To send content items to your account,
please confirm that you agree to abide by our usage policies.
If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account.
Find out more about sending content to .
To send content items to your Kindle, first ensure email@example.com
is added to your Approved Personal Document E-mail List under your Personal Document Settings
on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part
of your Kindle email address below.
Find out more about sending to your Kindle.
Note you can select to send to either the @free.kindle.com or @kindle.com variations.
‘@free.kindle.com’ emails are free but can only be sent to your device when it is connected to wi-fi.
‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
High-current switching performance of ovonic threshold switching (OTS) selectors have successfully enabled the commercialization of high-density three-dimensional (3D) stackable phase-change memory in Intel’s 3D Xpoint technology. This bridges the huge performance gap between dynamic random access memory (DRAM) and Flash. Similar to phase-change memory, OTS uses chalcogenide-based materials, but whereas phase-change memory reversibly switches between a high-resistance amorphous phase and a low-resistance crystalline phase, OTS freezes in the amorphous phase. In this article, we review recent developments in OTS materials and their performance in devices, especially current density and selectivity. Advantages and challenges of OTS devices in the integration with the phase-change memory are discussed. We introduce the evolution of theoretical models for explaining the OTS behavior, including thermal runaway, field-induced nucleation, and generation/recombination of charge carriers.
To examine urban–rural disparity in childhood stunting, wasting and malnutrition at national and subnational levels in Chinese primary-school children in 2010 and 2014.
Data were obtained from two nationwide cross-sectional surveys conducted in 2010 and 2014. Malnutrition was classified using the Chinese national ‘Screening Standard for Malnutrition of Children’.
All twenty-seven mainland provinces and four municipalities of mainland China.
Children aged 7–12 years (n 215 214; 107 741 in 2010 and 107 473 in 2014) from thirty-one provinces.
Stunting, wasting and malnutrition prevalence were 1·9, 12·3 and 13·7 % in 2010, but decreased to 1·0, 9·4 and 10·2 % in 2014, respectively. The prevalence of stunting, wasting and malnutrition in both urban and rural children was higher in western provinces, while lower in eastern provinces. Although the prevalence of wasting and malnutrition was higher in rural children than their urban counterparts, the urban–rural disparity in both wasting and malnutrition decreased from 2010 to 2014 (prevalence OR: wasting, 1·35 to 1·16; malnutrition, 1·50 to 1·27). A reversal occurred in 2014 in several eastern provinces where the prevalence of wasting and malnutrition in urban children surpassed their rural peers. The urban–rural disparity was larger in western provinces than eastern provinces.
The shrinking urban–rural disparity and the reversal in wasting and malnutrition suggest that the malnutrition situation has improved during the post-crisis period, especially in the western provinces. Region-specific policies and interventions can be useful to sustainably mitigate malnutrition in Chinese children, especially in rural areas and the western provinces.
In this study, a novel shape memory polymer (SMP), eggshell membrane (ESM), with macroscopic mesh structures and microscopic crosslinked protein fibers, has shown water-stimulated shape recovery characteristics. Our results show that the collagen triple-helical molecular chains and disulfide-rich motifs in the ESM function as net-points retaining essential structures during deformation, while hydrogen bonds play a key role as switch units for shape recovery through water stimulation. We also demonstrate that programmable shape recovery characteristics of ESM can be obtained by modulating the number of net-points. This study may inspire the design of new programmable SMPs.
