic meta-analysis of population-based studies was performed.METHODS:A total of 38 relevant reports published between January 1990 and August 2010 were identified,of which only 23 qualified for this meta-analysis based on our selection criteria.Five polymorphic variants of the VDR gene,including Cdx-2(intron 1e) and FokI(exon 2) present in the 5' region of the gene,and BsmI(intron 8),ApaI(intron 8),and TaqI(exon 9) sites present in the 3' untranslated region(UTR),were evaluated for possible associations with colorectalcancer risk.Review manager 4.2 was used to perform statistical analyses.RESULTS:In the meta-analysis performed,only the BsmI polymorphism was found to be associated with colorectal cancer risk.In particular,the BsmI B genotype was found to be related to an overall decrease in the risk for colorectal cancer [BB vs bb:odds ratio(OR) = 0.87,95% CI:0.80-0.94,P = 3 × 10-4;BB vs Bb + bb:OR = 0.90,95% CI:0.84-0.97,P = 5 × 10-4].Moreover,in subgroup analyses,the BsmI B genotype was significantly associated with colon cancer,and not rectal cancer.An absence of between-study heterogeneity was also observed.CONCLUSION:A meta-analysis of 23 published studies identified the BsmI polymorphism of the VDR gene to be associated with an increased risk of colon cancer.展开更多
Simulating the typical carbonation step in a mineral CO_2 sequestration, precipitated calcium carbonate(PCC) was prepared by bubbling CO_2 gas into a rich Ca solution. These carbonation reactions were conducted at thr...Simulating the typical carbonation step in a mineral CO_2 sequestration, precipitated calcium carbonate(PCC) was prepared by bubbling CO_2 gas into a rich Ca solution. These carbonation reactions were conducted at three p H ranges, namely 10.0–9.0, 9.0–8.0, and 8.0–7.0, in which temperature and CO_2 flow rate are additional experimental variables. The PCC obtained in experiments was examined by Fourier transform infrared spectroscopy(FTIR)and X-ray diffraction(XRD). It was found that supersaturation determined by p H value and flow rate of CO_2 has significant influence on polymorph of PCC. Vaterite was preferably formed at high supersaturation, while dissolution of metastable vaterite and crystallization of calcite occurred at low supersaturation. High temperature is a critical factor for the formation of aragonite. At 70 °C, vaterite, calcite and aragonite were observed to coexist in PCC because transformation from vaterite to aragonite via calcite occurred at this temperature. Scanning electron microscopy(SEM) technology was performed on prepared PCC, and various morphologies consistent with polymorphs were observed.展开更多
This paper proposes an outdoor guide system using vision-based augmented reality(AR) on mobile devices.Augmented reality provides a virtual-real fusion display interface for outdoor guide.Vision-based methods are more...This paper proposes an outdoor guide system using vision-based augmented reality(AR) on mobile devices.Augmented reality provides a virtual-real fusion display interface for outdoor guide.Vision-based methods are more accurate than GPS or other hardware-based methods.However,vision-based methods require more resources and relatively strong computing power of mobile devices.A C/S framework for vision based augmented reality system is introduced in this paper.In a server,a vocabulary tree is used for location recognition.In a mobile device,BRISK feature is combined with optical flow methods to track the offline keyframe.The system is tested on UKbench datasets and in real environment.Experimental results show that the proposed vision-based augmented reality system works well and yields relatively high recognition rate and that the mobile device achieves realtime recognition performance.展开更多
基金Supported by Zhejiang provincial top key discipline in surgery
文摘AIM:To investigate the relationship between polymorphisms present in the vitamin D receptor(VDR) gene and colorectal cancer risk,a systematic meta-analysis of population-based studies was performed.METHODS:A total of 38 relevant reports published between January 1990 and August 2010 were identified,of which only 23 qualified for this meta-analysis based on our selection criteria.Five polymorphic variants of the VDR gene,including Cdx-2(intron 1e) and FokI(exon 2) present in the 5' region of the gene,and BsmI(intron 8),ApaI(intron 8),and TaqI(exon 9) sites present in the 3' untranslated region(UTR),were evaluated for possible associations with colorectalcancer risk.Review manager 4.2 was used to perform statistical analyses.RESULTS:In the meta-analysis performed,only the BsmI polymorphism was found to be associated with colorectal cancer risk.In particular,the BsmI B genotype was found to be related to an overall decrease in the risk for colorectal cancer [BB vs bb:odds ratio(OR) = 0.87,95% CI:0.80-0.94,P = 3 × 10-4;BB vs Bb + bb:OR = 0.90,95% CI:0.84-0.97,P = 5 × 10-4].Moreover,in subgroup analyses,the BsmI B genotype was significantly associated with colon cancer,and not rectal cancer.An absence of between-study heterogeneity was also observed.CONCLUSION:A meta-analysis of 23 published studies identified the BsmI polymorphism of the VDR gene to be associated with an increased risk of colon cancer.
基金Supported by the National Natural Science Foundation of China(41471412)
文摘Simulating the typical carbonation step in a mineral CO_2 sequestration, precipitated calcium carbonate(PCC) was prepared by bubbling CO_2 gas into a rich Ca solution. These carbonation reactions were conducted at three p H ranges, namely 10.0–9.0, 9.0–8.0, and 8.0–7.0, in which temperature and CO_2 flow rate are additional experimental variables. The PCC obtained in experiments was examined by Fourier transform infrared spectroscopy(FTIR)and X-ray diffraction(XRD). It was found that supersaturation determined by p H value and flow rate of CO_2 has significant influence on polymorph of PCC. Vaterite was preferably formed at high supersaturation, while dissolution of metastable vaterite and crystallization of calcite occurred at low supersaturation. High temperature is a critical factor for the formation of aragonite. At 70 °C, vaterite, calcite and aragonite were observed to coexist in PCC because transformation from vaterite to aragonite via calcite occurred at this temperature. Scanning electron microscopy(SEM) technology was performed on prepared PCC, and various morphologies consistent with polymorphs were observed.
基金Supported by the National Science and Technology Major Project(No.2012ZX03002004)the National High Technology Research and Development Programme of China(No.2013AA013802)
文摘This paper proposes an outdoor guide system using vision-based augmented reality(AR) on mobile devices.Augmented reality provides a virtual-real fusion display interface for outdoor guide.Vision-based methods are more accurate than GPS or other hardware-based methods.However,vision-based methods require more resources and relatively strong computing power of mobile devices.A C/S framework for vision based augmented reality system is introduced in this paper.In a server,a vocabulary tree is used for location recognition.In a mobile device,BRISK feature is combined with optical flow methods to track the offline keyframe.The system is tested on UKbench datasets and in real environment.Experimental results show that the proposed vision-based augmented reality system works well and yields relatively high recognition rate and that the mobile device achieves realtime recognition performance.