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81.
Paweł Górnaś Inga Mišina Ilze Grāvīte Arianne Soliven Edīte Kaufmane Dalija Segliņa 《Natural product research》2015,29(13):1222-1227
Composition of tocochromanols in kernels recovered from 16 different apricot varieties (Prunus armeniaca L.) was studied. Three tocopherol (T) homologues, namely α, γ and δ, were quantified in all tested samples by an RP-HPLC/FLD method. The γ-T was the main tocopherol homologue identified in apricot kernels and constituted approximately 93% of total detected tocopherols. The RP-UPLC-ESI/MSn method detected trace amounts of two tocotrienol homologues α and γ in the apricot kernels. The concentration of individual tocopherol homologues in kernels of different apricots varieties, expressed in mg/100 g dwb, was in the following range: 1.38–4.41 (α-T), 42.48–73.27 (γ-T) and 0.77–2.09 (δ-T). Moreover, the ratio between individual tocopherol homologues α:γ:δ was nearly constant in all varieties and amounted to approximately 2:39:1. 相似文献
82.
Dai T Tegos GP St Denis TG Anderson D Sinofsky E Hamblin MR 《Photochemistry and photobiology》2011,87(1):250-255
Central venous catheters (CVC) are widely used in the United States and are associated with 250,000 to 500,000 CVC-related infections in hospitals annually. We used a catheter made from ultraviolet-C (UVC) transmissive material to test whether delivery of UVC from the lumen would allow inactivation of microorganisms on the outer surface of CVC. When the catheter was exposed to UVC irradiation from a cold cathode fluorescent lamp inside the catheter lumen at a radiant exposure of 3.6 mJ cm(-2) , more than 6-log(10) of drug-resistant Gram-positive bacteria adhered to the outer surface of the catheter were inactivated. Three to 7-log(10) of drug-resistant Gram-negative bacteria and 2.80-log(10) of fungi were inactivated at a radiant exposure of 11 mJ cm(-2).UVC irradiation also offered a highly selective inactivation of bacteria over keratinocytes under exactly comparable conditions. After 11 mJ cm(-2) UVC light had been delivered, over 6-log(10) of bacteria were inactivated while the viability loss of the keratinocytes was only about 57%. 相似文献
83.
Strotman NA Baxter CA Brands KM Cleator E Krska SW Reamer RA Wallace DJ Wright TJ 《Journal of the American Chemical Society》2011,133(21):8362-8371
The first example of an intramolecular asymmetric reductive amination of a dialkyl ketone with an aliphatic amine has been developed for the synthesis of Suvorexant (MK-4305), a potent dual Orexin antagonist under development for the treatment of sleep disorders. This challenging transformation is mediated by a novel Ru-based transfer hydrogenation catalyst that provides the desired diazepane ring in 97% yield and 94.5% ee. Mechanistic studies have revealed that CO(2), produced as a necessary byproduct of this transfer hydrogenation reaction, has pronounced effects on the efficiency of the Ru catalyst, the form of the amine product, and the kinetics of the transformation. A simple kinetic model explains how product inhibition by CO(2) leads to overall first-order kinetics, but yields an apparent zero-order dependence on initial substrate concentration. The deleterious effects of CO(2) on reaction rates and product isolation can be overcome by purging CO(2) from the system. Moreover, the rate of ketone hydrogenation can be greatly accelerated by purging of CO(2) or trapping with nucleophilic secondary amines. 相似文献
84.
A high-throughput microfluidic assay to study neurite response to growth factor gradients 总被引:1,自引:0,他引:1
Kothapalli CR van Veen E de Valence S Chung S Zervantonakis IK Gertler FB Kamm RD 《Lab on a chip》2011,11(3):497-507
Studying neurite guidance by diffusible or substrate bound gradients is challenging with current techniques. In this study, we present the design, fabrication and utility of a microfluidic device to study neurite guidance under chemogradients. Experimental and computational studies demonstrated the establishment of a steep gradient of guidance cue within 30 min and stable for up to 48 h. The gradient was found to be insensitive to external perturbations such as media change and movement of device. The effects of netrin-1 (0.1-10 μg mL(-1)) and brain pulp (0.1 μL mL(-1)) were evaluated for their chemoattractive potential on neurite turning, while slit-2 (62.5 or 250 ng mL(-1)) was studied for its chemorepellant properties. Hippocampal or dorsal root ganglion (DRG) neurons were seeded into a micro-channel and packed onto the surface of a 3D collagen gel. Neurites grew into the matrix in three dimensions, and a gradient of guidance cue was created orthogonal to the direction of neurite growth to impact guidance. The average turning angle of each neurite was measured and averaged across multiple devices cultured under similar conditions to quantify the effect of guidance cue gradient. Significant positive turning towards gradient was measured in the presence of brain pulp and netrin-1 (1 μg mL(-1)), relative to control cultures which received no external guidance cue (p < 0.001). Netrin-1 released from transfected fibroblasts had the most positive turning effect of all the chemoattractive cues tested (p < 0.001). Slit-2 exhibited strong chemorepellant characteristics on both hippocampal and DRG neurite guidance at 250 ng mL(-1) concentration. Slit-2 also showed similar behavior on DRG neuron invasion into 3D collagen gel (p < 0.01 relative to control cultures). Taken together, the results suggest the utility of this microfluidic device to generate stable chemogradients for studying neurobiology, cell migration and proliferation, matrix remodeling and co-cultures with other cell lines, with potential applications in cancer biology, tissue engineering and regenerative medicine. 相似文献
85.
86.
H. Erdmann H. Mennicke G. Romijn A. Fernau L. Spiegel Adrian und Ed. Schaer 《Fresenius' Journal of Analytical Chemistry》1902,41(11):703-706
Ohne Zusammenfassung 相似文献
87.
88.
Some fundamental fixed point theorems are proved for locally convex spaces whose generating family of seminorms satisfies the parallelogram law. 相似文献
89.
90.
We prove that Λ∞(α) × Λ1(β) has a regular basis iff Λ∞(α) ? Λ1(β) has a regular basis iff Λ∞(α) ? Λ1(β) is isomorphic to a Cartesian product of two power series spaces. We give a simple condition on α, β which determines when these equivalent statements hold. 相似文献