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Memristor-based accelerator (MBA) has demonstrated its capability in accelerating matrix-vector multiplication (MVM) with high performance and energy efficiency. However, it is hard to determine whether and how well an application can benefit from MBAs in a heterogeneous computing architecture. In this article, we propose a simulation framework called MHSim to evaluate the energy efficiency and performance of applications running with both MBAs and CPUs. MHSim provides flexible system-level interfaces and circuit-level simulation models for designers to configure heterogeneous computing architectures. We design a general-purpose MBA which enables floating-point computation models for general matrix-matrix multiplication (GEMM). Our simulation framework can quantify the performance and energy efficiency of different MBA architectures for various applications. We validate our simulation framework with SPICE and evaluate the accuracy and performance of MBAs via several case studies. Experimental results demonstrate that the deviations of energy consumption and latency are only 0.47% and 0.49% on average compared with SPICE-based simulation. [ABSTRACT FROM AUTHOR]

Atherosclerosis and atherothrombosis, the major contributors to cardiovascular diseases (CVDs), represent the leading cause of death worldwide. Current pharmacological therapies have been associated with side effects or are insufficient at halting atherosclerotic progression effectively. Pioneering work harnessing the passive diffusion or endocytosis properties of nanoparticles and advanced biotechnologies in creating recombinant proteins for site-specific delivery have been utilized to overcome these limitations. Since CVDs are complex diseases, the most challenging aspect of developing site-specific therapies is the identification of an individual and unique antigenic epitope that is only expressed in lesions or diseased areas. This review focuses on the pathological mechanism of atherothrombosis and discusses the unique targets that are important during disease progression. We review recent advances in site-specific therapy using novel targeted drug-delivery and nanoparticle-carrier systems. Furthermore, we explore the limitations and future perspectives of site-specific therapy for CVDs. [ABSTRACT FROM AUTHOR]

The series of novel phosphors Ca 9 La(PO 4) 5 [(Si 1- x Ge x O 4)]F 2 :0.15Dy3+ with x = 0, 0.25, 0.50, 0.75 and 1 (CLPS 1- x G x F:0.15Dy3+) with apatite-type structure (space group P 6 3 / m) has been synthesized. The crystal structure and electronic structure have been studied by powder X-ray diffraction (PXRD) in combination with the atomic-scale density functional theory (DFT) calculations. A combination of Raman, nuclear magnetic resonance (29Si NMR) spectroscopy and the evolution of Dy3+ ions photoluminescent properties was used to characterize the local crystal structure features. Based on the variation of the [SiO 4 ] by [GeO 4 ] tetrahedral substitutions in the apatite-type structure, the difference in the thermal stability and decay curves of CLPS 1- x G x F:0.15Dy3+ phosphors were referred to crystal chemical stability of as-prepared compounds, which is also confirmed by the values of polyhedral distortion, bond valence sum (BVS) and DFT calculations. The present study provides new insights the synthetic methodology and fundamental characterizations into the design of new phosphors combined with theoretical methods. [ABSTRACT FROM AUTHOR]

Hybrid memory systems composed of emerging non-volatile memory (NVM) and DRAM have drawn increasing attention in recent years. To fully exploit the advantages of both NVM and DRAM, a primary goal is to properly place application data on the hybrid memories. Previous studies have focused on page migration schemes to achieve higher performance and energy efficiency. However, those schemes all rely on online page access monitoring (costly), and data migration at the page granularity may cause additional overhead due to DRAM bandwidth contention and maintenance of cache/TLB consistency. In this article, we present Object-level memory Allocation and Migration (OAM) mechanisms for hybrid memory systems. OAM exploits a profiling tool to characterize objects’ memory access patterns at different execution phases of applications, and applies a performance/energy model to direct the initial static memory allocation and runtime dynamic object migration between NVM and DRAM. Based on our newly-developed programming interfaces for hybrid memory systems, application source codes can be automatically transformed via static code instrumentation. We evaluate OAM on an emulated hybrid memory system, and experimental results show that OAM can significantly reduce system energy-delay-product by 61 percent on average compared to a page-interleaving data placement scheme. It can also significantly reduce data migration overhead by 83 and 69 percent compared to the state-of-the-art page migration scheme CLOCK-DWF and 2PP, respectively, while improving application performance by up to 22 and 10 percent. [ABSTRACT FROM AUTHOR]

Abstract A set of Eu3+, Dy3+ and Tb3+ doped novel scheelite-type LiCaGd(WO 4) 3 (LCGW)-based phosphors was prepared via a conventional solid-state reaction method. The X-ray diffraction (XRD), transmission electron microscopy (TEM) analysis, characteristics of luminescence, PL thermostability, decay lifetimes, as well as CIE coordination were investigated to characterize the as-prepared samples in detail. The XRD analysis indicated that the Eu3+, Dy3+ and Tb3+ ions were incorporated into the LCGW host lattice. Under the ultraviolet radiation, the characteristic emission lines of Eu3+ (5D 0 –7F 2), Dy3+ (4F 9/2 –6H 13/2) and Tb3+ (5D 4 –7F 5) ions were observed. The Eu3+ and Tb3+ single-doped LCGW fluorescent powders showed bright red and green emissions, respectively, without concentration quenching. As well as the Dy3+ doped LCGW phosphors radiate a strong yellow light at optimal Dy3+ concentration 0.08 mol. The efficient energy transfer phenomenon was observed for the Eu3+/Dy3+ and Tb3+/Dy3+ ions. The emission color of the LCGW: x Tb3+/0.08Dy3+ samples was tuned from yellow (0.4074, 0.4727) to green (0.3604, 0.5521) via adjusting the Tb3+ concentration. The emission color of LCGW: y Eu3+/0.08Dy3+ can be tuned from yellow (0.491, 0.3856) to red (0.5694, 0.3512) by variation of the Eu3+/Dy3+ ratio. Additionally, the thermal stability of the luminescence in the LCGW phosphors doped by Eu3+, Tb3+, Dy3+ ions was studied. The results verified that the LCGW:Ln3+ (Ln = Tb, Eu, Dy) phosphors are promising for applications in white LEDs. [ABSTRACT FROM AUTHOR]

Abstract The novel apatite-type phosphor Ca 9 Tb(PO 4) 5 (SiO 4)F 2 :Mn2+ (CTPSF:Mn2+) has been successfully synthesized and it demonstrated a potential for optical thermometry. The energy transfer process between Tb3+ and Mn2+ was of resonant type via a dipole-dipole mechanism based on the Inokuti–Hirayama theoretical model, and the energy transfer (ET) efficiency and ET rate were estimated. In view of the energy transfer behavior, a strategy, involving the use of Tb3+ and Mn2+ dual-emitting centers with different thermal quenching behavior, has been developed to achieve temperature sensitivity and good signal discrimination. The temperature dependence of the fluorescence intensity ratios (FIR) for the dual-emission bands peaking at 548 and 595 nm was studied in the range of 298–573 K under excitation of 377 nm ultraviolet light and the maximum relative sensitivity was approximately 1.92% K−1 at 423 K. It is expected that this preliminary study will provide an important advance in exploring novel ratiometric optical thermometry. Highlights • Novel apatite-type phosphor Ca 9 Tb(PO 4) 5 (SiO 4)F 2 was synthesized. • Energy transfer mechanism is estimated based on Inokuti–Hirayama model. • Non-contact thermometry was developed with a new inorganic material. • The maximum S r of the as-prepared phosphor was as high as 1.92% K−1. • This work provides an insight to design ratiometric optical thermometry. [ABSTRACT FROM AUTHOR]

