In recent years , a second pathway for colonic carcinogenesis , distinct from the adenomatous pathway, has been explored. This is referred to as serrated pathway and includes three types of polyp,characterised by a se...In recent years , a second pathway for colonic carcinogenesis , distinct from the adenomatous pathway, has been explored. This is referred to as serrated pathway and includes three types of polyp,characterised by a serrated appearance of the crypts:hyperplastic polyps(HP),sessile serrated adenomas(SSA)or lesions,and traditional serrated adenomas.Each lesion has its own genetic,as well as macroscopic and microscopic morphological features.Because of their flat aspect,their detection is easier with chromoendoscopy(carmin indigo or narrow-band imaging).However,as we show in this review,the distinction between SSA and HP is quite difficult.It is now recommended to resect in one piece as it is possible the serrated polyps with a control in a delay depending on the presence or not of dysplasia.These different types of lesion are described in detail in the present review in general population,in polyposis and in inflammatory bowel diseases patients.This review highlights the need to improve characterization and understanding of this way of colorectal cancerogenesis.展开更多
Segmentation of the bladder in computerized tomography(CT) images is an important step in radiation therapy planning of prostate cancer. We present a new segmentation scheme to automatically delineate the bladder cont...Segmentation of the bladder in computerized tomography(CT) images is an important step in radiation therapy planning of prostate cancer. We present a new segmentation scheme to automatically delineate the bladder contour in CT images with three major steps. First,we use the mean shift algorithm to obtain a clustered image containing the rough contour of the bladder,which is then extracted in the second step by applying a region-growing algorithm with the initial seed point selected from a line-by-line scanning process. The third step is to refine the bladder contour more accurately using the rolling-ball algorithm. These steps are then extended to segment the bladder volume in a slice-by-slice manner. The obtained results were compared to manual segmentation by radiation oncologists. The average values of sensitivity,specificity,positive predictive value,negative predictive value,and Hausdorff distance are 86.5%,96.3%,90.5%,96.5%,and 2.8 pixels,respectively. The results show that the bladder can be accurately segmented.展开更多
Phase imaging coupled to micro-tomography acquisition has emerged as a powerful tool to investigate specimens in a non-destructive manner. While the intensity data can be acquired and recorded, the phase information o...Phase imaging coupled to micro-tomography acquisition has emerged as a powerful tool to investigate specimens in a non-destructive manner. While the intensity data can be acquired and recorded, the phase information of the signal has to be “retrieved” from the data modulus only. Phase retrieval is an ill-posed non-linear problem and regularization techniques including a priori knowledge are necessary to obtain stable solutions. Several linear phase recovery methods have been proposed and it is expected that some limitations resulting from the linearization of the direct problem will be overcome by taking into account the non-linearity of the phase problem. To achieve this goal, we propose and evaluate a non-linear algorithm for in-line phase micro-tomography based on an iterative Landweber method with an analytic calculation of the Fréchet derivative of the phase-intensity relationship and of its adjoint. The algorithm was applied in the projection space using as initialization the linear mixed solution. The efficacy of the regularization scheme was evaluated on simulated objects with a slowly and a strongly varying phase. Experimental data were also acquired at ESRF using a propagation-based X-ray imaging technique for the given pixel size 0.68 μm. Two regularization scheme were considered: first the initialization was obtained without any prior on the ratio of the real and imaginary parts of the complex refractive index and secondly a constant a priori value was assumed on ?. The tomographic central slices of the refractive index decrement were compared and numerical evaluation was performed. The non-linear method globally decreases the reconstruction errors compared to the linear algorithm and is achieving better reconstruction results if no prior is introduced in the initialization solution. For in-line phase micro-tomography, this non-linear approach is a new and interesting method in biomedical studies where the exact value of the a priori ratio is not known.展开更多
