Confinement effects of mandrel degradation in ICF target fabrication.

Understanding and further regulating the degradation of mandrel materials is a key aspect of target fabrication in inertial confinement fusion (ICF). Here, a quasi-one-dimensional confinement model is developed using a series of single-walled carbon nanotubes with varying diameters (Dm), and the degradation of poly-α-methylstyrene (PAMS) as a typical mandrel material is investigated under such confined conditions by using the combined method of quantum mechanics and molecular mechanics. In comparison to the isolated system, the calculations show that confinement can decrease or increase the energy barriers of PAMS degradation, which directly depends on Dm. Following which a clear exponential relationship between the degradation rate of PAMS and its own density is derived, indicating that the density of PAMS can be used to regulate mandrel degradation. This work highlights the important effects of confinement on degradation and provides a valuable reference for further development of polymer degradation technologies in ICF target fabrication and other fields.

Design of Surface Plasmon Resonance-Based D-Type Double Open-Loop Channels PCF for Temperature Sensing.

Here, we document a D-type double open-loop channel floor plasmon resonance (SPR) photonic crystal fiber (PCF) for temperature sensing. The grooves are designed on the polished surfaces of the pinnacle and backside of the PCF and covered with a gold (Au) film, and stomata are distributed around the PCF core in a progressive, periodic arrangement. Two air holes between the Au membrane and the PCF core are designed to shape a leakage window, which no longer solely averts the outward diffusion of Y-polarized (Y-POL) core mode energy, but also sets off its coupling with the Au movie from the leakage window. This SPR-PCF sensor uses the temperature-sensitive property of Polydimethylsiloxane (PDMS) to reap the motive of temperature sensing. Our lookup effects point out that these SPR-PCF sensors have a temperature sensitivity of up to 3757 pm/°C when the temperature varies from 5 °C to 45 °C. In addition, the maximum refractive index sensitivity (RIS) of the SPR-PCF sensor is as excessive as 4847 nm/RIU. These proposed SPR-PCF temperature sensors have an easy nanostructure and proper sensing performance, which now not solely improve the overall sensing performance of small-diameter fiber optic temperature sensors, but also have vast application prospects in geo-logical exploration, biological monitoring, and meteorological prediction due to their remarkable RIS and exclusive nanostructure.

Ultra-Wideband High-Efficiency Solar Absorber and Thermal Emitter Based on Semiconductor InAs Microstructures.

Since the use of chemical fuels is permanently damaging the environment, the need for new energy sources is urgent for mankind. Given that solar energy is a clean and sustainable energy source, this study investigates and proposes a six-layer composite ultra-wideband high-efficiency solar absorber with an annular microstructure. It achieves this by using a combination of the properties of metamaterials and the quantum confinement effects of semiconductor materials. The substrate is W-Ti-Al2O3, and the microstructure is an annular InAs-square InAs film-Ti film combination. We used Lumerical Solutions' FDTD solution program to simulate the absorber and calculate the model's absorption, field distribution, and thermal radiation efficiency (when it is used as a thermal emitter), and further explored the physical mechanism of the model's ultra-broadband absorption. Our model has an average absorption of 95.80% in the 283-3615 nm band, 95.66% in the 280-4000 nm band, and a weighted average absorption efficiency of 95.78% under AM1.5 illumination. Meanwhile, the reflectance of the model in the 5586-20,000 nm band is all higher than 80%, with an average reflectance of 94.52%, which has a good thermal infrared suppression performance. It is 95.42% under thermal radiation at 1000 K. It has outstanding performance when employed as a thermal emitter as well. Additionally, simulation results show that the absorber has good polarization and incidence angle insensitivity. The model may be applied to photodetection, thermophotovoltaics, bio-detection, imaging, thermal ion emission, and solar water evaporation for water purification.

Synthesis, Hole Doping, and Electrical Properties of a Semiconducting Azatriangulene-Based Covalent Organic Framework.

Two-dimensional covalent organic frameworks (2D COFs) containing heterotriangulenes have been theoretically identified as semiconductors with tunable, Dirac-cone-like band structures, which are expected to afford high charge-carrier mobilities ideal for next-generation flexible electronics. However, few bulk syntheses of these materials have been reported, and existing synthetic methods provide limited control of network purity and morphology. Here, we report transimination reactions between benzophenone-imine-protected azatriangulenes (OTPA) and benzodithiophene dialdehydes (BDT), which afforded a new semiconducting COF network, OTPA-BDT. The COFs were prepared as both polycrystalline powders and thin films with controlled crystallite orientation. The azatriangulene nodes are readily oxidized to stable radical cations upon exposure to an appropriate p-type dopant, tris(4-bromophenyl)ammoniumyl hexachloroantimonate, after which the network's crystallinity and orientation are maintained. Oriented, hole-doped OTPA-BDT COF films exhibit electrical conductivities of up to 1.2 × 10-1 S cm-1, which are among the highest reported for imine-linked 2D COFs to date.

