Vinylcarbene insertion into the nitrogen–hydrogen (N–H) bond of amines allows direct access to α,β-unsaturated γ-amino acid derivatives, meeting a marked challenge in the control of regio- and enantioselectivities. Here, we report a highly γ-selective and enantioselective insertion into N–H bonds of aliphatic or aromatic secondary amines with vinyl substituted α-diazo pyrazoleamides using a high-spin chiral N,N′-dioxide/cobalt­(II) complex catalyst. The method affords a wide variety of valuable optically active Z- and E-type vinyl γ-amino amides. Calculation reveals a spin state change from the quartet cobalt­(II) complex to a doublet Co­(II)-carbene species for facile Z-selective and enantioselective nucleophilic addition.

ObjectivesTo summarize recommendations of existing guidelines on the treatment of upper respiratory tract infections (URTIs) in children, and to assess the methodological quality of these guidelines.MethodsWe searched seven databases and web sites of relevant academic agencies. Evidence-based guidelines on pediatric URTIs were included. AGREE II was used to assess the quality of these guidelines. Two researchers selected guidelines independently and extracted information on publication years, institutions, target populations, recommendations, quality of evidence, and strength of recommendations. We compared the similarities and differences of recommendations and their strength. We also analyzed the reasons for variation.ResultsThirteen guidelines meeting our inclusion criteria were included. Huge differences existed among these 13 guidelines concerning the categorization of evidence and recommendations. Nearly all of these guidelines lacked the sufficient involvement of stake holders. Further, the applicability of these guidelines still needs to be improved. In terms of recommendations, penicillin and amoxicillin were suggested for group A streptococcal pharyngitis. Amoxicillin and amoxicillin-clavulanate were recommended for acute bacterial rhinosinusitis (ABRS). An observation of 2–3 days prior to antibiotic therapy initiation for mild acute otitis media (AOM) was recommended with amoxicillin as the suggested first choice agent. Direct evidence to support strong recommendations on the therapy for influenza is still lacking. In addition, the antimicrobial durations for pharyngitis and ABRS were still controversial. No consensus was reached for the onset of antibiotics for ABRS in children.ConclusionsFuture guidelines should use a consistent grading system for the quality of evidence and strength of recommendations. More effort needs to be paid to seek the preference of stake holders and to improve the applicability of guidelines. Further, there are still areas in pediatric URTIs that need more research.

Marine bacteria play a key role in marine ecosystems and are one of the main causes of biofouling. Biofouling of adsorbents that are used for uranium recovery usually results in a decrease in uranium recovery. A novel adsorbent with antibacterial activity for uranium recovery in bacterial environments was prepared in our study to address this concern. Amidoxime-functionalized wool fibers with nano-TiO2 particles (Wool-AO@TiO2) was synthesized by radiation-induced graft polymerization combined with in situ coprecipitation of nano-TiO2 particles onto the wool fibers. The presence of nano-TiO2 on the adsorbent was verified by scanning electron microscopy with energy-dispersive X-ray spectroscopy. The maximum uranium adsorption capacity of Wool-AO@TiO2, acquired from the Langmuir isotherm, was 113.12 mg/g. The introduced nano-TiO2 imparted excellent antibacterial activity to Wool-AO@TiO2. The inhibition of Staphylococcus aureus and Escherichia coli by Wool-AO@TiO2 was 95.2% and 90%, respectively. The adsorption capacity was mostly unaffected in bacterial environments, even after four cycles of culturing with bacteria. These results suggest that the prepared Wool-AO@TiO2 adsorbent may promote the development of novel antifouling adsorbents for uranium recovery from seawater.

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