BACKGROUND Secondary forms and hypertension-mediated organ damage(HMOD) may differ between younger and older hypertensive patients.The aim of the present study was to explore the specificity of HMOD and secondary form...BACKGROUND Secondary forms and hypertension-mediated organ damage(HMOD) may differ between younger and older hypertensive patients.The aim of the present study was to explore the specificity of HMOD and secondary forms in patients≥ 65 years in comparison to younger ones in a contemporary cohort.METHODS We analysed 938 patients recruited between 2004 and 2014(Cardiology department,Croix-Rousse Hospital,Lyon)who had at baseline HMOD and secondary forms screening among them 190 were≥ 65 years.RESULTS The mean(2.1±0.8 vs.1.2±0.9,P <0.001) and frequency of HMOD(96.3% vs.72.9%,P <0.001) was higher in patients≥ 65 years than younger ones.Carotid femoral pulse wave velocity> 10 m/s was the most frequent HMOD in patients≥ 65 years(90.1%),while echocardiographic left ventricular hypertrophy was the most common in the younger patients(45.0%).Among ECG left ventricular indexes,only R wave in aVL lead was significantly more frequently observed in patients≥ 65 years(32.6%) than in younger ones(19.0%,P <0.001).The frequency of secondary hypertension was not significantly different between younger and older patients(respectively;30.5% vs.27.8%,P=0.487).The most frequent aetiology was primary aldosteronism regardless of age,followed by renovascular hypertension(6.3% vs.3.3%,P=0.038).Among older patients,3.2% were treated with adrenalectomy and 6.3% with percutaneous transluminal renal angioplasty.CONCLUSION Extensive screening of HMOD in older patients may be questionable as nearly all patients had one;aetiology must however be explored as a third of older patients had a secondary form.展开更多
In this paper, we present a proof-of-concept study of the enhancement of photocatalytic activity via a combined strategy of fabricating a visible-light responsive ternary heterostructure and improving overall photosta...In this paper, we present a proof-of-concept study of the enhancement of photocatalytic activity via a combined strategy of fabricating a visible-light responsive ternary heterostructure and improving overall photostability by incorporating magnetic zinc oxide/graphene/iron oxide (ZGF). A solvothermal approach was used to synthesize the catalyst. X-ray diffraction (XRD), scanning electron microscopic, energy dispersive X-ray, transmission electron microscopic, vibrating sample magnetometric, and ultraviolet–visible diffuse reflectance spectroscopic techniques were used to characterize the synthesized samples. The obtained optimal Zn(NO_(3))_(2) concentration, temperature, and heating duration were 0.10 mol/L, 600℃, and 1 h, respectively. The XRD pattern revealed the presence of peaks corresponding to zinc oxide, graphene, and iron oxide, indicating that the ZGF catalyst was effectively synthesized. Furthermore, when the developed ZGF was used for methylene blue dye degradation, the optimum irradiation time, dye concentration, catalyst dosage, irradiation intensity, and solution pH were 90 min, 10 mg/L, 0.03 g/L, 100 W, and 8.0, respectively. Therefore, the synthesized ZGF system could be used as a catalyst to degrade dyes in wastewater samples. This hybrid nanocomposite consisting of zinc oxide, graphene, and iron oxide could also be used as an effective photocatalytic degrader for various dye pollutants.展开更多
Sporadic venous malformations are genetic conditions primarily caused by somatic gain-of-function mutation of PIK3CA or TEK,an endothelial transmembrane receptor signaling through PIK3CA.Venous malformations are assoc...Sporadic venous malformations are genetic conditions primarily caused by somatic gain-of-function mutation of PIK3CA or TEK,an endothelial transmembrane receptor signaling through PIK3CA.Venous malformations are associated with pain,bleedings,thrombosis,pulmonary embolism,esthetic deformities and,in severe cases,life-threatening situations.No authorized medical treatment exists for patients with venous malformations.Here,we created a genetic mouse model of PIK3CA-related capillary venous malformations that replicates patient phenotypes.We showed that these malformations only partially signal through AKT proteins.We compared the efficacy of different drugs,including rapamycin,a mTORC1 