Nanoscale metal–organic frameworks (NMOFs) have proven to be a class of promising drug carriers as a result of their high porosity, crystalline nature with definite structure information, and ...potential for further functionality. However, MOF‐based drug carriers with active tumor‐targeting function have not been extensively researched until now. Here we show a strategy for constructing active tumor‐targeted NMOF drug carriers by anchoring functional folic acid (FA) molecules onto the metal clusters of NMOFs. Two zirconium‐based MOFs, MOF‐808 and NH2‐UiO‐66, were chosen as models to reduce to the nanoscale for application as drug carriers, and then the terminal carboxylates of FA molecules were coordinated to Zr6 clusters on the surfaces of the nanoparticles by substitution of the original formate or terminal ‐OH ligands. The successful modification with FA was confirmed by solid‐state 13C MAS NMR and UV/Vis spectroscopy and other characterization methods. Drug loading and controlled release behavior at different pH were determined by utilizing the anticancer drug 5‐fluorouracil (5‐FU) as the model drug. Confocal laser scanning microscopy measurements further demonstrated that 5‐FU‐loaded FA‐NMOFs have excellent targeting ability through the efficient cellular uptake of FA‐NMOFs. This work opens up a new avenue to the construction of active tumor‐targeted NMOF‐based drug carriers with potential for cancer therapies.
Targeted drug delivery: Nanoscale metal–organic frameworks modified with folic acid (FA‐NMOFs) have been prepared as potential drug carriers for targeted delivery to tumor cells (see figure). The anticancer drug 5‐fluorouracil (5‐FU) was encapsulated in the pores of the FA‐NMOFs. The 5‐FU‐loaded FA‐NMOFs showed excellent biocompatibility and were found to effectively kill tumor cells through the targeting effect of the FA‐NMOFs.
Covalent‐organic frameworks (COFs) have been recognized as a new type of promising photocatalysts for hydrogen evolution. To investigate how different functional groups attached in the backbone of ...COFs affect the overall photocatalytic H2 evolution, for the first time, we selected and synthesized a series of ketoenamine‐based COFs with the same host framework as model system. It includes TpPa−COF−X (X=−H, −(CH3)2, and −NO2) with three different groups attached in the backbone of TpPa−COF. We systematically investigated the differences in morphology, light‐absorption intensity and band gap of these 2D COFs. The results of photocatalytic H2 evolution measurements indicate that the TpPa−COF−(CH3)2 shows the best activity, while the activity of TpPa−COF−NO2 is relatively low compared to that of other two COFs in the system. Moreover, the separation ability of photogenerated charge was also followed the order of TpPa−COF−(CH3)2>TpPa−COF>TpPa−COF−NO2. The best photocatalytic H2 production performance of TpPa−COF−(CH3)2 in these systems should be mainly attributed to the better electron‐donating ability of −CH3 groups compared to −H or −NO2 group, which result in more efficient charge transferring in the inner of the material. This work demonstrates that reasonably adding electron‐donating group in TpPa−COFs can lead to a better photocatalytic H2 evolution activity, and which is meaningful for further design of efficient COF‐based photocatalysts for H2 evolution.
Photocatalysis: A series ketoenamine‐based COFs of TpPa−COF−X (X=−H, −(CH3)2, and −NO2) exhibit significant difference on the visible light absorbance and efficiency of photocatalytic H2 evolution, which can be attributed to strengthen charge carrier mobilities both in‐plane and in the stacking direction because of the electron‐donating groups.
Breast cancer (BC) and prostate cancer (PC) are the second most common malignant tumors in women and men in western countries, respectively. The risks of death are 14% for BC and 9% for PC. Abnormal ...estrogen and androgen levels are related to carcinogenesis of the breast and prostate. Estradiol stimulates cancer development in BC. The effect of estrogen on PC is concentration‐dependent, and estrogen can regulate androgen production, further affecting PC. Estrogen can also increase the risk of androgen‐induced PC. Androgen has dual effects on BC via different metabolic pathways, and the role of the androgen receptor (AR) in BC also depends on cell subtype and downstream target genes. Androgen and AR can stimulate both primary PC and castration‐resistant PC. Understanding the mechanisms of the effects of estrogen and androgen on BC and PC may help us to improve curative BC and PC treatment strategies.
Abnormal levels of estrogen and androgen are related to carcinogenesis of the breast and prostate. For breast cancer, estradiol stimulates cancer development. The effect of estrogen on prostate cancer was estrogen concentration‐dependent. Androgen had dual effects on breast cancer in different metabolic pathways, and the role of the androgen receptor on breast cancer is also dependent on cell subtype and downstream target genes. While both primary prostate cancer and castration‐resistant prostate cancer can be stimulated by androgen and androgen receptor.
