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Abstract

Most genome-wide association studies (GWAS) of major depression (MD) have been conducted in samples of European ancestry. Here we report a multi-ancestry GWAS of MD, adding data from 21 cohorts with 88,316 MD cases and 902,757 controls to previously reported data. This analysis used a range of measures to define MD and included samples of African (36% of effective sample size), East Asian (26%) and South Asian (6%) ancestry and Hispanic/Latin American participants (32%). The multi-ancestry GWAS identified 53 significantly associated novel loci. For loci from GWAS in European ancestry samples, fewer than expected were transferable to other ancestry groups. Fine mapping benefited from additional sample diversity. A transcriptome-wide association study identified 205 significantly associated novel genes. These findings suggest that, for MD, increasing ancestral and global diversity in genetic studies may be particularly important to ensure discovery of core genes and inform about transferability of findings.

In this paper, we consider a cooperative communication network where multiple low-Earth-orbit (LEO) satellites provide services to multiple ground users (GUs) cooperatively at the same time and on the same frequency. The multi-satellite cooperation has great potential in extending communication coverage and increasing spectral efficiency. Considering that the on- board radio-frequency circuit resources and computation resources on each satellite are restricted, we aim to propose a low-complexity yet efficient multi-satellite cooperative transmission framework. Specifically, we first propose a hybrid beamforming method consisting of analog beamforming for beam alignment and digital beamforming for interference mitigation. Then, to establish appropriate connections between the satellites and GUs, we propose a heuristic user scheduling algorithm which determines the connections according to the total spectral efficiency increment of the multi-satellite cooperative network. Next, considering the intrinsic connection between beamforming and user scheduling, a joint hybrid beamforming and user scheduling (JHU) scheme is proposed to dramatically improve the performance of the multi-satellite cooperative network. In addition to the single-connection scenario, we also consider the multi-connection case using the JHU scheme. Extensive simulations conducted over different LEO satellite constellations and across various GU locations demonstrate the superiority of the proposed schemes in both overall and per-user spectral efficiencies.

Vegetable oil as a kind of renewable resource has been considered as promising raw material to replace petrochemical resources. This article focuses on several highly reactive sites of triglycerides, including carbon-carbon double bonds, allyl groups, and ester groups. The vegetable oil-based platform monomers/polymers with different structures and functions are obtained via chemical modification such as epoxidation, ozone decomposition, hydroformylation, transesterification and thiolene. Vegetable oil-based chemicals mainly include polyols, biodiesel fuels, lubricants and plasticizers, and vegetable oil-based polymers mainly include inks, coatings and polyurethane foams. This paper summarizes and analyzes the review of vegetable oil-based chemicals and polymers in various industries, and puts forward the prospect for their future applications.

This paper defines cyclic and minimal derivative descendants (DDs) of an extended cyclic code from the derivative of Mattson-Solomon polynomials. First, it demonstrates that the cyclic DDs are the same extended cyclic code. It allows us to efficiently decode extended cyclic codes based on their cyclic DDs. Second, since the minimal DDs are equivalent codes, it also allows us to perform soft-decision decoding based on the minimal DDs with permutations. Simulation result shows that our proposed derivative decoding can be close to the maximum likelihood decoding for certain extended cyclic codes, including some extended BCH codes.

• Updated hydrolysis enhancing mechanisms of Mg-based alloys/hydrides are summarized. • Main hydrolysis enhancing mechanisms were classified into 4: electrochemical corrosion promotion, active sites increment, mass transfer enhancement and corresponding kinetic improvement. • The feasibility, economy and safety of the relevant methods are further discussed. Hydrogen energy is considered to be an ideal new energy carrier in the 21st century due to its clean, environmentally friendly, renewable characteristics and high energy density. The generation of hydrogen by hydrolysis of Mg-based alloys/hydrides has attracted extensive attention attributed to the high hydrogen yield, environmentally-benign by-products, high crust abundance, and well-developed industrial production of Mg. However, in the hydrolysis process of Mg or MgH 2 to generate hydrogen, the formed Mg(OH) 2 passivation layer attaches to the surface of the active materials to prevent the reaction from continuing. To improve the hydrolysis performance, a series of methods have been put forward. In this paper, focusing on the mechanisms of hydrogen generation by hydrolysis of Mg-based alloys/hydrides, we summarize the recent research progress from four different perspectives: electrochemical corrosion promotion by constructing galvanic cells, active sites increment by refining the particles, mass transfer enhancement by breaking Mg(OH) 2 and corresponding kinetic improvement. [Display omitted] [ABSTRACT FROM AUTHOR]

