The transverse relaxation time (T_(2)) cut-off value plays a crucial role in nuclear magnetic resonance for identifying movable and immovable boundaries, evaluating permeability, and determining fluid saturation in pe...The transverse relaxation time (T_(2)) cut-off value plays a crucial role in nuclear magnetic resonance for identifying movable and immovable boundaries, evaluating permeability, and determining fluid saturation in petrophysical characterization of petroleum reservoirs. This study focuses on the systematic analysis of T_(2) spectra and T_(2) cut-off values in low-permeability reservoir rocks. Analysis of 36 low-permeability cores revealed a wide distribution of T_(2) cut-off values, ranging from 7 to 50 ms. Additionally, the T_(2) spectra exhibited multimodal characteristics, predominantly displaying unimodal and bimodal morphologies, with a few trimodal morphologies, which are inherently influenced by different pore types. Fractal characteristics of pore structure in fully water-saturated cores were captured through the T_(2) spectra, which were calculated using generalized fractal and multifractal theories. To augment the limited dataset of 36 cores, the synthetic minority oversampling technique was employed. Models for evaluating the T_(2) cut-off value were separately developed based on the classified T_(2) spectra, considering the number of peaks, and utilizing generalized fractal dimensions at the weight <0 and the singular intensity range. The underlying mechanism is that the singular intensity and generalized fractal dimensions at the weight <0 can detect the T_(2) spectral shift. However, the T_(2) spectral shift has negligible effects on multifractal spectrum function difference and generalized fractal dimensions at the weight >0. The primary objective of this work is to gain insights into the relationship between the kurtosis of the T_(2) spectrum and pore types, as well as to predict the T_(2) cut-off value of low-permeability rocks using machine learning and data augmentation techniques.展开更多
AIM:To observe changes in the best-corrected visual acuity(BCVA),central macular thickness(CMT),and central choroidal thickness(CCT)of patients with macular edema(ME)secondary to ischemic retinal vein occlusion(i RVO)...AIM:To observe changes in the best-corrected visual acuity(BCVA),central macular thickness(CMT),and central choroidal thickness(CCT)of patients with macular edema(ME)secondary to ischemic retinal vein occlusion(i RVO)following intravitreal Conbercept injection.METHODS:This retrospective study included 33 eyes from 33 patients who received intravitreal injections of Conbercept for ME secondary to i RVO.Treatments were performed on a 3+pro re nata(3+PRN)basis.All of the patients were examined by fundus fluorescein angiography and spectral domain optical coherence tomography at the first visit.Laser photocoagulation was performed in the nonperfusion area of the retina of all eyes after the first injection.BCVA,CMT,and CCT were observed before and after 6 mo of treatment.The number of injections necessary to achieve improved vision was also noted.RESULTS:Following Conbercept treatment,the mean BCVA significantly improved from 0.81±0.39 at baseline to 0.41±0.25 and 0.43±0.29 log MAR in the third and sixth months,respectively(both P=0.000).The CMT of the patients at baseline was 556.75±98.57μm;304.78±68.53 and 306.85±76.77μm 3 and 6 mo after treatment,respectively(both P=0.000 vs baseline).The CCTs of the patients at baseline,3 and 6 mo after treatment were 304.63±57.83,271.31±45.53,and 272.29±39.93μm,respectively(P=0.026 and 0.035 vs baseline).No severe adverse event relevant to the therapy was noted,and the average number of injections delivered was 3.35.CONCLUSION:Intravitreal Conbercept injection combined with laser photocoagulation appears to be a safe and effective treatment for ME secondary to i RVO in the short-term.展开更多
Scleroderma is an autoimmune fibrosing disorder that can be further subclassified as localized scleroderma(LSc)and systemic sclerosis(SSc).LSc is characterized by sclerotic and pigmented skin lesions,while SSc is a mo...Scleroderma is an autoimmune fibrosing disorder that can be further subclassified as localized scleroderma(LSc)and systemic sclerosis(SSc).LSc is characterized by sclerotic and pigmented skin lesions,while SSc is a more generalized disorder of the connective tissue involving a number of organs.SSc is characterized by the thickening of dermal collagen bundles,fibrosis,and vascular abnormalities in the visceral organs.[1]Despite the differences in their morphologic features and clinical presentation,these two diseases do share some characteristics including endothelial cell dysfunction,T helper 2(Th2)cell dominance during immune activation and excess fibrosis of the skin with similar pathologic findings,leading to the hypothesis that SSc and LSc share an underlying mechanism of pathogensis.Currently,multiple lines of evidence suggest that genetic factors may contribute to SSc susceptibility.展开更多
基金supported by National Natural Science Foundation of China(Nos.42002171,42172159)China Postdoctoral Science Foundation(Nos.2020TQ0299,2020M682520)Postdoctoral Innovation Science Foundation of Hubei Province of China.