Side-chain engineering for high degradation performance of mandrel materials in ICF target fabrication.

The exploration of mandrel materials with superior degradation performance to the traditionally adopted hydrocarbon polymer of poly-α-methylstyrene (PAMS), has always been an important pursuit for fabricating high-quality inertial confinement fusion (ICF) targets. Here, we propose a method to enhance the degradation performance of mandrel material based on side-chain engineering. A series of hydrocarbon cyclic functional groups, including cyclopentane, cyclopentadiene, naphthalene and azulene, are used to replace the benzene ring on the side chain of PAMS to form new polymer structures. The results show that the degradation performance of structures can be largely regulated by different side chains. In particular, one of the naphthalene-substituted structures has similar properties to PAMS, but the required degradation condition is lower. Furthermore, the reaction rate calculations indicate that this structure is expected to be synthesized experimentally. This work provides a direction for side-chain engineering for research into the key technology of ICF target fabrication in the future.

PKM2 Interacts With the Cdk1-CyclinB Complex to Facilitate Cell Cycle Progression in Gliomas.

PKM2 is a phosphotyrosine-binding glycolytic enzyme upregulated in many cancers, including glioma, and contributes to tumor growth by regulating cell cycle progression. We noted, however, that in multiple glioma cell lines, PKM2 knock-down resulted in an accumulation of cells in G2-M phase. Moreover, PKM2 knock-down decreased Cdk1 activity while introducing a constitutively active Cdk1 reversed the effects of PKM2 knock-down on cell cycle progression. The means by which PKM2 increases Cdk1 activity have not been described. Transient interaction of T14/Y15-phosphorylated Cdk1 with cyclin B allows Cdk7-mediated pT161 Cdk1 phosphorylation followed by cdc25C-mediated removal of pT14/Y15 and activation of Cdk1 in cycling cells. In the present course of investigation, PKM2 modulation did not influence Cdk7 activity, but phosphotyrosine binding forms of PKM2 co-immunoprecipitated with pY15-containing Cdk1-cyclinB and enhanced formation of active pT161 Cdk1-cyclin B complexes. Moreover, exogenous expression of phosphotyrosine binding forms of PKM2 reversed the effects of PKM2 knock-down on G2-M arrest. We here show that PKM2 binds and stabilize otherwise transient pY15-containing Cdk1-cyclinB complexes that in turn facilitate Cdk1-cyclin B activation and entry of cells into mitosis. These results, therefore, establish metabolic enzyme PKM2 as a direct interactor and activator of Cdk1-cyclin B complex and thereby directly controls mitotic progression and the growth of brain tumor cells.

Synthesis of Uranium Single Atom from Radioactive Wastewater for Enhanced Water Dissociation and Hydrogen Evolution.

As a common nuclide in radioactive wastewater, uranium (U) is generally treated by landfill, which induces the massive abandonment of uranium resources. In this work, a pulse voltammetry method for the synthesis of U single atoms on MoS2 (U/MoS2 ) nanosheets from radioactive wastewater for the electrocatalytic alkaline hydrogen evolution reaction (HER) is reported. The mass loading of U single atoms is facilely controlled with high selectivity for coexisting ions in radioactive wastewater. In the electrolyte of 1 m of KOH, U/MoS2 nanosheets with 5.2% of U single atoms exhibit relatively low overpotentials of 72 mV at 10 mA cm-2 . The mechanistic study reveals that the HER on U/MoS2 includes the water dissociation on U single atoms to form OH* and H transfer from OH* to adjacent S-edge atoms. This procedure exhibits decreased activation energy for transition state in water dissociation and optimized Gibbs free energy for H* adsorption.

MRE11 and UBR5 Co-Operate to Suppress RNF168-Mediated Fusion of Dysfunctional Telomeres.