A series of novel luminescent emission-tunable phosphors Mg 2 La 8 (SiO 4 ) 6 O 2 :Ce 3+ ,Tb 3+ (MLS:Ce 3+ ,Tb 3+ ) have been prepared by a solid-state reaction. The phase formation was firstly confirmed through X-ray diffraction technique and refined by the Rietveld method. The MLS:Ce 3+ ,Tb 3+ phosphors, which crystallized in apatite-type hexagonal phase, exhibited a broad excitation band ranging from 200 to 400 nm and several emission bands centered at 426 nm and 551 nm. Energy transfer from Ce 3+ to Tb 3+ ions via a dipole-dipole mechanism occurred in the as-synthesized phosphors upon ultraviolet (UV) excitation. The energy transfer efficiency increases with increasing doping content of Tb 3+ ions, which was confirmed by the luminescence spectra and fluorescence decay curves of corresponding ions simultaneously. The energy transfer critical distance was calculated and evaluated by both the concentration quenching and spectral overlap methods. The chromaticity of emission-tunable phosphors was also characterized by the Commission International de l'éclairage (CIE) chromaticity indexes, and the color tone can be tuned from blue (0.179, 0.122) to green (0.267, 0.408) by controlling the ratio of Ce 3+ /Tb 3+ . [ABSTRACT FROM AUTHOR]

A series of solid solution phosphors Ca 9 La(PO 4 ) 5 [(Si 1- x Ge x )O 4 ]F 2 :Ce 3+ with apatite structure in the P 6 3 / m space group have been prepared. The novel solid solution phosphors show continuously controlled violet-blue emission. It is found that both substantial spectra broadening (45 → 100 nm) and red-shift (404 → 422 nm) can be realized with the continuous introduction of [GeO 4 ] 4- into the crystal lattice which has been simulated by a crystal-field model. The above results indicate that the tetrahedral substitution is interesting to induce spectral tuning properties based on the chemical composition control of the iso-structural solid solutions. [ABSTRACT FROM AUTHOR]

Human induced pluripotent stem cells (hiPSCs) may provide potential resource for regenerative medicine research, including generation of insulin-producing cells for diabetes research and insulin production. Testosterone (T) is an androgen hormone which promotes protein synthesis and improves the management of type 2 diabetes in clinical studies. Concurrently, co-existed hyperandrogenism and hyperinsulinism is frequently observed in polycystic ovary syndrome, congenital adrenal hyperplasia and some of Wermer's syndrome. However, the relationship among androgens, insulin and the differentiation of pancreatic β cells is still not fully clear. Here we find that T improves the differentiation efficiency of insulin-producing cells from hiPSCs. The addition of T into routine differentiation formula for pancreatic β cells increases the differentiation efficiency from 12% to 35%. The administration of T promotes the expression of key genes associated with β cells differentiation including NGN3, NEUROD1 and INS. This finding benefits the ongoing process to optimize the differentiation protocol of pancreatic β cells from hiPSCs, and provides some degree of understanding the clinical management of T for type 2 diabetes. [ABSTRACT FROM AUTHOR]

The structural and luminescence properties of apatite-type compound Mn 2 Gd 8 (SiO 4 ) 6 O 2 have been investigated. The crystal structure of Mn 2 Gd 8 (SiO 4 ) 6 O 2 has been obtained from the X-ray diffraction data by Rietveld method in the hexagonal system, space group P6 3 / m , a = 9.3851 Å, c = 6.7904 Å, V = 517.97 Å 3 , Z = 1. The Mn 2 Gd 8 (SiO 4 ) 6 O 2 phase contains two cationic sites, one site ( 4f site with point symmetry C 3 ) is a distorted tricapped trigonal prismatic polyhedron formed by nine oxygen atoms, and other site ( 6h sites with point symmetry C s ) is an irregular polyhedron of pentagonal bipyramidal geometry with the coordination by seven oxygen atoms. It is found that the Mn 2+ ions occupy only 4f sites with C 3 point symmetry, that has been verified by photoluminescence spectrum and decay curves. This work provides an insight to the novel inorganic compound design and gives an impetus to discover new functional materials and develop new applications. [ABSTRACT FROM AUTHOR]

The Ca 9 La(PO 4 ) 5 (SiO 4 )Cl 2 :Dy 3+ (CLPSCl:Dy 3+ ) powder phosphor with apatite structure has been successfully synthesized via high-temperature solid state method. Single phase in such phosphor was verified through X-ray diffraction (XRD) technique. The Dy ions concentration dependent luminescence properties including emission, excitation and lifetimes of Dy ions were characterized using photoluminescence (PL) spectroscopy. The results showed that CLPSCl:Dy 3+ phosphor could efficiently assimilate the n -UV light and emit blue (~486 nm) and yellow light (~578 nm), originating from the f-f transitions of Dy 3+ . The critical Dy 3+ quenching concentration (QC) was determined to be about 12 mol%. The concentration quenching mechanism was also determined to be dipole–dipole interaction. [ABSTRACT FROM AUTHOR]

Tb 3+ -Sm 3+ co-doped Sr 9 Gd(PO 4 ) 5 (SiO 4 )F 2 (SGPSF) phosphors were prepared through a solid-state reaction, and their luminescence properties as well as energy transfer mechanism have been investigated in detail. The SGPSF:Tb 3+ , Sm 3+ phosphors system could be efficiently excited at wavelengths ranging from 200 to 500 nm, which is well matched with the spectra of near ultraviolet chips. The emission of SGPSF:Tb 3+ , Sm 3+ phosphor covers the entire visible region with sharp peaks in the blue, green, and red regions. The emission color of SGPSF:Tb 3+ , Sm 3+ could be adjusted from green (0.275, 0.378) to red (0.519, 0.295) by controlling the doping content of Sm 3+ /Tb 3+ . [ABSTRACT FROM AUTHOR]