文摘The transverse relaxation time (T_(2)) cut-off value plays a crucial role in nuclear magnetic resonance for identifying movable and immovable boundaries, evaluating permeability, and determining fluid saturation in petrophysical characterization of petroleum reservoirs. This study focuses on the systematic analysis of T_(2) spectra and T_(2) cut-off values in low-permeability reservoir rocks. Analysis of 36 low-permeability cores revealed a wide distribution of T_(2) cut-off values, ranging from 7 to 50 ms. Additionally, the T_(2) spectra exhibited multimodal characteristics, predominantly displaying unimodal and bimodal morphologies, with a few trimodal morphologies, which are inherently influenced by different pore types. Fractal characteristics of pore structure in fully water-saturated cores were captured through the T_(2) spectra, which were calculated using generalized fractal and multifractal theories. To augment the limited dataset of 36 cores, the synthetic minority oversampling technique was employed. Models for evaluating the T_(2) cut-off value were separately developed based on the classified T_(2) spectra, considering the number of peaks, and utilizing generalized fractal dimensions at the weight <0 and the singular intensity range. The underlying mechanism is that the singular intensity and generalized fractal dimensions at the weight <0 can detect the T_(2) spectral shift. However, the T_(2) spectral shift has negligible effects on multifractal spectrum function difference and generalized fractal dimensions at the weight >0. The primary objective of this work is to gain insights into the relationship between the kurtosis of the T_(2) spectrum and pore types, as well as to predict the T_(2) cut-off value of low-permeability rocks using machine learning and data augmentation techniques.
基金Supported by the Key Research and Development Plan of Shandong Province(No.2017G006033)the Natural Science Foundation of Shandong Province(No.ZR2017LH042)+1 种基金the Development Project of Medicine and Health Science Technology of Shandong Province(No.2017WS073)the Excellent Youth Science Foundation of Shandong University of Traditional Chinese Medicine(No.2018zk26)。
文摘AIM:To observe changes in the best-corrected visual acuity(BCVA),central macular thickness(CMT),and central choroidal thickness(CCT)of patients with macular edema(ME)secondary to ischemic retinal vein occlusion(i RVO)following intravitreal Conbercept injection.METHODS:This retrospective study included 33 eyes from 33 patients who received intravitreal injections of Conbercept for ME secondary to i RVO.Treatments were performed on a 3+pro re nata(3+PRN)basis.All of the patients were examined by fundus fluorescein angiography and spectral domain optical coherence tomography at the first visit.Laser photocoagulation was performed in the nonperfusion area of the retina of all eyes after the first injection.BCVA,CMT,and CCT were observed before and after 6 mo of treatment.The number of injections necessary to achieve improved vision was also noted.RESULTS:Following Conbercept treatment,the mean BCVA significantly improved from 0.81±0.39 at baseline to 0.41±0.25 and 0.43±0.29 log MAR in the third and sixth months,respectively(both P=0.000).The CMT of the patients at baseline was 556.75±98.57μm;304.78±68.53 and 306.85±76.77μm 3 and 6 mo after treatment,respectively(both P=0.000 vs baseline).The CCTs of the patients at baseline,3 and 6 mo after treatment were 304.63±57.83,271.31±45.53,and 272.29±39.93μm,respectively(P=0.026 and 0.035 vs baseline).No severe adverse event relevant to the therapy was noted,and the average number of injections delivered was 3.35.CONCLUSION:Intravitreal Conbercept injection combined with laser photocoagulation appears to be a safe and effective treatment for ME secondary to i RVO in the short-term.
文摘Scleroderma is an autoimmune fibrosing disorder that can be further subclassified as localized scleroderma(LSc)and systemic sclerosis(SSc).LSc is characterized by sclerotic and pigmented skin lesions,while SSc is a more generalized disorder of the connective tissue involving a number of organs.SSc is characterized by the thickening of dermal collagen bundles,fibrosis,and vascular abnormalities in the visceral organs.[1]Despite the differences in their morphologic features and clinical presentation,these two diseases do share some characteristics including endothelial cell dysfunction,T helper 2(Th2)cell dominance during immune activation and excess fibrosis of the skin with similar pathologic findings,leading to the hypothesis that SSc and LSc share an underlying mechanism of pathogensis.Currently,multiple lines of evidence suggest that genetic factors may contribute to SSc susceptibility.
