Figure 4. a) Guest exchange of TMOF-5(Br) with Eu 3+ .b)Emission spectra of 0.2 mol %-exchanged Eu 3+ @TMOF-5(Br) upon 340 nm excitation. c) CIE chromaticity coordinates of 0.2 mol %-exchanged Eu 3+ @TMOF-5(Br) and TMOF-5(Br).
Ultrafine gold nanoclusters (Au‐NCs) are susceptible to migrate and aggregate, even in the porosity of many crystalline solids. N‐heterocyclic carbenes (NHCs) are a class of structurally diverse ligands for the stabilization of Au‐NCs in homogeneous chemistry, showing catalytic reactivity in CO2 activation. Herein, for the first time, we demonstrate a heterogeneous nucleation approach to stabilize ultrasmall and highly dispersed gold nanoclusters in an NHC‐functionalized porous matrix. The sizes of gold nanoclusters are tunable from 1.3 nm to 1.8 nm based on the interpenetration of the metal‐organic framework (MOF) topology. Control experiments using amine or imidazolium‐functionalized MOFs afforded the aggregation of Au species. The resultant Au‐NC@MOF composite exhibits a steady and excellent activity in photocatalytic CO2 reduction, superior to control mixtures without NHC‐ligand stabilization. Mechanistic studies reveal the synergistic catalytic effect of MOFs and Au‐NCs through the MOF‐NHC‐Au covalent‐bonding bridges.
BackgroundThere is limited literature investigating the effects of body mass index (BMI) and androgen level on in vitro fertilization (IVF) outcomes with a gonadotropin-releasing hormone (GnRH)-antagonist protocol in polycystic ovary syndrome (PCOS). Androgen-related variation in the effect of body mass index (BMI) on IVF outcomes remains unknown.MethodsIn this retrospective study, 583 infertile women with PCOS who underwent IVF using the conventional GnRH-antagonist protocol were included. Patients were divided into four groups according to BMI and androgen level: overweight- hyperandrogenism(HA) group, n = 96, overweight-non-HA group, n = 117, non-overweight-HA group, n = 152, and non-overweight-non-HA group, n = 218.ResultsA significantly higher number of oocytes were retrieved, and the total Gn consumption as well Gn consumption per day was significantly lower, in the non-overweight groups than in the overweight groups. The number of available embryos was significantly higher in the HA groups than in the non-HA groups. Clinical pregnancy rate was of no significant difference among four groups. Live-birth rates in the overweight groups were significantly lower than those in non-overweight-non-HA group (23.9, 28.4% vs. 42.5%, P<0.05). The miscarriage rate in overweight-HA group was significantly higher than that in non-overweight-non-HA group (45.2% vs. 14.5%, P<0.05). Multivariate logistic regression analysis revealed that BMI and basal androstenedione (AND) both acted as significantly influent factors on miscarriage rate. The area under the curve (AUC) in receiver operating characteristic (ROC) analysis for BMI and basal AND on miscarriage rate were 0.607 (P = 0.029) and 0.657 (P = 0.001), respectively, and the cut-off values of BMI and basal AND were 25.335 kg/m2 and 10.95 nmol/L, respectively.ConclusionsIn IVF cycles with GnRH-antagonist protocol, economic benefits were seen in non-overweight patients with PCOS, with less Gn cost and more retrieved oocytes. BMI and basal AND were both significantly influential factors with moderate predictive ability on the miscarriage rate. The predictive value of basal AND on miscarriage was slightly stronger than BMI.
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