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Abstract Background There are various frailty assessment tools in the world, and the application choice of frailty assessment tools for the elderly perioperative population varies. It remains unclear which frailty assessment tool is more suitable for the perioperative population in China. To validate the Perioperative Frailty Index (FI-32) derived from the Chinese Hospital Information System by investigating the impact of preoperative frailty on postoperative outcomes, and ascertain the diagnostic value of FI-32 for predicting postoperative complications through comparing with the FRAIL scale and the modified Frailty Index (mFI-11). Methods A prospective cohort study was conducted in a tertiary hospital. Elderly patients who were 60 years or older and underwent selective operation were included. The FI-32, FRAIL scale, and mFI-11 were assessed. Demographic, surgical variables and outcome variables were extracted from medical records. The data of readmission and mortality within 30 days and 90 days of surgery were ascertained by Telephone follow-up by professionally trained researchers. Multiple logistic regression was used to examine the association between frailty and complications. Receiver operating characteristic curves(ROC) were used to compare FI-32 with mFI-11 and FRAIL, to explore the predictive ability of frailty. Results 335 patients qualified for the inclusion criteria and were enrolled in the study, and among them, 201 (60.0%) were females, and the Median(P 25, P 75)age at surgery was 69 (65,74) years. The prevalence of frailty in the study population was 16.4% (assessed by FI-32). After adjusting for concomitant variables including demographic characteristics (such as gender, BMI, smoking, drinking, average monthly income and educational level) and surgical factors (such as surgical approach, surgical site, anesthesia method, operation time, intraoperative bleeding, and intraoperative fluid intake), there was a statistically significant association between frailty and the development of postoperative complication after surgery (OR = 3.051, 95% CI:1.460–6.378, P = 0.003). There were also significant differences in mortality within 30 days of surgery, the length of hospital stay (LOS) and the hospitalization costs. FI-32, FRAIL and mFI-11 showed a moderate predictive ability for postoperative complications, the Area Under Curves (AUCs) were 0.582, 0.566 and 0.531, respectively. With adjusting concomitant variables associated with postoperative complications, the AUCs of FI-32, FRAIL and mFI-11 in the adjusted prediction models were 0.824, 0.827 and 0.820 respectively. Conclusions The FI-32 has a predictive effect on postoperative adverse outcomes in elderly Chinese patients. Compared to FRAIL and mFI-11, the FI-32 had the same ability to predict postoperative complications, and FI-32 can be extracted directly from HIS, which greatly saves the time for clinical medical staff to evaluate perioperative frailty.

Indolent natural killer cell lymphoproliferative disorder of the gastrointestinal tract (iNKLPD-GI) is an uncommon, recently recognized lymphoid proliferation of mature NK cells primarily manifesting in the GI tract. Unlike NK/T lymphoma, iNKLPD-GI exhibits a rather indolent clinical course, underscoring the need for cautious management to prevent unnecessary interventions. However, clinical and molecular features of this entity have not been thoroughly understood. This study aimed to add more information to the current knowledge of this disease. Seven patients with iNKLPD-GI were included in our study. Clinical data included initial symptoms, endoscopic manifestations, pathological features, and therapies. Besides, next-generation sequencing was arranged to explore the underlying genetic mechanism of this disease. In our study, iNKLPD-GI in the urinary bladder was first identified. Edema of extremities (3, 42.8 %) was the most prevalent onset symptom which was reported for the first time. Pathological and immunohistological features were found to display the phenotype of NK cells. Unlike extranodal NK/T cell lymphoma, Epstein-Barr virus-encoded small RNA (EBER) were negative in all patients. Moreover, we found that two patients harbored JAK3 mutation. Apart from JAK3 K563_C565del previously reported in the literature, we discovered new JAK3 mutation sites. Other mutations including BRAF, KRAS, and SH2B3 were also identified. In conclusion, iNKLPD-GI was an indolent atypical NK-cell proliferation with diverse clinical characteristics. “Watch and wait” therapy was preferable to intense chemotherapy. Recurrent JAK3 mutation may be the underlying mechanism responsible for the neoplastic nature of the disease and may serve as a potential target for patients with severe symptoms.

Background: Mycosis fungoides (MF) and Sezary Syndrome (SS) comprise over half of all Cutaneous T-cell lymphoma diagnoses. Current risk stratification is largely based on TNMB staging, few research investigated the prognostic value of clinical exams. Current systemic therapy for advanced disease includes immunomodulatory drugs, chemotherapy, and HADC inhibitors. Few clinical trials or retrospective research compared the efficacy of different drugs.Method: Here, we performed a retrospective analysis of prognostic factors and treatment outcomes of 92 patients diagnosed with MF/SS at the Peking Union Medical College Hospital from 2013-2023.Results: Cox regression analysis identified that age ≥ 50 years, WBC ≥ 8 × 109/L, serum LDH ≥ 250U/L, β2-MG ≥ 4.50 mg/L, and stage IV were associated with reduced overall survival, age ≥ 50 years, serum LDH ≥ 250U/L and stage IV were associated with reduced progression free survival. Kaplan-Meier analysis established that immunomodulatory therapy was associated with longer progression free survival.Conclusion: These results suggested new factors in predicting prognosis and selecting appropriate treatments in patients with advanced MF/SS.

The enrichment and migration patterns of different chemical elements record paleoclimatic information in loess formations. The chemical elemental measurements of 245 samples from the Shiyang profile in the Weinan Region were compared with the geochemical characteristics of typical wind-formed profiles, and the paleoclimatic evolution was discussed. The results showed the following: (1) the standardized curves of the cumulative concentrations of SiO2, Al2O3, and CaO along with the Upper Continental Crust (UCC) in the Shiyang profile exhibited significant similarities with typical wind-formed profiles. This strongly suggests that the Shiyang profile has a wind-formed origin. (2) The mean value of the chemical index of alteration (CIA) of the Shiyang profile is 62.06, indicating that the Shiyang profile has been in the stage of primary chemical weathering. (3) The ratios of K2O/Al2O3, TiO2/Al2O3, and Fe2O3/Al2O3 in the Shiyang profile are comparable to those found in typical wind-formed profiles, suggesting a common source area and supporting the premise that the Shiyang profile is of wind-induced origin.(4) The regional climate has undergone a series of transitions: from a dry and cool phase in the early Holocene to warm and humid yet unstable conditions in the middle Holocene, and returning to dry and cool during the late Holocene.