inhibitor,miransertib,an AKT inhibitor and alpelisib,a PI3Kαinhibitor at improving the lesions seen in the mouse model.We demonstrated the effectiveness of alpelisib in preventing vascular malformations’occurrence,improving the already established ones,and prolonging survival.Considering these findings,we were authorized to treat 25 patients with alpelisib,including 7 children displaying PIK3CA(n=16)or TEK(n=9)-related capillary venous malformations resistant to usual therapies including sirolimus,debulking surgical procedures or percutaneous sclerotherapies.We assessed the volume of vascular malformations using magnetic resonance imaging(MRI)for each patient.Alpelisib demonstrated improvement in all 25 patients.Vascular malformations previously considered intractable were reduced and clinical symptoms were attenuated.MRI showed a decrease of 33.4%and 27.8%in the median volume of PIK3CA and TEK malformations respectively,over 6 months on alpelisib.In conclusion,this study supports PI3Kαinhibition as a promising therapeutic strategy in patients with PIK3CA or TEK-related capillary venous malformations.展开更多
In this study, we followed the biodegradation of ultra-small superparamagnetic iron oxide nanoparticles injected intravenously at clinical doses in mice. An advanced fitting procedure for magnetic susceptibility curve...In this study, we followed the biodegradation of ultra-small superparamagnetic iron oxide nanoparticles injected intravenously at clinical doses in mice. An advanced fitting procedure for magnetic susceptibility curves and low- temperature hysteresis loops was used to fully characterize the magnetic size distribution as well as the magnetic anisotropy energy of the injected P904 nano- particles （Guerbet Laboratory）. Additional magnetometry measurements and transmission electronic microscopy observations were systematically performed to examine dehydrated samples from the spleen and liver of healthy C57B16 mice after nanoparticle injection, with sacrifice of the mice for up to 14 months. At 3 months after injection, the magnetic properties of the spleen and liver were dramatically different. While the liver showed no magnetic signals other than those also present in the reference species, the spleen showed an increased magnetic signal attributed to ferritin. This surplus of ferritin remained constant up to 14 months after injection.展开更多
文摘In recent years , a second pathway for colonic carcinogenesis , distinct from the adenomatous pathway, has been explored. This is referred to as serrated pathway and includes three types of polyp,characterised by a serrated appearance of the crypts:hyperplastic polyps(HP),sessile serrated adenomas(SSA)or lesions,and traditional serrated adenomas.Each lesion has its own genetic,as well as macroscopic and microscopic morphological features.Because of their flat aspect,their detection is easier with chromoendoscopy(carmin indigo or narrow-band imaging).However,as we show in this review,the distinction between SSA and HP is quite difficult.It is now recommended to resect in one piece as it is possible the serrated polyps with a control in a delay depending on the presence or not of dysplasia.These different types of lesion are described in detail in the present review in general population,in polyposis and in inflammatory bowel diseases patients.This review highlights the need to improve characterization and understanding of this way of colorectal cancerogenesis.
基金Project (No. 60675023) supported by the National Natural Science Foundation of China
文摘Segmentation of the bladder in computerized tomography(CT) images is an important step in radiation therapy planning of prostate cancer. We present a new segmentation scheme to automatically delineate the bladder contour in CT images with three major steps. First,we use the mean shift algorithm to obtain a clustered image containing the rough contour of the bladder,which is then extracted in the second step by applying a region-growing algorithm with the initial seed point selected from a line-by-line scanning process. The third step is to refine the bladder contour more accurately using the rolling-ball algorithm. These steps are then extended to segment the bladder volume in a slice-by-slice manner. The obtained results were compared to manual segmentation by radiation oncologists. The average values of sensitivity,specificity,positive predictive value,negative predictive value,and Hausdorff distance are 86.5%,96.3%,90.5%,96.5%,and 2.8 pixels,respectively. The results show that the bladder can be accurately segmented.
