Mesenchymal stem cells (MSCs) have been used in clinic for approximately 20 years. During this period, various new populations of MSCs have been found or manipulated. However, their characters and ...relative strength for bone regeneration have not been well known. For a comprehensive understanding of MSCs, we reviewed the literature on the multipotent cells ranging from the definition to the current research progress for bone regeneration. Based on our literature review, bone marrow MSCs have been most widely studied and utilized in clinical settings. Among other populations of MSCs, adipose-derived MSCs and perivascular MSCs might be potential candidates for bone regeneration, whose efficacy and safety still require further investigation.
Abstract
Covalent organic frameworks (COFs) with structural designability and tunability of photophysical properties enable them to be a promising class of organic luminescent materials by ...incorporating well‐designed fluorescent units directly into the periodic skeletons. The photophysical properties of COFs are mainly affected by the structural features, which determine the conjugation degree, charge delocalization ability, and exciton dynamics of COFs. To understand the relationship between COF structures and their photophysical properties, two COFs with the same pyrene chromophore units but different linkages (imine or vinylene) were designed and synthesized. Interestingly, different linkages endow COFs with huge differences in solid‐state photoluminescence quantum yield (PLQY) for imine‐ and vinylene‐linked pyrene‐based COFs, which possess PLQY values of 0.34 % and 15.43 %, respectively. The femtosecond‐transient absorption spectra and time‐dependent density functional theory reveal the different charge‐transfer pathways in imine‐ and vinylene‐linked COFs, which influence the exciton relaxation way and fluorescence intensity. In addition, an effective white‐light device was obtained by coating the vinylene‐linked COF on a light‐emitting diode strip.
The ecosystem of the Source Region of Yangtze River (SRYR) is highly susceptible to climate change. In this study, the spatial-temporal variation of NPP from 2000 to 2014 was analyzed, using outputs ...of Carnegie-Ames-Stanford Approach model. Then the correlation characteristics of NPP and climatic factors were evaluated. The results indicate that: (1) The average NPP in the SRYR is 100.0 gC/m
from 2000 to 2014, and it shows an increasing trend from northwest to southeast. The responses of NPP to altitude varied among the regions with the altitude below 3500 m, between 3500 to 4500 m and above 4500 m, which could be attributed to the altitude associated variations of climatic factors and vegetation types; (2) The total NPP of SRYR increased by 0.18 TgC per year in the context of the warmer and wetter climate during 2000-2014. The NPP was significantly and positively correlated with annual temperature and precipitation at interannual time scales. Temperature in February, March, May and September make greater contribution to NPP than that in other months. And precipitation in July played a more crucial role in influencing NPP than that in other months; (3) Climatic factors caused the NPP to increase in most of the SRYR. Impacts of human activities were concentrated mainly in downstream region and is the primary reason for declines in NPP.
Constructing a powerful photocatalytic system that can achieve the carbon dioxide (CO2) reduction half‐reaction and the water (H2O) oxidation half‐reaction simultaneously is a very challenging but ...meaningful task. Herein, a porous material with a crystalline topological network, named viCOF‐bpy‐Re, was rationally synthesized by incorporating rhenium complexes as reductive sites and triazine ring structures as oxidative sites via robust −C=C− bond linkages. The charge‐separation ability of viCOF‐bpy‐Re is promoted by low polarized π‐bridges between rhenium complexes and triazine ring units, and the efficient charge‐separation enables the photogenerated electron–hole pairs, followed by an intramolecular charge‐transfer process, to form photogenerated electrons involved in CO2 reduction and photogenerated holes that participate in H2O oxidation simultaneously. The viCOF‐bpy‐Re shows the highest catalytic photocatalytic carbon monoxide (CO) production rate (190.6 μmol g−1 h−1 with about 100 % selectivity) and oxygen (O2) evolution (90.2 μmol g−1 h−1) among all the porous catalysts in CO2 reduction with H2O as sacrificial agents. Therefore, a powerful photocatalytic system was successfully achieved, and this catalytic system exhibited excellent stability in the catalysis process for 50 hours. The structure–function relationship was confirmed by femtosecond transient absorption spectroscopy and density functional theory calculations.