"Strain engineering" in functional materials has been widely explored to tailor the physical properties of electronic materials and improve their electrical and/or optical properties. Here, we ...exploit both in plane and out of plane uniaxial tensile strains in MoS2 to modulate its band gap and engineer its optical properties. We utilize X-ray diffraction and cross-sectional transmission electron microscopy to quantify the strains in the as-synthesized MoS2 nanosheets and apply measured shifts of Raman-active modes to confirm lattice strain modification of both the out-of-plane and in-plane phonon vibrations of the MoS2 nanosheets. The induced band gap evolution due to in-plane and out-of-plane tensile stresses is validated by photoluminescence (PL) measurements, promising a potential route for unprecedented manipulation of the physical, electrical and optical properties of MoS2.
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•For the first time, we designed and constructed a series of Ni(OH)2-modified COFs.•Ni(OH)2 acts as noble-metal free cocatalyst in catalyst system.•Ni(OH)2-X%/TpPa-2 photocatalyst is ...comparable to Pt-containing COF-based catalyts.•Ni(OH)2-X%/TpPa-2 photocatalysts master a high rate of electron transport.•The synergistic effect of TpPa-2 and Ni(OH)2 has been systematic studied.
Covalent-organic frameworks (COFs) have been recognized as an emerging type of photocatalysts for H2 evolution and some of them have shown really outstanding photocatalytic activity with the help of Pt co-catalyst. To avoid the utilization of noble metal in COF-based photocatalysts, for the first time, we designed and constructed a series of nickel hydroxide-modified COF (TpPa-2) composite materials Ni(OH)2-X%/TpPa-2 (X: molar fraction of Ni(OH)2), which show apparently improved photocatalytic H2 evolution activity than that of the parent COF and the activity is comparable to that with Pt (0.3 wt%) co-catalyst. A series of Ni(OH)2-X%/TpPa-2 were prepared by in-situ adding TpPa-2 into the reaction system of Ni(OH)2, and the resulting Ni(OH)2-X%/TpPa-2 exhibit a novel sandwich-like morphology. The results of photocatalytic hydrogen evolution under visible light irradiation show that the optimized photocatalytic H2-evolution rate for Ni(OH)2–2.5%/TpPa-2 is up to 1895.99 μmol·h−1·g−1, which is about 26.3 times higher than that of the parent TpPa-2 and is one of the best performing 2D COF-based photocatalyst for H2 evolution. Further investigation confirm the improved activity should be attributed to the enhanced visible-light absorption of the composite materials contributed from Ni(OH)2 and the synergetic effect of Ni(OH)2 and metallic Ni derived from the in-situ reduction of Ni(OH)2, which promoted the separation of photogenerated electron–holes of the resulting materials. This work not only presents a series of new photocatalysts for efficient H2 evolution but also open an avenue for future design and synthesis of COF-based composite materials acting as a substitute of noble-metal-containing photocatalytic systems.
Solid superbases can catalyze diverse reactions under mild conditions, while they suffer from aggregation of basic sites and poor stability during recycling. Here we report a new generation of solid ...superbases derived from K single atoms (SAs) prepared by a tandem redox strategy. The initial redox reaction takes place between base precursor KNO3 and graphene support, producing K2O at 400 °C. Further increasing the temperature to 800 °C, the graphene reduces K2O to K anchored by its vacancies, leading to the generation of K SAs (denoted as K1/G). The source of basicity in the K1/G is K SAs, and neighboring single atoms (NSAs) possess superbasicity, which is different from conventional basicity originated from oxygen and nitrogen atoms. Due to the superbasicity as well as high dispersion and anchoring of basic sites, the K1/G shows excellent catalytic activity and stability in transesterification reaction, which is much superior to the reported catalysts.
A new generation of solid superbase derived from potassium single atoms anchored on graphene is developed by a tandem redox strategy. The source of the basicity is the single K atoms, thus differing from conventional basicity which originates from oxygen and nitrogen atoms. The high dispersion and anchoring of superbasic sites endows the catalyst with excellent activity and stability in transesterification reactions.
Thyroid dysfunction is associated with cardiovascular diseases. However, the role of thyroid function in lipid metabolism remains partly unknown. The present study aimed to investigate the causal ...association between thyroid function and serum lipid metabolism via a genetic analysis termed Mendelian randomization (MR).