文摘Phase imaging coupled to micro-tomography acquisition has emerged as a powerful tool to investigate specimens in a non-destructive manner. While the intensity data can be acquired and recorded, the phase information of the signal has to be “retrieved” from the data modulus only. Phase retrieval is an ill-posed non-linear problem and regularization techniques including a priori knowledge are necessary to obtain stable solutions. Several linear phase recovery methods have been proposed and it is expected that some limitations resulting from the linearization of the direct problem will be overcome by taking into account the non-linearity of the phase problem. To achieve this goal, we propose and evaluate a non-linear algorithm for in-line phase micro-tomography based on an iterative Landweber method with an analytic calculation of the Fréchet derivative of the phase-intensity relationship and of its adjoint. The algorithm was applied in the projection space using as initialization the linear mixed solution. The efficacy of the regularization scheme was evaluated on simulated objects with a slowly and a strongly varying phase. Experimental data were also acquired at ESRF using a propagation-based X-ray imaging technique for the given pixel size 0.68 μm. Two regularization scheme were considered: first the initialization was obtained without any prior on the ratio of the real and imaginary parts of the complex refractive index and secondly a constant a priori value was assumed on ?. The tomographic central slices of the refractive index decrement were compared and numerical evaluation was performed. The non-linear method globally decreases the reconstruction errors compared to the linear algorithm and is achieving better reconstruction results if no prior is introduced in the initialization solution. For in-line phase micro-tomography, this non-linear approach is a new and interesting method in biomedical studies where the exact value of the a priori ratio is not known.
文摘BACKGROUND Secondary forms and hypertension-mediated organ damage(HMOD) may differ between younger and older hypertensive patients.The aim of the present study was to explore the specificity of HMOD and secondary forms in patients≥ 65 years in comparison to younger ones in a contemporary cohort.METHODS We analysed 938 patients recruited between 2004 and 2014(Cardiology department,Croix-Rousse Hospital,Lyon)who had at baseline HMOD and secondary forms screening among them 190 were≥ 65 years.RESULTS The mean(2.1±0.8 vs.1.2±0.9,P <0.001) and frequency of HMOD(96.3% vs.72.9%,P <0.001) was higher in patients≥ 65 years than younger ones.Carotid femoral pulse wave velocity> 10 m/s was the most frequent HMOD in patients≥ 65 years(90.1%),while echocardiographic left ventricular hypertrophy was the most common in the younger patients(45.0%).Among ECG left ventricular indexes,only R wave in aVL lead was significantly more frequently observed in patients≥ 65 years(32.6%) than in younger ones(19.0%,P <0.001).The frequency of secondary hypertension was not significantly different between younger and older patients(respectively;30.5% vs.27.8%,P=0.487).The most frequent aetiology was primary aldosteronism regardless of age,followed by renovascular hypertension(6.3% vs.3.3%,P=0.038).Among older patients,3.2% were treated with adrenalectomy and 6.3% with percutaneous transluminal renal angioplasty.CONCLUSION Extensive screening of HMOD in older patients may be questionable as nearly all patients had one;aetiology must however be explored as a third of older patients had a secondary form.
基金supported by the Research and Development Institute at Nakhon Si Thammarat Rajabhat University and the Nanomaterials Chemistry Research Unit at Nakhon Si Thammarat Rajabhat University,Nakhon Si Thammarat,Thailand(Grant No.004/2563).
文摘In this paper, we present a proof-of-concept study of the enhancement of photocatalytic activity via a combined strategy of fabricating a visible-light responsive ternary heterostructure and improving overall photostability by incorporating magnetic zinc oxide/graphene/iron oxide (ZGF). A solvothermal approach was used to synthesize the catalyst. X-ray diffraction (XRD), scanning electron microscopic, energy dispersive X-ray, transmission electron microscopic, vibrating sample magnetometric, and ultraviolet–visible diffuse reflectance spectroscopic techniques were used to characterize the synthesized samples. The obtained optimal Zn(NO_(3))_(2) concentration, temperature, and heating duration were 0.10 mol/L, 600℃, and 1 h, respectively. The XRD pattern revealed the presence of peaks corresponding to zinc oxide, graphene, and iron oxide, indicating that the ZGF catalyst was effectively synthesized. Furthermore, when the developed ZGF was used for methylene blue dye degradation, the optimum irradiation time, dye concentration, catalyst dosage, irradiation intensity, and solution pH were 90 min, 10 mg/L, 0.03 g/L, 100 W, and 8.0, respectively. Therefore, the synthesized ZGF system could be used as a catalyst to degrade dyes in wastewater samples. This hybrid nanocomposite consisting of zinc oxide, graphene, and iron oxide could also be used as an effective photocatalytic degrader for various dye pollutants.
