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To provide safe drinking water, fluoride in water must be removed and adsorption processes appear to be the most widely used method. Metal organic frameworks (MOFs) represent a new ...class of adsorbents that have been used in various adsorption applications. To study the adsorption mechanism of fluoride to MOFs in water and obtain related adsorption parameters, we synthesized a zirconium-based MOF with a primary amine group on its ligand, named UiO-66-NH2. The kinetics, adsorption isotherm and thermodynamics of fluoride adsorption to UiO-66-NH2 were investigated. The crystalline structure of UiO-66-NH2 remained intact and the local structure of zirconium in UiO-66-NH2 did not change significantly after being exposed to fluoride. The kinetics of the fluoride adsorption in UiO-66-NH2 could be well represented by the pseudo second order rate law. The enthalpy of the adsorption indicates that the F− adsorption to UiO-66-NH2 was classified as a physical adsorption. However, the comparison between the adsorption capacities of UiO-66-NH2 and UiO-66 suggests that the fluoride adsorption to UiO-66-NH2 might primarily involve a strong interaction between F− and the metal site. The fluoride adsorption capacity of UiO-66-NH2 was found to decrease when pH>7. While the presence of chloride/bromide ions did not noticeably change the adsorption capacity of UiO-66-NH2, the ionic surfactants slightly affected the adsorption capacity of UiO-66-NH2. These findings provide insights to further optimize the adsorption process for removal of fluoride using zirconium-based MOFs.
Complex hydrogels formed with chitosan (CS) and ring-opened polyvinyl pyrrolidone (roPVP) as a swellable mucoadhesive gastroretentive drug dosage form (smGRDDF) were prepared and characterized. ...CS/roPVP hydrogels were produced by blending CS with roPVP obtained by basic treatment of PVP. Effects of the heating time and NaOH concentration employed for preparing roPVP, and CS molecular weights (Mws), and roPVP/CS ratios on the swelling ability of the resultant hydrogels were characterized. Rheological characteristics were further examined. Results demonstrated that roPVP obtained in a 0.5 M NaOH solution heated to 50 °C for 4 h was suitable for producing complex hydrogels with CS. At a roPVP/CS ratio of 20:1, hydrogels composed of three different Mws of CS possessed optimal swelling and mucoadhesive abilities and rheological properties. In vitro dissolution revealed sustained drug release. A pharmacokinetic study exhibited that the plasma profile of alendronate followed a sustained manner with 3-fold enhancement of the oral bioavailability. In conclusion, the smGRDDF composed of CS/roPVP complex hydrogels was successfully developed and is potentially applicable to improve the clinical efficacy of bisphosphonates.
The present work aims to prove the concept of tumor-targeted drug delivery mediated by platelets. Doxorubicin (DOX) attached to nanodiamonds (ND-DOX) was investigated as the model payload drug of ...platelets. In vitro experiments first showed that ND-DOX could be loaded in mouse platelets in a dose-dependent manner with a markedly higher efficiency and capacity than free DOX. ND-DOX-loaded platelets (Plt@ND-DOX) maintained viability and ND-DOX could be stably held in the platelets for at least 4 hr. Next, mouse Lewis lung cancer cells were found to activate Plt@ND-DOX and thereby stimulate cargo unloading of Plt@ND-DOX. The unloaded ND-DOX was taken up by co-cultured cancer cells which consequently exhibited loss of viability, proliferation suppression and apoptosis. In vivo, Plt@ND-DOX displayed significantly prolonged blood circulation time over ND-DOX and DOX in mice, and Lewis tumor grafts demonstrated infiltration, activation and cargo unloading of Plt@ND-DOX in the tumor tissue. Consequently, Plt@ND-DOX effectively reversed the growth of Lewis tumor grafts which exhibited significant inhibition of cell proliferation and apoptosis. Importantly, Plt@ND-DOX displayed a markedly higher therapeutic potency than free DOX but without the severe systemic toxicity associated with DOX. Our findings are concrete proof of platelets as efficient and efficacious carriers for tumor-targeted nano-drug delivery with the following features: 1) large loading capacity and high loading efficiency, 2) good tolerance of cargo drug, 3) stable cargo retention and no cargo unloading in the absence of stimulation, 4) prolonged blood circulation time, and 5) excellent tumor distribution and tumor-activated drug unloading leading to high therapeutic potency and few adverse effects. Platelets hold great potential as efficient and efficacious carriers for tumor-targeted nano-drug delivery.
To systematically review and meta-analyze the associations between sleep disturbances and suicidal ideation, plans, and attempts in adolescents and explore potential moderators of these associations.