Coded distributed computing can alleviate the communication load by leveraging the redundant storage and computation resources with coding techniques in distributed computing. In this paper, we study a MapReduce-type distributed computing framework over star topological network, where all the workers exchange information through a common access point. The optimal tradeoff among the normalized number of stored files (storage load), computed intermediate values (computation load), and transmitted bits in the uplink and downlink (communication loads) is characterized. A coded computing scheme is proposed to achieve the Pareto-optimal tradeoff surface, in which the access point only needs to perform simple chain coding between the signals it receives, and information- theoretical bound matching the surface is also provided.

Our understanding of the genetics of the human cerebral cortex is limited both in terms of the diversity and the anatomical granularity of brain structural phenotypes. Here we conducted a genome-wide association meta-analysis of 13 structural and diffusion magnetic resonance imaging-derived cortical phenotypes, measured globally and at 180 bilaterally averaged regions in 36,663 individuals and identified 4,349 experiment-wide significant loci. These phenotypes include cortical thickness, surface area, gray matter volume, measures of folding, neurite density and water diffusion. We identified four genetic latent structures and causal relationships between surface area and some measures of cortical folding. These latent structures partly relate to different underlying gene expression trajectories during development and are enriched for different cell types. We also identified differential enrichment for neurodevelopmental and constrained genes and demonstrate that common genetic variants associated with cortical expansion are associated with cephalic disorders. Finally, we identified complex interphenotype and inter-regional genetic relationships among the 13 phenotypes, reflecting the developmental differences among them. Together, these analyses identify distinct genetic organizational principles of the cortex and their correlates with neurodevelopment.

This letter proposes an integrated sensing and communications (ISAC) system with multiple cyclic prefixes (CPs) to achieve effectiveness of ISAC in high Doppler scenarios. Multiple CPs include sensing CP and communication CP, which are prepended at the beginning of the transmitted signal and before each modulation symbol, respectively. For transmission, the introduction of multiple CPs obtains abundant maximum unambiguous Doppler by decoupling sensing and communication requirements. For sensing reception, a sensing parameter estimation method is developed which achieves robustness to Doppler shifts. Moreover, the multiple CPs are utilized to enhance sensing processing gain and reduce the complexity of sensing parameter estimation. Theoretical and numerical analyses reveal that the proposed system possesses robustness to Doppler shifts, high processing gain, reliable estimation accuracy and affordable complexity.

Pacinian corpuscle is a tactile receptor that responds to high-frequency (20–1000 Hz) vibration and has high-pass filtering and mechanical signal amplification functions. It is the main receptor of vibration tactility closely related to fine touch sensation, which is the ability to perceive and localize objects’ shape, texture, and size. Currently, it is still difficult to measure and calculate the friction generated by robots grasping objects. The resolution of touch and vibration sensors cannot satisfy the demand for understanding tribological behavior. The simulation of Pacinian corpuscles’ structure and replication of its key functions will bring richer touch information to robots. In this review article, the structure and functions of Pacinian corpuscles are summarized from the internal structure of a single Pacinian corpuscle and the spatial distribution of multiple Pacinian corpuscles. Then, theoretical models and research on the bionics design of Pacinian corpuscles are introduced based on the three reception processes of Pacinian corpuscles: mechanical transmission, electromechanical transduction, and neural excitation. Finally, the bottlenecks of current research on the simulation of Pacinian corpuscles are summarized, followed by the proposal of research ideas on the simulation of Pacinian corpuscles.

