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This paper reports a low-damage interface treatment process for AlN/GaN high-electron-mobility transistors (HEMTs) and demonstrates the excellent power characteristics of radio frequency (RF) enhancement-mode (E-mode) AlN/GaN HEMTs. An RF E-mode device fabricated by remote plasma oxidation (RPO) treatment with 2.9-nm AlN barrier layer at 300 ℃. The device with a gate length of 0.12-μm has a threshold voltage (Vth) of 0.5 V, a maximum saturation current of 1.16 A/mm, a high Ion/Ioff ratio of 1*108, and a 440 mS/mm peak transconductance. During continuous wave (CW) power testing, it demonstrated a power added efficiency of 61.9% and a power density of 1.38 W/mm at 3.6 GHz, and a power added efficiency of 41.6% and a power density of 0.85 W/mm at 30 GHz. Furthermore, RPO treatment improves the mobility of RF E-mode AlN/GaN HEMTs. All results show that the RPO processing method has good applicability for scaling ultrathin barrier E-mode AlN/GaN HEMTs for 5G compliable frequency ranging from sub-6 GHz to Ka-band.

Well-done cooked red meat consumption is linked to aggressive prostate cancer (PC) risk. Identifying mutation-inducing DNA adducts in the prostate genome can advance our understanding of chemicals in meat that may contribute to PC. 2-Amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), a heterocyclic aromatic amine (HAA) formed in cooked meat, is a potential human prostate carcinogen. PhIP was measured in the hair of PC patients undergoing prostatectomy, bladder cancer patients under treatment for cystoprostatectomy, and patients treated for benign prostatic hyperplasia (BPH). PhIP hair levels were above the quantification limit in 123 of 205 subjects. When dichotomizing prostate pathology biomarkers, the geometric mean PhIP hair levels were higher in patients with intermediate and elevated-risk prostate-specific antigen values than lower-risk values < 4 ng/mL (p = 0.03). PhIP hair levels were also higher in patients with intermediate and high-risk Gleason scores ≥7 compared to lower-risk Gleason score 6 and BPH patients (p = 0.02). PC patients undergoing prostatectomy had higher PhIP hair levels than cystoprostatectomy or BPH patients (p = 0.02). PhIP-DNA adducts were detected in 9.4% of the patients assayed; however, DNA adducts of other carcinogenic HAAs, and benzo[a]pyrene formed in cooked meat, were not detected. Prostate specimens were also screened for 10 oxidative stress-associated lipid peroxidation (LPO) DNA adducts. Acrolein 1,N(2)–propano-2′-deoxyguanosine adducts were detected in 54.5% of the patients; other LPO adducts were infrequently detected. Acrolein adducts were not associated with prostate pathology biomarkers, although DNA adductomic profiles differed between PC patients with low and high-grade Gleason scores. Many DNA adducts are of unknown origin; however, dG adducts of formaldehyde and a series of purported 4-hydroxy-2-alkenals were detected at higher abundance in a subset of patients with elevated Gleason scores. The PhIP hair biomarker and DNA adductomics data support the paradigm of well-done cooked meat and oxidative stress in aggressive PC risk.

With the advent of the 5G era, the rapid development of communication networks has provided comparatively favorable conditions for the popularity of mobile learning. Mobile learning devices, mainly smartphones and tablets, have gradually replaced traditional computer-assisted devices as one of the important forms of learning for learners in the new era. This study summarizes the characteristics of mobile learning as: Ubiquitous; Portable; Personalized; Interactive; Updated; and Seamless. Based on the above characteristics, mobile vocabulary learning has its advantages such as convenience and efficiency, but due to its fragmented learning characteristics, however, the fragmented nature of learning makes it difficult for learners to achieve deep learning. In the content of vocabulary acquisition, deep learning refers to after a word has been learnt, it may trigger associations, images or stories on the basis of the learner's past experiences. In the field of education deep learning provides an effective solution to the problem of fragmentation in mobile learning and provides a new path and idea for effective vocabulary acquisition. This study uses a combination of questionnaires and empirical research to ask the following research questions: Question 1: To what extent do learners have an understanding of mobile learning of English vocabulary? Question 2: To what extent can deep learning-based mobile learning of English vocabulary improve students' English vocabulary? After the questionnaire survey and the empirical study, we can see that Learners have a degree of understanding of deep learning-based mobile vocabulary learning and that deep learning-based mobile learning of English vocabulary can will contribute positively to the acquisition of English vocabulary.