基金supported by the European Research Council(CoG 2020 grant number 101000948 awarded to GC)the Agence Nationale de la Recherche-Programme d’Investissements d’Avenir(ANR-18-RHUS-005 to GC)+1 种基金the Agence Nationale de la Recherche-Programme de Recherche Collaborative(19-CE14-0030-01 to GC)supported by the CLOVES SYNDROME COMMUNITY(West Kennebunk,USA),Association Syndrome de CLOVES(Nantes,France),Fondation d’entreprise IRCEM(Roubaix,France),Fonds de dotation Emmanuel BOUSSARD(Paris,France),the Fondation DAY SOLVAY(Paris,France),the Fondation TOURRE(Paris,France)to GC,the Fondation BETTENCOURT SCHUELLER(Paris,France)to GC,the Fondation Simone et Cino DEL DUCA(Paris,France),the Fondation Line RENAUD-Loulou GASTE(Paris,France,the Fondation Schlumberger pour l’Education et la Recherche(Paris,France),the Association Robert Debrépour la Recherche.
文摘Sporadic venous malformations are genetic conditions primarily caused by somatic gain-of-function mutation of PIK3CA or TEK,an endothelial transmembrane receptor signaling through PIK3CA.Venous malformations are associated with pain,bleedings,thrombosis,pulmonary embolism,esthetic deformities and,in severe cases,life-threatening situations.No authorized medical treatment exists for patients with venous malformations.Here,we created a genetic mouse model of PIK3CA-related capillary venous malformations that replicates patient phenotypes.We showed that these malformations only partially signal through AKT proteins.We compared the efficacy of different drugs,including rapamycin,a mTORC1 inhibitor,miransertib,an AKT inhibitor and alpelisib,a PI3Kαinhibitor at improving the lesions seen in the mouse model.We demonstrated the effectiveness of alpelisib in preventing vascular malformations’occurrence,improving the already established ones,and prolonging survival.Considering these findings,we were authorized to treat 25 patients with alpelisib,including 7 children displaying PIK3CA(n=16)or TEK(n=9)-related capillary venous malformations resistant to usual therapies including sirolimus,debulking surgical procedures or percutaneous sclerotherapies.We assessed the volume of vascular malformations using magnetic resonance imaging(MRI)for each patient.Alpelisib demonstrated improvement in all 25 patients.Vascular malformations previously considered intractable were reduced and clinical symptoms were attenuated.MRI showed a decrease of 33.4%and 27.8%in the median volume of PIK3CA and TEK malformations respectively,over 6 months on alpelisib.In conclusion,this study supports PI3Kαinhibition as a promising therapeutic strategy in patients with PIK3CA or TEK-related capillary venous malformations.
文摘In this study, we followed the biodegradation of ultra-small superparamagnetic iron oxide nanoparticles injected intravenously at clinical doses in mice. An advanced fitting procedure for magnetic susceptibility curves and low- temperature hysteresis loops was used to fully characterize the magnetic size distribution as well as the magnetic anisotropy energy of the injected P904 nano- particles （Guerbet Laboratory）. Additional magnetometry measurements and transmission electronic microscopy observations were systematically performed to examine dehydrated samples from the spleen and liver of healthy C57B16 mice after nanoparticle injection, with sacrifice of the mice for up to 14 months. At 3 months after injection, the magnetic properties of the spleen and liver were dramatically different. While the liver showed no magnetic signals other than those also present in the reference species, the spleen showed an increased magnetic signal attributed to ferritin. This surplus of ferritin remained constant up to 14 months after injection.
