ABSTRACT
Covalent organic frameworks(COFs)are a novel type of crystalline porous organic polymer materials recently developed.It has several advantages in chromatographic separation field,such as high thermal stability,porosity,structural regularity,and large specific surface area.Here,a novel spherical COF 1,3,5-tris(4-aminophenyl)benzene(TAPB)and 2,5-bis(2-propyn-1-yloxy)-1,4-benzenedicarboxaldehyde(BPTA)was developed as an electrochromatographic stationary phase for capillary electro-chromatography separation.The COFTTAPB-BPTA modified capillary column was fabricated via a facile in situ growth method at room temperature.The characterization results of scanning electron microscopy(SEM),Fourier transform infrared(FT-IR)spectroscopy,and X-ray diffraction(XRD)confirmed that COF TAPB-BPTA were successfully modified onto the capillary inner surface.The electrochromatography separation performance of the COF TAPB-BPTA modified capillary was investigated.The prepared column demonstrated outstanding separation performance toward alkylbenzenes,phenols,and chlorobenzenes compounds.Furthermore,the baseline separations of non-steroidal anti-inflammatory drugs(NSAIDs)and parabens with good efficiency and high resolution were achieved.Also,the prepared column possessed satisfactory precision of the intra-day runs(n=5),inter-day runs(n=3),and parallel columns(n=3),and the relative standard deviations(RSDs)of the retention times of tested alkylbenzenes were all less than 2.58％.Thus,this new COF-based stationary phase shows tremendous application potential in chromatographic separation field.
ABSTRACT
Purpose To investigate the clinicopathologic characteristics of colorectal metastatic tumors. Methods Cases which were clinically diagnosed as metastatic tumors to the colorectum were retrieved from the data base of the Department of Pathology, Peking U-niversity Third Hospital. The clinicopathologic features were studied and immunohistochemical stains were performed on some of the ca-ses for differential diagnosis. Results Fifty three cases which showed intestinal wall involvement were studied. In 43. 4% (23/53) of them, only serosa/subserosa was involved and mucosal involvement was observed in 37. 7% (20/53) of the cases. Sigmoid colon and rectum were the most frequently involved intestinal segments (24/53, 45. 3%). Female reproductive system was the most common ori-gin of the metastatic tumors (33/53, 62. 3%), followed by the digestive system (15/53, 28. 3%). The most common histological type was ovarian serous carcinoma (22/53, 41. 5%). 96. 2% (51/53) of the metastatic tumors were centrally located at the serosa/subserosa or the muscular propria and prominent lymphovascular invasion was observed in 26. 4% (14/53) of the cases. In cases with mucosal involvement, 35% ( 7/20 ) had foci that were lack of desmoplastic reaction, 20% ( 4/20 ) exhibited in-situ growth and/or paradoxical maturation of tumor cells which led to misdiagnosis in 2 of the 17 pre-operative biopsies. Conclusions Metastatic carcino-ma in the colorectum can be highly informed by predominantly involving the serosa/subserosa or muscular propria and prominent lym-phovascular invasion. In-situ growth and paradoxical maturation of tumor cells in the mucosa are diagnostic pitfalls in pre-operative co-lonic biopsy and should be aware in practice.
ABSTRACT
Objective To explore the performance of the novel nitric oxide(NO) electrochemical microsensor based on Au nano-particles(nano-Au) modified glass-fiber .Methods With columnar glass-fiber as the substrate material ,the in-situ chemical seed-growth technology was adopted to fabricate one kind of electrochemical microsensor based on gold nanoparticles pole electrodes and the amperometric response method was used to investigate the various properties of the NO microsensor .Results This microsensor had high sensitivity response to NO ,its linear range was 7 .2 nmol/L -11 .7μmol/L(r=0 .998) with a detection limit of 3 .6 nmol/L .Conclusion A novel electrochemical microsensor based on nano-Au pole electrode was fabricated .The NO microsensor posseses high sensitivity ,wide linear range ,good reproducibility and excellent anti-interference ability .