In this work, the mechanism of reliability of high resistance state (HRS) in AlOxNy-based resistive random access memory (RRAM) has been studied. The Ta/AlOxNy/Pt devices with high quality of the Schottky contact in the Ta/AlOxNy interface show excellent HRS reliability and low power consumption characteristics. We propose that the resistive switching (RS) process is caused by the migration of oxygen ions in the AlOxNy-based RRAM device, and the quality of the metal–semiconductor Schottky contact directly determines HRS reliability in AlOxNy-based RRAM.

Bright and efficient deep-red light-emitting diodes (LEDs) are important for applications in medical therapy and biological imaging due to the high penetration of deep-red photons into human tissues. Metal-halide perovskites have potential to achieve bright and efficient electroluminescence due to their favorable optoelectronic properties. However, efficient and bright perovskite-based deep-red LEDs have not been achieved yet, due to either Auger recombination in low-dimensional perovskites or trap-assisted nonradiative recombination in three-dimensional perovskites. Here, we demonstrate a lateral Cs

Two-dimensional materials (2DMs) have been used widely in constructing photodetectors (PDs) because of their advantages in flexible integration and ultrabroad operation wavelength range. Specifically, 2DM PDs on silicon have attracted much attention because silicon microelectronics and silicon photonics have been developed successfully for many applications. 2DM PDs meet the imperious demand of silicon photonics on low-cost, high-performance, and broadband photodetection. In this work, a review is given for the recent progresses of Si/2DM PDs working in the wavelength band from near-infrared to mid-infrared, which are attractive for many applications. The operation mechanisms and the device configurations are summarized in the first part. The waveguide-integrated PDs and the surface-illuminated PDs are then reviewed in details, respectively. The discussion and outlook for 2DM PDs on silicon are finally given.

A novel software has been created to comprehensively characterize covalent modifications of DNA through mass spectral analysis of enzymatically hydrolyzed DNA using the neutral loss of 2'-deoxyribose, a nearly universal MS2 fragmentation process of protonated 2'-deoxyribonucleosides. These covalent modifications termed DNA adducts form through xenobiotic exposures or by reaction with endogenous electrophiles and can induce mutations during cell division and initiate carcinogenesis. DNA adducts are typically present at trace levels in the human genome, requiring a very sensitive and comprehensive data acquisition and analysis method. Our software, wSIM-City, was created to process mass spectral data acquired by a wide selected ion monitoring (wSIM) with gas-phase fractionation and coupled to wide MS2 fragmentation. This untargeted approach can detect DNA adducts at trace levels as low as 1.5 adducts per 109 nucleotides. This level of sensitivity is sufficient for comprehensive analysis and characterization of DNA modifications in human specimens.

Osteoporosis bone defect is a refractory orthopaedic disease which characterized by impaired bone quality and bone regeneration capacity. Current therapies, including antiosteoporosis drugs and artificial bone grafts, are not always satisfactory. Herein, a strontium-substituted calcium phosphate silicate bioactive ceramic (Sr-CPS) was fabricated. In the present study, the extracts of Sr-CPS were prepared for in vitro study and Sr-CPS scaffolds were used for in vivo study. The cytocompatibility, osteogenic and osteoclastogenic properties of Sr-CPS extracts were characterized in comparison to CPS. Molecular mechanisms were also evaluated by Western blot. Sr-CPS extracts were found to promote osteogenesis by upregulating Wnt/β-catenin signal pathways and inhibit osteoclastogenesis through downregulating NF-κB signal pathway. In vivo, micro-CT, histological and histomorphometric observation were conducted after 8 weeks of implantation to evaluate the bone formation using calvarial defects model in ovariectomized rats. Compared with CPS, Sr-CPS significantly promoted critical sized ovariectomy (OVX) calvarial defects healing. Among all the samples, Sr-10 showed the best performance due to a perfect match of bone formation and scaffold degradation rates. Overall, the present study demonstrated that Sr-CPS ceramic can dually modulate both bone formation and resorption, which might be a promising candidate for the reconstruction of osteoporotic bone defect., Graphical abstract Image 1, Highlights • Easy-to-perform and cost-effective fabrication of Sr-CPS scaffold. • Dual modulation of bone formation and resorption. • Outstanding performances in the osteoporotic bone defect healing process.