This paper presents F2C, a cooperative resource management system for Infrastructure-as-a-Service (IaaS) clouds. Inspired by group-buying mechanisms in real product and service markets, F2C advocates a group of cloud tenants (called tenant coalition) to buy resource capacity in bulk and share the resource pool in the form of virtual machines (VMs). Tenant coalitions leads to vast opportunities for fine-grained resource sharing among multiple tenants. However, resource sharing, especially for multiple resource types, poses several challenging problems in pay-as-you-use cloud environments, such as sharing incentive, free-riding, lying and economic fairness. To address those problems, we propose Reciprocal Resource Fairness (RRF) , a novel resource allocation mechanism to enable fair sharing on multiple resource types within a tenant coalition. RRF is implemented in two complementary and hierarchical mechanisms: inter-tenant resource trading and intra-tenant weight adjustment. RRF satisfies several highly desirable properties to ensure fairness. We implement F2C in Xen platform. The experimental results show F2C is promising for both cloud providers and tenants. For cloud providers, F2C improves VM density and cloud providers’ revenue by 2.2X compared to the current IaaS cloud models. For tenants, F2C improves application performance by 45 percent and guarantees 95 percent economic fairness among multiple tenants. [ABSTRACT FROM PUBLISHER]

Tb 3+ –Sm 3+ co-doped Ba 3 NaLa(PO 4 ) 3 F phosphors with apatite structure have been prepared by a high temperature solid-state reaction, and their luminescence properties have been investigated in detail. The energy transfer (ET) mechanism was verified as the dipole–quadrupole mechanism, and the ET efficiency as well as the critical distance is also estimated. As a result of fine-tuning of the emission composition of the Tb 3+ and Sm 3+ ions, tunable luminescence properties can be realized by combining the emission of Tb 3+ and Sm 3+ in a single host lattice under UV light excitation. The emission color of the obtained phosphors can be modulated from green to yellow by controlling the doping content of the Sm 3+ ions with the fixed Tb 3+ content. Additional, as the temperature increases from RT to 150 °C, the PL intensities of Ba 3 NaLa 0.7 (PO 4 ) 3 F:0.10Tb 3+ ,0.20Sm 3+ decreased to 80.4% and 78.6% of the initial PL intensity, corresponding to the intensity of transition of Sm 3+ and transition of Tb 3+ in the Ba 3 NaLa 0.7 (PO 4 ) 3 F:0.10Tb 3+ ,0.20Sm 3+ phosphor, respectively. These results indicate the series of Ba 3 NaLa 1− x − y (PO 4 ) 3 F: x Tb 3+ , y Sm 3+ phosphors can be acted as a good candidate for the application in white light-emitting diodes. [ABSTRACT FROM AUTHOR]

A series of Eu 2+ and Eu 2+ /Tb 3+ co-doped Ba 3 GdNa(PO 4 ) 3 F phosphors have been synthesized via a high temperature solid-state reaction. The relative intensity of PL spectra of Ba 3 GdNa(PO 4 ) 3 F: x Eu 2+ increases with increasing x value, and reaches a maximum at x =0.04. Ba 3 GdNa(PO 4 ) 3 F:Eu 2+ , Tb 3+ phosphors exhibit a broad excitation band ranging from 220 to 450 nm, which matches perfectly with the characteristic emission of n -UV light-emitting diode (LED) chips. Upon 365 nm excitation, the Ba 3 GdNa(PO 4 ) 3 F:Eu 2+ , Tb 3+ phosphors show two dominating bands peaked at 466 and 543 nm, which are assigned to the 4f 7 →4f 6 5d 1 transition of the Eu 2+ ions and the 5 D 4 → 7 F 5 transition of the Tb 3+ ions, respectively. In view of the energy transfer mechanism between Eu 2+ and Tb 3+ , the Ba 3 GdNa(PO 4 ) 3 F:Eu 2+ , Tb 3+ emission color can adjust from blue to green, and their chromatic coordinates ( x , y ) vary from (0.16, 0.135) to (0.254, 0.398). The critical distance was also calculated to be 16.90 Å. The above results indicate that the Ba 3 GdNa(PO 4 ) 3 F: Eu 2+ , Tb 3+ phosphors are a candidate for blue–green components in the application of n -UV w -LEDs. [ABSTRACT FROM AUTHOR]

In virtualization environments, static memory allocation for virtual machines (VMs) can lead to severe service level agreement (SLA) violations or inefficient use of memory. Dynamic memory allocation mechanisms such as ballooning and memory hotplug were proposed to handle the dynamics of memory demands. However, these mechanisms so far have not been quantitatively or comparatively studied. In this paper, we first develop a runtime system called U-tube, which provides a framework to adopt memory hotplug or ballooning for dynamic memory allocation. We then implement fine-grained memory hotplug in Xen. We demonstrate the effectiveness of U-tube for dynamic memory management through two case studies: dynamic memory balancing and memory overcommitment. With these two case studies, we make a quantitative comparison between memory hotplug and ballooning. The experiments show that there is no absolute winner for different scenarios. Our findings can be very useful for practitioners to choose the suitable dynamic memory management techniques in different scenarios. [ABSTRACT FROM AUTHOR]

Enabled by virtualization technologies, various multi-tier applications (such as web applications) are hosted by virtual machines (VMs) in cloud data centers. Live migration of multi-tier applications across geographically distributed data centers is important for load management, power saving, routine server maintenance and quality-of-service. Different from a single-VM migration, VMs in a multi-tier application are closely correlated, which results in a correlated VM migrations problem. Current live migration algorithms for single-VM cause significant application performance degradation because intermediate data exchange between different VMs suffers relatively low bandwidth and high latency across distributed data centers. In this paper, we design and implement a coordination system called VMbuddies for correlated VM migrations in the cloud. Particularly, we propose an adaptive network bandwidth allocation algorithm to minimize the migration cost in terms of migration completion time, network traffic and migration downtime. Experiments using a public benchmark show that VMbuddies significantly reduces the performance degradation and migration cost of multi-tier applications. [ABSTRACT FROM AUTHOR]

Eu 2+ –Tb 3+ co-doped Sr 3.5 Y 6.5 O 2 (PO 4 ) 1.5 (SiO 4 ) 4.5 (SYPSO) phosphors with apatite structure have been synthesized via a high temperature solid-state reaction and their luminescence properties have been investigated in detail. The two kinds of cations׳ sites and complex phosphate-silicate anions׳ structural character of SYPSO host have been studied. The SYPSO:Eu 2+ ,Tb 3+ phosphors show a broad absorption band ranging from 250 to 420 nm, which is well matched with the emission of near ultraviolet (UV) chips, and it exhibited two dominating bands peaked at 502 and 543 nm upon 365 nm excitation. The emission color of SYPSO:0.05Eu 2+ , y Tb 3+ shows a controlled luminescence evolution of the color hue in the green area owing to the Eu 2+ –Tb 3+ energy transfer (ET) process, and their chromaticity coordinates ( x , y ) can be varied from (0.2723, 0.3766) to (0.2812, 0.4537). The ET efficiency as well as the critical distance is also estimated. The quantum efficiency and thermal quenching properties have also been studied in this paper in order to demonstrate its potential application for white light-emitting diodes ( w -LEDs) phosphors. [ABSTRACT FROM AUTHOR]