...Embase, PubMed, ProQuest, and the China Knowledge Resource Integrated Database were searched from their inception dates to October 19, 2018. We selected cross-sectional, prospective, or retrospective studies without time or language restrictions.
Nine cross-sectional studies, four prospective studies, and one retrospective report that, respectively, involved 37 536, 9295, and 80 adolescents were included in the meta-analysis. Cross-sectional analyses revealed that adolescents with sleep disturbances were at higher risks of suicidal ideation, plans, and attempts (pooled odds ratios ORs = 2.35, 1.58, and 1.92) than those without sleep disturbances. Prospective reports indicated that sleep disturbances in adolescents significantly predicted the risk of suicidal ideation but not suicide attempts (pooled ORs = 1.79 and 1.98, 95% confidence intervals = 1.36-2.36 and 0.62-6.29, respectively). The retrospective study did not support the association between sleep disturbances and suicide attempts. Depression did not moderate the associations between sleep disturbances and suicidal ideation or attempts in adolescents. Adolescents with insomnia complaints had a higher risk of suicidal ideation than those with other sleep complaints. Age, the female percentage, and reliable sleep measures were significant moderators (all p < .05).
Sleep disturbances, particularly insomnia, should be considered an influencing factor when developing preventive strategies against adolescent suicidal ideation. Additional prospective studies are warranted to establish causality of sleep disturbances in youth suicide plans and attempts.
As one of the most promising renewable energy sources, the amount of solar photovoltaics has reached 104.1 GW in 2018. China not only has the natural advantages of abundant solar energy resources, ...but the photovoltaic industry under the government’s support has also become the main driving force for global development. Facing the structural adjustment of solar photovoltaic parity online and the important contribution of solar power generation to energy conservation and emission reduction, this paper based on the radial and non-radial comprehensive consideration of EBM (Epsilon-Based Measure) DEA (Data envelopment analysis) model from the input-output perspective on solar photovoltaic industry CO2 emission reduction and efficiency analyze. It is concluded that the total efficiency of the solar photovoltaic industry in China’s six regions shows a growing trend, but the regional differences are obvious. The overall efficiency of the northwest region is superior. Among the index efficiency, CO2 emission reduction efficiency is better than cumulative installed capacity efficiency, solar energy utilization hour efficiency is the lowest, and CO2 emission reduction and cumulative installed capacity efficiency all show a consistent trend. It shows that the efficiency of cumulative installed capacity has a positive impact on CO2 emission reduction, but the efficiency of solar power generation needs to be improved.
•Evaluating the efficiency of china’s solar photovoltaic industry from the input-output perspective.•Using the EBM model based on linear and nonlinear factors.•Discussing the contribution of China’s solar photovoltaic industry to CO2 emission reduction.•The efficiency of cumulative installed capacity has positive impact on CO2 emission reduction, but need to be improved.
Agricultural lands adjacent to industrial activities are vulnerable due to the risk of trace elements (TEs) being accumulated into crops and subsequently humans. One such case concerns the industrial ...area of Volos, Greece, a suspected contaminated area which has never been studied. We measured Ag, Al, As, Cd, Co, Cr, Cu, Fe, Mn, Mo, Ni, Pb, Sb, Se, Sn, Tl, V, and Zn in soil and maize (leaves and grains) and assessed health risk of human exposure via soil ingestion and grain consumption. We found that the most highly enriched elements in soils were Tl (enrichment factor = 19), Se (17.68), Sb (14.81), As (7.89), Ni (6.91), Mo (5.22) and Cr (4.33); they all likely derived from anthropogenic activities and in particular from a nearby major steel factory, except for Ni which is known to be lithogenically elevated in that area. Synchrotron XANES spectra analysis revealed that As species were associated with ferrihydrite, and predominant species were As(V) (at ca. 85%) and As(III) (at ca. 15%). Although the total content of the studied elements was high, the ammonium bicarbonate-DTPA extractions recovered very low element concentrations, probably due to the fact that soil conditions decelerated solubility (i.e., soils were alkaline, clayey, and with high Fe oxides content). This was confirmed by the soil-to-grain transfer index, which was particularly low for all studied elements. In 5% of sampled grains concerning Cd, and in 40% concerning Pb, the European food-related regulation limits were surpassed. Health risk assessment showed a dramatically elevated risk for Tl via soil ingestion (hazard quotient, HQ = 2.399), a value that contributed 74% of the total risk. Similarly, concerning the grain consumption-related health risk, Tl was the predominant contributor (HQ = 0.128, contributing 40% of the total risk). Such elevated Tl risk which has rarely been reported previously, led to a considerably high hazard index (HI) well above the threshold of HI = 1. Cancer risk was below the 1 × 10−4 risk threshold for As and Pb. Our findings indicate that this study should be pivotal concerning similar industrially-affected agricultural soils of suspected contamination, since less-expected toxic elements such as Tl here may be primary contributors to health risk.
