Heterogeneous catalysts with ultra-small clusters and atomically dispersed(USCAD)active sites have gained increasing attention in recent years.However,developing USCAD catalysts with high-density metal sites anchored ...Heterogeneous catalysts with ultra-small clusters and atomically dispersed(USCAD)active sites have gained increasing attention in recent years.However,developing USCAD catalysts with high-density metal sites anchored in porous nanomaterials is still challenging.Here,through the template-free S-assisted pyrolysis of low-cost Fe-salts with melamine(MA),porous alveolate Fe/g-C3N4 catalysts with high-density(Fe loading up to 17.7 wt%)and increased USCAD Fe sites were synthesized.The presence of a certain amount of S species in the Fe-salts/MA system plays an important role in the formation of USCAD S-Fe-salt/CN catalysts;the S species act as a"sacrificial carrier"to increase the dispersion of Fe species through Fe-S coordination and generate porous alveolate structure by escaping in the form of SO2 during pyrolysis.The S-Fe-salt/CN catalysts exhibit greatly promoted activity and reusability for degrading various organic pollutants in advanced oxidation processes compared to the corresponding Fe-salt/CN catalysts,due to the promoted accessibility of USCAD Fe sites by the porous alveolate structure.This S-assisted method exhibits good feasibility in a large variety of S species(thiourea,S powder,and NH4SCN)and Fe salts,providing a new avenue for the low-cost and large-scale synthesis of high-density USCAD metal/g-C3N4 catalysts.展开更多
This paper discusses mineral composition and pore microstructure characteristics of water-cooled manganese slag and its effects on durability of concrete. The Mn slag has an alveolate pore structure, and the ground Mn...This paper discusses mineral composition and pore microstructure characteristics of water-cooled manganese slag and its effects on durability of concrete. The Mn slag has an alveolate pore structure, and the ground Mn slag is characterized by multiangular shape which consists of a＇-C2S, C3M82, CaO.MnO-2SiOu and C2AS. Experimental results show that the Mn slag has potential hydraulic reactivity. Concrete made with Mn slag as supplementary cementitious materials （SCMs） exhibits very low strength loss and weight loss in the synthetic seawater corrosion and freezing-thawing cycle tests. The research provides useful reference for knowing about Mn slag and for applying Mn slag to improve the durability of concrete.展开更多
Objective To assess the spectrum of causes, clinical features, differences between disease phases, and prognosis of extrinsic allergic alveolitis （EAA）. Methods Patients with EAA diagnosed at Peking Union Medical C...Objective To assess the spectrum of causes, clinical features, differences between disease phases, and prognosis of extrinsic allergic alveolitis （EAA）. Methods Patients with EAA diagnosed at Peking Union Medical College Hospital from August 1983 to May 2007 were analyzed retrospectively. Their medical records were examined to gather clinical, laboratorial, radiological, and histopathological data. Patients were divided to three phases （acute, subacute, and chronic） according to clinical presentations. Follow-up data regarding treatment response, subsequent radio- logical and pulmonary function studies, and clinical outcomes were collected. Results A total of 21 cases were enrolled. Among them, 11 were subacute, 10 were chronic. The most common exposure was pet birds （6 cases, 28.6%）. The primary abnormality of pulmonary function was restriction and/or reduction in diffusing capacity （12 cases, 63.2%）. The most common findings on high-resolution computed tomography （HRCT） were ground-glass opacities （13 cases, 68.4%） and centri- lobular nodules （8 cases, 42.1%）. Airway obstruction in pulmonary function test, emphysema, hmg cysts, and fibrosis on HRCT were more frequently seen in chronic than in subacute patients, though the differences were not statistically significant. Bronchoalveolar lavage fluid （BALF） showed lymphocytosis. The total＇cell count and the percentage of neutrophils were significantly higher in subacute than in chronic patients （P〈0.05）. Nonnecrotizing granulomas were seen in 8 （47.1%） cases. Improvement or normalization in symptoms, radiography, and pulmonary function test after treatment were seen in all 18 patients with avail- able follow-up data. Five patients recurred. Conclusions The characteristic abnormalities of pulmonary function, findings on HRCT, and pa- thology are essential for all phases of EAA, and the atypical manifestations such as obstruction and fibrosis can also be present frequently, particularly in chronic cases. Differential cell counts of BALF are related to the phase of the disease. The treatment response and prognosis of EAA are good.展开更多
Celiac disease (CD) is an autoimmune disorder of the small intestine that occurs in genetically predisposed people at all ages.However,it can be associated also to other immunopathological disorders,and may be associa...Celiac disease (CD) is an autoimmune disorder of the small intestine that occurs in genetically predisposed people at all ages.However,it can be associated also to other immunopathological disorders,and may be associated with abnormal histology in segments of the gut other than the small bowel including colonic inflammation.While guidelines for endoscopic investigation of the jejunum are well defined,no indication is defined for colonic investigation.We describe four cases of concurrent CD and microscopic colitis (MC) diagnosed at our department over a 10-year period and analyzed the main features and outcomes of CD in this setting.The symptoms of these patients were improved initially by a gluten-free diet before the onset of MC symptoms.Two of the patients were siblings and had an atypical form of CD.The other two patients with CD and MC also presented with fibrosing alveolitis and were anti-Saccharomyces cerevisiae antibody positive.The co-existence of immune-mediated small bowel and colonic inflammatory and pulmonary diseases are not well-known,and no systematic approach has been used to identify the lifelong patterns of these immune-based diseases.Patients can develop,or present with CD at any stage in life,which can co-exist with other gastrointestinal diseases of (auto-) immune origin.In addition,the fa-milial co-existence and prevalence of MC in patients with a prior diagnosis of CD are unclear.Clinicians managing celiac disease should be aware of these associations and understand when to consider colon investigation.展开更多
文摘Heterogeneous catalysts with ultra-small clusters and atomically dispersed(USCAD)active sites have gained increasing attention in recent years.However,developing USCAD catalysts with high-density metal sites anchored in porous nanomaterials is still challenging.Here,through the template-free S-assisted pyrolysis of low-cost Fe-salts with melamine(MA),porous alveolate Fe/g-C3N4 catalysts with high-density(Fe loading up to 17.7 wt%)and increased USCAD Fe sites were synthesized.The presence of a certain amount of S species in the Fe-salts/MA system plays an important role in the formation of USCAD S-Fe-salt/CN catalysts;the S species act as a"sacrificial carrier"to increase the dispersion of Fe species through Fe-S coordination and generate porous alveolate structure by escaping in the form of SO2 during pyrolysis.The S-Fe-salt/CN catalysts exhibit greatly promoted activity and reusability for degrading various organic pollutants in advanced oxidation processes compared to the corresponding Fe-salt/CN catalysts,due to the promoted accessibility of USCAD Fe sites by the porous alveolate structure.This S-assisted method exhibits good feasibility in a large variety of S species(thiourea,S powder,and NH4SCN)and Fe salts,providing a new avenue for the low-cost and large-scale synthesis of high-density USCAD metal/g-C3N4 catalysts.