The substituted activator ions Eu2+ in the β-Ca3(PO4)2-type structure, Ca9NaMg(PO4)7 compound, have been studied as emission centers, as well as structural probes. The crystal structure and crystallographic sites of Eu2+ in Ca9NaMg(PO4)7 have been identified by Rietveld refinements, electron paramagnetic resonance (EPR) spectroscopy analysis and combined photoluminescence spectral analysis, respectively. Ca9NaMg(PO4)7:Eu2+ phosphor exhibits a broad emission band in the visible light region with three distinguished peaks centered at 415, 458, and 615 nm, which are ascribed to different Eu2+ emission centers occupied in three different Ca crystallographic sites. The concentration quenching behavior, variation in lifetimes and the temperature dependent luminescence properties have been investigated as a function of different emission centers, 415, 458, and 625 nm for Ca9NaMg(PO4)7:Eu2+ phosphor. Accordingly, the relationship among three different Eu2+ luminescence centers originating from three different Ca2+ crystallographic sites has been found and verified. [ABSTRACT FROM AUTHOR]

Abstract: We report a series of color-tunable Sr3.45Y6.5O2(PO4)1.5(SiO4)4.5:Eu2+,Mn2+ (SYPSO:Eu2+,Mn2+) phosphors in this work. The photoluminescence excitation and emission spectra, lifetime, and concentration-dependent effect were investigated, respectively. The energy transfer (ET) mechanism was verified as the dipole–dipole interaction, and the ET efficiency as well as the critical distance is also estimated. The emission colors of the obtained phosphors can be tuned from green to yellow by controlling the doping content of the Mn2+ ions with the fixed Eu2+ content. These results indicate that SYPSO:Eu2+,Mn2+ can be acted as a good candidate for the application in white light-emitting diodes. [Copyright &y& Elsevier]

Live migration of virtual machine (VM) provides a significant benefit for virtual server mobility without disrupting service. It is widely used for system management in virtualized data centers. However, migration costs may vary significantly for different workloads due to the variety of VM configurations and workload characteristics. To take into account the migration overhead in migration decision-making, we investigate design methodologies to quantitatively predict the migration performance and energy consumption. We thoroughly analyze the key parameters that affect the migration cost from theory to practice. We construct application-oblivious models for the cost prediction by using learned knowledge about the workloads at the hypervisor (also called VMM) level. This should be the first kind of work to estimate VM live migration cost in terms of both performance and energy in a quantitative approach. We evaluate the models using five representative workloads on a Xen virtualized environment. Experimental results show that the refined model yields higher than 90% prediction accuracy in comparison with measured cost. Model-guided decisions can significantly reduce the migration cost by more than 72.9% at an energy saving of 73.6%. [ABSTRACT FROM AUTHOR]

Processing-In-Memory(PIM) has emerged as a high-performance and energy-efficient computing paradigm for accelerating convolutional neural network (CNN) applications. Resistive random access memory (ReRAM) has been widely used in PIM architectures due to its extremely high efficiency for accelerating matrix-vector multiplications through analog computing. However, because CNN training usually requires high-precision computation in the backward propagation (BP) stage, the limited precision of analog PIM accelerators impedes their adoption in CNN training. In this article, we propose ReHy, a hybrid PIM accelerator to support CNN training in ReRAM arrays. It is composed of Analog PIM (APIM) and Digital PIM (DPIM) modules. ReHy uses APIM to accelerate the feed-forward propagation (FP) stage for high performance, and DPIM to process the BP stage for high accuracy. We exploit the capability of ReRAM for Boolean logic operations to design the DPIM architecture. Particularly, we design floating-point multiplication and addition operators to support matrix multiplications in ReRAM arrays. We also propose a performance model to offload high-precision matrix multiplications to DPIM according to the data parallelism. Experimental results show that ReHy can speed up CNN training by 48.8× and 2.4×, and reduce energy consumption by 35.1× and 2.33×, compared with CPU/GPU architectures (baseline) and the state-of-the-art FloatPIM, respectively. [ABSTRACT FROM AUTHOR]

Abstract: SiO2-coated Ca2BO3Cl:Eu2+ phosphors were prepared by the sol–gel method in order to enhance the chemical and thermal stabilities of Ca2BO3Cl:Eu2+ phosphor. The phase structures, microstructures and luminescence properties were studied by the X-ray diffraction (XRD), scanning electron microscopy (SEM) and fluorescence spectrometer, respectively. The emission intensity of SiO2-coated Ca2BO3Cl:Eu2+ phosphor decreased a little compared to that of the uncoated phosphor. The moisture resistances of the phosphors were comparatively examined by the aging treatment experiment in the water, and the thermal stability was studied by the temperature dependent photoluminescence spectra. The results indicated that SiO2 coating on the surface of the phosphor particles improved the moisture-resistance and thermal stability to a large extent. [Copyright &y& Elsevier]

The Sr 2 La 8 (SiO 4 ) 6 O 2 :Ce 3+ powder phosphor with apatite structure has been successfully synthesized via a facile route of sol-combustion technique. X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), and photoluminescence (PL) spectroscopy were used to characterize the as-prepared samples. Sr 2 La 8 (SiO 4 ) 6 O 2 :Ce 3+ phosphor was composed of particles with average sizes range about 300 nm. The phosphor exhibited an absorption ranging from 220 to 390 nm in ultraviolet range and a broad blue-violet emission band peaked at 403 nm with a CIE coordinates of (0.167, 0.028). The concentration quenching mechanism was also determined to be dipole–dipole interaction. [ABSTRACT FROM AUTHOR]

• Chicken EDN1 , EDN2, and EDN3 cDNAs were cloned from heart or brain. • Chicken EDNRA can be potently activated by cEDN1 and cEDN2. • Chicken EDNRB and EDNRB2 can be potently activated by three EDNs. • Activation of three cEDNRs stimulates multiple signaling pathways. • cEDNs / cEDNRs are widely, but differentially, expressed in adult chicken tissues. Endothelins (EDNs) and their receptors (EDNRs) are reported to be involved in the regulation of many physiological/pathological processes, such as cardiovascular development and functions, pulmonary hypertension, neural crest cell proliferation, differentiation and migration, pigmentation, and plumage in chickens. However, the functionality, signaling, and tissue expression of avian EDN-EDNRs have not been fully characterized, thus impeding our comprehensive understanding of their roles in this model vertebrate species. Here, we reported the cDNAs of three EDN genes (EDN1 , EDN2 , EDN3) and examined the functionality and expression of the three EDNs and their receptors (EDNRA, EDNRB and EDNRB2) in chickens. The results showed that: 1) chicken (c-) EDN1 , EDN2 , and EDN3 cDNAs were predicted to encode bioactive EDN peptides of 21 amino acids, which show remarkable degree of amino acid sequence identities (91–95%) to their respective mammalian orthologs; 2) chicken (c-) EDNRA expressed in HEK293 cells could be preferentially activated by chicken EDN1 and EDN2, monitored by the three cell-based luciferase reporter assays, indicating that cEDNRA is a functional receptor common for both cEDN1 and cEDN2. In contrast, both cEDNRB and cEDNRB2 could be activated by all three EDN peptides with similar potencies, indicating that both receptors can function as common receptors for the three EDNs and share functional similarity. Moreover, activation of three EDNRs could stimulate intracellular calcium, MAPK/ERK, and cAMP/PKA signaling pathways. 3) qPCR assay revealed that cEDNs and cEDNRs are widely, but differentially, expressed in adult chicken tissues. Taken together, our data establishes a clear molecular basis to uncover the physiological/pathological roles of EDN-EDNR system in birds and helps to reveal the conserved actions of EDN-EDNR signaling across vertebrates. [ABSTRACT FROM AUTHOR]