Rock mass consists of many discontinuities, such as faults, joints, etc., and layered joints are a common kind of rock mass structure. The joints affect the stress wave propagation, and blasting is an economical and efficient rock fragmentation method for rock mass engineering. So, the rock mass fragmentation effect and construction progress are affected by these layered joints. Numerical studies were carried out to analyze the damage evolution process of intact rock and rock mass with layered joints subjected to blasting loads based on the Riedel–Hiermaier–Thoma (RHT) model in LS-DYNA software (smp s R11.0.), and the effects of the location of initiation points and the fracture distribution on dynamic damage evolution of the rock mass were discussed. Bottom initiation tends to direct the blasting energy toward the blasthole mouth, resulting in effective rock fragmentation and ejection. Gradually adjusting the initiation point upward can improve the stress and damage distribution, allowing some of the blasting stress waves to propagate toward the bottom and enhance the fragmentation of the rock at the bottom. The distribution of layered joints exacerbates the damage to the rock mass on the upstream surface, but also acts as a certain shield to the propagation of stress waves, increasing the asymmetry of the damage distribution. It is useful to know the damage mechanism of the rock mass with layered joints to improve the effect of rock mass fragmentation by blasting. These results have very important theoretical significance and application value for the optimization of blasting construction technology.

Although plant genotypes are known to be a determinant of microbiome composition, the genetic mechanisms underlying how genotypes affect the microbiome are poorly understood. Citrus is an important, perennial fruit crop that normally contains scion grafted on the rootstock. Here, we investigated the genetic traits underlying the citrus microbiome. We sequenced the metagenome of leaf, root, and rhizosphere soil samples and the genome of corresponding citrus genotypes, which included 66 unique rootstock–scion combinations (56 scion genotypes and 9 rootstock genotypes) from one location using deep shotgun sequencing. Using a genome-wide association study (GWAS) analysis, we identified significant associations between citrus genes and a subset of genera and functional traits of the microbiome. Intriguingly, we found that bacterial secretion systems and mobility-related genes were present in single-nucleotide polymorphism-associated microbial functional traits of leaf and root microbiomes but not in the rhizosphere microbiome, indicating that they are important factors for bacteria to colonize inside or on leaf and root tissues but less so in the rhizosphere. We also discovered that chemotaxis and flagella genes play critical roles for bacteria colonizing leaf tissues but not in root tissues and the rhizosphere. Microbiome-associated host genes were mainly involved in plant immunity, transporters, hormones, cell walls, and the metabolism of carbohydrates, amino acids, and nitrogen. We identified genetic determinants that are associated with the abundance of Bacillus, Bradyrhizobium, Burkholderia, and Cellvibrio, genera that are known to comprise many beneficial bacteria for citrus. This study unraveled the genetic traits underneath the mutual selection of citrus and microbes via GWAS analyses. This study provides useful information that aids the utilization of genotypes and key members of a healthy microbiota for microbiome engineering as well as the editing of specific genes to improve host microbiota. [Graphic: see text] Copyright © 2023 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.

This study used a static bidirectional multifunctional loading system. The system conducted bidirectional compression tests on scaled specimens of slurry masonry schist under freeze–thaw cycling conditions. This study aimed to investigate the influence of bidirectional stress coupling with freeze–thaw cycles on the mechanical properties of slurry masonry schist. The results indicate that lateral pressure can increase the peak stress of slurry masonry schist, while freeze–thaw cycles have an adverse effect on the material’s internal pore structure, counteracting the gain effect of lateral pressure. This study also employed acoustic emission (AE) technology to analyze the evolution of slurry masonry schist failure characteristics. The findings reveal that freeze–thaw cycles accelerate the failure of slurry masonry schist during loading, and lateral pressure to some extent mitigates the damage development of slurry masonry schist. The synergistic effect of lateral pressure and freeze–thaw cycles alters the fracture mode of slurry masonry schist. Acoustic emission signal localization demonstrates numerous AE localization points in the interface transition zone, forming a coherent signal band where cracks propagate toward complete interface penetration. The crack extension process of the slurry masonry schist was investigated using the digital image correlation (DIC) method. The results indicated that macroscopic cracks formed in the strain localization zone, resulting in fracture damage to the specimens, with interfacial debonding identified as the primary failure mode for slurry masonry schist structures.

The Huangling region is located in the central part of the Chinese Loess Plateau, which is sensitive to climate change due to the transitional characteristics of the natural environmental zone in which it is located. In this study, we utilized a spore–pollen analysis of the Tianjiahe (TJH) profile in Huangling to apply the pollen–climate factor conversion function method. This approach allowed us to quantitatively reconstruct the paleotemperature and paleoprecipitation of the Huangling area during the Middle and Late Holocene. The results show that the Huangling area experienced four climatic stages during the Middle and Late Holocene, including mild and slightly humid → warm and humid → warm and slightly humid → warm and humid. Except for the period of 5.3–4.72 kaBP, during which the climate was relatively cool and dry compared to the present, the climate in the remaining period (4.72–0.03 kaBP) was warmer and more humid than that of the present. The above results provide an important insight for further exploring the mechanism of paleoclimate change and predicting future climate change.

Plant genotype alone appears to be insufficient to explain trait variations. This study integrates GWAS, MWAS and mGWAS in 827 foxtail millet cultivars, revealing that root-associated microbiota affect plant phenotypes in a host genotype-dependent manner.

Introduction: The lack of prior knowledge of the marine environment increases the difficulty of passive ranging of underwater sound sources by using a single hydrophone. The dispersion curve of the normal mode contains extensive marine environmental information, which can be extracted without prior knowledge, but the characteristics of dispersion curves of different modes vary, and the mode order cannot be determined from the received data.Methods: Herein, a method based on a single hydrophone that can jointly identify the mode order and estimate the propagation range in unknown marine environment is proposed. The method uses Bayesian theory as the main methodology and is applicable to broadband pulse sound sources in shallow seas with long-range propagation. The dispersion curves extracted from the data and those calculated by the dispersion formula are the input signal and the replica of the methods, respectively. Accurate identification of the normal mode order and estimation of the propagation range can be achieved by establishing the joint cost function.Results: In the case of unknown a priori knowledge of the marine environment, the method enables rapid inversion, is tolerant to environmental parameter mismatch, and is low cost and practical.Discussion: The simulation and measured data analysis results demonstrate the accuracy and validity of the method. The measured data contains linear frequency modulation impulse source signal and explosion sound source signals, and the mean relative error of range estimation is less than 5%.

