Local quantification of mesoporous silica microspheres using multiscale electron tomography and lattice Boltzmann simulations

The multiscale pore structure of mesoporous silica microspheres plays an important role for tuning mass transfer kinetics in technological applications such as liquid chromatography. While local analysis of a pore network in such materials has been previously achieved, multiscale quantification of microspheres down to the nanometer scale pore level is still lacking. Here we demonstrate for the first time, by combining low convergence angle scanning transmission electron microscopy tomography (LC-STEM tomography) with image analysis and lattice Boltzmann simulations, that the multiscale pore network of commercial mesoporous silica microspheres can be quantified. This includes comparing the local tortuosity and intraparticle diffusion coefficients between different regions within the same microsphere. The results, spanning more than two orders of magnitude between nanostructures and entire object, are in good agreement with bulk characterization techniques such as nitrogen gas physisorption and add valuable local information for tuning mass transfer behavior (in liquid chromatography or catalysis) on the single microsphere level

ARDD 2020: from aging mechanisms to interventions

Aging is emerging as a druggable target with growing interest from academia, industry and investors. New technologies such as artificial intelligence and advanced screening techniques, as well as a strong influence from the industry sector may lead to novel discoveries to treat age-related diseases. The present review summarizes presentations from the 7th Annual Aging Research and Drug Discovery (ARDD) meeting, held online on the 1st to 4th of September 2020. The meeting covered topics related to new methodologies to study aging, knowledge about basic mechanisms of longevity, latest interventional strategies to target the aging process as well as discussions about the impact of aging research on society and economy. More than 2000 participants and 65 speakers joined the meeting and we already look forward to an even larger meeting next year. Please mark your calendars for the 8th ARDD meeting that is scheduled for the 31st of August to 3rd of September, 2021, at Columbia University, USA

Response of selected antioxidants and pigments in tissues of Rosa hybrida and Fuchsia hybrida to supplemental UV-A exposure

The effect of supplemental UV-A (320-400 nm) radiation on tissue absorption at 355 nm, levels of various antioxidants (ascorbate, glutathione, carotenoids and flavonoids) and of antioxidant scavenging capacity were investigated with leaves and petals of Rosa hybrida, cv. Honesty and with leaves, petals and sepals of Fuchsia hybrida, cv. Dollarprinzessin. Supplemental UV-A did not result in visible changes in plant morphology of either species. In leaves it induced small increases in levels of chlorophylls a and b, the carotenoids antheraxanthin, lutein and -carotene, and high increases in the flavonols quercetin and kaempferol. Petals hardly responded, while the coloured sepals of fuchsia showed an increase in quercetin derivatives. HPLC of unhydrolysed flavonoids showed that individual quercetin derivatives in leaves of both species and kaempferol derivatives in rose leaves increased 2-fold. Some kaempferol derivatives in fuchsia leaves were more than 2-fold enhanced or were newly induced by supplemental UV-A. Increases in l-ascorbic acid levels in fuchsia leaves, and decreases in rose leaves as result of supplemental UV-A were observed, but differences appeared statistically not significant, while l-ascorbate levels remained unchanged in the other tissues investigated. Anthocyanins and reduced glutathione levels were unaffected in all tissues. The combined UV-A induced increases in concentrations of these antioxidant species, did not lead to significant increases in antioxidant capacity of tissues, measured as Trolox equivalents in 50¿zthanol extracts. Light absorption at 355 nm of leaf extracts was significantly increased upon UV-A exposure. Our results indicate that the major protection towards UV-A exposure, in particular in the leaves, will originate from absorption of irradiation, and not from scavenging reactive oxygen species

Response of selected antioxidants and pigments in tissues of Rosa hybrida and Fuchsia hybrida to supplemental UV-A exposure