ABSTRACTBackgroundSIM0295, a novel inhibitor of human uric acid transporter 1 (hURAT1), is used to treat patients with gout and hyperuricemia. This study aimed to develop population pharmacokinetics and pharmacodynamics (popPK/PD) models of SIM0295 and explore potential covariates to inform clinical drug development.Research design and methodsData were obtained from four phase I studies conducted in healthy Korean and Chinese subjects and two phase II studies conducted in Korean patients with gout and hyperuricemia. The popPK/PD model of SIM0295 was developed using nonlinear mixed effects modeling.ResultsSIM0295 pharmacokinetics was described using a two-compartment model with the absorption of four transit compartments and first-order elimination. PK parameters were normalized to weight via allometric scaling. Food was identified as a factor significantly affecting the absorption rate, with no clinical relevance. The sigmoid Emaxmodel with a semi-mechanism of inhibition of serum uric acid (sUA) reabsorption was used to describe the exposure-response relationship. Additionally, Monte Carlo simulations demonstrated that approimately 9 mg/day of SIM0295 for 7 days could achieve the maximum decrease in sUA.ConclusionThe established popPK/PD model characterized the dose-exposure-response relationship for SIM0295 in healthy subjects and patients with gout and hyperuricemia and could be used to inform the drug development.

The characteristics of the raindrop size distribution (DSD) during regional freezing rain (FR) events that occur throughout the phase change (from liquid to solid) are poorly understood due to limited observations. We investigate the evolution of microphysical parameters and the key formation mechanisms of regional FR using the DSDs from five disdrometer sites in January 2018 in the Jianghan Plain (JHP) of Central China. FR is identified via the size and velocity distribution measured from a disdrometer, the discrete Fréchet distancemethod, surface temperature, human observations, and sounding data.

Ovarian cancer is a gynecological tumor with a poor prognosis. The chemotherapy failure and recurrence induced by paclitaxel (Ptx) resistance are the main reason for the failure of ovarian cancer treatment. In this study, we aimed to explore the role of circular RNA (circRNA) in the regulation of Ptx resistance in ovarian cancer. Quantitative reverse transcription PCR was performed to detect the expression of circRNA SET domain bifurcated histone lysine methyltransferase 1 (circSETDB1), microRNA (miR)-508-3p and ATP-binding cassette subfamily C member 1 (ABCC1) mRNA. The effects of circSETDB1 on Ptx resistance were explored by cell counting kit-8, 5-ethynyl-2′-deoxyuridine, and flow cytometry experiments in vitro. The protein level was assessed by western blot. Dual-luciferase reporter and RNA pull-down assays were carried out to confirm the interactions among circSETDB1, miR-508-3p, and ABCC1. Xenograft tumor experiment was performed to investigate the effect of circSETDB1 on Ptx resistance in vivo. CircSETDB1 was highly expressed in Ptx-resistant ovarian cancer. CircSETDB1 knockdown inhibited cell proliferation viability, half maximal inhibitory concentration value of Ptx, cell cycle progression, and induced cell apoptosis in Ptx-resistant ovarian cancer cells. miR-508-3p was a target of circSETDB1, and inhibition of miR-508-3p overturned the effects of circSETDB1 knockdown on the Ptx resistance of ovarian cancer cells. miR-508-5p could bind to ABCC1. Overexpression of ABCC1reversed the effects of circSETDB1 knockdown on the Ptx resistance of ovarian cancer cells. CircSETDB1 knockdown also enhanced Ptx sensitivity in vivo. In conclusion, circSETDB1 regulated Ptx resistance of ovarian cancer by targeting miR-508-3p/ABCC1axis.

Low-density parity-check (LDPC) codes are not only capacity-approaching, but also greatly suitable for high-throughput implementation. Thus, they are the most popular codes for high-speed data transmission in the past two decades. Thanks to the low-density property of their parity-check matrices, the optimal maximum a posteriori probability decoding of LDPC codes can be approximated by message-passing decoding with linear complexity and highly parallel nature. Then, it reveals that the approximation has to carry on Tanner graphs without short cycles and small trapping sets. Last, it demonstrates that well-designed LDPC codes with the aid of computer simulation and asymptotic analysis tools are able to approach the channel capacity. Moreover, quasi-cyclic (QC) structure is introduced to significantly facilitate their high-throughput implementation. In fact, compared to the other capacity-approaching codes, QC-LDPC codes can provide better area-efficiency and energy-efficiency. As a result, they are widely applied in numerous communication systems, e.g., Landsat satellites, Chang'e Chinese Lunar mission, 5G mobile communications and so on. What's more, its extension to non-binary Galois fields has been adopted as the channel coding scheme for BeiDou navigation satellite system.