Abstract Little is known about the epidemiology and impact of atrial fibrillation (AF) on cardiovascular diseases (CVD) mortality among hypertensive elderly population in northeast China. The community‐based study included 4497 hypertensive elderly residents aged ≥65 years who lived in northeast China from September 2017 to March 2019. Information on CVD deaths was obtained from baseline until July 31, 2021. Cox proportional hazard regression models were performed in the evaluation of CVD mortality. We identified 101 persons with AF. The prevalence of AF was 2.2% among elderly hypertensive population, which increased significantly with age. The prevalence of AF was higher in men than in women. The awareness rate was 51.5%, higher in urban areas than in rural areas (68.8% vs 43.5%, P = .018). Only 4.0% patients received oral anticoagulant (OAC) therapy among AF patients. Moreover, diabetes (26.7%) and dyslipidemia (37.6%) were highly prevalent in AF patients. Furthermore, 212 persons died due to CVD (14.7/1000 person‐years) during a median follow‐up of 3.2 years. AF patients had a 3.42 (95% CI: 2.07‐5.63) times higher risk of CVD mortality than the patients without AF in the fully adjusted model. Therefore, the burden of AF among hypertensive elderly population in northeast China was considerable. Long‐term screening and management strategies for AF and related risk factors are required among hypertensive elderly in northeast China.

Lead-free ceramic capacitors have the application prospect in the dielectric pulse power system due to the advantages of large dielectric constant, lower dielectric loss and good temperature stability. Nevertheless, most reported dielectric ceramics have limitation of realizing large energy storage density (Wrec) and high energy storage efficiency (η) simultaneously due to the low breakdown electric field (Eb), low maximum polarization and large remanent polarization (Pr). These issues above can be settled by raising the bulk resistivity of dielectric ceramics and optimizing domain structure. Therefore, we designed a new system by doping (Bi0.5Na0.5)0.7Sr0.3TiO3 into 0.9NaNbO3-0.1Bi(Ni0.5Zr0.5)O3 ceramics, which simultaneously obtained a higher bulk resistivity by decreasing the grain size and achieved a smaller Pr by optimizing domain structure, thus the better Eb of 530 kV/cm and Wrec of 6.43 J/cm3 were achieved, η was improved from 34% to 82%. Besides, the 0.4BNST ceramics show excellent temperature, frequency and fatigue stability under the conditions of 20–180 °C, 1–100 Hz and 104 cycles, respectively. Meanwhile, superior power density (PD = 107 MW/cm3), large current density (CD = 1070 A/cm2) and discharge speed (1.025 μs) were achieved in 0.4BNST ceramic. Finally, the charge-discharge performance displayed good temperature stability in the temperature range of 30 °C–180 °C. The above results indicated that the ceramics have potential practical value in the field of energy storage capacitor.

Abstract Malignant eyelid tumors can invade adjacent structures and pose a threat to vision and even life. Early identification of malignant eyelid tumors is crucial to avoiding substantial morbidity and mortality. However, differentiating malignant eyelid tumors from benign ones can be challenging for primary care physicians and even some ophthalmologists. Here, based on 1,417 photographic images from 851 patients across three hospitals, we developed an artificial intelligence system using a faster region-based convolutional neural network and deep learning classification networks to automatically locate eyelid tumors and then distinguish between malignant and benign eyelid tumors. The system performed well in both internal and external test sets (AUCs ranged from 0.899 to 0.955). The performance of the system is comparable to that of a senior ophthalmologist, indicating that this system has the potential to be used at the screening stage for promoting the early detection and treatment of malignant eyelid tumors.

SiO2 aerogel is a super-insulating material that can be used for tunnel fireproofing to eliminate high-temperature spalling and extend the safe evacuation time of personnel. This study aimed to replace traditional aggregates with SiO2 aerogel in mortar preparation and evaluate its mechanical properties, thermal conductivity, and durability (freeze–thaw, water, and moisture resistance). Furthermore, the high-temperature characteristics of SiO2 aerogel and the damage evolution pattern of SiO2 aerogel mortar were investigated with varying fire durations (0.5, 1, 1.5, 2, 2.5, and 3 h) and fire temperatures (1000, 1100, and 1200 °C) as environmental variables. The results revealed that the critical temperature and critical time of SiO2 aerogel particles from amorphous to crystalline structures were about 1100 °C and 1.5 h, respectively. SiO2 aerogel mortar exhibited a compressive strength of 3.5 MPa, a bond strength of 0.36 MPa, and a thermal conductivity of 0.165 W/m·K. The residual mass ratio and residual compressive strength of SiO2 aerogel mortar were 81% and 1.8 MPa after 1100 °C for 2.5 h. The incorporation of SiO2 aerogel significantly improved the fire resistance of the mortar. Therefore, SiO2 aerogel mortar has the potential to be used as a fireproof coating and can be applied in tunnels to reduce high-temperature spalling and extend the safe evacuation time for personnel.

Objectives. To evaluate the short-term outcome of treatment by auricular acupressure (AA) on postoperative pain among hip fracture (HF) patients. Methods. A systematic search for randomized controlled trials on this topic was conducted through May 2022 by searching multiple English and Chinese databases. The methodological quality of the included trails was assessed by the Cochrane Handbook tool, and relevant data were extracted and statistically analyzed by RevMan 5.4.1 software. The quality of the evidence supporting each outcome was evaluated by GRADEpro GDT. Results. Fourteen trials with a total of 1390 participants were included in this study. Compared with conventional treatment (CT) alone, the combination of AA and CT had a significantly greater effect on the visual analog scale at 12 h (MD −0.53, 95% CI −0.77 to −0.30), 24 h (MD −0.59, 95% CI −0.92 to −0.25), 36 h (MD −0.07, 95% CI −0.13 to −0.02), 48 h (MD −0.52, 95% CI −0.97 to −0.08), and 72 h (MD −0.72, 95% CI −1.02 to −0.42), amount of analgesics used (MD −12.35, 95% CI −14.21 to −10.48), Harris Hip Score (MD 6.58, 95% CI 3.60 to 9.56), effective rate (OR 6.37, 95% CI 2.68 to 15.15), and adverse events (OR 0.35, 95% CI 0.17 to 0.71). Conclusions. Compared with CT alone, the combination of AA and CRT had a significantly greater effect on postoperative pain in HF patients. However, trails with a rigorous methodology, including standard protocols for AA and multiethnic subjects, are still needed.

