Two optically active (100% enantiomeric excess) isomers of ofloxacin [(+/-)-ofloxacin; DL-8280; (+/-)-9-fluoro-2,3-dihydro-3-methyl-10-(4-methyl-1-piperazinyl)-7-oxo-7 H-pyrido[1,2,3-de] [1,4] benzoxazine-6-carboxylic acid] were prepared by use of their optically resolved synthetic intermediates. One of the isomers, (-)-ofloxacin, was 8 to 128 times more potent in inhibiting the multiplication of gram-positive and gram-negative bacteria than the other, (+)-ofloxacin, and approximately two times more active than the racemate, (+/-)-ofloxacin.

Raman spectra of graphene nanoribbons with zigzag and armchair edges are calculated within non-resonant Raman theory. Depending on the edge structure and polarization direction of the incident and scattered photon beam relative to the edge direction, a symmetry selection rule for the phonon type appears. These Raman selection rules will be useful for the identification of the edge structure of graphene nanoribbons.

Using surface and interference co-enhanced Raman scattering measurements, we detected two welldistinguished Raman bands at 1450 and 1530 cm −1 from individual mono-and few-layer graphene nanoribbons ͑GNRs͒ prepared by chemical exfoliation and mechanical cleavage of graphite. The intensities of these two peaks strongly depend on the width and edge structure of the GNRs. Combining with first-principles calculations, the 1450 and 1530 cm −1 Raman bands are assigned to the localized vibration of the edge atoms of zigzag and armchair GNRs terminated with H atoms, respectively. In addition, two weak peaks at ϳ1140 and 1210 cm −1 are also observed, which are coupled with 1450 and 1530 cm −1 , respectively. These findings enrich the understanding on the fine structure of mono-and few-layer GNRs by Raman spectroscopy.

The evolutionary strategy of transferring maternal antibodies via milk profoundly impacts the survival, lifelong health, and wellbeing of all neonates, including a pronounced impact on human breastfeeding success and infant development. While there has been increased recognition that interorgan connectivity influences the quality of a mother's milk, potentially to personalize it for her offspring, the underlying bases for these processes are incompletely resolved. Here, we define an essential role of Peyer's patches (PPs) for the generation of plasma cells that secrete maternal immunoglobulin A (IgA) into milk. Our metagenomic analysis reveals that the presence of certain residential microorganisms in the gastrointestinal (GI) tract, such as Bacteroides acidifaciens and Prevotella buccalis, is indispensable for the programming of maternal IgA synthesis prior to lactational transfer. Our data provide important insights into how the microbiome of the maternal GI environment, specifically through PPs, can be communicated to the next generation via milk.

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