A crystalline network is constructed by incorporating rhenium complexes and triazine ring structures as catalytic sites via robust −C=C− bonding. Appreciable charge‐separation and transfer efficiency drive both the photocatalytic oxidative and reductive reactions in the conversion of CO2 to CO with H2O, and without any additional sacrificial agents or photosensitizers.
In this paper, an innovative multitasking device (MTD) regulated by the gravity field realizing the functions of metamaterial absorber (MMA) and linear polarization converter (LPC) is proposed and ...theoretically investigated. When the device operates in the function of MMA, the engineered SRR structure offers robust conditions for the formation of anapole mode. The anapole mode can lead to destructive interference in the far‐field and constructive interference within the configuration synchronously; thereby, the incident wave energy can be consumed strongly. It is verified that the proposed MTD in the MMA state can acquire a high absorption rate exceeding 0.9 from 10.82 to 13.55 GHz, with a broad relative bandwidth (RBW) of 22.4%. While in the LPC state, the utilization of the “L”‐shaped structure successfully introduces an equivalent magnetic resonance to achieve the translation of the incident wave polarization state. In this case, the orthogonal state of the incident beam can be obtained by the MTD with the polarization conversion ratio (PCR) over 0.9 in the range of 2.62–3.72 GHz, whose RBW is 34.7%. The design accomplishes the functional combination of MMA and LPC through the gravity field regulation, simultaneously staggering the operating bands to guarantee their independence and anti‐interference.
An innovative multitasking device regulated by the gravity field realizing the functions of metamaterial absorber (MMA) and linear polarization converter (LPC) is proposed and theoretically investigated. In the MMA state, the anapole mode is excited and leads to broadband absorption. While in the LPC state, an equivalent magnetic resonance is introduced to achieve the conversion of the polarization state.
Bone loss with aging and menopause increases the risk of fragile vertebral fracture, osteoporotic vertebral compression fracture (OVCF). The fracture causes severe pain, impedes respiratory function, ...lower the quality of life, and increases the risk of new fractures and deaths. Various medications have been prescribed to prevent a secondary fracture, but few study summarized their effects. Therefore, we investigated their effects on preventing subsequent OVCF via meta-analyses of randomized controlled trials.
Electronic databases, including MEDLINE, EMBASE, CENTRAL, and Web of Science were searched for published randomized controlled trials from June 2015 to June 2019. The trials that recruited participants with at least one OVCF were included. We assessed the risk of bias of every study, estimated relative risk ratio of secondary OVCF, non-vertebral fracture, gastrointestinal complaints and discontinuation due to adverse events. Finally, we evaluated the quality of evidence.
Forty-one articles were included. Moderate to high quality evidence proved the effectiveness of zoledronate (Relative Risk, RR: 0.34; 95% CI, 0.17-0.69, p = 0.003), alendronate (RR: 0.54; 95% CI: 0.43-0.68; p < 0.0001), risedronate (RR: 0.61; 95% CI: 0.51-0.73; p < 0.0001), etidronate (RR, 0.50; 95% CI, 0.29-0.87, p < 0.01), ibandronate (RR: 0.52; 95% CI: 0.38-0.71; p < 0.0001), parathyroid hormone (RR: 0.31; 95% CI: 0.23-0.41; p < 0.0001), denosumab (RR, 0.41; 95% CI, 0.29-0.57; p < 0.0001) and selective estrogen receptor modulators (Raloxifene, RR: 0.58; 95% CI: 0.44-0.76; p < 0.0001; Bazedoxifene, RR: 0.66; 95% CI: 0.53-0.82; p = 0.0002) in preventing secondary fractures. Moderate quality evidence proved romosozumab had better effect than alendronate (Romosozumab vs. alendronate, RR: 0.64; 95% CI: 0.49-0.84; p = 0.001) and high quality evidence proved that teriparatide had better effect than risedronate (risedronate vs. teriparatide, RR: 1.98; 95% CI: 1.44-2.70; p < 0.0001).