CIC, or Capicua, encodes a transcriptional repressor that is itself repressed by RAS/MAPK signalling. CIC is a recurrent target of somatic mutation in type 1 low grade gliomas (LGG), with at least half of the alterations predicted to be deleterious. Type 1 LGGs are a cohort of tumours that are molecularly defined by the loss of heterozygosity of chromosome arms 1p and 19q and the presence of neomorphic IDH1/2 mutations. Despite the high frequency of mutations in CIC within this tumour type, CIC’s putative tumour suppressive role remains to be elucidated. It is also unclear how CIC may cooperate with neomorphic IDH1/2 to promote gliomagenesis. To comprehensively characterize the molecular consequences of CIC loss, we performed RNA-seq, Whole Genome Bisulfite Sequencing, and ChIP-seq on 6 different histone modifications on isogenic CIC-wildtype (WT) and CIC-knockout (KO) normal human astrocytes. To also investigate the collective effects of CIC deficiency and neomorphic IDH1 on the transcriptome and epigenome, we generated the same dataset in isogenic CIC-WT and CIC-KO astrocytes possessing the IDH1 R132H mutation. Analysis of differentially expressed genes illustrates the enrichment of oncogenic pathways in specifically the CIC-KO, IDH1-R132H cells, supporting a synergistic relationship between CIC loss and IDH1-R132H in driving tumour progression. Integrative analyses are ongoing to unveil the epigenetic mechanisms underpinning the regulatory changes in these isogenic cell line models.
Multiple human immunodeficiency virus (HIV)-1 genotypes in China were first discovered in Yunnan Province before disseminating throughout the country. As the HIV-1 epidemic continues to expand in Yunnan, genetic characteristics and transmitted drug resistance (TDR) should be further investigated among the recently infected population. Among 2828 HIV-positive samples newly reported in the first quarter of 2014, 347 were identified as recent infections with BED-captured enzyme immunoassay (CEIA). Of them, 291 were successfully genotyped and identified as circulating recombinant form (CRF)08_BC (47.4%), unique recombinant forms (URFs) (18.2%), CRF01_AE (15.8%), CRF07_BC (14.4%), subtype C (2.7%), CRF55_01B (0.7%), subtype B (0.3%) and CRF64_BC (0.3%). CRF08_BC and CRF01_AE were the predominant genotypes among heterosexual and homosexual infections, respectively. CRF08_BC, URFs, CRF01_AE and CRF07_BC expanded with higher prevalence in central and eastern Yunnan. The recent common ancestor of CRF01_AE, CRF07_BC and CRF08_BC dated back to 1983.1, 1992.1 and 1989.5, respectively. The effective population sizes (EPS) for CRF01_AE and CRF07_BC increased exponentially during 1991–1999 and 1994–1999, respectively. The EPS for CRF08_BC underwent two exponential growth phases in 1994–1998 and 2001–2002. Lastly, TDR-associated mutations were identified in 1.8% of individuals. These findings not only enhance our understanding of HIV-1 evolution in Yunnan but also have implications for vaccine design and patient management strategies.
Human cystic echinococcosis is a widespread, chronic, endemic, helminthic zoonosis caused by larval tapeworms of the species Echinococcus granulosus. At present, there is no rational and effective therapy for patients with echinococcosis. The present study evaluated whether the combination of alkaloids from Sophora moorcroftiana seeds (SMSa2) and Bacillus Calmette–Guérin (BCG) was effective in the treatment of experimental echinococcosis. After 20 weeks of secondary infection with protoscoleces, mice were randomly allocated to five groups and treated for 6 weeks by daily intragastric administration of albendazole (ABZ, 100 mg/kg), SMSa2 (100 mg/kg), BCG (abdominal subcutaneous injection at 5 × 106 CFU), SMSa2 + BCG (100 mg/kg SMSa2 and 5 × 106 CFU BCG) or normal saline (untreated group), respectively. The results indicated a significant reduction in the weight of hydatid cysts in the SMSa2 + BCG group compared with the untreated, SMSa2 and BCG groups. The rate of inhibition of hydatid cyst growth in the SMSa2 + BCG group (76.1%) was obviously increased compared with that in the SMSa2 (25.7%) and BCG (26.6%) groups, respectively. Compared with the untreated control, the SMSa2 + BCG group showed a non-significant increase in serum interleukin-4 (IL-4). Furthermore, the serum levels of interferon-γ (IFN-γ) between the untreated and SMSa2 + BCG groups were not statistically different. Therefore, the combination of alkaloids from S. moorcroftiana seeds and BCG can reduce cyst burden and is an effective therapeutic regimen against echinococcosis.