Carbon allocation has been fundamental for long‐lived trees to survive cold stress at their upper elevation range limit. Although carbon allocation between non‐structural carbohydrate (NSC) storage and structural growth is well‐documented, it still remains unclear how ongoing climate warming influences these processes, particularly whether these two processes will shift in parallel or respond divergently to warming. Using a combination of an in situ downward‐transplant warming experiment and an ex situ chamber warming treatment, we investigated how subalpine fir trees at their upper elevation limit coordinated carbon allocation priority among different sinks (e.g., NSC storage and structural growth) at whole‐tree level in response to elevated temperature. We found that transplanted individuals from the upper elevation limit to lower elevations generally induced an increase in specific leaf area, but there was no detected evidence of warming effect on leaf‐level saturated photosynthetic rates. Additionally, our results challenged the expectation that climate warming will accelerate structural carbon accumulation while maintaining NSC constant. Instead, individuals favored allocating available carbon to NSC storage over structural growth after 1 year of warming, despite the amplification in total biomass encouraged by both in situ and ex situ experimental warming. Unexpectedly, continued warming drove a regime shift in carbon allocation priority, which was manifested in the increase of NSC storage in synchrony to structural growth enhancement. These findings imply that climate warming would release trees at their cold edge from C‐conservative allocation strategy of storage over structural growth. Thus, understanding the strategical regulation of the carbon allocation priority and the distinctive function of carbon sink components is of great implication for predicting tree fate in the future climate warming. [ABSTRACT FROM AUTHOR]

Current DRAM-based memory systems face the scalability challenges in terms of memory density, energy consumption, and monetary cost. Hybrid memory architectures composed of emerging nonvolatile memory (NVM) and DRAM is a promising approach to large-capacity and energy-efficient main memory. However, hybrid memory systems pose a new challenge to on-chip cache management due to the asymmetrical penalty of memory access to DRAM and NVM in case of cache misses. Cache hit rate is no longer an effective metric for evaluating memory access performance in hybrid memory systems. Current cache replacement policies that aim to improve the cache hit rate are not efficient either. In this article, we take into account the asymmetry of the cache miss penalty on DRAM and NVM, and advocate a more general metric, average memory access time (AMAT), to evaluate the performance of hybrid memories. We propose a miss penalty aware LRU-based cache replacement policy (MALRU) for hybrid memory systems. MALRU is aware of the source (DRAM or NVM) of missing blocks and preserves high-latency NVM blocks as well as low-latency DRAM blocks with good temporal locality in the last level cache. The experimental results show that MALRU can improve system performance by up to 22.8% and 13.1%, compared to LRU and the state-of-the-art hybrid memory aware cache partitioning technique policy, respectively. [ABSTRACT FROM AUTHOR]

A novel orange-red emitting orthosilicate phosphor LiGd 9 (SiO 4) 6 :Mn2+ (LGS:Mn2+) belongs to hexagonal lattice with P 6 3 / m space group was synthesized via solid-state method and the phase composition, crystal structure as well as luminescence properties were examined for potential application in near ultraviolet (n -UV) pumped white light emitting diodes (w -LEDs). The as-prepared LGS:Mn2+ phosphor exhibits three excitation bands peaked at 273, 312 and 410 nm, which corresponds to the transitions of Gd3+ from ground state 8S 7/2 to 6I 7/2 , 6P 7/2 and Mn2+ from ground state 6A 1 (6S) to the individual components of the multiplets [4A 1 (4G), 4E(4G)], respectively. Upon excitation at 312 nm, the phosphors display an intense broad orange-red emission peaked around 594 nm, which ascribed to the typical spin-forbidden transition (4T 1 (4G)-6A 1 (6S)) of the Mn2+ ions. The concentration quenching mechanism and average separation distance in conjunction with fluorescence decay times of Mn2+ ions in LGS:Mn2+ phosphor were discussed. The indispensable parameters for application in n -UV high-powered w -LEDs, such as the thermal quenching of photoluminescence and internal quantum efficiency of LGS:Mn2+ phosphor, have also been investigated in detail. The above results indicate that LGS:Mn2+ could play a key role as an orange-red emission for potential application in n -UV-based w -LEDs. • LiGd 9 (SiO 4) 6 O 2 :Mn2+ luminescent materials were synthesized successfully. • This phosphor have excellent thermal stability and emission efficiency. • High energy transfer efficiency could be obtained between Gd3+ and Mn2+ ions. [ABSTRACT FROM AUTHOR]

Abstract A series of novel luminescence phosphors Ca 9 La(PO 4) 5 (SiO 4)Cl 2 : x Eu2+ (CLPSCl:Eu2+) with apatite structure have been synthesized by a high temperature solid-state reaction. The phased purity of as-prepared phosphors was verified through XRD technique. For further discussion, a series of analysis were performed such as the photoluminescence emission and excitation spectrum and decay lifetime to identify the luminescent properties of CLPSCl:Eu2+ phosphors. The CLPSCl:Eu2+ displays broad excitation spectra ranging from 250 to 450 nm, and intends emission intensity at 461 nm under 345 nm. The optimum Eu2+ concentration of CLPSCl is 8 mol%. The luminescence decay lifetime of the optimum phosphors was measured to be 275 ns. All of the results obtained highly indicate that CLPSCl:Eu2+ is potentially blue-emitting phosphor for application in white LEDs. [ABSTRACT FROM AUTHOR]

Abstract A single-component white-emitting phosphor Sr 9 La(PO 4) 5 (SiO 4)F 2 :Dy3+ pumped for n -UV-light emitting diodes was firstly presented by solid state method and the crystal structures, luminescence properties, especially the concentration quenching behaviors were discussed in detail. Accordingly, the quantum efficiencies as well as lifetime studies of Dy3+ in CLPGF phosphor were also carried out. The results revealed that the Sr 9 La(PO 4) 5 (SiO 4)F 2 :Dy3+ phosphor could be efficiently excited in a broad wavelength ranging near ultraviolet (n -UV) regions, which matched perfectly with n -UV white light emitting diodes (w -LEDs) chips. Under the excitation at 349 nm, the phosphor exhibited three prominent emission peaks in the visible wavelength region located at 483, 578 and 670 nm, which is ascribed to the 4F 9/2 -6H 15/2 , 4F 9/2 -6H 13/2 and 4F 9/2 -6H 11/2 transitions of Dy3+, respectively. It was also proved that the dipole-dipole interactions results in the concentration quenching in Sr 9 La(PO 4) 5 (SiO 4)F 2 :Dy3+ phosphors. Fascinatingly, when the temperature turned up to 150 °C, the emission intensity at 483 and 578 nm was 83.4 and 89.1% of the initial value at room temperature. Additional, the corresponding activation energy Δ E was determined to be 0.16999 and 0.17451 eV, which indicated the excellent thermal stability of the samples. All these findings demonstrated that as-prepared phosphors could act as a high-performance candidate for the application. Highlights • A single-component white-emitting phosphor has been successfully prepared. • As-prepared phosphor has good thermal stability and luminescence efficiency. • The structural data of Sr 9 La(PO 4) 5 (SiO 4)F 2 :Dy3+ is firstly reported. [ABSTRACT FROM AUTHOR]