Silicon photonics is becoming more and more attractive in the applications of optical interconnections, optical computing, and optical sensing. Although various silicon photonic devices have been developed rapidly, it is still not easy to realize active photonic devices and circuits with silicon alone due to the intrinsic limitations of silicon. In recent years, two-dimensional (2D) materials have attracted extensive attentions due to their unique properties in electronics and photonics. 2D materials can be easily transferred onto silicon and thus provide a promising approach for realizing active photonic devices on silicon. In this paper, we give a review on recent progresses towards hybrid silicon photonics devices with 2D materials, including two parts. One is silicon-based photodetectors with 2D materials for the wavelength-bands from ultraviolet (UV) to mid-infrared (MIR). The other is silicon photonic switches/modulators with 2D materials, including high-speed electro-optical modulators, high-efficiency thermal-optical switches and low-threshold all-optical modulators, etc. These hybrid silicon photonic devices with 2D materials devices provide an alternative way for the realization of multifunctional silicon photonic integrated circuits in the future.

Graphene has attracted much attention for the realization of high-speed photodetection for silicon photonics over a wide wavelength range. However, the reported fast graphene photodetectors mainly operate in the 1.55 μm wavelength band. In this work, we propose and realize high-performance waveguide photodetectors based on bolometric/photoconductive effects by introducing an ultrathin wide silicon−graphene hybrid plasmonic waveguide, which enables efficient light absorption in graphene at 1.55 μm and beyond. When operating at 2 μm, the present photodetector has a responsivity of ~70 mA/W and a setup-limited 3 dB bandwidth of >20 GHz. When operating at 1.55 μm, the present photodetector also works very well with a broad 3 dB bandwidth of >40 GHz (setup-limited) and a high responsivity of ~0.4 A/W even with a low bias voltage of −0.3 V. This work paves the way for achieving high-responsivity and high-speed silicon–graphene waveguide photodetection in the near/mid-infrared ranges, which has applications in optical communications, nonlinear photonics, and on-chip sensing., 2 µm photodetectors: silicon−graphene−metal hybrid plasmonics The use of a silicon−graphene plasmonic waveguide has enabled the realization of fast and sensitive photodetectors that operate at the wavelength of 2 µm. In order to satisfy the demands for the applications in optical communication and optical sensing, there is the need to extend silicon photonics to wavelengths beyond 1.55 µm. However, it is a challenge to create high-performance photodetectors at these wavelengths. Now, Daoxin Dai and coworkers from Zhejiang University and Southeast University in China have proposed and realized a silicon−graphene hybrid plasmonic waveguide photodetector that operates at 2 µm with a responsivity of ~70 mA/W and a 3-dB bandwidth over 20 GHz. In this design, efficient light absorption in graphene is enabled by using a hybrid plasmonic waveguide with a wide thin silicon ridge core and a metal cap that serves as a signal electrode.

Tendon repair was an important part during tendon to bone healing. In the present study, heparin molecules were immobilized on the aminolyzed PCL surface to improve the cellular bioactivity for potential tendon repair. The effects of heparin immobilization on protein adsorption behavior and cellular bioactivity of NIH3T3 and ATDC5 cells were investigated. The results were shown as follows.

In this Letter, a Pt/SiNx/TiN/Ta resistive random access memory (RRAM) is proposed, which has low switching voltage, uniform resistance distribution, excellent cycle-to-cycle stability, and excellent nonvolatile performance. As an insertion layer, TiN prevents excessive absorption of nitrogen ions by a Ta electrode and avoids the formation of the unstable metal–semiconductor interface, which significantly reduces cycle-to-cycle variability of SiNx-based RRAM. Due to high conductivity, the TiN layer has a small voltage divider effect when voltage was applied, which helps to achieve low power consumption characteristics. This paper provides a direction for improving performance of nitride-based RRAM, which is useful for further development of highly reliable RRAM.