Fluid flows in nature and applications are frequently subject to periodic velocity modulations. Surprisingly, even for the generic case of flow through a straight pipe, there is little consensus regarding the influence of pulsation on the transition threshold to turbulence: while most studies predict a monotonically increasing threshold with pulsation frequency (i.e. Womersley number,
), others observe a decreasing threshold for identical parameters and only observe an increasing threshold at low
. In the present study we apply recent advances in the understanding of transition in steady shear flows to pulsating pipe flow. For moderate pulsation amplitudes we find that the first instability encountered is subcritical (i.e. requiring finite amplitude disturbances) and gives rise to localized patches of turbulence (‘puffs’) analogous to steady pipe flow. By monitoring the impact of pulsation on the lifetime of turbulence we map the onset of turbulence in parameter space. Transition in pulsatile flow can be separated into three regimes. At small Womersley numbers the dynamics is dominated by the decay turbulence suffers during the slower part of the cycle and hence transition is delayed significantly. As shown in this regime thresholds closely agree with estimates based on a quasi-steady flow assumption only taking puff decay rates into account. The transition point predicted in the zero
limit equals to the critical point for steady pipe flow offset by the oscillation Reynolds number (i.e. the dimensionless oscillation amplitude). In the high frequency limit on the other hand, puff lifetimes are identical to those in steady pipe flow and hence the transition threshold appears to be unaffected by flow pulsation. In the intermediate frequency regime the transition threshold sharply drops (with increasing
) from the decay dominated (quasi-steady) threshold to the steady pipe flow level.
While a classic result by Merton (1973, Bell J. Econ. Manage. Sci., 141–183) is that one should never exercise an American call option just before expiration if the underlying stock pays no dividends, the conclusion of a very recent empirical study conducted by Jensen and Pedersen (2016, J. Financ. Econ.121(2), 278–299) suggests that one should ‘never say never’. This paper complements Jensen and Pedersen's empirical study by presenting a theoretical study on how to price American call options under a hard-to-borrow stock model proposed by Avellaneda and Lipkin (2009, Risk22(6), 92–97). Our study confirms that it is the lending fee that results in the early exercise of American call options and we shall also demonstrate to what extent lending fees have affected the early exercise decision.
Oxygen vacancies have a significant impact on the structure and electrical/magnetic properties of doped manganites. Magnetic La0.5Sr0.5MnO3 (LSMO) films were epitaxial grown on (001) SrTiO3 substrate by pulsed laser deposition. Structural studies from the x-ray diffraction suggest that the as-grown films are fully constrained by the substrate with the thickness ranging from 8 to 40 nm. By examining the valence of Mn by x-ray photoelectron spectroscopy and x-ray absorption spectroscopy, we find the ratio of Mn4+/Mn3+ increases along with the increased film thickness, which implies that the oxygen vacancies concentration induced by tensile strain correspondingly decreases. Therefore, the magnetization of LSMO is depressed with the exchange bias effect arising, and the electrical conductivity decreases significantly. This work builds a bridge between modulation of electric/magnetic properties and epitaxial strain in LSMO films.
The effects of stress-aging processing on corrosion resistance of an Al–Zn–Mg–Cu alloy were investigated. It is found that the one-stage stress-aged alloy is strongly sensitive to the electrochemical corrosion. The poor corrosion resistance of the one-stage stress-aged alloy can be attributed to fine intragranular aging precipitates and continuous distribution of grain boundary precipitates. Meanwhile, the incomplete precipitation of solute atoms results in high electrochemical activity of aluminum matrix. However, when the alloy is two-stage stress-aged, the corrosion resistance is greatly improved. Furthermore, the corrosion resistance decreases firstly and then increases with increasing the first stage stress-aging temperature. Increasing external stress can enhance the corrosion resistance of the two-stage stress-aged alloy. These phenomena are mainly related to aging precipitates within grains and along grain boundaries. The coarse and relatively low-density intragranular aging precipitates, as well as the discontinuously distributed grain boundary precipitates can enhance the corrosion resistance of the stress-aged alloy.