Objective This study systematically reviewed the effect of melatonin (MLT) on quality of life (QoL) and symptoms among patients with cancer.Design Systematic review and meta-analysis.Data sources Cochrane Library, PubMed, Embase, Web of Science, Medline, CINAHL, Scopus, ClinicalTrials.gov, China Biology Medicine (CBM), ProQuest and Open Grey were searched from inception to November 2021.Eligibility criteria We included randomised controlled trials (RCTs) assessing the effects of MLT on QoL, sleep quality, fatigue, depression, pain, stomatitis rate and stomatitis severity in adult patients with cancer, without language restrictions. Studies that reported the effects of MLT along with other interventions and had incomplete or absent outcome data were excluded.Data extraction and synthesis Two independent reviewers extracted data, and another two reviewers assessed the risk of bias. The risk of bias for each eligible study was assessed using the Cochrane assessment tool. The mean difference or standard mean difference (SMD) with 95% CIs was used in the computation of continuous variables to synthesise data. The relative risk was used for dichotomous outcomes. Heterogeneity was assessed and quantified (I2 statistic).Results A total of 19 qualified studies that included 2101 patients with cancer (MLT: 1078, control: 1023) were included in the meta-analysis. The results indicated that MLT had no significant effect on QoL (SMD=−0.01, 95% CI (−0.14 to 0.11), p=0.83), sleep quality (SMD=−0.18, 95% CI (−0.62 to 0.26), p=0.42), fatigue (SMD=−0.34, 95% CI (−0.73 to 0.06), p=0.10), pain (SMD=−0.34, 95% CI (−0.7 to 0.02), p=0.06) or stomatitis severity (RR=0.78, 95% CI (0.47 to 1.30), p=0.35). MLT reduced stomatitis rate among patients with cancer (RR=0.47, 95% CI (0.26 to 0.88), p=0.02), except those with head and neck cancer (RR=1.09, 95% CI (0.92 to 1.29), p=0.35). MLT eased depression in patients who received administration for more than 14 days (SMD=−0.14, 95% CI (−0.27 to –0.01), p=0.03) and those who underwent surgery (SMD=−0.17, 95% CI (−0.32 to –0.03), p=0.02).Conclusion The findings showed that MLT did not improve the QoL, sleep quality, fatigue, pain or stomatitis severity among patients with cancer. It had a limited effect on decreasing the stomatitis rate and easing depression. Different treatments, durations and cancer types were the main sources of heterogeneity. Further large-scale RCTs are urgently needed. In addition, the effects of different combinations of MLT dosage and duration, administration types and joint measures are worthy of further study.PROSPERO registration number CRD42021292855.

Objectives Little is known about the prevalence and impact of isolated diastolic hypertension (IDH) in northeast China. We aimed to investigate the current epidemiology of IDH and to illustrate whether IDH accounted for cardiovascular disease (CVD) mortality.Design A prospective cohort study.Setting A population-based study carried out in northeast China.Participants We built a community-based study of 18 796 residents aged ≥40 years who were living in northeast China with blood pressure measurements between September 2017 and March 2019.Outcome measures Information on CVD death was obtained from baseline until 31 July 2021. IDH was defined as a diastolic blood pressure ≥90 mm Hg together with systolic blood pressure

High-performance lead-free dielectric ceramics with simultaneously high energy storage density and power density are in high demanded for pulse power systems. To realize excellent energy-storage characteristics, a strategy to enhance antiferroelectricity and construct a local random field simultaneously was proposed in this study. Based on the above strategy, a series of (1-x)NaNbO3-xBi(Ni1/2Sn1/2)O3 [xBNS, x = 0.05, 0.10, 0.15, 0.20, and 0.22] solid solutions were designed and fabricated. An ultrahigh energy storage density (Utotal) of 7.35 J/cm3, and recoverable energy density (Urec) of 5.00 J/cm3 were achieved in the 0.10BNS ceramics. In addition, an adequate stability of energy storage properties at a range of temperatures (20–140 °C), frequencies (1–100 Hz), and fatigue test durations (1–104 cycles) were realized in 0.10BNS ceramics. 0.10BNS ceramics displayed a high current density of 1005 A/cm2, an ultrahigh power density of 100.5 MW/cm3, and an ultrashort discharge time of 46.5 ns? This remarkable performance not only justified our strategy but also confirmed 0.10BNS ceramics as a promising candidate for energy storage.

Paleoclimate studies of loess in China have focused mostly on the time series of a single borehole or profile. However, research on loess strata and regional paleoenvironmental patterns could facilitate a deeper understanding of loess as a paleoenvironmental indicator and provide new insights into interpreting loess in sedimentary records of the paleoclimate. In this study, we determined the spatial pattern and regional characteristics of the paleoclimate during the Last Interglacial period in the Luohe River Basin, Shaanxi Province, China. We selected four representative boreholes in the study area (ZK04, ZK18, ZK13, and ZK19) from different landforms and zones, distributed from the northwest to the southeast, as well as three classic profiles (JB, JD, and LC). From north to south, comparative analyses were conducted of the loess strata, magnetic susceptibility, and grain size, and we analyzed the distribution characteristics of loess and paleosols in different geomorphological regions. The results showed that both the thickness and the sedimentation rate of loess in this river basin decreased from north to south. There were few paleosol horizons in the northern Liangmao area, but numerous such horizons in the southern plateau, and the degree of paleosol development increased from north to south. The magnetic susceptibility increased, whereas the particle composition tended to become thinner from north to south. The climate fluctuations of the Last Glacial recorded by the loess and paleosols in different regions were inconsistent.

As a typical multisource sediment, the grain size distribution of loess presents multi-peak distribution.End member analysis can be used to separate the end member components representing different sediment sources and sedimentary dynamics from the complex sediment size, which has been widely used in loess research.In this paper, Paterson parametric end member model was used to separate and explained the end member size of Sandaogou profile located in the southeastern margin of the Mu Us Desert.The analyzed results indicated that the Sandaogou loess in Jingbian was divided into four end members: EM1(8.93 μm) was the background dust; EM2(25.18 μm) was a component related to monsoon circulation.EM3(39.91 μm) and EM4(56.37 μm) were components related to winter wind.Among them, EM3 was the main component of loess in the loess plateau and EM4 was roughly the same grain size as modern sandstorms.Through the analysis of the curves of the end member components with age, the following conclusions were drawn: the profile recorded that the Jingbian area had experienced MIS 3(32.8-29.8 ka BP), LGM(29.8-22.8 ka BP), last deglacial(22.8-11.3 ka BP) and Holocene(8.7-1.7 ka BP) since MIS 3. Three climatic rapid change evented and cycles Dansgaard-Oeschger in deglaciation Heinrich 1(16.2-13.8 ka BP), Bølling-Allerød(13.8-12.8 ka BP) and Younger Dryas(12.8-11.3 ka BP) were recorded.The profile also recorded three major expansion-contraction cycles during last glacial period of the Mu Us Desert, and three dry sand events during the Holocene(8.7-8.2 ka, 6.0-5.0 ka, and 3.5-2.5 ka).

