A facile paper-based chromatography coupled Au nanodendrite on nickel foam for application in separation and SERS measurement.

A simple paper-based chromatography coupling with nickel foam decorated Au nanodendrite (PP-AuND/NiF) was fabricated for simultaneous separation and surface-enhanced Raman scattering (SERS) detection of Rhodamine-6G (R6G) from a mixture of analytes. The three-dimensional porous nickel foam (NiF) was employed as a sampling diffusion platform, and AuND with a high surface active area beneficial for SERS efficiency was electro-deposited directly onto the NiF frame. The structure of AuND/NiF was characterized by X-ray diffraction and scanning electron microscopy. The AuND/NiF could detect R6G at 0.1 nM, and the enhancement factor was 1.84 x 106. The AuND/NiF was durable, with a slight signal decrease after 6 m of drop-testing. Also, upon three days of exposure to ambient air, the signal droped only 3.35 %. Subsequently, the PP-AuND/NiF was constructed by directly situating AuND/NiF on a paper strip, serving as a sample in and out to AuND/NiF. A mixture of two SERS active compounds, namely 2-Naphthalenethiol (2-NpSH) and Rhodamine 6G (R6G), was prepared in ethanol: water (1:1) solution to evaluate PP-AuND/NiF separation capability. Raman measurements along different distances of AuND/NiF were performed, and the signal of 2-NpSH was dismissed after 3.0 mm, while R6G's signals were observed throughout AuND/NiF. In general, the PP-AuND/NiF demonstrated effective separation and SERS measurement of analytes in a mixture, which could be applicable for more complex samples in the future, especially in clinical analysis.

Pd(0)-catalyzed domino C-N coupling/hydroamination/C-H arylation reactions: efficient synthesis and photophysical properties of azaindolo[1,2-f]phenanthridines.

A series of new 7- and 4-azaindolo[1,2-f]phenanthridines were synthesized by a domino Pd(0)-catalyzed reaction, which involves three sequential steps: C-N coupling, hydroamination, and intramolecular C-H arylation. The products show promising fluorescence properties with high quantum yields (12-65%).

Palladium catalyzed synthesis and physical properties of indolo[2,3-b]quinoxalines.

A series of indolo[2,3-b]quinoxaline derivatives were efficiently synthesized from 2,3-dibromoquinoxaline by two pathways. A one-pot approach using Pd-catalyzed two-fold C-N coupling and C-H activation reactions gave indolo[2,3-b]quinoxaline derivatives in good yields, but with limited substrate scope. In addition, a two-step approach to indolo[2,3-b]quinoxalines was developed which is based on Pd-catalyzed Suzuki coupling reactions and subsequent annulation by Pd-catalyzed two-fold C-N coupling with aromatic and aliphatic amines. The electrochemical and photochemical properties of indolo[2,3-b]quinoxaline derivatives were investigated. These studies show that 6-(4-methoxyphenyl)-6H-indolo[2,3-b]quinoxaline showed the highest HOMO energy level and lowest band gap.

Efficient synthesis of biscarbazoles by palladium-catalyzed twofold C-N coupling and C-H activation reactions.

A new and efficient strategy for the synthesis of 3,9'- and 2,9'-biscarbazoles was developed. Our strategy relies on the cyclization of 1,1'-biphenyl-2,2'-diyl bis(trifluoromethanesulfonate) with 4- or 3-anisidine, transformation of the methoxy to a triflate group and subsequent oxidative Pd-catalyzed cyclization with various anilines.

Mass psychogenic illness following oral cholera immunization in Ca Mau City, Vietnam.

INTRODUCTION: Targeted cholera immunization of high-risk populations in Vietnam is conducted based on routine surveillance data. Following mass immunization of schoolchildren in Ca Mau City using an oral bivalent killed cholera vaccine, adverse reactions were noted. METHODS: Salient data were collected in a systematic fashion including the review of medical records; interview of the school principal, teachers, students, parents and doctors; and review of the storage and handling of the vaccine. FINDINGS: On 18 December 2001, 234 children at a primary school in Ca Mau City received the cholera vaccine. Within 1h of immunization, three children in one of the classrooms complained of trembling, nausea and headache and were brought to the library and soon other children followed. Out of 234, 97 (42%) pupils were affected and brought to the Municipal Health Center or Ca Mau Provincial Hospital. Those who were affected were younger (mean age=9.6 years; 95% CI=9.4-9.7) compared to those who were not affected (mean age=10 years; 95% CI=9.7-10.3; t-test=-2.4; P-value=0.02). The proportion of affected females among those who had received the vaccine (49/114 or 43%) was similar to the proportion in males (48/120 or 40%; RR=1.07; 95% CI=0.79-1.46). The most frequent presenting complaint was cold extremities (60%) followed by headache (27%). All affected children recovered and were discharged in a few hours. None reported any sequelae or relapse. Once the situation was recognized, the cholera immunization campaign was continued. Laboratory tests of vaccine samples from the same batch detected no abnormality or contaminating agent. DISCUSSION: The findings suggest that the children at primary school number 1 suffered from a mass psychogenic illness. This incident was unusual in that a similar number of boys and girls were affected, in contrast to the frequently reported preponderance of female cases. Furthermore the underlying cause was very quickly diagnosed, medical interventions were kept to a minimum, and no relapse was observed. Future vaccination campaigns have to assure that the families are informed in advance.