Recently, deep shale reservoirs are emerging as time requires and commence occupying a significant position in the further development of shale gas. However, the understanding of pore characteristics in deep shale remains poor, prohibiting accurate estimation of the hydrocarbon content and insights into fluid mobility. This study focuses on the Longmaxi Formation from the Luzhou (LZ) region, southern Sichuan. Scanning electron microscopy (SEM), low-temperature N2/CO2 adsorption, X-ray diffraction, and geochemical analysis were performed to investigate the micro-nanopore size distribution, main controlling factors, and unique pore features distinct from other regions. Results showed that the pores can be classified into four categories, organic matter (OM) pores, intergranular pores, intragranular pores, and microfractures, according to SEM images. The total pore volume is overwhelmingly dominated by mesopores and contributed by pores in the range of 0.5-0.6, 2-4, and 10-30 nm. The specific surface area is primarily contributed by micropores and mesopores in the range of 0.5-0.7 and 2-4 nm. By analyzing the influencing factors extensively, it is concluded that the buried depth, geochemical factors, and mineral composition can impact the pore structure in the overmature deep shales. Specifically, the total organic carbon content plays a more effective and positive role in the development of micropores, mesopores, total pores, and the porosity when compared with vitreous reflectance (Ro). The micropores are inferred to be OM-related. On the contrary, clay mineral is detrimental to the development of micropores and mesopores and the petrophysical properties (porosity and permeability), which may be attributed to the occurrence of chlorite and kaolinite instead of illite. The plagioclase conforms to the same law as clay due to their coexistence. Quartz, carbonate minerals, and pyrite can barely contribute to the pores. Eventually, the compared results suggest that the Longmaxi Formation of the LZ region are qualified with a superior pore size distribution, complicated structure, and diverse morphology, implying a potential to generate and store hydrocarbons. Overall, this study improves the understanding of complex pore structures in deep shale and provides significant insights into the development and exploration of unconventional resources in the future.

Long-term function of dental implants relies on not only stable osseointegration but also strong soft tissue-sealing ability. Ideal soft tissue sealing around implants is an effective protective barrier between the external environment and alveolar bone, preventing the invasion of bacteria that is considered as a vital trigger of irreversible marginal bone loss. Carbon-based materials have been reported to be beneficial to soft tissue sealing, which can be regulated through the hybridization type of carbon atoms (sp2 or sp3), but its internal mechanism is still not clear. In this work, graphene oxide with both sp2- and sp3-hybridized carbons was electrophoretic deposited on titanium and reduced to regulate the hybridization type of carbon atoms to investigate its effect and possible mechanism on human gingival fibroblasts (HGFs). X-ray photoelectron spectroscopy and Raman mapping test show the increase of sp2 domain content and the decrease of their size after reduction. Through computer simulation, the possible mechanism of the decrease of sp2 domain size was proposed. In vitro studies disclose that the HGFs exhibit higher proliferation rate, better adhesion, and migration ability with the increase of sp2 domains and the decrease of their sizes. It may be due to the amount and size of sp2 domains that synergistically regulate the amount and properties of adsorbed proteins, thereby influencing the cellular behaviors of HGFs. Our results may offer a different perspective on material designing and academic research to enhance the soft tissue integration of implants.

Frequent exposure to chemicals in the environment, diet, and endogenous electrophiles leads to chemical modification of DNA and the formation of DNA adducts. Some DNA adducts can induce mutations during cell division and, when occurring in critical regions of the genome, can lead to the onset of disease, including cancer. The targeted analysis of DNA adducts over the past 30 years has revealed that the human genome contains many types of DNA damages. However, a long-standing limitation in conducting DNA adduct measurements has been the inability to screen for the total complement of DNA adducts derived from a wide range of chemicals in a single assay. With the advancement of high-resolution mass spectrometry (MS) instrumentation and new scanning technologies, nontargeted “omics” approaches employing data-dependent acquisition and data-independent acquisition methods have been established to simultaneously screen for multiple DNA adducts, a technique known as DNA adductomics. However, notable challenges in data processing must be overcome for DNA adductomics to become a mature technology. DNA adducts occur at low abundance in humans, and current softwares do not reliably detect them when using common MS data acquisition methods. In this perspective, we discuss contemporary computational tools developed for feature finding of MS data widely utilized in the disciplines of proteomics and metabolomics and highlight their limitations for conducting nontargeted DNA-adduct biomarker discovery. Improvements to existing MS data processing software and new algorithms for adduct detection are needed to develop DNA adductomics into a powerful tool for the nontargeted identification of potential cancer-causing agents.