Generally, the obvious work hardening, dynamic recrystallization (DRX), and dynamic recovery behaviors can be found during hot deformation of Ni-based superalloys. In the present study, the classical dislocation density theory is improved by introducing a new dislocation annihilation item to represent the influences of DRX on dislocation density evolution for a Ni-based superalloy. Based on the improved dislocation density theory, the peak strain corresponding to peak stress and the critical strain for initiating DRX can be determined, and the improved DRX kinetics equations and grain size evolution models are developed. The physical framework and algorithmic idea of the improved dislocation density theory are clarified. Moreover, the deformed microstructures are characterized and quantitatively correlated to validate the improved dislocation density theory. It is found that the improved dislocation density-based models can precisely characterize hot deformation and DRX behaviors for the studied superalloy under the tested conditions.
Picoeukaryotes (<2–3 μm) perform key roles for the functioning of marine ecosystems, but little is known regarding the composition and diversity of picoeukaryotes in aquaculture areas. In this study, the Illumina MiSeq platform was used for sequencing the V4 variable region within the 18S rDNA gene to analyse genetic diversity and relative abundance of picoeukaryotic communities in the Qinhuangdao scallop cultivation area of the Bohai Sea. The community was dominated by three super groups, the alveolates (54%), stramenopiles (41%) and chlorophytes (3%), and three groups, dinoflagellates (54%), pelagomonadales (40%) and prasinophytes (3%). Furthermore, a contrasting station with open water away from the eutrophic aquaculture area was chosen. The communities collected from the two stations exhibited significant differences, with higher diversity in the aquaculture area. These results provide the first snapshot of the picoeukaryotic diversity in surface waters of the Qinhuangdao scallop cultivation area, and basic data for future studies on picoeukaryote community in an aquaculture region.
Postmenopausal women are at increased risk of CVD: the increased serum ferritin level may be involved in the pathogenesis. The aim of the present study is to investigate the relationship of ferritin and carotid atherosclerosis in postmenopausal women. A total of 1178 postmenopausal women (mean age, 60·8 years) were enrolled from the Changfeng Study. A standard interview, anthropometric measurements and laboratory analyses were performed for each participant. Bilateral CIMT (carotid intima–media thickness) were measured using ultrasonography, and the presence of carotid plaques was assessed. Serum ferritin was measured using electrochemiluminescence immunoassay. The results showed that serum ferritin was 181·9 (sd 65·8) ng/ml in the postmenopausal women. Multivariate, linear, stepwise regression analysis demonstrated that age (standardised β = 0·233, P< 0·001), alanine transaminase (standardised β = 0·194, P< 0·001), log homeostasis model assessment index for insulin resistance (standardised β = 0·181, P< 0·001), TAG (standardised β = 0·083, P= 0·003), Hb (standardised β = 0·080, P= 0·004) and PPG (2-h glucose levels following a 75-g oral glucose challenge) (standardised β = 0·079, P= 0·004) were independently associated with serum ferritin. Compared with the ferritin level of subjects in the first quartile, that in the fourth quartile had greater CIMT, and higher prevalence of carotid plaque. After adjusting for conventional CVD risk factors, Hb, leucocytes, log urine albumin:creatinine ratio and liver function, the ferritin level of postmenopausal women in the fourth quartile had a 1·587-fold increased risk of carotid plaques relative to those in the lowest quartile. In conclusion, these results suggest that serum ferritin is independently and positively associated with carotid atherosclerosis in postmenopausal women and that ferritin may be implicated in atherosclerosis.
Following the LAMOST Spectroscopic Survey and Xuyi's Photometric Survey of the Galactic anti-center (GAC), we plan to conduct a time-domain survey of GAC to study the variable sky using Nanshan 1m telescope. The survey will be conducted during winter (in Nov., Dec., and Jan.). The first goal of the survey is to cover 270 sq.deg. of sky area in three years. The survey intends to detect some strong transient events of stars and find some short time-scale variable stars of different types. In this paper, we introduce the survey and present the preliminary results already carried out.