TRF2 is part of the shelterin complex that hides telomeric DNA ends and prevents the activation of the cNHEJ pathway that can lead to chromosomal fusion. TRF2, however, also actively suppresses the cNHEJ pathway by recruiting two proteins, MRE11 and UBR5. MRE11 binds BRCC3, which in turn deubiquitinates γH2AX deposited at exposed telomeric DNA ends and limits RNF168 recruitment to the telomere. UBR5, in contrast directly ubiquitinates and destroys RNF168. The loss of telomeric RNF168 in turn blocks the subsequent recruitment of 53BP1 and prevents the cNHEJ-mediated fusion of chromosomes with exposed telomeric DNA ends. Although MRE11 and UBR5 are both involved in the control of telomeric RNF168 levels and the chromosome fusion process, their relative contributions have not been directly addressed. To do so we genetically suppressed MRE11 and UBR5 alone or in combination in glioma cell lines which we previously showed contained dysfunctional telomeres that were dependent on TRF2 for suppression of telomeric fusion and monitored the effects on events associated with telomere fusion. We here show that while suppression of either MRE11 or UBR5 alone had minimal effects on RNF168 telomeric accumulation, 53BP1 recruitment, and telomeric fusion, their combined suppression led to significant increases in RNF168 and 53BP1 telomeric recruitment and telomeric fusion and eventually cell death, all of which were reversible by suppression of RNF168 itself. These results show that MRE11 and UBR5 co-operate to suppress fusion at dysfunctional telomeres.

RETRACTED: A subset of PARP inhibitors induces lethal telomere fusion in ALT-dependent tumor cells.

About 10% of all tumors, including most lower-grade astrocytoma, rely on the alternative lengthening of telomere (ALT) mechanism to resolve telomeric shortening and avoid limitations on their growth. Here, we found that dependence on the ALT mechanism made cells hypersensitive to a subset of poly(ADP-ribose) polymerase inhibitors (PARPi). We found that this hypersensitivity was not associated with PARPi-created genomic DNA damage as in most PARPi-sensitive populations but rather with PARPi-induced telomere fusion. Mechanistically, we determined that PARP1 was recruited to the telomeres of ALT-dependent cells as part of a DNA damage response. By recruiting MRE11 and BRCC3 to stabilize TRF2 at the ends of telomeres, PARP1 blocked chromosomal fusion. Exposure of ALT-dependent tumor cells to a subset of PARPi induced a conformational change in PARP1 that limited binding to MRE11 and BRCC3 and delayed release of the TRF2-mediated block on lethal telomeric fusion. These results therefore provide a basis for PARPi treatment of ALT-dependent tumors, as well as establish chromosome fusion as a biomarker of their activity.

A novel integrated system using patient-derived glioma cerebral organoids and xenografts for disease modeling and drug screening.

A physiologically relevant glioma tumor model is important to the study of disease progression and screening drug candidates. However, current preclinical glioma models lack the brain microenvironment, and the established tumor cell lines do not represent glioma biology and cannot be used to evaluate the therapeutic effect. Here, we reported a real-time integrated system by generating 3D ex vivo cerebral organoids and in vivo xenograft tumors based on glioma patient-derived tissues and cells. Our system faithfully recapitulated the histological features, response to chemotherapy drugs, and clinical progression of their corresponding parental tumors. Additionally, our model successfully identified a case from a grade II astrocytoma patient with typical grade IV GBM features in both organoids and xenograft models, which mimicked the disease progression of this patient. Further genomic and transcriptomic characterization was associated with individual clinical features. We have demonstrated the "GBM-&Normal-like" signature to predict prognosis. In conclusion, we developed an integrated system of parallel models from patient-derived glioma cerebral organoids and xenografts for understanding the glioma biology and prediction of response to chemotherapy drugs, which might lead to a new strategy for personalized treatment for this deadly disease.

High-Performance Zwitterionic Nanofiltration Membranes Fabricated via Microwave-Assisted Grafting of Betaine.

The thin-film composite (TFC) nanofiltration (NF) membrane is a very important method in solving the water crisis. However, the fabrication and industrialization of high-performance NF membranes still remains challenging. In this work, zwitterionic NF membranes via microwave-assisted grafting of betaine was first proposed. The resulting polyamide layer showed leaflike nanostructures after modification. Because of the enlarged permeation area and enhanced hydrophilicity derived from the unique leaflike structure, the optimal membrane permeability reached 40.8 L m-1 h-1 bar-1. This water permeance was 2.2 times as high as the original polypiperazine-amide membrane, with a Na2SO4 rejection maintained at 97.0%. More importantly, the membrane demonstrated excellent selectivity to monovalent and divalent anions. This zwitterionic membrane fabricated by microwave-assisted grafting of betaine provides new insight for industrial scalable NF membranes with great potentials.

