In human cells, the heterogeneous nuclear ribonucleoproteins (hnRNP) are represented by a group of polypeptides, with various molecular properties, comprizing the most abundant constituents of the cell nucleus. Autoan...In human cells, the heterogeneous nuclear ribonucleoproteins (hnRNP) are represented by a group of polypeptides, with various molecular properties, comprizing the most abundant constituents of the cell nucleus. Autoantibodies to hnRNPs have been reported in patients suffering from different rheumatic dieseases since 1980s. Experimental evidence indicates that hnRNP complexes undergo substantial structural changes during mRNA formation and export. However, how this contributes to disease development still has to be elucidated. Here some preliminary physicochemical features of RNA-protein folding and stability patterns of newly characterized hnRNP A3 with further functional implications in development of systemic human autoimmune states are reported.展开更多
We investigated the effects of different CO2 tensions on oxygenation, pulmonary blood flow(Qp), cerebral blood flow, and systemic blood flow(Qs) after the bidirectional superior cavopulmonary anastomosis (BCPA). Hypox...We investigated the effects of different CO2 tensions on oxygenation, pulmonary blood flow(Qp), cerebral blood flow, and systemic blood flow(Qs) after the bidirectional superior cavopulmonary anastomosis (BCPA). Hypoxemia refractory to management of a high pulmonary vascular resistance index(PVRI) may complicate recovery from the BCPA. After BCPA, CO2 was added to the inspired gas of mechanically ventilated patients. The Qp, Qs, PVRI, and systemic vascular resistance index(SVRI) were calculated from oxygen consumption, intravascular pressures, and oxygen saturations. Cerebral blood flow was estimated by near infrared spectroscopy and transcranial Doppler. In nine patients(median age 7.1, range 2 to 23 months), arterial oxygen tension increased significantly (p< 0.005) from 36±6 mm Hg to 44±6 to 50±7 mm Hg at arterial carbon dioxide tensions (PaCO2) of 35, 45, and 55 mm Hg, respectively and decreased to 40±8 mm Hg at PaCO2 40 mm Hg. At a PaCO2 of 55 and 45 compared with 35 mm Hg, Qp, cerebral blood flow, and Qs increased significantly, PVRI, Qp/Qs, and the ratio of Qp to inferior vena caval blood flow were unchanged, but SVRI decreased. We have demonstrated that after the BCPA, systemic oxygenation, Qp, Qs, and cerebral blood flow increased and SVRI decreased at CO2 tensions of 45 and 55 mm Hg compared with 35 mm Hg. We suggest that hypoxemia after the BCPA is ameliorated by a higher PaCO2 and that low PaCO2 or alkalosis may be detrimental. Hypercarbic management strategies may allow earlier progression to the BCPA, which may contribute to reducing the interval morbidity in patients with a functional single ventricle.展开更多
To determine the ash characteristics during fluidized bed combustion and gasification purposes, the investigation of the impacts of chemical composition of Jincheng coal ash on the sintering temperature was conducted....To determine the ash characteristics during fluidized bed combustion and gasification purposes, the investigation of the impacts of chemical composition of Jincheng coal ash on the sintering temperature was conducted. A series of experiments on the sintering behavior at 0.5 MPa was performed using the pressurized pressure-drop technique in the combustion and gasification atmospheres. Meanwhile, the mineral transformations of sintered ash pellets were observed using X-ray diffractometer （XRD） analyzer to better understand the experimental results. In addition, quantitative XRD and field emission scanning electron microscope/energy dispersive X-ray spectrometer （FE-SEM/EDS） analyses of ash samples were used for clarifying the detailed ash melting mechanism. These results show that the addition of Fe203 can obviously reduce the sintering temperatures under gasification atmospheres, and only affect a little the sintering temperature under combustion atmosphere. This may be due to the presence of iron-bearing minerals, which will react with other ash compositions to produce low-melting-point eutectics. The FE-SEM/EDS analyses of ash samples with Fe203 additive show consistent results with the XRD measurements. The CaO and Na20 can reduce the sintering temperatures under both the combustion and gasification atmospheres. This can be also contributed to the formation of low-melting-point eutectics, decreasing the sintering temperature. Moreover, the fluxing minerals, such as magnetite, anhydrite, muscovite, albite and nepheline, contribute mostly to the reduction of the sintering temperature while the feldspar minerals, such as anorthite, gehlenite and sanidine, can react with other minerals to produce low-melting-point eutectics, and thereby reduce the sintering temperatures.展开更多
文摘In human cells, the heterogeneous nuclear ribonucleoproteins (hnRNP) are represented by a group of polypeptides, with various molecular properties, comprizing the most abundant constituents of the cell nucleus. Autoantibodies to hnRNPs have been reported in patients suffering from different rheumatic dieseases since 1980s. Experimental evidence indicates that hnRNP complexes undergo substantial structural changes during mRNA formation and export. However, how this contributes to disease development still has to be elucidated. Here some preliminary physicochemical features of RNA-protein folding and stability patterns of newly characterized hnRNP A3 with further functional implications in development of systemic human autoimmune states are reported.