基金the National Basic Research Program(973) of China(No.2009CB326200)the Guangxi Technology and Science Development Program (Nos.11107024-4,0842003-17 and 0842003-3A)
文摘This paper discusses mineral composition and pore microstructure characteristics of water-cooled manganese slag and its effects on durability of concrete. The Mn slag has an alveolate pore structure, and the ground Mn slag is characterized by multiangular shape which consists of a＇-C2S, C3M82, CaO.MnO-2SiOu and C2AS. Experimental results show that the Mn slag has potential hydraulic reactivity. Concrete made with Mn slag as supplementary cementitious materials （SCMs） exhibits very low strength loss and weight loss in the synthetic seawater corrosion and freezing-thawing cycle tests. The research provides useful reference for knowing about Mn slag and for applying Mn slag to improve the durability of concrete.
文摘Objective To assess the spectrum of causes, clinical features, differences between disease phases, and prognosis of extrinsic allergic alveolitis （EAA）. Methods Patients with EAA diagnosed at Peking Union Medical College Hospital from August 1983 to May 2007 were analyzed retrospectively. Their medical records were examined to gather clinical, laboratorial, radiological, and histopathological data. Patients were divided to three phases （acute, subacute, and chronic） according to clinical presentations. Follow-up data regarding treatment response, subsequent radio- logical and pulmonary function studies, and clinical outcomes were collected. Results A total of 21 cases were enrolled. Among them, 11 were subacute, 10 were chronic. The most common exposure was pet birds （6 cases, 28.6%）. The primary abnormality of pulmonary function was restriction and/or reduction in diffusing capacity （12 cases, 63.2%）. The most common findings on high-resolution computed tomography （HRCT） were ground-glass opacities （13 cases, 68.4%） and centri- lobular nodules （8 cases, 42.1%）. Airway obstruction in pulmonary function test, emphysema, hmg cysts, and fibrosis on HRCT were more frequently seen in chronic than in subacute patients, though the differences were not statistically significant. Bronchoalveolar lavage fluid （BALF） showed lymphocytosis. The total＇cell count and the percentage of neutrophils were significantly higher in subacute than in chronic patients （P〈0.05）. Nonnecrotizing granulomas were seen in 8 （47.1%） cases. Improvement or normalization in symptoms, radiography, and pulmonary function test after treatment were seen in all 18 patients with avail- able follow-up data. Five patients recurred. Conclusions The characteristic abnormalities of pulmonary function, findings on HRCT, and pa- thology are essential for all phases of EAA, and the atypical manifestations such as obstruction and fibrosis can also be present frequently, particularly in chronic cases. Differential cell counts of BALF are related to the phase of the disease. The treatment response and prognosis of EAA are good.
文摘Celiac disease (CD) is an autoimmune disorder of the small intestine that occurs in genetically predisposed people at all ages.However,it can be associated also to other immunopathological disorders,and may be associated with abnormal histology in segments of the gut other than the small bowel including colonic inflammation.While guidelines for endoscopic investigation of the jejunum are well defined,no indication is defined for colonic investigation.We describe four cases of concurrent CD and microscopic colitis (MC) diagnosed at our department over a 10-year period and analyzed the main features and outcomes of CD in this setting.The symptoms of these patients were improved initially by a gluten-free diet before the onset of MC symptoms.Two of the patients were siblings and had an atypical form of CD.The other two patients with CD and MC also presented with fibrosing alveolitis and were anti-Saccharomyces cerevisiae antibody positive.The co-existence of immune-mediated small bowel and colonic inflammatory and pulmonary diseases are not well-known,and no systematic approach has been used to identify the lifelong patterns of these immune-based diseases.Patients can develop,or present with CD at any stage in life,which can co-exist with other gastrointestinal diseases of (auto-) immune origin.In addition,the fa-milial co-existence and prevalence of MC in patients with a prior diagnosis of CD are unclear.Clinicians managing celiac disease should be aware of these associations and understand when to consider colon investigation.