High failure rate of tendon to bone healing after surgery has always been a challenging problem in rotator cuff repair. Considering the flexibility of PLLA and osteogenic activity of calcium phosphate silicate (CPS) ceramic, PLLA/CPS composite films were produced by a simple melt-pressing technique, the in vitro and in vivo biocompatibility and bioactivity were investigated. With an increase of CPS content, the adhesion and proliferation of cells on composite films were improved. The sample with a PLLA/CPS volume ratio of 5/1 (5P/C) showed a highest ALP activity expression. The in vivo results also revealed that the 5P/C composite sample had good biocompatibility and biodegradability, which could improve the organization of collagen and the formation of cartilage and bone. Moreover, the biomechanical test demonstrated that 5P/C group displayed the best mechanical performance among the three groups. 12 weeks after surgery, a well engineered tendon to bone interface was formed in the PLLA/CPS composite film case.

This Letter investigates the effect of non-inert electrode thickness on the performance of complementary resistive switching (CRS). Five devices with different Ta electrode thicknesses (0, 2, 5, 10, and 20-nm) are fabricated. For devices with 2, 5, and 10-nm electrode thicknesses, CRS behavior can be obtained through an evolution process, while devices with 0 and 20-nm Ta electrode thicknesses always maintain stable bipolar resistive switching behavior. By analyzing the evolution process and current conduction mechanisms, the influence of non-inert electrode thickness on the performance of CRS is studied, and different oxidation degrees of a non-inert electrode are used to explain the different resistive switching performance in these devices. Aside from that, the model is verified by applying an asymmetric voltage sweeping method. This paper further clarifies the physical mechanism of CRS behavior in non-inert electrode resistive random access memory and provides a way to optimize the performance of CRS behavior.

The introduction of PbS QD (quantum dot) films has been proved, dramatically, to optimize the resistive switching (RS) performance in oxide resistive random access memory. In order to optimize parameters to a greater extent, the necessity of in-depth understanding of the resistance switching mechanism is self-evident. In this paper, PbS QD layers were inserted into a Ta/AlOxNy/Pt structure device in different positions in order to investigate the influence of the device structure in the PbS QD film inserted device. The Ta/PbS QDs/AlOxNy/Pt device with a Ta anion reservoir and a PbS QD film anion reservoir in the same direction exhibits excellent optimization of parameters, which is ideal for low-power devices. A model is constructed to elaborate the resistive switching process. Moreover, modulation of PbS QD film thickness on RS has been studied. A device with middle thickness of the PbS QD films combines low voltage, low current, and excellent stability, which is believed to be a favorable structure for the PbS QD inserted device.

High-sensitivity and high-bandwidth receivers are always demanded for high-speed optical link systems. As a key element, an avalanche photodiode (APD) is often regarded as one of the most attractive options for achieving high sensitivity owing to the potential high internal gain. In this paper, a 48-GHz waveguide Ge/Si avalanche photodiode operating at the O-band (1310 nm) is designed with a lateral reach-through structure and fabricated with simplified processes. The fabricated APD shows a high primary responsivity of 0.93 A/W at the unit-gain voltage of−4.7V. It has an avalanche gain of 12.8 and a record gain-bandwidth product of∼615GHzwith an input optical power of−15dBmwhen operating at a bias voltage of−14V. The present Ge/Si APD is used successfully for high-speed data receiving, showing a sensitivity improvement about 7.6 dB for KP4-FEC operation (i.e., BER=2.4×10−4) with 50 Gbps non-return-to-zero (NRZ) data, compared with the case of using the reference PIN PD on the same chip. The sensitivity of the receiver with the present APD for NRZ signals is about−21.3dBm,−17.8dBm, and−12.6dBmfor KP4-FEC operation with different data rates of 50 Gbps, 80 Gbps, and 100 Gbps, while the sensitivity for four-level pulse amplitude modulation signals is about−13.2dBmand−11.3dBmfor KP4-FEC operation with different data rates of 25 and 50 Gbaud. Such high-performance APDs pave the way to achieve high-speed and high-sensitivity data transmissions.

A novel software has been created to comprehensively characterize covalent modifications of DNA through mass spectral analysis of enzymatically hydrolyzed DNA using the neutral loss of 2′-deoxyribose, a nearly universal MS(2) fragmentation process of protonated 2′-deoxyribonucleosides. These covalent modifications termed DNA adducts form through xenobiotic exposures or by reaction with endogenous electrophiles and can induce mutations during cell division and initiate carcinogenesis. DNA adducts are typically present at trace levels in the human genome, requiring a very sensitive and comprehensive data acquisition and analysis method. Our software, wSIM-City, was created to process mass spectral data acquired by a wide selected ion monitoring (wSIM) with gas-phase fractionation and coupled to wide MS(2) fragmentation. This untargeted approach can detect DNA adducts at trace levels as low as 1.5 adducts per 10(9) nucleotides. This level of sensitivity is sufficient for comprehensive analysis and characterization of DNA modifications in human specimens.

