Small molecules containing 1,1-dimethylcyclopropanes are prevalent throughout nature but are difficult to synthesize using state-of-the-art metal-catalyzed carbene transfer methods without competing 1,2-hydride shifts. Herein, we introduce a mechanistically distinct platform to transfer 1,1-dialkylcarbene units to olefins using carbometalation reactions of dialkyl sulfonyl anions. In the presence of NaNH or -BuLi in ethereal solvents, dialkyl sulfones react with styrenes and arylbutadienes between 23 and 70 °C to produce the corresponding 1,1-dialkylcyclopropanes.
View Article and Find Full Text PDFObjectives: Evidence on the effectiveness and safety of fingolimod in real-world clinical practice in the Middle East and North African (MENA) region is limited. This study aimed to evaluate the effectiveness and safety of fingolimod in patients with relapsing-remitting multiple sclerosis (RRMS) in real-world setting in the MENA region.
Patients And Methods: RRMS patients who had been treated with fingolimod for at least 12 months were retrospectively identified from the databases of 34 centers across the MENA region.
Polyphosphate, an energy-rich polymer conserved in all kingdoms of life, is integral to many cellular stress responses, including nutrient deprivation, and yet, the mechanisms that underlie its biological roles are not well understood. In this work, we elucidate the physiological function of this polymer in the acclimation of the model alga to nutrient deprivation. Our data reveal that polyphosphate synthesis is vital to control cellular adenosine 5'-triphosphate homeostasis and maintain both respiratory and photosynthetic electron transport upon sulfur deprivation.
View Article and Find Full Text PDFDisulfide heterogeneity and other non-native crosslinks introduced during therapeutic antibody production and storage could have considerable negative effects on clinical efficacy, but tracking these modifications remains challenging. Analysis must also be carried out cautiously to avoid introduction of disulfide scrambling or reduction, necessitating the use of low pH digestion with less specific proteases. Herein we demonstrate that 213 nm ultraviolet photodissociation streamlines disulfide elucidation through bond-selective dissociation of sulfur-sulfur and carbon-sulfur bonds in combination with less specific backbone dissociation.
View Article and Find Full Text PDFWe report two cases of neuromyelitis optica spectrum disorder (NMOSD) who were misdiagnosed as multiple sclerosis (MS) and developed catastrophic relapses following initiation of dimethyl fumarate. Both patients developed a severe myelitis extending from the cervical cord to the medulla with significant cord swelling, resulting in complete quadriplegia and respiratory difficulties, in addition to severe bilateral visual loss in one patient. It is of note that both catastrophic relapses occurred 2 and 3 months following initiation of dimethyl fumarate.
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