文摘We investigated the effects of different CO2 tensions on oxygenation, pulmonary blood flow(Qp), cerebral blood flow, and systemic blood flow(Qs) after the bidirectional superior cavopulmonary anastomosis (BCPA). Hypoxemia refractory to management of a high pulmonary vascular resistance index(PVRI) may complicate recovery from the BCPA. After BCPA, CO2 was added to the inspired gas of mechanically ventilated patients. The Qp, Qs, PVRI, and systemic vascular resistance index(SVRI) were calculated from oxygen consumption, intravascular pressures, and oxygen saturations. Cerebral blood flow was estimated by near infrared spectroscopy and transcranial Doppler. In nine patients(median age 7.1, range 2 to 23 months), arterial oxygen tension increased significantly (p< 0.005) from 36±6 mm Hg to 44±6 to 50±7 mm Hg at arterial carbon dioxide tensions (PaCO2) of 35, 45, and 55 mm Hg, respectively and decreased to 40±8 mm Hg at PaCO2 40 mm Hg. At a PaCO2 of 55 and 45 compared with 35 mm Hg, Qp, cerebral blood flow, and Qs increased significantly, PVRI, Qp/Qs, and the ratio of Qp to inferior vena caval blood flow were unchanged, but SVRI decreased. We have demonstrated that after the BCPA, systemic oxygenation, Qp, Qs, and cerebral blood flow increased and SVRI decreased at CO2 tensions of 45 and 55 mm Hg compared with 35 mm Hg. We suggest that hypoxemia after the BCPA is ameliorated by a higher PaCO2 and that low PaCO2 or alkalosis may be detrimental. Hypercarbic management strategies may allow earlier progression to the BCPA, which may contribute to reducing the interval morbidity in patients with a functional single ventricle.
基金Project (No. 2011DFA72730-202) supported by the Research Project of US-China Clean Energy Research Center
文摘To determine the ash characteristics during fluidized bed combustion and gasification purposes, the investigation of the impacts of chemical composition of Jincheng coal ash on the sintering temperature was conducted. A series of experiments on the sintering behavior at 0.5 MPa was performed using the pressurized pressure-drop technique in the combustion and gasification atmospheres. Meanwhile, the mineral transformations of sintered ash pellets were observed using X-ray diffractometer （XRD） analyzer to better understand the experimental results. In addition, quantitative XRD and field emission scanning electron microscope/energy dispersive X-ray spectrometer （FE-SEM/EDS） analyses of ash samples were used for clarifying the detailed ash melting mechanism. These results show that the addition of Fe203 can obviously reduce the sintering temperatures under gasification atmospheres, and only affect a little the sintering temperature under combustion atmosphere. This may be due to the presence of iron-bearing minerals, which will react with other ash compositions to produce low-melting-point eutectics. The FE-SEM/EDS analyses of ash samples with Fe203 additive show consistent results with the XRD measurements. The CaO and Na20 can reduce the sintering temperatures under both the combustion and gasification atmospheres. This can be also contributed to the formation of low-melting-point eutectics, decreasing the sintering temperature. Moreover, the fluxing minerals, such as magnetite, anhydrite, muscovite, albite and nepheline, contribute mostly to the reduction of the sintering temperature while the feldspar minerals, such as anorthite, gehlenite and sanidine, can react with other minerals to produce low-melting-point eutectics, and thereby reduce the sintering temperatures.