Local Photothermal Control of Phase Transitions for On-Demand Room-Temperature Rewritable Magnetic Patterning.

The ability to make controlled patterns of magnetic structures within a nonmagnetic background is essential for several types of existing and proposed technologies. Such patterns provide the foundation of magnetic memory and logic devices, allow the creation of artificial spin-ice lattices, and enable the study of magnon propagation. Here, a novel approach for magnetic patterning that allows repeated creation and erasure of arbitrary shapes of thin-film ferromagnetic structures is reported. This strategy is enabled by epitaxial Fe0.52 Rh0.48 thin films designed so that both ferromagnetic and antiferromagnetic phases are bistable at room temperature. Starting with the film in a uniform antiferromagnetic state, the ability to write arbitrary patterns of the ferromagnetic phase is demonstrated by local heating with a focused laser. If desired, the results can then be erased by cooling below room temperature and the material repeatedly re-patterned.

Enhanced capacitive performance by improving the graphitized structure in carbon aerogel microspheres.

Herein, good electrical conductivity and high specific surface area carbon aerogel (CA) microspheres were synthesized by a facile and economical route using a high temperature carbonization and CO2 activation method. The electroconductive graphitized structure of the CA microspheres could be easily improved by increasing the carbonization temperature. Then the CA microspheres were activated with CO2 to increase the specific surface area of the electrode material for electric double layer capacitors (EDLC). The sample carbonized at 1500 °C for 0.5 h and CO2 activated at 950 °C for 8 h showed an acceptable specific surface area and excellent cycle performance and rate capability for EDLC: 98% of the initial value of the capacitance was retained after 10 000 cycles, a specific capacitance of 121 F g-1 at 0.2 A g-1 and 101 F g-1 at 2 A g-1.

Exosomal hsa-miR-21-5p derived from growth hormone-secreting pituitary adenoma promotes abnormal bone formation in acromegaly.

Growth hormone-secreting pituitary adenoma (GHPA), a benign endocrine tumor located in the base of the skull, results in acromegaly. In addition to the mass effect of the tumor itself in the sellar region, GHPA can lead to the overgrowth of almost every organ. Previous findings indicated that the processes underlying acromegaly were partly attributable to hyperactivity of the growth hormone/insulin-like growth factor-1 (GH/IGF-1) axis. However, the mechanisms driving this syndrome remains largely unknown. Additionally, the roles of GHPA-derived exosomes, which contain functional microRNAs and proteins that manipulate target cell proliferation and differentiation in distal extremities, are also unknown. In this study, we demonstrated that GHPA exosomes promote bone formation in vitro and trabecula number in vivo. The mechanism of increased trabecula formation may be attributable to GHPA exosome-induced osteoblast proliferation via increased cell viability and DNA replication. We further discovered that exosomal hsa-miR-21-5p plays a distinct role from the GH/IGF-1 axis in these processes. Accordingly, the results of this study provide a novel mechanism whereby GHPA influences distal extremities and a new perspective for treating GHPA.

Fabrication of ZnO@Ag3PO4 Core-Shell Nanocomposite Arrays as Photoanodes and Their Photoelectric Properties.

In this study, we combine the methods of magnetron sputtering, hydrothermal growth, and stepwise deposition to prepare novel ZnO@Ag3PO4 core-shell nanocomposite arrays structure. Through scanning electron microscope (SEM) topography test, energy dispersive spectrometer (EDS) element test and X-ray diffractometry (XRD) component test, we characterize the morphology, element distribution and structural characteristics of ZnO@Ag3PO4 core-shell nanocomposite arrays structure. At the same time, we test the samples for light reflectance, hydrophilicity and photoelectric performance. We find that after deposition of Ag3PO4 on ZnO nanorods, light reflectance decreases. As the time of depositions increases, light reflectance gradually decreases. After the deposition of Ag3PO4, the surface of the sample shows super hydrophilicity, which is beneficial for the photoelectric performance test. Through the optical transient response test, we find that the photo-generated current reaches a maximum when a small amount of Ag3PO4 is deposited. As the time of depositions of Ag3PO4 increases, the photogenerated current gradually decreases. Finally, we conducted an alternating current (AC) impedance test and also verified the correctness of the photocurrent test. Therefore, the structure is expected to be prepared into a photoanode for use in fields such as solar cells.