The MR approach uses a genetic variant as the instrumental variable in epidemiological studies to mimic a randomized controlled trial. A two-sample MR was performed to assess the causal association, using summary statistics from the Atrial Fibrillation Genetics Consortium (n = 537,409) and the Global Lipids Genetics Consortium (n = 188,577). The clinical measures of thyroid function include thyrotropin (TSH), free triiodothyronine (FT3) and free thyroxine (FT4) levels, FT3:FT4 ratio and concentration of thyroid peroxidase antibodies (TPOAb). The serum lipid metabolism traits include total cholesterol (TC) and triglycerides, high-density lipoprotein, and low-density lipoprotein (LDL) levels. The MR estimate and MR inverse variance-weighted method were used to assess the association between thyroid function and serum lipid metabolism.
The results demonstrated that increased TSH levels were significantly associated with higher TC (β = 0.052, P = 0.002) and LDL (β = 0.041, P = 0.018) levels. In addition, the FT3:FT4 ratio was significantly associated with TC (β = 0.240, P = 0.033) and LDL (β = 0.025, P = 0.027) levels. However, no significant differences were observed between genetically predicted FT4 and TPOAb and serum lipids.
Taken together, the results of the present study suggest an association between thyroid function and serum lipid metabolism, highlighting the importance of the pituitary-thyroid-cardiac axis in dyslipidemia susceptibility.
The assumption of conditional independence between the responses and the response times (RTs) for a given person is common in RT modeling. However, when the speed of a test taker is not constant, ...this assumption will be violated. In this article we propose a conditional joint model for item responses and RTs, which incorporates a covariance structure to explain the local dependency between speed and accuracy. To obtain information about the population of test takers, the new model was embedded in the hierarchical framework proposed by van der Linden (2007). A fully Bayesian approach using a straightforward Markov chain Monte Carlo (MCMC) sampler was developed to estimate all parameters in the model. The deviance information criterion (DIC) and the Bayes factor (BF) were employed to compare the goodness of fit between the models with two different parameter structures. The Bayesian residual analysis method was also employed to evaluate the fit of the RT model. Based on the simulations, we conclude that (1) the new model noticeably improves the parameter recovery for both the item parameters and the examinees' latent traits when the assumptions of conditional independence between the item responses and the RTs are relaxed and (2) the proposed MCMC sampler adequately estimates the model parameters. The applicability of our approach is illustrated with an empirical example, and the model fit indices indicated a preference for the new model.
Background
In most situations, many patients undergoing coronary artery bypass graft (CABG) are on dual antiplatelet therapy (DAPT), which is also required after CABG. The adjustment of antiplatelet ...strategy remains controversial. In this study, we systematically review current guidelines, seeking consensus and controversies to facilitate clinical practice.
Methods and Results
Guidelines are searched in PubMed, Embase, ECRI Guidelines Trust and websites of guidelines organizations and professional society. Guidelines with recommendations of DAPT for patients undergo CABG are included. Two reviewers appraised guidelines with the Appraisal of Guidelines for Research and Evaluation II (AGREE II). Relevant recommendations are extracted and summarized. A total of 14 guidelines meeting inclusion criteria are selected, with average AGREE II scores from 44% to 86%. Most guidelines score high in domains other than ‘applicability’. Many guidelines are not detailed enough in reporting considerations behind recommendations. Current guidelines are consistent on the management of antiplatelet strategy before elective CABG and using DAPT after surgery for preventing graft vessel occlusion. Evidence is still lacking in urgent CABG and resumption of the previous DAPT after surgery.
Conclusions
Current guidelines on DAPT in CABG are generally satisfying. Suspending P2Y12 inhibitors while aspirin continued before elective CABG is recommended, as well as 12 months of DAPT following CABG. More evidence is needed to guide antiplatelet therapy in urgent CABG and to prove the benefits of resuming previous DAPT.
Composites are usually better than a single material because they combine advantages of their component materials and, as a result, achieve better performance. Using a high temperature sulfuration ...process, a Co1−xS/ZnS@C composite was successfully synthesized by using a 3D disordered polystyrene spheres (PS) template coated on metal-organic framework (ZIF) precursor. The Co1−xS/ZnS in the composite was firmly encapsulated by C that came from the 3D disordered PS template. The carbon can efficiently reduce the volume expansion triggered by metal sulfide particles during the charge/discharge process. Furthermore, due to a synergistic effect between the composite's components, the Co1−xS/ZnS@C composite displays better cycling performance and rate capacity compared to Co1−xS@C and ZnS@C. The Co1−xS/ZnS@C composite electrode showed a higher stable capacity of ~586 mAh g−1 after ~100 cycles with a current density is 0.3 A/g and it also exhibited a more excellent rate capability compare with Co1−xS@C and ZnS@C.
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•A new Co1−xS/ZnS@C structure is presented and applied to lithium ion storage.•The C from polystyrene can effectively reduce the volume expansion of composites.•Vacancy engineering and synergetic effect brings a better electrochemical performance.
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