Ca9La(PO4)5 (SiO4)F2:Dy3+ is prepared by solid state reaction of stoichiometric quantities of CaCO3, (NH4)2HPO4, SiO2, Dy2O3, and excess NH4HF2 as a flux ( 5% H2/N2 reducing atmosphere, alumina crucible, 1450 °C, 5 h). [ABSTRACT FROM AUTHOR]

Two-dimensional nanomaterials hold great promise as electrode materials for the construction of excellent electrochemical energy storage and transformation apparatuses. In the study, metallic layered cobalt sulfide was, firstly, applied to the area of energy storage as a supercapacitor electrode. By a facile and scalable method for cathodic electrochemical exfoliation, metallic layered cobalt sulfide bulk can be exfoliated into high-quality and few-layered nanosheets with size distributions in the micrometer scale range and thickness in the order of several nanometers. With a two-dimensional thin sheet structure of metallic cobalt sulfide nanosheets, not only was a larger active surface area created, but also, the insertion/extraction of ions in the procedure of charge and discharge were enhanced. The exfoliated cobalt sulfide was applied as a supercapacitor electrode with obvious improvement compared with the original sample, and the specific capacitance increased from 307 F∙g−1 to 450 F∙g−1 at the current density of 1 A∙g−1. The capacitance retention rate of exfoliated cobalt sulfide enlarged to 84.7% from the original 81.9% of unexfoliated samples while the current density multiplied by 5 times. Moreover, a button-type asymmetric supercapacitor assembled using exfoliated cobalt sulfide as the positive electrode exhibits a maximum specific energy of 9.4 Wh∙kg−1 at the specific power of 1520 W∙kg−1. [ABSTRACT FROM AUTHOR]

Dopamine (DA) D2-like (and D1-like) receptors are suggested to mediate the dopamine actions in the anterior pituitary and/or CNS of birds. However, the information regarding the structure, functionality, and expression of avian D2-like receptors have not been fully characterized. In this study, we cloned two D2-like receptors (c DRD2 , c DRD4 ) from chicken brain using RACE PCR. The cloned cDRD4 is a 378-amino acid receptor, which shows 57% amino acid (a.a.) identity with mouse DRD4. As in mammals, two cDRD2 isoforms, cDRD2L (long isoform, 437 a.a.) and cDRD2S (short isoform, 408 a.a.), which differ in their third intracellular loop, were identified in chickens. Using cell-based luciferase reporter assays or Western blot, we demonstrated that cDRD4, cDRD2L and cDRD2S could be activated by dopamine and quinpirole (a D2-like receptor agonist) dose-dependently, and their activation inhibits cAMP signaling pathway and stimulates MAPK/ERK signaling cascade, indicating that they are functional receptors capable of mediating dopamine actions. Quantitative real-time PCR revealed that cDRD2 and cDRD4 are widely expressed in chicken tissues with abundant expression noted in anterior pituitary, and their expressions are likely controlled by their promoters near exon 1, as demonstrated by dual-luciferase reporter assays in DF-1 cells. In accordance with cDRD2 / cDRD4 expression in the pituitary, DA or quinpirole could partially inhibit vasoactive intestinal peptide-induced prolactin expression in cultured chick pituitary cells. Together, our data proves the functionality of DRD2 and DRD4 in birds and aids to uncover the conserved roles of DA/D2-like receptor system in vertebrates, such as its action on the pituitary. [ABSTRACT FROM AUTHOR]

A novel apatite structure phosphor Ca 9 La(PO 4 ) 5 (GeO 4 )F 2 :Dy 3+ (CLPGF:Dy 3+ ) with a hexagonal lattice in the P 6 3 / m space group was synthesized via a facile solid state technique. The crystal and fine local structure as well as their photoluminescence properties were investigated in detail. The CLPGF:Dy 3+ phosphor can absorb in the UV-vis spectral region of 290–475 nm and exhibit two intense emission bands centered at 485 and 580 nm, which ascribes to 4 F 9/2 → 6 H 15/2 and 4 F 9/2 → 6 H 13/2 transitions of Dy 3+ , respectively. The concentration quenching of Dy 3+ emission occurs via the energy transfer among the nearest-neighbor ions and the corresponding quenching mechanism was verified to be the dipole-dipole interaction. The quantum efficiencies of the phosphors were examined to be 72.9% and its luminescence intensity at 150 °C decreases to 93.8% and 98.6% of the initial value at room temperature, which corresponds to 4 F 9/2 to 6 H 15/2 transition and 4 F 9/2 to 6 H 13/2 transition of Dy 3+ ions, respectively. Their interesting photoluminescence properties indicate that the CLPGF:Dy 3+ phosphor is a promising white-emitting candidate for w -LEDs applications. [ABSTRACT FROM AUTHOR]

The simple high-temperature solid-state route was adopted to synthesize a series of related Ba 3 LaK(PO 4 ) 3 F: x Eu 2+ (BLKPF: x Eu 2+ ) blue phosphors. The photoluminescence (PL) and diffuse reflection spectra have been investigated in detail. These phosphors which can be well excited by the 388 nm near ultraviolet light, produce the emitted blue light peaks located at about 460 nm. The critical Eu 2+ concentration quenching mechanism was ascribed to the dipole–dipole interaction, and the optimum concentration was eventually proved to be 0.1 mol. All above results indicate that Ba 3 LaK(PO 4 ) 3 F: x Eu 2+ phosphor can act as an appropriate candidate of the blue phosphor in the future. [ABSTRACT FROM AUTHOR]

In this paper, La 1.45 Ce 0.05 Ba 3.5 (SiO 4 ) 1.5 (PO4) 1.5 F compound with apatite structure was synthesized via solid state reaction method. The phosphor exhibits two strong excitation bands at 279 nm and 345 nm in near ultraviolet light region. When excited at 345 nm, the emission peaks of the phosphor give a red-shift from 406 nm to 418 nm compared with that of 279 nm excitation. Besides, the site occupation of Ce 3+ was proposed based on structure refinement, luminescence, fluorescence decay curves, as well as CIE diagram. All the results indicated that Ce 3+ can occupy sites of La 3+ with nine and seven coordination and a possible mechanism was proposed to explain the luminescence properties observed. [ABSTRACT FROM AUTHOR]