The primary stability and final osseointegration of endosseous implants may be hindered by certain abnormal bone-metabolism conditions, such as osteoporosis. Polyetheretherketone (PEEK), which shows similar adjustable elastic modulus with cortical bone, is considered to be an ideal candidate to replace metallic implants, especially for osteoporotic bone. However, the bioinertness and poor osteogenic properties of PEEK fail to pave the way for clinical application. Here, a novel coating (EBE-SrSi) with bioactive elements on PEEK implants was generated via electron beam evaporation (EBE) to enhance the rapid osseointegration by inducing osteogenesis, as well as angiogenesis. In vitro, the dual Sr/Si ion modified surface exihibits a better osteo-inductive effect on the BMSCs derived from ovariectomized rats (rBMSCs-OVX). Furthermore, the modified samples also stimulated human umbilical vein endothelial cells (HUVECs) migration and angiogenesis. Finally, in the OVX rat bonedefect model, the EBE-SrSi group exhibited faster bone formation which might be attributed to the impact of the transformation of endogenous MSC accompanied by promotion of the angiogenic activity of endothelial cells. Our results unveiled the potential of dual Sr/Si modified PEEK in promoting osseointegration under osteoporotic conditions and will further broaden the adoption of PEEK materials in dental fields.

Multimode silicon photonics have drawn tremendous attention because the introduction of higher-order modes greatly enhances the capacity of mode-division-multiplexing (MDM) data transmission systems as well as improves the flexibility of on-chip photonic device designs. As the cornerstone of multimode silicon photonics, plentiful multimodemanipulation photonic devices have been developed successfully. On the other hand, more and more emerging applications have been stimulated by higher-order modes introduced in multimode silicon photonics. This paper gives a review for our recent processes in the development of multimode silicon photonic devices. Keywords: mode, multiplexer, conversion, bend, filter, silicon, waveguide.

Long-term function of dental implants relies on not only stable osseointegration but also strong soft tissue-sealing ability. Ideal soft tissue sealing around implants is an effective protective barrier between the external environment and alveolar bone, preventing the invasion of bacteria that is considered as a vital trigger of irreversible marginal bone loss. Carbon-based materials have been reported to be beneficial to soft tissue sealing, which can be regulated through the hybridization type of carbon atoms (sp

We propose and demonstrate a silicon-graphene heterojunction photodetector with a 100-nm-thick silicon core. The measured 3-dB bandwidth of >14 GHz at 1570 nm and the normalized photocurrent-to-dark-current ratio (NPDR) of 340 mW-1 are obtained.

This paper reported the Pt/AlOxNy/Ta structure with oxygen scavenging metal Ta as a top electrode in order to achieve excellent data storage and the artificial synaptic function. As a series resistance layer and a thermal enhanced layer, the TaOx interface layer between the resistance switching (RS) layer and the top electrode (TE) can greatly affect the RS characteristics. These effects can be attributed to properties of the interface layer such as thermal and electrical conductivities, suggesting that properties of the interface layer should be carefully and systematically considered if excellent RS characteristics are desirable. Based on the electrical testing and current conduction mechanism analyses, the major factors affecting the bipolar gradual RS behavior can be concluded as the property of the interface layer between the RS layer and TE, the Joule heating caused by current, and the distribution of the electric field on the interface layer.

At present, the physical mechanism of complementary resistive switching (CRS) devices remains controversial. In this Letter, stable CRS can be achieved in Pt/AlOxNy/Ta resistive random access memory (RRAM). A dynamic evolution from bipolar resistive switching to CRS can be evidently observed in non-inert electrodes RRAM. The causes of CRS behavior are analyzed in detail, and these phenomena are attributed to the different oxidation degrees of the top electrode and propose that the transition state can be used as a signal for the emergence of CRS behavior. Moreover, the model is partially supported by measured switching behavior of the Pt/AlOxNy/TaOx device. This research contributes to the understanding of the CRS behavior physical mechanism in non-inert electrodes RRAM devices.