With the development of astronautic technology, communication satellites now have a tremendous gain in both quantity and quality, and have already shown their capability on multi-functional converged communication other than telecommunication. Under this circumstance, increasing the transmission efficiency of satellite communication network becomes a top priority. In this paper, we focus on content delivery service on satellite networks, where each ground station may have prefetched some file fragments. We cast this problem into a coded caching framework so as to exploit the coded multicast gain for minimizing the satellite communication load. We first propose an optimization-based coded multicast scheme by considering the special property that the satellite network topology is predictable and time-variant. Then, a greedy based fast algorithm is proposed, which can tremendously reduce the computation complexity with a small loss in optimality. Simulation experiments conducted on two Walker constellation satellite networks show that our proposed coded multicast method can efficiently reduce the communication load of satellite networks.

Constructions of high-performance hard-decision decodable error correction codes are important for high-speed communication systems. In this paper, we present the generalized integrated interleaved (GII) zipper codes, in which multiple zipper codes are coupled together by the constraint of the GII code. The resulting codes are referred to as GII-zipper codes. Firstly, since the performances of GII-zipper codes are sensible to miscorrections, we propose an enhanced anchor decoder (AD) which uses the hard-decision results during the GII decoding to assign anchor reliability to reduce miscorrections. We then analyze the size and multiplicity of the minimum-sized stall patterns (MSSPs) of the GII-zipper codes. The analytical results show that the size of the MSSPs of the GII-zipper codes is larger that of the zipper codes. Finally, we present extensive simulation results to show the performance advantages of the GII-zipper codes. The results show that, when decoded with the original AD, the GII-zipper codes perform better than the comparable zipper codes and we can obtain further performance gain by the enhanced AD. Particularly, a GII-staircase code with a rate of 0.846 can achieve 0.74 dB from capacity at a bit error rate (BER) of 10−15.

Analog fountain codes (AFC) are a class of near-capacity rateless codes which have a great potential for meeting the requirements of ultra-reliable low latency communication. In this letter, an online feedback scheme is introduced to enhance error performance and achievable rate of AFC. The retransmission messages are chosen according to Euclidean distance between AFC codewords. Our simulation results show that the proposed online AFC can improve achievable rate up to 0.49 bits/symbols at 25 dB, and reduce block error rate by more than one order of magnitude.

Analyzing eye movements of workers in safe and unsafe behaviors can reduce accidents. With a video-based method, the angular velocity of gaze direction (AVGD) represents micro-movements in gaze and angular velocity in saccade is used to analyze eye movements. A similar behavior simulation experiment is designed to collect operation videos, and an eye movement information extraction and processing framework is constructed to quantify and analyze eye movements. The results show that: the root mean square and movement frequency of AVGD can be used to recognize unsafe behavior; in operations with attention target fixation, compared with safe behavior, workers in unsafe behavior have higher angular velocity, movement frequency and turn frequency of eye movements; and in operations with attention target change, eye movement rules of workers in safe and unsafe behaviors depend on operation types. The results can provide features for unsafe behavior recognition and theoretical bases for safety training.

Maximum distance separable array codes with small sub-packetization level (MDS-SSL) are of practical importance in distributed storage systems. This letter addresses their repair of a single failed node in the case that there exists a busy node during the repair. Additional check relations among codeword symbols excluding those in the busy node are formed to compensate for the absence of information. Then, it allows us to repair the failed node without symbols in the busy node. A lower bound of the busy-node repair bandwidth is derived for $(k+4,k,4)$ MDS-SSL codes, consisting of four groups of nodes. It indicates that its achievability requires a cubic constraint among elements in the parity-check matrix. Then, an explicit busy-node repair scheme is proposed to achieve a lower bound in the case of the failed node and the busy node being in different groups.

This letter considers the joint design of transmit and receive beamforming (TRBF) vectors for multi-target single-user joint radar and communication (JRC) systems in the presence of signal-dependent interference. An iterative framework is devised to maximize the signal-to-interference-plus-noise ratio (SINR) of a target while guaranteeing the SINRs of the user and the rest of the targets. At each iteration, the problem of designing transmit beamformer is non-convex and can be solved by semidefinite programming (SDP) optimization. Moreover, an orthogonalization-based transmit beamforming method is proposed to efficiently obtain a suboptimal analytical solution. Numerical results verify the effectiveness of the proposed framework.