A series of Dy3+-doped MGd 9 (SiO 4) 6 O 2 :Dy3+ (M = Li, Na, K) phosphors that generated white emission were prepared using the high temperature solid-state technique. Simultaneously, the phase composition, crystal structure, electronic structure, as well as the luminescence properties of the as-prepared phosphors were investigated in detail. The structural refinement showed that the MGd 9 (SiO 4) 6 O 2 crystallized with the hexagonal apatite-type structure. The unit cell parameters increased gradually and the main peaks of the samples in XRD patterns shifted towards high angles with the substitution of alkali-metal ions (from Li+ to K+). Under the excitation of 350 nm, the as-obtained MGd 9 (SiO 4) 6 O 2 :Dy3+ phosphors gave bright white emission with the major emission peaks centering at 454, 477 and 573 nm. And the R y/b , CIE chromaticity coordinate and the corrected color temperature (CCT) of the phosphors were adjusted from 0.96, (0.3256, 0.3625) and 4602 K to 1.13, (0.3369, 0.3582) and 4201 K attributing to the substitution in the crystal structure. The thermoluminescence study of MGd 8.90 (SiO 4) 6 O 2 :0.10Dy3+ (M = Li, Na, K) showed good stability and the decay lifetimes of the samples were estimated to be about 470 μs. All the results suggested that the luminescence properties could be modified by the substitution of alkali metal ions, and the MGd 9 (SiO 4) 6 O 2 :Dy3+ (M = Li, Na, K) phosphors have potential application as white emission candidate for w -LEDs. • Novel Dy3+ doped apatite structure phosphors were successfully synthesized. • The symmetrical environment could be modified to a certain extent owing to substitution of alkali metal ions. • The DFT calculation was used to check the electronic structure. [ABSTRACT FROM AUTHOR]

Live migration of virtual machines (VM) across physical hosts provides a significant new benefit for administrators of data centers and clusters. Previous memory-to-memory approaches demonstrate the effectiveness of live VM migration in local area networks (LAN), but they would cause a long period of downtime in a wide area network (WAN) environment. This paper describes the design and implementation of a novel approach, namely, CR/TR-Motion, which adopts checkpointing/recovery and trace/replay technologies to provide fast, transparent VM migration for both LAN and WAN environments. With execution trace logged on the source host, a synchronization algorithm is performed to orchestrate the running source and target VMs until they reach a consistent state. CR/TR-Motion can greatly reduce the migration downtime and network bandwidth consumption. Experimental results show that the approach can drastically reduce migration overheads compared with memory-to-memory approach in a LAN: up to 72.4 percent on application observed downtime, up to 31.5 percent on total migration time, and up to 95.9 percent on the data to synchronize the VM state. The application performance overhead due to migration is kept within 8.54 percent on average. The results also show that for a variety of workloads migrated across WANs, the migration downtime is less than 300 milliseconds. [ABSTRACT FROM PUBLISHER]

An appropriate solid-state route was adopted to synthesize a series of related Ba 3 Sc(PO 4 ) 3 : x Sm 3+ red-orange phosphors. The Rietveld method was used to explore the structure of the phosphor. At present the PL, PLE, diffuse reflection and decay curves have been investigated in detail. These phosphors can be accurately excited by the 406 nm n-UV light and produce the emitted red-orange light whose peaks locate at about 566 nm, 603 nm and 650 nm. The quantum efficiency of Ba 3 Sc 0.95 (PO 4 ) 3 :0.05Sm 3+ was 53.5%. All above results indicate that Ba 3 Sc(PO 4 ) 3 :Sm 3+ phosphor can act as a suitable candidate of the warm components of n -UV w-LEDs. [ABSTRACT FROM AUTHOR]

Ba 3 Sc(PO 4 ) 3 :Eu 2+ ,Tb 3+ (BSP:Eu 2+ ,Tb 3+ ) phosphors were successfully prepared via conventional high-temperature solid-state reaction, their luminescence properties as well as energy transfer mechanism have been investigated in detail. The energy transfer mechanism was proposed to be the dipole–quadrupole mechanism, and the energy transfer efficiency was also estimated. BSP:Eu 2+ ,Tb 3+ phosphors showed a broad emitting band centered at 518 nm and several sharp emission peaks, which were assigned to the 5 d →4 f allowed transitions of Eu 2+ ions and characteristic optical 5 D 4 – 7 F J ( J =6, 5, 4, and 3) transitions of Tb 3+ ions, respectively. The emission color of BSP:Eu 2+ , y Tb 3+ exhibited a controlled luminescence evolution in the green area owing to the Eu 2+ –Tb 3+ energy transfer process. [ABSTRACT FROM AUTHOR]

Er 3+ and/or Yb 3+ doped Sr 2 ScF 7 up-conversion (UC) phosphors were synthesized, and the optimum doping concentrations of Yb 3+ and Er 3+ in the Sr 2 ScF 7 host were found to be 20% mol and 7% mol, respectively. Under excitation of 980 nm laser, the UC spectra of the samples is composed of three green emission bands from 510 to 570 nm centered at 525, 543 and 551 nm and two red emission band from 640 to 690 nm with two peaks at 657 and 671 nm, which is attributed to the 2 H 11/2 , 4 S 3/2 → 4 I 15/2 and 4 F 9/2 → 4 I 15/2 transitions of Er 3+ , respectively. The UC emission color of Er 3+ can be tuned by adjusting the intensity ratio of red to green emission through manipulating the population of red and green emitting states. [ABSTRACT FROM AUTHOR]

SrAl 2 Si 2 O 8 : x Eu ( x = 0.5–8%) phosphors were prepared by the high-temperature solid-state reaction in air atmosphere. The phenomenon of Eu 2+ /Eu 3+ coexistence was observed and the color of the SrAl 2 Si 2 O 8 : x Eu phosphor could shift from light pink to blue by controllable and reproducible means. Photoluminescence (PL), excitation (PLE) spectra, X-ray photoelectron spectroscopy (XPS), and the fluorescence decay curves were employed to detect the presence of Eu 2+ and Eu 3+ ions in the compound. Under ultraviolet excitation, the broad band emission peaked at 410 nm originated from the transition of 4 f 6 5 d –4 f 7 from Eu 2+ and narrow band emissions peaked at 591 nm, 614 nm, 655 nm, and 703 nm are derived from the 4 f –4 f transition of Eu 3+ ions, although the Eu 3+ precursors were employed. The reduction mechanism from Eu 3+ to Eu 2+ in this compound was discussed in detail and verified by photoluminescence properties through changing the addition amount of Eu, temperature rise and holding time. [ABSTRACT FROM AUTHOR]