The effect of supplemental UV-A (320-400 nm) radiation on tissue absorption at 355 nm, levels of various antioxidants (ascorbate, glutathione, carotenoids and flavonoids) and of antioxidant scavenging capacity were investigated with leaves and petals of Rosa hybrida, cv. Honesty and with leaves, petals and sepals of Fuchsia hybrida, cv. Dollarprinzessin. Supplemental UV-A did not result in visible changes in plant morphology of either species. In leaves it induced small increases in levels of chlorophylls a and b, the carotenoids antheraxanthin, lutein and -carotene, and high increases in the flavonols quercetin and kaempferol. Petals hardly responded, while the coloured sepals of fuchsia showed an increase in quercetin derivatives. HPLC of unhydrolysed flavonoids showed that individual quercetin derivatives in leaves of both species and kaempferol derivatives in rose leaves increased 2-fold. Some kaempferol derivatives in fuchsia leaves were more than 2-fold enhanced or were newly induced by supplemental UV-A. Increases in l-ascorbic acid levels in fuchsia leaves, and decreases in rose leaves as result of supplemental UV-A were observed, but differences appeared statistically not significant, while l-ascorbate levels remained unchanged in the other tissues investigated. Anthocyanins and reduced glutathione levels were unaffected in all tissues. The combined UV-A induced increases in concentrations of these antioxidant species, did not lead to significant increases in antioxidant capacity of tissues, measured as Trolox equivalents in 50¿zthanol extracts. Light absorption at 355 nm of leaf extracts was significantly increased upon UV-A exposure. Our results indicate that the major protection towards UV-A exposure, in particular in the leaves, will originate from absorption of irradiation, and not from scavenging reactive oxygen species

Expression and functional activity of the very late activation antigen-4 molecule on human natural killer cells in different states of activation

In the present study we describe the expression and functional activity of the α4β1 heterodimer molecule on human natural killer (NK) cells. Flow cytometric analyses showed that fresh and activated NK cells expressed high levels of very late activation antigen-4 (VLA-4) molecules. These cells bound to fibronectin (FN) and to its 38 000-MW proteolytic fragment through the VLA-4 integrin that was blocked with HP2/1 anti-α4 monoclonal antibodies (mAbs) and with the FN peptide fragment CS1. No inhibitory effects were observed in the presence of anti-α5 mAb, FN peptide fragment CS2 or other irrelevant mAb. Fresh NK cells were unable to aggregate, despite their expression of VLA-4, and only activated (cultured and lymphocyte-activated killer cells) NK cells showed homotypic aggregation with HP1/7 and HP2/4 anti-α4 mAb related to cellular activation. These results underline new evidence of how NK cells in different states of activation maintain different constitutive levels of α4β1 integrin activity, and highlight the possibility of a different functional regulation by the cells bearing VLA-4, in the expression of these epitopes and their ability to interact with their ligands

Impact of the COVID-19-pandemic on patients with gynecological malignancies undergoing surgery: A Dutch population-based study using data from the ‘Dutch Gynecological Oncology Audit’

Objective: The COVID-19-pandemic caused drastic healthcare changes worldwide. To date, the impact of these changes on gynecological cancer healthcare is relatively unknown. This study aimed to assess the impact of the COVID-19-pandemic on surgical gynecological-oncology healthcare. Methods: This population-based cohort study included all surgical procedures with curative intent for gynecological malignancies, registered in the Dutch Gynecological Oncology Audit, in 2018–2020. Four periods were identified based on COVID-19 hospital admission rates: ‘Pre-COVID-19’, ‘First wave’, ‘Interim period’, and ‘Second wave’. Surgical volume, perioperative care processes, and postoperative outcomes from 2020 were compared with 2018–2019. Results: A total of 11,488 surgical procedures were analyzed. For cervical cancer, surgical volume decreased by 17.2% in 2020 compared to 2018–2019 (mean 2018–2019: n = 542.5, 2020: n = 449). At nadir (interim period), only 51% of the expected cervical cancer procedures were performed. For ovarian, vulvar, and endometrial cancer, volumes remained stable. Patients with advanced-stage ovarian cancer more frequently received neoadjuvant chemotherapy in 2020 compared to 2018–2019 (67.7% (n = 432) vs. 61.8% (n = 783), p = 0.011). Median time to first treatment was significantly shorter in all four malignancies in 2020. For vulvar and endometrial cancer, the length of hospital stay was significantly shorter in 2020. No significant differences in complicated course and 30-day-mortality were observed. Conclusions: The COVID-19-pandemic impacted surgical gynecological-oncology healthcare: in 2020, surgical volume for cervical cancer dropped considerably, waiting time was significantly shorter for all malignancies, while neoadjuvant chemotherapy administration for advanced-stage ovarian cancer increased. The safety of perioperative healthcare was not negatively impacted by the pandemic, as complications and 30-day-mortality remained stable