Mass spectrometry-based DNA adductomics is an emerging approach for the human biomonitoring of hazardous chemicals. A mass spectral database of DNA adducts will be created for the scientific community to investigate the associations between chemical exposures, DNA damage, and disease risk.

Epidemiological studies have linked aromatic amines (AAs) from tobacco smoke and some occupational exposures with bladder cancer risk. Several epidemiological studies have also reported a plausible role for structurally related heterocyclic aromatic amines present in tobacco smoke or formed in cooked meats with bladder cancer risk. DNA adduct formation is an initial biochemical event in bladder carcinogenesis. We examined paired fresh-frozen (FR) and formalin-fixed paraffin-embedded (FFPE) non-tumor bladder tissues from 41 bladder cancer patients for DNA adducts of 4-aminobiphenyl (4-ABP), a bladder carcinogen present in tobacco smoke, and 2-amino-9H-pyrido[2,3-b]indole, 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine, and 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline, possible human carcinogens, which occur in tobacco smoke and cooked meats. These chemicals are present in urine of tobacco smokers or omnivores. Targeted DNA adduct measurements were done by ultra-performance liquid chromatography-electrospray ionization multi-stage hybrid Orbitrap MS. N-(2′-Deoxyguanosin-8-yl)-4-ABP (N-(dG-C8)-4-ABP) was the sole adduct detected in FR and FFPE bladder tissues. Twelve subjects (29%) had N-(dG-C8)-4-ABP levels above the limit of quantification, ranging from 1.4 to 33.8 adducts per 10(9) nucleotides (nt). DNA adducts of other human AA bladder carcinogens, including 2-naphthylamine (2-NA), 2-methylaniline (2-MA), 2,6-dimethylaniline (2,6-DMA), and lipid peroxidation (LPO) adducts were screened for in bladder tissue, by our untargeted data-independent adductomics method, termed wide-selected ion monitoring (wide-SIM)/MS(2). Wide-SIM/MS(2) successfully detected N-(dG-C8)-4-ABP, N-(2′-deoxyadenosine-8-yl)-4-ABP and the presumed hydrazo linked adduct, N-(2′-deoxyguanosin-N(2)-yl)-4-ABP, and several LPO adducts in bladder DNA. Wide-SIM/MS(2) detected multiple DNA adducts of 2-NA, 2-MA and, 2,6-DMA, when calf thymus DNA was modified with reactive intermediates of these carcinogens. However, these AA-adducts were below the limit of detection in unspiked human bladder DNA (< 1 adduct per 10(8) nt). Wide-SIM/MS(2) can screen for many types of DNA adducts formed with exogenous and endogenous electrophiles and will be employed to identify DNA adducts of other chemicals that may contribute to the etiology of bladder cancer.

Light-emitting diodes (LEDs), which convert electricity to light, are widely used in modern society—for example, in lighting, flat-panel displays, medical devices and many other situations. Generally, the efficiency of LEDs is limited by nonradiative recombination (whereby charge carriers recombine without releasing photons) and light trapping1–3. In planar LEDs, such as organic LEDs, around 70 to 80 per cent of the light generated from the emitters is trapped in the device4,5, leaving considerable opportunity for improvements in efficiency. Many methods, including the use of diffraction gratings, low-index grids and buckling patterns, have been used to extract the light trapped in LEDs6–9. However, these methods usually involve complicated fabrication processes and can distort the light-output spectrum and directionality6,7. Here we demonstrate efficient and high-brightness electroluminescence from solution-processed perovskites that spontaneously form submicrometre-scale structures, which can efficiently extract light from the device and retain wavelength- and viewing-angle-independent electroluminescence. These perovskites are formed simply by introducing amino-acid additives into the perovskite precursor solutions. Moreover, the additives can effectively passivate perovskite surface defects and reduce nonradiative recombination. Perovskite LEDs with a peak external quantum efficiency of 20.7 per cent (at a current density of 18 milliamperes per square centimetre) and an energy-conversion efficiency of 12 per cent (at a high current density of 100 milliamperes per square centimetre) can be achieved—values that approach those of the best-performing organic LEDs. The formation of submicrometre-scale structure in perovskite light-emitting diodes can raise their external quantum efficiency beyond 20%, suggesting the possibility of both high efficiency and high brightness.