Boryl radical catalysis enables asymmetric radical cycloisomerization reactions.

The development of functionally distinct catalysts for enantioselective synthesis is a prominent yet challenging goal of synthetic chemistry. In this work, we report a family of chiral -heterocyclic carbene (NHC)-ligated boryl radicals as catalysts that enable catalytic asymmetric radical cycloisomerization reactions. The radical catalysts can be generated from easily prepared NHC-borane complexes, and the broad availability of the chiral NHC component provides substantial benefits for stereochemical control.

Sequential C-F bond functionalizations of trifluoroacetamides and acetates via spin-center shifts.

Defluorinative functionalization of readily accessible trifluoromethyl groups constitutes an economical route to partially fluorinated molecules. However, the controllable replacement of one or two fluorine atoms while maintaining high chemoselectivity remains a formidable challenge. Here we describe a general strategy for sequential carbon-fluorine (C-F) bond functionalizations of trifluoroacetamides and trifluoroacetates.

Direct Csp-H methylenation of 2-arylacetamides using DMF/MeNH-BH as the methylene source.

A direct Csp3-H methylenation of 2-arylacetamides using DMF/Me2NH-BH3 as the methylene source was developed. The formyl group of DMF delivered the carbon and one hydrogen atoms, and the Me2NH-BH3 donated the remaining one hydrogen atom. This protocol offers a new alternative to make useful 2-arylacrylamides from simple starting materials.

CRMP2 and CRMP4 Are Differentially Required for Axon Guidance and Growth in Zebrafish Retinal Neurons.

Axons are directed to their correct targets by guidance cues during neurodevelopment. Many axon guidance cues have been discovered; however, much less known is about how the growth cones transduce the extracellular guidance cues to intracellular responses. Collapsin response mediator proteins (CRMPs) are a family of intracellular proteins that have been found to mediate growth cone behavior ; however, their roles in axon development are much less explored.

Thomsen-Friedenreich activation in infants with necrotizing enterocolitis in Taiwan.

Background: Thomsen-Friedenreich (T) activation in infants with neonatal necrotizing enterocolitis (NEC) has in some cases led to severe hemolysis after transfusions of plasma-containing blood components, causing some authors to advise routine screening for T activation in all infants with NEC. However, no data are available on the frequency of T activation in infants with NEC in Taiwan.

Study Design And Methods: We retrospectively reviewed the medical records of 43 infants with NEC managed in our hospital from 2000 to 2007.

[The analysis of fundus fluorescein angiography, indocyanine green angiography and hemodynamics of retrobulbar blood vessels in central serous chorioretinopathy].

Objective: To analyze the characteristics of the retrobulbar blood vessels' hemodynamics changes and the choroidal circulation disorder, and to observe the relations between retinal pigment epithelium's (RPE) pathological changes and them.

Methods: It was a case control study. For 57 (57 affected eyes and 57 contralateral eyes) unilateral eye affected patients and 25 (50 eyes) normal health adults, we examined ophthalmic arteries (OA), posterior ciliary arteries (PCA) and short posterior ciliary arteries (SPCA) by color Doppler flow Imaging (CDFI), and recorded the peak systolic velocities (PSV), end diastolic velocities (EDV) and resistance indexes (RI) of them.

Anti-"Mi(a)" immunization is associated with HLA-DRB1*0901.

Background: Anti-"Mi(a)" is one of the most important irregular red blood cell antibodies found in Taiwan. The aim of this study was to investigate whether specific HLA-DRB1 alleles are associated with anti-"Mi(a)" production.

Study Design And Methods: A case-control retrospective study was performed on 68 patients showing presence of anti-"Mi(a)" and 219 unrelated control subjects from the Mackay Memorial Hospital.

Primary autoimmune neutropenia in children in Taiwan.

Background: Autoimmune neutropenia in children is caused by granulocyte-specific autoantibodies. These antibodies react to the patient's own neutrophils but disappear when the neutropenia spontaneously remits. This study reviewed our experience with autoimmune neutropenia in children and investigated possible associations with HLA-DR and HLA-DQ alleles.

Structure-activity study on the spatial arrangement of the third aromatic ring of endomorphins 1 and 2 using an atypical constrained C terminus.

The discovery of endomorphins (EMs) has opened the possibility of searching for new analgesics. However, the design of peptide analgesics has proven to be very difficult as a result of their conformational flexibility and a lack of clarity in structure-activity relationships (SAR). In EMs, the amino acid side chains exhibit considerable conformational flexibility, especially in the third aromatic ring, which is free to adopt a bioactive conformation.