A thermo-, mechano-, and vapochromic bimetallic cuprous-emissive complex has been reported, and the origin and application of its tri-stimuli-responsive luminescence have been explored. As revealed by single-crystal structure analysis, thermo- and vapochromic luminescence adjusted by heating at 60 °C and CH3CN vapor fuming, accompanied by a crystalline-to-crystalline transition, is due to the breaking and rebuilding of the CH3CN–Cu bond, as supported by 1H nuclear magnetic resonance (NMR), Fourier-transform infrared (FT-IR) spectroscopy, powder X-ray diffraction (PXRD), thermogravimetry (TG), and time-dependent density functional theory (TD-DFT) analyses of the CH3CN-coordinated species [Cu2(μ-dppa)2(μ-η1(N)η2(N,N)-fptz)(CH3CN)](ClO4)·H2O (1) and its CH3CN-removed derivative [Cu2(μ-dppa)2(μ-η1(N)η2(N,N)-fptz)](ClO4)·H2O (2). Luminescence mechanochromism, mixed with a crystalline-to-amorphous transition where the initial crystalline is different for 1and 2, is mainly assigned as the destruction of the CH3CN–Cu bonding and/or the O···HNdppaand OH···Ntriazolylhydrogen bonds. It is also suggested that a rational use of switchable coordination such as weak metal–solvent bonding is a feasible approach to develop multi-stimuli-responsive luminescent materials and devices.

Abstract

Background: Diffusion kurtosis imaging (DKI) and neurite orientation dispersion and density imaging (NODDI) provide more comprehensive and informative perspective on microstructural alterations of cerebral white matter (WM) than single-shell diffusion tensor imaging (DTI), especially in the detection of crossing fiber. However, studies on systemic lupus erythematosus patients without neuropsychiatric symptoms (non-NPSLE patients) using multi-shell diffusion imaging remain scarce. Methods: Totally 49 non-NPSLE patients and 41 age-, sex-, and education-matched healthy controls underwent multi-shell diffusion magnetic resonance imaging. Totally 10 diffusion metrics based on DKI (fractional anisotropy, mean diffusivity, axial diffusivity, radial diffusivity, mean kurtosis, axial kurtosis and radial kurtosis) and NODDI (neurite density index, orientation dispersion index and volume fraction of the isotropic diffusion compartment) were evaluated. Tract-based spatial statistics (TBSS) and atlas-based region-of-interest (ROI) analyses were performed to determine group differences in brain WM microstructure. The associations of multi-shell diffusion metrics with clinical indicators were determined for further investigation. Results: TBSS analysis revealed reduced FA, AD and RK and increased ODI in the WM of non-NPSLE patients (P< 0.05, family-wise error corrected), and ODI showed the best discriminative ability. Atlas-based ROI analysis found increased ODI values in anterior thalamic radiation (ATR), inferior frontal-occipital fasciculus (IFOF), forceps major (F_major), forceps minor (F_minor) and uncinate fasciculus (UF) in non-NPSLE patients, and the right ATR showed the best discriminative ability. ODI in the F_major was positively correlated to C3. Conclusion: This study suggested that DKI and NODDI metrics can complementarily detect WM abnormalities in non-NPSLE patients and revealed ODI as a more sensitive and specific biomarker than DKI, guiding further understanding of the pathophysiological mechanism of normal-appearing WM injury in SLE.