Zoledronate, alendronate, risedronate, etidronate, ibandronate, parathyroid hormone, denosumab and selective estrogen receptor modulators had significant secondary prevention effects on OVCF. Moderate quality evidence proved romosozumab had better effect than alendronate. High quality evidence proved PTH had better effect than risedronate, but with higher risk of adverse events.
The Poyang Lake Region (PLR) is well known for its ecological and economic importance. This paper first analyzed the changes in land use/land cover (LULC), followed by changes in landscape patterns ...and ecosystem services by landscape metrics and equivalent coefficients table method. Then, the influence of LULC change on landscape pattern and ecosystem services in both historical period (from 1990 to 2015) and future period (2030) was explored. The results showed that the area of construction land was 607.9 km
2
in 1990 and 972.5 km
2
in 2015. The increased construction land mainly converted from cultivated land. For the entire PLR, a higher use degree of LULC and a trend of fragmentation existed in recent years. The total ecosystem service values (ESVs) decreased by ¥2.44 × 10
9
from 1990 to 2015, mainly because of shrinkage of cultivated land and sharp increase in construction land. It was predicted that the areas of construction land and waterbody would increase by 34.6% and 2.2% compared with those in 2015. These changes would lead to more regular in patch shape, longer in patch edge, less connectivity of patches, and an increase of ¥6.2 × 10
8
ESVs in 2030.
A collision system scan involving α-clustered 12C and 16O is studied by using a multiphase transport model for central collisions at sNN=6.37 TeV. Background subtracted away-side dihadron azimuthal ...correlation is performed via the zero yield at minimum (ZYAM) method from raw signals, and the quantitative parameters, such as RMS width and Kurtosis, seem nicely follow the A−1/3 law of the system size if the nucleus has the normal Woods-Saxon nucleon distribution. However, for α-clustering light nuclei, specifically for 12C and 16O, the RMS width and Kurtosis of away-side azimuthal correlation are deviated from the baseline of A−1/3 law. In addition, the momentum dependence of away-side broadening parameters is also presented. The results show that there is a distinction in away-side broadening parameters of dihadron correlation function between the Woods-Saxon distribution and the α-clustered structures, which sheds light on that the collision system scan for dihadron azimuthal correlation as a potential probe to distinguish α-clustered nuclei.
This paper proposes a geothermal-solar-wind renewable energy hub framework for community multi-energy supplies. In this framework, multi-energy complementarities of geothermal-solar-wind hybrid ...renewable energy are fully explored based on electrolytic thermo-electrochemical effects of geothermal-to-hydrogen (GTH), which is integrated with the multi-energy conversion and storage devices for multi-energy supplies. In order to exploit the inherent multi-energy operational dispatchability and flexibility of geothermal-solar-wind renewables, a multi-energy coupling matrix is formulated for the modeling of production, conversion, storage, and consumption of hub-internal electricity, hydrogen and heating energy. A multi-energy operation scheme is further developed to dispatch the energy flows of the coupling matrix for cost-effective accommodation of community renewables. Case studies on a community microgrid under grid-connected and grid-disconnected modes are performed to verify the effectiveness and superiority of the proposed methodology. Simulations results show that the solar-wind accommodation can be improved by at most 1.59% with a significantly lower system operating cost.
•An electrolytic thermodynamic network is formulated to model the thermo-electrochemical effects.•Geothermal-solar-wind 100% renewables is proposed for multi-energy supplies.•A multi-energy operation scheme is developed to dispatch the electricity, thermal, and hydrogen flows.•The costs during production, conversion, storage, and consumption process are considered.
Herein we report a novel and straightforward protocol for the construction of valuable gem‐BPs by means of proton‐coupled electron‐transfer (PCET)‐triggered enamido C(sp2)−H diphosphorylation. This ...reaction represents a rare example of realizing the challenging double C−P bond formation at a single carbon atom, thus providing facile access to a broad variety of structurally diverse bisphosphonates from simple enamides under silver‐mediated conditions. Initial mechanistic studies demonstrated that the diphosphorylation involves two rounds of PCET‐initiated radical relay process.
C−P bond formation: By taking advantage of a PCET‐triggered radical relay process, a new general method to versatile valuable functionalized gem‐bisphosphonates is described (see scheme).
PDF