Objective: This study aimed to assess the occurrence of chemotherapy-induced nausea and vomiting (CINV) in acute phase (24 h after chemotherapy) and delayed phase (2–5 days after chemotherapy) after standard antiemetic therapy and to explore the risk factors of CINV in the acute and delayed phases. Methods: This prospective and observational study analyzed the data of 400 breast cancer patients scheduled for chemotherapy in two hospitals. The self-report survey was developed to assess the occurrence of CINV and their associated factors. On day 2 and day 6 of chemotherapy, CINV was evaluated by the Multinational Association of Supportive Care in Cancer Antiemetic Tool (MAT). The incidence of acute and delayed CINV was expressed as frequency and percentage. Results: Among 400 patients, 29.8% and 23.5% experienced acute and delayed CINV, respectively. Logistic regression analysis showed that the risk factors associated with acute CINV included pain/insomnia, history of CINV, and highly emetogenic chemotherapy. The history of motion sickness (MS), history of CINV, number of chemotherapy cycles completed, and the incidence of acute CINV were significant risk factors for delayed CINV (all P < 0.05). Conclusions: The results of this study are helpful for nurses to identify high-risk patients with CINV, formulate effective treatment plans, and reduce the incidence of CINV.

BackgroundElderly people are susceptible to atrial fibrillation (AF) and ischemic stroke (IS); however, less information is known about the association between AF and the risk of cardiovascular disease (CVD) mortality in elderly population with IS. We aimed to investigate the features of AF among aged people with IS and to illustrate whether AF accounted for CVD mortality.MethodsAt baseline, 790 patients with IS were enrolled from the general northeast Chinese elderly population (>60 years) between September 2017 to March 2019. The prevalence, awareness, and treatment of AF in each age group were analyzed, as well as major-related cardiovascular risk factors. The population was followed until July 31, 2021, and information on CVD death was obtained.ResultsA total of 25 people had AF, and the prevalence of AF in the elderly population with IS was 3.2%. The AF prevalence grew along with age from 1% (60–64 years) to 4.3% (70–74 years) and 4.2% (≥75 years), which was higher in the urban residents than in the rural residents (5.7 vs. 2.2%, P = 0.014). The awareness and treatment rates of patients with AF were 80 and 8%. After a median follow-up period of 3.3 years, 58 subjects died due to CVD and 5 subjects were accompanied with AF (rate 70.6/1,000 person-years). Elderly IS patients with AF had a 3.65-fold increased risk of CVD death in the fully adjusted model when compared with non-AF participants.ConclusionThe AF prevalence increased with age among the elderly population with IS. Moreover, elderly patients with IS in northeast China with AF had a higher CVD mortality. Therefore, early screening and prompt management of AF in elderly population with IS in northeast China are required.

The mid-Pleistocene transition is recognized as a shift in paleoclimatic periodicity from 41- to 100-kyr cycles. Here the authors present a unique mid-Pleistocene transition of coupled monsoon-vegetation changes from 23- to 100-kyr cycles, which indicates varied sensitivity of past climate to astronomical and ice/CO2 forcing.

This paper describes an extensive experimental study of the compressive failure of different types of aggregates and the influence of aggregate type on the interfacial properties of mortars. Interfacial debonding was the main failure mode of mortar rubbles. The interlocking strength of aggregate and mortar strongly affected the compressive strength of materials. When basalt was used as the aggregate, I-II composite failure of the deflection crack occurred as well as interfacial debonding. The highest instantaneous AE energy of the granite mortar rubble was 1349 mV·ms, which was 4.1 times greater than that of the basalt mortar rubble (326 mV·ms). Acoustic emissions of mortar rubble were strongest in the 150–220 kHz range and gave an early warning of the damage load at high frequencies (160–320 kHz). The C-S-H gel formed by the hydration reaction adhered to the aggregate pores and exhibited a “root pile” effect that improved the bonding performance of the interfacial zone. The interfacial porosity of the basalt, granite and limestone mortar rubble was 21.29%, 18.70% and 30.0%, respectively. The limestone interface has a large porosity, the fractal cones was small (1.19), and there was an obvious sidewall effect, but the interfacial strength was weak. The pore structure had a significant effect on the interfacial bond strength. This multi-faceted analysis truly reflected the state and evolution of the damage of mortar rubbles, and the results were very effective for determining the mechanical mode of damage of mortar rubbles.

Carbon nanotube (CNT)/rubber nanocomposites have wide applications in wearable devices and robotics, as stretchable conductors or sensitive/flexible piezoresistive sensors. However, the modification and optimization of the electrical properties of these nanocomposites are highly dependent on the dispersion quality of CNTs, and more severally, the high dosage of CNTs could inevitably increase the modulus of rubber, which limits their interaction with soft materials, such as human tissue. A liquid metal (LM), such as eutectic gallium indium, can be considered as a soft and conductive additive to increase the conductivity of rubber. Here, we investigate the modification of the electrical and mechanical properties of CNT/rubber nanocomposites by LMs. We found that LMs are well dispersed in the rubber matrix with the average size increasing with its loading. Wrinkles formed on LM droplets, indicating that the oxide layer was subjected to compressive stress during the polymerization of rubber. Although the conductivity of the CNT/rubber nanocomposites can be improved by about 328% at 10 vol. % of LMs with negligible loss of mechanical properties, further increasing the loading of LMs would decrease the conductivity, suggesting their limited contribution for the conductive network formation in the rubber matrix.

It is of both fundamental and practical importance to develop effective adsorbents for removing phosphate from aqueous solutions continuously. In this study, magnetic amorphous lanthanum silicate alginate hydrogel beads (MALS-B) were prepared and used for phosphate removal. Mesoporous silica materials with highly ordered and hexagonal channel structures were synthesized from natural mineral rectorite (REC) at room temperature. On this basis, amorphous lanthanum silicate (ALS) was synthesized by theone-pot method using a silicon source from REC and a commercial lanthanum source. Further, MALS-B were synthesized from sodium alginate (SA) with ALS and Fe3O4 as the incorporated adsorbable and magnetic nanoparticles via a simple cross-linking method in CaCl2 solution. The synthesized hydrogel beads were characterized by various techniques. ALS and Fe3O4 existed relatively independently in MALS-B, where ALS provided adsorption sites and Fe3O4 provided magnetism. They played a synergistic role in phosphate removal. The saturation magnetization value of MALS-B was 17.38 emu/g, enabling theirfacile separation from aqueous solutions after phosphate adsorption. MALS-B exhibited a preferable adsorption capacity of 40.14 mg P/g for phosphorus compared to other hydrogel beads based on adsorption experiments. More significantly, MALS-B exhibited excellent selectivity for phosphate in aqueous solutions with various interfering ions and possessed a high affinity to phosphate in a wide pH range. MALS-B showed the treatment volume of 480 BV when effluent phosphate concentration was below 0.5 mg/L in fixed-bed column adsorption. The adsorption mechanism was also revealed. Our work demonstrates that MALS-B can serve as a promising adsorbent for continuous phosphate adsorption.