Background Most children with neurocritical illness are at risk of physical, neurocognitive, and psychosocial sequelae and need centralized early rehabilitation care.Objective To identify the effectiveness and safety of centralized early rehabilitation care for children with severe acquired brain injury.Methods This is a mixed methods study—an implementation study and single-center retrospective cohort study with historical control. All children with severe acquired brain injury hospitalized in a specialized rehabilitation center in a comprehensive tertiary pediatric hospital between September 2016 and August 2020 were included. Patients treated in the centralized early rehabilitation unit were compared to historical controls dispersed in the normal inpatient rehabilitation ward. The effectiveness outcomes were measured by the Pediatric Cerebral Performance Category (PCPC) scale and the incidence of newly onset comorbidities. The safety outcomes were indicated by the mortality rate and the incidence of unexpected referrals.Results One hundred seventy-five patients were included. The delta PCPC scores of the first 4 weeks of inpatient rehabilitation in the intervention group were significantly lower than the control group (Z = −2.395, p = 0.017). The PCPC scores at 1 year in the intervention group were significantly reduced as compared to the control group (Z = −3.337, p = 0.001). The incidence of newly onset pneumonia/bronchitis was also decreased in the intervention group (χ2 = 4.517, p = 0.034). No death of patients was recorded, and there was no significant difference in unexpected referral rate between the two groups (χ2 = 0.374, p = 0.541).Conclusions The centralized pediatrics early rehabilitation unit is effective and safe for children with severe acquired brain injury. Further multicenter prospective implementation studies on effectiveness, safety, and economic evaluation are needed.

Endoscopy is the primary modality for detecting asymptomatic esophageal squamous cell carcinoma (ESCC) and precancerous lesions. Improving detection rate remains challenging. We developed a system based on deep convolutional neural networks (CNNs) for detecting esophageal cancer and precancerous lesions [high-risk esophageal lesions (HrELs)] and validated its efficacy in improving HrEL detection rate in clinical practice (trial registration ChiCTR2100044126 at www.chictr.org.cn). Between April 2021 and March 2022, 3117 patients ≥50 years old were consecutively recruited from Taizhou Hospital, Zhejiang Province, and randomly assigned 1:1 to an experimental group (CNN-assisted endoscopy) or a control group (unassisted endoscopy) based on block randomization. The primary endpoint was the HrEL detection rate. In the intention-to-treat population, the HrEL detection rate [28 of 1556 (1.8%)] was significantly higher in the experimental group than in the control group [14 of 1561 (0.9%), P= 0.029], and the experimental group detection rate was twice that of the control group. Similar findings were observed between the experimental and control groups [28 of 1524 (1.9%) versus 13 of 1534 (0.9%), respectively; P= 0.021]. The system’s sensitivity, specificity, and accuracy for detecting HrELs were 89.7, 98.5, and 98.2%, respectively. No adverse events occurred. The proposed system thus improved HrEL detection rate during endoscopy and was safe. Deep learning assistance may enhance early diagnosis and treatment of esophageal cancer and may become a useful tool for esophageal cancer screening.

The traditional von Neumann computing architecture has relatively-low information processing speed and high power consumption, making it difficult to meet the computing needs of artificial intelligence (AI). Neuromorphic computing systems, with massively parallel computing capability and low power consumption, have been considered as an ideal option for data storage and AI computing in the future. Memristor, as the fourth basic electronic component besides resistance, capacitance and inductance, is one of the most competitive candidates for neuromorphic computing systems benefiting from the simple structure, continuously adjustable conductivity state, ultra-low power consumption, high switching speed and compatibility with existing CMOS technology. The memristors with applying MXene-based hybrids have attracted significant attention in recent years. Here, we introduce the latest progress in the synthesis of MXene-based hybrids and summarize their potential applications in memristor devices and neuromorphological intelligence. We explore the development trend of memristors constructed by combining MXenes with other functional materials and emphatically discuss the potential mechanism of MXenes-based memristor devices. Finally, the future prospects and directions of MXene-based memristors are briefly described.

Objective This study investigated the relationship between glycated serum protein (GSP) and progressive infarction (PI).Methods From April 2017 to December 2020, we recruited 477 patients within 48 hours after the onset of acute ischemic stroke into this case–control study. Demographic characteristics, clinical information, and laboratory and neuroimaging data were recorded after admission.Results PI occurred in 144 (30.8%) patients. Patients with PI had higher initial National Institute of Health Stroke Scale (NIHSS) scores, higher discharge NIHSS scores, higher modified Rankin scale scores at 3 months after onset, higher GSP levels, lower prothrombin times, and lower creatinine levels than patients without PI. The likelihood of PI increased with increases in the GSP quartile. Multiple regression analysis revealed that high GSP levels (>2.14 mmol/L) were independently associated with PI. Subgroup analyses identified high GSP levels as an independent predictor of PI in patients with large artery atherosclerosis (third quartile: odds ratio [OR] = 3.793; 95% confidence interval [CI] = 1.555–9.250; fourth quartile: OR = 2.675; 95% CI = 1.056–6.776) and anterior circulation small vessel occlusion (fourth quartile: OR = 13.859; 95% CI = 2.024–94.885).Conclusions GSP might be an independent predictor for PI in certain patients with acute ischemic stroke.