•Studied soils were highly enriched with Tl, a highly toxic metal.•Se, Sb, and Mo were also found severely enriched, as well as As, Ni and Cr.•Health risk assessment via soil ingestion indicated a significant risk.•Carcinogenic risk was below the 1 × 10−4 threshold for both As and Pb.•There is an urgent future need for monitoring other similar areas in Greece.
Intrauterine adhesion refers to endometrial repair disorders which are usually caused by uterine injury and may lead to a series of complications such as abnormal menstrual bleeding, recurrent ...abortion and secondary infertility. At present, therapeutic approaches to intrauterine adhesion are limited due to the lack of effective methods to promote regeneration following severe endometrial injury. Therefore, to develop new methods to prevent endometrial injury and intrauterine adhesion has become an urgent need. For severely damaged endometrium, the loss of stem cells in the endometrium may affect its regeneration. This article aimed to discuss the characteristics of various stem cells and their applications for uterine tissue regeneration.
A
bstract
We compute the six-particle maximally-helicity-violating (MHV) amplitude in planar
N
= 4 super-Yang-Mills theory at eight loops, using antipodal duality and the recently computed eight-loop ...three-point form factor for the chiral stress energy tensor multiplet. Antipodal duality maps the form factor symbol to the amplitude symbol on a two-dimensional parity-preserving surface in the three-dimensional amplitude kinematics. There are remarkably few ambiguities in lifting from two to three dimensions, nor in promoting the symbol to a function. The amplitude passes many tests, including near-collinear, multi-Regge, factorization, self-crossing and origin limits. These checks also constitute a validation of antipodal duality at eight loops.
Mutations in isocitrate dehydrogenase (
) are the most prevalent genetic abnormalities in lower grade gliomas. The presence of these mutations in glioma is prognostic for better clinical outcomes ...with longer patient survival. In the present study, we found that defects in oxidative metabolism and 2-HG production confer chemosensitization in IDH1-mutated glioma cells. In addition, temozolomide (TMZ) treatment induced greater DNA damage and apoptotic changes in mutant glioma cells. The PARP1-associated DNA repair pathway was extensively compromised in mutant cells due to decreased NAD
availability. Targeting the PARP DNA repair pathway extensively sensitized IDH1-mutated glioma cells to TMZ. Our findings demonstrate a novel molecular mechanism that defines chemosensitivity in IDH-mutated gliomas. Targeting PARP-associated DNA repair may represent a novel therapeutic strategy for gliomas.
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A high‐sensitivity and low‐power theranostic nanosystem that combines with synergistic photothermal therapy and surface‐enhanced Raman scattering (SERS) mapping is constructed by mesoporous silica ...self‐assembly on the reduced graphene oxide (rGO) nanosheets with nanogap‐aligned gold nanoparticles (AuNPs) encapsulated and arranged inside the nanochannels of the mesoporous silica layer. Rhodamine 6G (R6G) as a Raman reporter is then encapsulated into the nanochannels and anti‐epidermal growth factor receptor (EGFR) is conjugated on the nanocomposite surface, defined as anti‐EGFR‐PEG‐rGO@CPSS‐Au‐R6G, where PEG is polyethylene glycol and CPSS is carbon porous silica nanosheets. SERS spectra results show that rGO@CPSS‐Au‐R6G enhances 5 × 106 magnification of the Raman signals and thus can be applied in the noninvasive cell tracking. Furthermore, it displays high sensitivity (detection limits: 10−8m R6G solution) due to the “hot spots” effects by the arrangements of AuNPs in the nanochannels of mesoporous silica. The highly selective targeting of overexpressing EGFR lung cancer cells (A549) is observed in the anti‐EGFR‐PEG‐rGO@CPSS‐Au‐R6G, in contrast to normal cells (MRC‐5). High photothermal therapy efficiency with a low power density (0.5 W cm−2) of near‐infrared laser can be achieved because of the synergistic effect by conjugated AuNPs and rGO nanosheets. These results demonstrate that the anti‐EGFR‐PEG‐rGO@CPSS‐Au‐R6G is an excellent new theranostic nanosystem with cell targeting, cell tracking, and photothermal therapy capabilities.
By integrating targeting antibody (anti‐epidermal growth factor receptor), hot‐spots between arrayed gold nanoparticles and surface‐enhanced Raman scattering mapping image, a controllable porous silica/carbon nanostructure is developed. Supported on a reduced graphene oxide substrate to achieve real‐time diagnosis with synergistic photothermal effects, on‐demand eradication of tumor cells in vitro is enabled.
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