Abstract We propose a scheme for nonreciprocal light propagation in two coupled cavities system, in which a two-level quantum emitter is coupled to one of the optical microcavities. For the case of parity-time ( $${\mathscr{P}}{\mathscr{T}}$$ P T ) symmetric system (i.e., coupled active-passive cavities system), the cavity gain can significantly enhance the optical nonlinearity induced by the interaction between a quantum emitter and cavity field beyond weak-excitation approximation. The increased optical nonlinearity results in the non-lossy nonreciprocal light propagation with high isolation ratio in proper parameters range. In addition, our calculations show that nonreciprocal light propagation will not be affected by the unstable output field intensity caused by optical bistability, and we can even switch directions of nonreciprocal light propagation by appropriately adjusting the system parameters.

It's significantly urgent to develop the polymer film capacitor with large energy density and high charge-discharge efficiency for the applications of portable electronics and power hybrid system. In this study, poly(vinylidene fluoride) (PVDF) nanocomposite film incorporated with tetradecylphosphonic acid modified BaTiO(3) was prepared via solution casting to achieve high dielectric property and large energy density. The strong interactions were formed between modifier and polymer segments, which was characterised by X-ray absorption near edge structure of synchrotron radiation. The decrease of activation energy indicates that the functionalisation of BaTiO(3) weakens the heterogeneous nucleation of nanoparticle. The dielectric constant of 30 vol.% nanocomposite film achieves 50.1 with low loss of 0.02 at 100 Hz, which is attributed to the strong interaction between the phosphonic acid and fluoride atoms of PVDF segments. The energy density of 20 vol.% nanocomposite is 4.4 J/cm^3 with charge-discharge efficiency of 78% at 120 MV/m due to the large interfacial polarisation. The functionalisation strategy of high-k nanofillers enhances the compatibility in polymer nanocomposite, which contributes to the flexible polymer capacitor with large energy density and high charge-discharge efficiency.

Silica reagents are expensive and toxic for use in the synthesis of mesoporous silica materials. It is imperative to take an interest in green silicon sources. In this paper, we report the synthesis of hexagonal and ordered aluminum-containing mesoporous silica materials (Al−MCM−41) from natural perlite mineral without addition of silica or aluminum reagents. A pretreatment process involving acid leaching, alkali leaching, and strongly acidic cation exchange resins treatment was critical to obtain silicon and aluminum sources from natural perlite mineral. The Al−MCM−41 material was synthesized via a hydrothermal reaction with hexadecyl trimethyl ammonium bromide (CTAB) as the template and subsequent calcination. The resulting mesophase had a hexagonal and ordered mesoporous structure, confirmed by small-angle X-ray diffraction (SAXRD) and transmission electron microscopy (TEM). Al−MCM−41 material had a high Brunauer−Emmet−Teller (BET) surface area of 1024 m2/g, pore volume of 0.72 cm3/g and an average pore diameter of 2.8 nm with a pore size distribution centered at 2.5 nm. The thermal behavior of the as-synthesized samples during calcination was investigated by thermogravimetry (TG) and differential thermogravimetry (DTG) analysis. The Al−MCM−41 material showed a negative surface charge in aqueous solution with the pH value ranging from 2 to 13. The variations of chemical structures from natural perlite to Al−MCM−41 were traced by wide-angle X-ray diffraction (WAXRD) and Fourier-transform infrared spectroscopy (FTIR). A proposed mechanism for the synthesis of hexagonal and ordered mesoporous silica materials from natural perlite is discussed.

High-voltage electrical pulses (HVEP) technology was applied in grinding of a magnetite ore as a comminution pretreatment. The effect of HVEP pretreatment on grindability, liberation and separation performance of a magnetite ore was investigated by a systematic experimental study. The results showed that the pretreatment of high-voltage electrical pulses created some intergranular microcracks inside the ore, reduced the mechanical strength and improved liberation. This gave the additional advantage of further breakage,thereby reducing the energy consumption and grinding time. In addition, the HVEP pretreatment before grinding was potentially beneficial in the recovery of the liberated minerals in the subsequent magnetic separation.

The previous literatures have insufficient content on spatial dependence and heterogeneity of agricultural carbon emissions (ACEs), which is inconsistent with the actual situation, weakening the practical significance of research conclusions. To fill this knowledge gap, this study attempts to explore the spatial evolution pattern of ACEs at the city-scale in the Fujian Province of China from spatio-temporal latitudes and adopts the exploratory spatial data analysis method (ESDA) to analyze the spatial correlation effects of ACEs. The findings revealed that ACEs in Fujian show a downtrend as a whole. From the perspective of carbon sources of ACEs, agricultural materials and livestock breeding caused the largest emissions, accounting for 73.82% of the total ACEs, while rice growth led to the smallest carbon emissions, accounting for 26.18% of the total ACEs. We also found that there is obvious non-equilibrium in the spatial distribution of ACEs and their intensity, showing a strong spatial correlation; and although a relatively obvious clustering area has been formed, the spatial autocorrelation of most regions is not significant. Accordingly, we suggest that exploring the "carbon compensation mechanism", is conducive to stimulating the low-carbon agricultural production behavior with positive externalities, to reduce agricultural carbon emissions. [ABSTRACT FROM AUTHOR]