Two types of CdS QDs with the capped ligands of thioglycollic acid (TGA) and mercaptopropionic acid (MPA) were successfully prepared by in situ electron beam radiation at room temperature. These morphologies and microstructures of CdS QDs were determined efficiently by FTIR, UV–vis, XRD, DLS, XPS, Inverted-FL, BET, FE-SEM and HR-TEM and so on. In view of CdS QDs were prepared by different methods and each one had its own unique properties, which may lead to different potential toxicity. In this study, the effects of two types of CdS QDs on the cytotoxicity in mouse embryonic osteoblast precursor cells (MC3T3-E1) were evaluated. The cytotoxicity results revealed that the water soluble CdS QDs were toxic and inhibiting activity to MC3T3-E1 cells. Specially, compared with MPA-CdS QDs with longer ligands and larger sizes, TGA-CdS QDs with shorter ligands and smaller sizes were more significantly cytotoxicity on MC3T3-E1 cells. A possible mechanism for the cytotoxicity behavior was established. This work will be beneficial to the design and modification of CdS QDs by electron beam radiation method for probing the cytotoxicity on MC3T3-E1 cells and further benefit to cell imaging and tissue engineering.

A sensitive, selective and convenient method for the simultaneous determination of 9 nitrosamines (NAs) in biological samples was developed using isotope dilution ultra-high performance liquid chromatography-triple quadrupole linear ion trap mass spectrometry (UPLC-QTRAP-MS). Multiple reaction monitoring-information dependent acquisition-enhanced product ion (MRM-IDA-EPI) scan mode was performed to eliminate false positive results, and the whole detection procedure was characterized by less time consuming and simple sample preparation. 9 NAs were separated through a T3 column with the gradient elution of acetonitrile and water, and detected by UPLC-QTRAP-MS with an atmospheric pressure chemical ionization (APCI) source in the positive mode. The quantitative analysis was carried out viathe isotope internal standard method with a matrix calibration curve. Under the optimized conditions, good linearity for the 9 NAs was achieved in the range of 0.2–20 μg L−1with correlation coefficients (r) higher than ≥0.9991, and the limits of detection and limits of quantitation were 0.02–0.1 μg L−1(S/N = 3) and 0.06–0.3 μg L−1(S/N = 10), respectively. Satisfactory recoveries ranging from 79.4% to 108.0% were obtained, and the precision of the proposed method, indicated by the relative standard deviations (RSDs), was 2.3–12.9%. The matrix effect study showed that NDMA, NMOR and NMEA presented a matrix suppression effect, NDPHA displayed a matrix enhancement effect, and the matrix effects of the other 5 analytes could be ignored. Real application of the developed method in 13 urine and 24 plasma samples demonstrated that NDBA, NPIP and NPYR occurred in both urine and plasma samples with the concentration of 0.038–0.60 μg L−1, while other NAs were not detected. Such a method was sensitive and selective, and could be applied to the rapid qualitative and quantitative analysis of the 9 NAs in biological samples.

Herein, we reported a tumor cell-targeting aptamer-nano-train to deliver paclitaxel(PTX) and combretastatin A4(CA4) at a predefined ratio to cancer cells based on DNA nanotechnology. Such a drug-carrying aptamer-nano-train(aptamer-NT-PTX/CA4) was prepared viaself-assembly of two DNA hairpins, which were conjugated with PTX and CA4, respectively, induced by aptamer trigger. Our research revealed that the aptamer-NT-PTX/CA4 could specifically recognize CD71-positive cancer cells, but not CD71-negative healthy normal cells, and achieve synergistic therapeutic effect on cancer cells. The aptamer-nano-train-based strategy is simple and efficient, and provides a new platform for drug combination cancer therapy.