Emission-tunable phosphors Ca 9 La(PO 4 ) 5 (SiO 4 )F 2 :Ce 3+ ,Tb 3+ with apatite structure were synthesized by a solid-state reaction. The phase structure, photoluminescence (PL) properties, lifetimes and the PL thermal stability were investigated, respectively. The phosphor exhibited an asymmetric broad-band blue emission (Ce 3+ ) with peak at 403 nm and the line-type green emission with peak at 543 nm (Tb 3+ ). The varied color of the phosphors from blue to green can be achieved by properly tuning the relative ratio of Ce 3+ /Tb 3+ through the energy transfer from Ce 3+ to Tb 3+ ions. The critical distance was calculated to be 8.78 Å by using the concentration quenching method. When the temperature turned up to 150 °C, the emission intensity of Ca 9 La(PO 4 ) 5 (SiO 4 )F 2 :Ce 3+ ,Tb 3+ phosphor was 77% of its initial value at room temperature, which indicated the good thermal stability of the sample. All the properties indicate that the Ca 9 La(PO 4 ) 5 (SiO 4 )F 2 :Ce 3+ ,Tb 3+ phosphor has potential application of color-tunable w -LEDs. [ABSTRACT FROM AUTHOR]

[Display omitted] • Al, as a non-transition metal, is doped on phosphorene for electrochemical nitrogen reduction for the first time. • Dual-atom para -doping of Al on phosphorene exhibits the promising performance with an ultra-low over-potential of 0.15 V. • Meanwhile, it possesses high thermal stability under ambient conditions indicated by ab initio molecular dynamics. The electrochemical nitrogen reduction reaction (NRR) is regarded as the most promising alternative to the traditional Haber-Bosch route in current context of developing sustainable and green technologies. However, challenges around low kinetics and low selectivity of NRR are significant barriers for this enticing goal. Different from the transition metal-based NRR catalysts that are prevalent in artificial nitrogen fixation, here, novel p-block non-transition metal catalysts, constructed from an Al-doped phosphorene monolayer, are reported for electrochemical NRR through the density functional theory (DFT) calculations for the first time. We surmised the empty sp3-orbital of doped Al with sp3 hybridization can act as strong Lewis acid sites for N 2 adsorption and activation. Among investigated concept-models, Al 2 @P (-para) exhibits a high activity with an ultra-low limiting potential (U L) of −0.31 V, significantly exceeding the benchmark stepped Ru(0001) surface (U L = −0.98 V), which originates from the strong Lewis acid property of Al sites, good activation on adsorbed N 2 , and improved redox capacity by 2D phosphorene electron reservoir. Additionally, Al 2 @P (-para) demonstrates high NRR selectivity and thermal stability under ambient conditions. This research offers a new way of designing effective catalysts and will further boost the study of p-block elements for NRR. [ABSTRACT FROM AUTHOR]

[Display omitted] • The single Fe atom loaded on anatase TiO 2 (001) has excellent stability. • Fe/TiO 2 (001) shows well-balanced activity for nitrogen reduction reaction. • Fe promotes TiO 2 electron-hole separation to enhance photocatalytic performance. In great contrast to energy-extensive Haber-Bosch process, electrochemical nitrogen reduction reaction offers green and sustainable ammonia production at ambient reaction conditions. Among them, the demand for low-consumption and high-performance non-noble-metal catalysts is still a hot spot in the field of electrocatalysts. Herein, we demonstrate that single Fe atom loaded on anatase TiO 2 (0 0 1) shows well-balanced activity for N 2 fixation and NH 3 dissociation. In addition, it is active to catalyze nitrogen reductions with the initial hydrogenation to the distal N as the potential-determining step (1.27 eV). Considering that TiO 2 is a model photocatalyst, single Fe atom can promote electron-hole separation to enhance the photocatalytic performance. Thus, Fe/TiO 2 (0 0 1) has been identified as a potential catalyst for photo-electrochemical ammonia synthesis. [ABSTRACT FROM AUTHOR]

Highlights: [•] Novel Na0.60Ca0.40Sc0.60Mg0.40Si2O6:Eu2+,Mn2+ phosphors have been prepared. [•] Full-color white emission can be realized in the single host with different emission centers. [•] A white LED lamp was fabricated to demonstrate good luminescence properties. [ABSTRACT FROM AUTHOR]

Highlights: [•] Blue-emitting phosphor K2Ca2Si2O7:Ce3+ was synthesized. [•] The critical quenching concentration and concentration quenching mechanism was discussed. [•] Ce3+ emission centre in K2Ca2Si2O7 were studied by the photoluminescence spectra and decay curves. [ABSTRACT FROM AUTHOR]

Highlights: [•] Ca10(PO4)6F2:Bi3+, Eu3+ phosphors have been synthesized. [•] Energy transfer happens from Bi3+ to Eu3+ with an optimum efficiency of 50.3%. [•] The energy transfer mechanism has been discussed. [ABSTRACT FROM AUTHOR]

DNA-double strand break (DSB), detected by immunostaining of key proteins orchestrating repair, like γH2AX and 53BP1, is well established as a surrogate for tissue radiosensitivity. We hypothesized that the generation of normal brain 3D organoids ("mini-brains") from human induced pluripotent stem cells (hiPSC) combined with detection of DNA damage repair (DDR) may hold the promise towards developing personalized models for the determination of normal tissue radiosensitivity. In this study, cerebral organoids, an in vitro model that stands in its complexity between 2D cellular system and an organ, have been used. To quantify radiation-induced response, immunofluorescent staining with γH2AX and 53BP1 were applied at early (30 min, initial damage), and late time points (18 and 72 h, residual damage), following clinical standard 2 Gy irradiation. Based on our findings, assessment of DDR kinetics as a surrogate for radiosensitivity in hiPSC derived cerebral organoids is feasible. Further development of mini-brains recapitulating mature adult neuronal tissue and implementation of additional signaling and toxicity surrogates may pave the way towards development of next-generation personalized assessment of radiosensitivity in healthy neuronal tissue. [ABSTRACT FROM AUTHOR]

Abstract: Green-emitting phosphors Ca3SiO4Cl2:Eu2+ were prepared by the high temperature solid-state method. Sol–gel process was adopted to encapsulate the as-prepared phosphors with tetraethylorthosilicate (TEOS) as silicon coating reagent. Fluorescence spectrometer, scanning electron microscopy (SEM) and powder X-ray diffraction (XRD) patterns were employed to characterize the emission spectra, the surface morphologies and the phase structures, respectively. The chemical stability testing was operated by the method of soaking the phosphors in deionized water and roasting them at different temperatures. The results indicated that the surfaces of the green phosphors were evenly coated by SiO2 and the phase structure of the coated phosphors remained the same as the uncoated samples. The luminance centre of Eu2+ did not shift after surface treatment and the luminance intensity of coated phosphors was lower than that of the uncoated samples. The results demonstrated that the water-resistance stability of the coated phosphor was improved to some degree because the pH value and the luminance intensity variation were both smaller than the uncoated phosphor after steeping within the same time. Moreover, the thermal stability of coated phosphors was enhanced obviously compared to the original samples based on the temperature dependent emission spectra measurement. [ABSTRACT FROM AUTHOR]