Objective: To evaluate the epidemiology of atrial fibrillation (AF) in northeast China.Methods: This cross-sectional survey using a multistage, stratified and cluster random sampling method was conducted in Liaoning Province between September 2017 and March 2019. A total of 18 796 participants (28.9% urban, 71.1% rural) aged ≥40 years were included. All participants completed a questionnaire and underwent a physical examination and ECG. AF was diagnosed according to history and ECG findings.Results: The overall AF prevalence was 1.1%; it increased steeply with age. AF was more prevalent in men than in women (1.5% vs 0.9%, p<0.001); however, the difference between urban and rural areas was not significant (1.3% vs 1.1%, p=0.228). Among the AF population, the overall AF awareness rate was 52.6%, higher in women than in men (61.5% vs 44.1%, p=0.011); however, the difference between areas was not statistically significant (60.0% vs 49.0%, p=0.129). According to the CHA2DS-VASc score, almost all (90.2%, 194/215) of our subjects required oral anticoagulant (OAC) therapy; however, only 4.1% actually received it. Moreover, hypertension (66.5%), dyslipidaemia (32.6%) and diabetes (24.2%) were highly prevalent in patients with AF, but their control rates were unacceptably low (7.0%, 8.6% and 28.8%, respectively).Conclusions: The burden of AF in northeast China was substantial. Underuse of OAC therapy and uncontrolled comorbidities will likely contribute to the cardiovascular outcomes of patients with AF in the coming decades. Long-term management strategies for AF and related risk factors are required in northeast China. [ABSTRACT FROM AUTHOR]

Abstract Physical mechanical stimulation can maintain and even increase bone mass. Here, we report an important role of osteocytic integrin α5 in regulating the anabolic response of bone to mechanical loading using an Itga5 conditional gene knockout (cKO) mouse model. Integrin α5 gene deletion increased apoptotic osteocytes and reduced cortical anabolic responses to tibial compression including decreased endosteal osteoblasts and bone formation, and increased endosteal osteoclasts and bone resorption, contributing to the decreased bone area fraction and biomechanical properties, leading to an enlarged bone marrow area in cKO mice. Similar disruption of anabolic responses to mechanical loading was also detected in cKO trabecular bone. Moreover, integrin α5 deficiency impeded load-induced Cx43 hemichannel opening, and production and release of PGE2, an anabolic factor, resulting in attenuated effects of the loading on catabolic sclerostin (SOST) reduction and anabolic β-catenin increase. Together, this study shows an indispensable role of integrin α5 in osteocytes in the anabolic action of mechanical loading on skeletal tissue through activation of hemichannels and PGE2-evoked gene expression. Integrin α5 could act as a potential new therapeutic target for bone loss, especially in the elderly population with impeded mechanical sensitivity.

Summary: Cataract is the leading cause of blindness worldwide. Here, we reported a potential, effective therapeutic mean for cataract prevention and treatment. Gap junction communication, an important mechanism in maintaining lens transparency, is increased by protein kinase A (PKA). We found that PKA activation reduced cataracts induced by oxidative stress, increased gap junctions/hemichannels in connexin (Cx) 50, Cx46 or Cx50 and Cx46 co-expressing cells, and decreased reactive oxygen species (ROS) levels. However, ROS reduction was shown in wild-type, Cx46 and Cx50 knockout, but not in Cx46/Cx50 double KO lens. In addition, PKA activation protects lens fiber cell death induced by oxidative stress via hemichannel-mediated glutathione transport. Connexin deletion increased lens opacity induced by oxidative stress associated with reduction of anti-oxidative stress gene expression. Together, our results suggest that PKA activation through increased connexin channels in lens fiber cell decreases ROS levels and cell death, leading to alleviated cataracts.

The characteristics of urban dust aerosols and the contributions of their natural and anthropogenic sources are of scientific interest as well as being of substantial sociopolitical and economic concern. Here we present the results of a comprehensive study of dust flux and magnetic signatures, including magnetic susceptibility (Χ) and the morphology and elemental composition of magnetic particulates, of atmospheric dustfall originating from natural dust sources in East Asia and local anthropogenic sources in Xi'an, China. The results reveal a significant inverse relationship, on a seasonal basis, between variations in dust flux and Χ. By comparing Χ records of desert surface sediments and local polluted dust, the relative contributions of natural and anthropogenic sources can be estimated for the urban atmospheric dustfall. Analysis using Scanning Electron Microscopy (SEM) combined with Energy Dispersive Spectroscopy (EDS) indicates that magnetic particulates from different sources have distinctive morphological and elemental characteristics. Detrital magnetic particles originating from natural sources are characterized by relatively smooth surfaces with Fe and O as the major elements and a minor contribution from Ti. The anthropogenic particles have angular, spherule, aggregate, and porous shapes with distinctive contributions from marker elements, including S, Cr, Cu, Zn, Ni, Mn and Ca. Our results demonstrate that this multidisciplinary approach is effective in distinguishing dust derived from distant natural sources and local anthropogenic sources, and for quantitative assessment of the contributions of the two end-members. [ABSTRACT FROM AUTHOR]

Flight on-time performance is one of the most important issues in the National Airspace System, a very complex and dynamic system. To avoid negative impacts to the aviation industry, the Federal Aviation Administration has set a long-term objective of understanding and mitigating flight delays. Building an effective and accurate prediction model of flight-delay incidents will help airport executives make the best decisions in delay scenarios. This article utilized two advanced prediction methods to predict the probability of a flight-delay incident--data mining using the decision tree and data mining using Bayesian inference. Prediction models were built using flight on-time performance data collected from different sources. The results indicated important airport-related factors and their effects on the flight on-time performance. [ABSTRACT FROM AUTHOR]

Summary: Emerging evidence challenges the lens as an immune-privileged organ. Here, we provide a direct mechanism supporting a role of macrophages in lens capsule rupture repair. Posterior lens capsule rupture in a connexin 50 and aquaporin 0 double-knockout mouse model resulted in lens tissue extrusion into the vitreous cavity with formation of a “tail-like” tissue containing delayed regressed hyaloid vessels, fibrotic tissue and macrophages at postnatal (P) 15 days. The macrophages declined after P 30 days with M2 macrophages detected inside the lens. By P 90 days, the “tail-like” tissue completely disappeared and the posterior capsule rupture was sealed with thick fibrotic tissue. Colony-stimulating factor 1 (CSF-1) accelerated capsule repair, whereas inhibition of the CSF-1 receptor delayed the repair. Together, these results suggest that lens posterior rupture leads to the recruitment of macrophages delivered by the regression delayed hyaloid vessels. CSF-1-activated M2 macrophages mediate capsule rupture repair and development of fibrosis.

