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To characterize the size distribution and chemical ompsitins f abiet prtices t a agicuturesit intheNorh o Chinese Plain, a single particle aerosol mass spectrometer (SPAMS) was deployed from June 30 to July 8, 2013. A total of 230,152 particles in the size range of 0.2-2.0 pm were chemically analyzed with both positive and negative ion spectra. The results revealed that aerosol could he classified into eight dominant groups, including elemental carbon (EC, 55.5%), organic carbon (OC, 10.7%), alkalis (Na-K, 17.4%), other metals (1.7%), Fe-rich (6.3%), Pb-rich (3.1%), dust (4.8%), and other (0.8%). The observed eight types of particles contained secondary components such as 46NO2-, 62NO3-, 96SO3-, 96SO4-, 97HSO4-, showing that they probably went through different aging processes. The analysis of particle size distribution showed that 700-800 nm was the peak value of all particles, and that dust and Fe particles were mainly in the coarse size range. EC particles subtype group research revealed EC particles tended to be aging with the above mentioned secondary ions and eventually led to a particle type conversion from EC to the less aging ECN and the more serious aging ECS, the diurnal variation of which was obviously negatively correlated, and there was a possibility of forming OC/EC mixture with the adsorption of secondary organic matter on EC surface.

Disseminated tuberculosis usually occurs in immunocompromised hosts. Involvement of bone marrow, liver, and spleen is infrequent. A previously healthy 15-year-old boy presented with body weight loss, prolonged fever, neck lymphadenopathy, pancytopenia, and hepatosplenic microabscesses within the recent month and was transferred to our hospital. Bone marrow studies showed hypocellular marrow. Based on his clinical manifestations, hemophagocytic syndrome was initially suspected. Pancytopenia resolved after administration of intravenous immunoglobulin but caseous necrosis and/or positive acid-fast stain were subsequently demonstrated in the lymph node biopsy and sputum. Cultures from these 2 specimens grew Mycobacterium tuberculosis. Fever continued in a low-grade pattern even under antituberculous therapy with rifampin, isoniazid, pyrazinamide and ethambutol. Five months after admission, fever subsided after splenectomy and liver wedge resection. Microscopic examinations of both the liver and spleen showed mycobacteria-related granulomatous inflammation and caseating necrosis. This report suggests that tuberculosis infection should be considered in the differential diagnosis in patients with prolonged fever, pancytopenia and hepatosplenic abscesses.