Entropy-driven catalytic reaction-induced hairpin structure switching for fluorometric detection of uranyl ions.

An ultra-sensitive and "turn-on" method is demonstrated for the determination of uranyl ion. The assay is based on hairpin-to-DNAzyme structure switching that is induced by an entropy-driven catalytic reaction. An UO22+-specific DNAzyme is cleaved by UO22+ to produce a DNA fragment. This fragment initiates the entropy-driven catalytic reaction to produce a large number of a sequence "R". The sequence R initiates the circular cleavage of FAM-labeled hairpins by switching the hairpin to Mg2+-specific DNAzyme structure. This causes the recovery of green fluorescence. The method works in the 20 pM to 800 pM concentration range and the limit of detection is 4 pM. Graphical abstract Entropy driven catalytic reaction induced hairpin structure switching for fluorometric detection of uranyl ions.

Dual-Band Plasmonic Perfect Absorber Based on Graphene Metamaterials for Refractive Index Sensing Application.

We demonstrate a dual-band plasmonic perfect absorber (PA) based on graphene metamaterials. Two absorption peaks (22.5 µm and 74.5 µm) with the maximal absorption of 99.4% and 99.9% have been achieved, respectively. We utilize this perfect absorber as a plasmonic sensor for refractive index (RI) sensing. It has the figure of merit (FOM) of 10.8 and 3.2, and sensitivities of about 5.6 and 17.2 µm/RIU, respectively. Hence, the designed dual-band PA-based RI sensor exhibits good sensing performance in the infrared regime, which offers great potential applications in various biomedical, tunable spectral detecting, environmental monitoring and medical diagnostics.

Thymine-Hg2+-thymine coordination chemistry induced entropy driven catalytic reaction to form Hemin/G-quadruplex-HRP-mimicking DNAzyme for colorimetric and visual determination of Hg2.

A sensitive and visible colorimetric strategy was proposed for Hg2+ detection by thymine-Hg2+-thymine (T-Hg2+-T) coordination chemistry and entropy driven catalytic reaction. The entropy driven catalytic reaction is induced by T-Hg2+-T coordination chemistry, resulting the releasing of G-riched sequence. Hemin/G-quadruplex-HRP-mimicking DNAzyme can be formed with the help of hemin, catalyzing TMB to TMB+ with a color change from colorless to blue. The sensitivity of this strategy can be reached to 2 pM, which is significantly improved by entropy driven catalytic reaction. In addition, entropy driven catalytic reaction provides a more reliable and accurate results. This method shows great promise for on-site analysis and in-house diagnosis of Hg2+ in water.

A dynamic, ultra-sensitive and "turn-on" strategy for fluorescent detection of uranyl based on DNAzyme and entropy-driven amplification initiated circular cleavage amplification.

A uranyl detection strategy with ultra-sensitivity was developed based on entropy-driven amplification and DNAzyme circular cleavage amplification. The cleavage of UO22+-specific DNAzyme produces a DNA fragment to initiate the entropy-driven amplification. Two DNA sequences released from the entropy-driven amplification are partly complementary. They can form an entire enzyme strand (E-DNA) of Mg2+-specific DNAzyme. The formed E-DNA can circularly cleave FAM-labeled probes on gold nanoparticles (AuNPs), causing the leaving of FAM from AuNPs and recovery of fluorescent signal. A linear relationship was obtained in the range from 30 pM to 5 nM between fluorescence intensity and concentration of UO22+. The limit of detection was low to 13 pM. This method showed a promising future for practical application in real water samples.

Proximity ligation assay induced hairpin to DNAzyme structure switching for entropy-driven amplified detection of thrombin.

A proximity ligation assay (PLA) induced hairpin to DNAzyme structure switching strategy has been described for entropy-driven amplified detection of thrombin. The enzyme-strand (E-DNA) and substrate-strand (S-DNA) of DNAzyme are locked in hairpins structure, and the catalytic activity of DNAzyme is inhibited simultaneously. However, in the presence of thrombin, the PLA can induce the unlocking of hairpin, and then the forming of active DNAzyme. Subsequently, the cleavage of DNAzyme can release DNA fragment to induce the entropy-driven amplification reaction, resulting significant recovery of fluorescent intensity by the separation of FAM from quencher. There was a good linear relationship in the range of 5 pM - 1 nM. This method provides high reliability and sensitivity under enzyme- and hairpin-free conditions.