Mixed metal oxide (MMO) films containing Ni 2+and Al 3+have been fabricated by a simple process involving calcination of layered double hydroxide (LDH) film precursors at 300−600 °C for 4 h in air. Scanning electron microscopy (SEM) reveals that the resulting Ni/Al−O thin films maintain the original nestlike morphology of the precursor films without any deformation of the microstructure during the thermal decomposition process. After surface treatment with an aqueous solution of sodium laurate, the wettability of the NiAl-LDH and Ni/Al−O thin film surfaces changes from hydrophilic to hydrophobic. Moreover, whereas the NiAl-LDH film exhibits a low adhesion for water (Cassie−Baxter behavior) after surface modification, the Ni/Al−O films exhibit a high adhesion for water (Wenzel behavior). A possible explanation for this phenomenon has been suggested. [ABSTRACT FROM AUTHOR]

Abstract: A real time reverse-transcription polymerase chain reaction (RT-PCR) was developed for efficient detection of Cucumber green mottle mosaic virus (CGMMV). The method was designed to use a duo-primer system with a TaqMan probe targeting the conserved sequence in 3′ noncoding region (NCR) of CGMMV to detect isolates of this virus collected in China. The sensitivity of the real time RT-PCR assay was 0.13pg of total RNA or 50 molecules of RNA transcripts. This level of sensitivity indicated that the one step real time RT-PCR developed in the present study could be used for routine testing assays. The real time RT-PCR method could assist in the implementation of quarantine measures for prevention and control of the disease caused by CGMMV. [Copyright &y& Elsevier]

We demonstrate a 1×4 waveguide array produced by an IR femtosecond laser in z-cut lithium niobate (LiNbO3). The polarization dependence of light coupling in this waveguide structure is experimentally investigated. The coupling constants of the waveguide array are obtained by measuring the ratio of output power of each waveguide for extraordinary rays and ordinary rays, and the variation of coupled power in each waveguide as a function of the waveguide length are demonstrated. [ABSTRACT FROM AUTHOR]

Breast cancer (BC) is the most common malignant tumor in women. Although overexpression of CD155 has been detected in many types of human cancer cells, it is not completely understood about its expression and function in BC and its prognostic significance. In the present study, we detected the expression level of CD155 in 216 cases of BC by immunohistochemistry (IHC), and we evaluated its relationship with BC patients’ clinical information. We also analyzed the characteristics of CD163, CD8, and CD68 in 216 cases of BC patients through IHC. The results indicated that the CD155 expression level was significantly associated with primary tumor size (x2 = 23.593, P < 0.001), lymph node metastasis (x2 = 15.426, P < 0.001), tumour–node–metastasis (TNM) stage (x2 = 19.693, P < 0.001), Ki-67 (x2 = 9.355, P = 0.002), and CD163/CD8/CD68 expression on statistical analysis. BC patients with high expression of CD155 had poor overall survival rate, on both univariate analysis (Hazard ratio = 2.681, 95% CI = 1.458–4.928, P < 0.001) and multivariate analysis (Hazard ratio = 2.029, 95% CI = 1.059–3.887, P = 0.033). These results suggest an interaction between CD155 expression and tumor-infiltrating lymphocytes (TILs) in BC, and they also suggest that CD155 could be an effective prognostic biomarker for BC.

The miniaturization of electronics provides an opportunity for the polymer film capacitor due to its lightweight and flexibility. In order to improve energy density and charge–discharge efficiency of the film capacitor, the development of a polymer nanocomposite is one of the effective strategies, in which the distribution of the fillers plays a key role in the enhancement of the electrical energy capability. In this work, the few-layer boron nitride nanosheets (BNNSs) was exfoliated with assistance of the fluoro hyperbranched polyethylene-graft-poly(trifluoroethyl methacrylate) (HBPE-g-PTFEMA) copolymer as stabilizer, which was adsorbed on the surface of the nanosheets via a CH-π non-covalent interaction. The morphological results confirm the lateral size of ∼0.4 μm for resultant nanosheets with the intact crystal structure. The loading of 0.5 vol% BNNSs was embedded into poly(vinylidene fluoride-chlorotrifluoroethylene) (P(VDF-CTFE)) matrix by solution casting method, and then the nanocomposite film was uniaxial stretched to achieve the orientation of nanosheets in polymer host. The dielectric constant of stretching nanocomposite with ratio of 4 at 50 mm min−1 reaches 51.1 at 100 Hz with low loss as 0.016, while the energy density of 7.0 J cm−3 at 250 MV m−1 with charge–discharge efficiency of 56% is obtained in current nanocomposite film, which is attributed to the interfacial polarization as well as parallel nanosheets blocking the growth of electrical treeing branches. This strategy of the aligned nanosheets/polymer nanocomposite establishes a simple route to construct heterogeneity in polymer films with enhanced electrical energy capability for flexible capacitors. [ABSTRACT FROM AUTHOR]

A coupled active–passive double-cavity system with balanced effective gain and loss provides a powerful platform for sideband generation. In different input limits, we explore the gain-saturation nonlinearity of the active cavity with regard to sideband generation. Using a perturbation method, we give an explicit analytical expression for second-order sideband generation (SSG), showing a conversion efficiency of over 80% and pump powers as low as ∼μW. A remarkable mode-splitting is also observed during the SSG process in the unbroken parity–time () symmetry phase. With change in the system parameters, our numerical method shows that high-order sideband generation (HSG) in the unbroken phase is controllable, including increasing its amplitude and changing its order number, especially when switching HSG between perturbative and non-perturbative regimes. In the broken phase, field localization effect leads to a stronger output spectral intensity than that in the unbroken phase. [ABSTRACT FROM AUTHOR]

Thermal interface materials with high thermal conductivity are essential to transfer the redundant heat and improve the reliability of integrated circuits. Here we reported high thermal conductivity in polydimethylsiloxane (PDMS) nanocomposite incorporated with few-layer graphene, which was exfoliated in chloroform with assistance of hyperbranched polyethylene-g-polyhedral oligomeric silsesquioxane copolymer (HBPE@POSS) as the stabilizer. In order to improve the compatibility and enhance the thermal property, the HBPE@POSS copolymer was synthesized via the unique chain walking polymerization mechanism, which subsequently was applied to exfoliate natural graphite into few-layer graphene in low-boiling-point solvents. The majority of resultant nanosheets with low defects was verified with lateral dimension of ~400 nm and the thickness of ~1.6 nm, which is attributed to the presence of CH-π noncovalent interaction between graphene and HBPE@POSS copolymer. The graphene nanoplates (GNPs)/polydimethylsiloxane (PDMS) nanocomposites were prepared by solution casting, in which graphene nanofillers were dispersed uniformly in the matrix due to good compatibility between PDMS and oligomeric silsesquioxane segments adsorbed on the nanosheets. The thermal conductivity of 4.0 wt% GNPs/PDMS nanocomposite reaches 0.93 W m−1 K−1, which is 400% higher than that of pure PDMS. The PDMS nanocomposite incorporated with few-layer graphene exhibits a promising prospect in thermal interface for thermal management of electronic devices, and sheds a light on the interfacial improvement mechanism of thermal conductivity for polymer composite. [ABSTRACT FROM AUTHOR]