Introduction: The mortality of Parkinson’s disease (PD) and its associated risk factors among clinically definite PD patients in China has been rarely investigated. Our study aimed to identify the mortality rates and predictors of death in PD patients in China. Methods: 157 consecutive, clinically definite PD patients from the urban area of Shanghai were recruited from a central hospital based movement disorder clinic in 2006. All patients were regularly followed up at the clinic until December 31, 2011, or death. Mortality and associations with baseline demographics, health and medical factors were then determined within the cohort. Results: After 5 years, 11(7%) patients had died. The standardised mortality ratio was 0.62 (95% CI 0.32 to 1.07, P=0.104). The main causes of death were pneumonia (54.5%, 6/11) and digestive disorders (18.2%, 2/11), respectively. Age at onset, independent living, the mini mental state examination score, the Parkinson’s disease sleep scale score and the Epworth sleepiness scale score at baseline were statistically significantly different between the survival group and the deceased group (P<0.05). Across all participants, risk factors for death included low mini mental state examination score, and high Epworth sleepiness scale score according to a binary variable logistic regression analysis. Conclusions: This study confirms the similar survival of patients with PD to the control population up to a follow-up of 5 years. Interventions tailored to potential risk factors associated with death may offer further benefits.
To examine the acceptability and feasibility of using smartphone technology to assess beverage intake and evaluate whether the feasibility of smartphone use is greater among key sub-populations.
An acceptability and feasibility study of recording the video dietary record, the acceptability of the ecological momentary assessment (EMA), wearing smartphones and whether the videos helped participants recall intake after a cross-over validation study.
Rural and urban area in Shanghai, China.
Healthy adults (n 110) aged 20–40 years old.
Most participants reported that the phone was acceptable in most aspects, including that videos were easy to use (70 %), helped with recalls (77 %), EMA reminders helped them record intake (75 %) and apps were easy to understand (85 %). However, 49 % of the participants reported that they had trouble remembering to take videos of the beverages before consumption or 46 % felt embarrassed taking videos in front of others. Moreover, 72 % reported that the EMA reminders affected their consumption. When assessing overall acceptability of using smartphones, 72 % of the participants were favourable responders. There were no statistically significant differences in overall acceptability for overweight v. normal-weight participants or for rural v. urban residents. However, we did find that the overall acceptability was higher for males (81 %) than females (61 %, P=0·017).
Our study did not find smartphone technology helped with dietary assessments in a Chinese population. However, simpler approaches, such as using photographs instead of videos, may be more feasible for enhancing 24 h dietary recalls.
The algorithm flow of an inertial-based Pedestrian Navigation System (PNS) can be divided into a trajectory-generation stage and trajectory-calibration stage. The Zero-velocity UPdaTe (ZUPT)-aided Extended Kalman Filter (EKF) algorithm is commonly used to resolve the trajectory of a walking person, but it still suffers from long-term drift. Many methods have been developed to suppress these drifts and thus to calibrate the trajectory generated by the previous stage. However, these methods have certain requirements, such as explicit map information or frequent location revisits, which are hard to satisfy in such situations as Search and Rescue (SAR) operations. A new approach is proposed in this paper that requires no explicit presupposition. This approach is based on a particle filter framework, with the weight of particles being adaptively adjusted according to the a priori knowledge of building structures and human behaviours. The distribution of particle weights is designed with awareness of the regular structures of buildings. The time-varying parameter of the distribution is acquired from a Hidden Markov Model (HMM) based on the foregoing odometry, which has a close relation with human behaviour. HMM is trained offline based on samples acquired in advance. Many real-world experiments under various scenarios were performed, and the results indicate good accuracy and robustness of the proposed approach.
The way in which the NE Tibetan Plateau uplifted and its impact on climatic change are crucial to understanding the evolution of the Tibetan Plateau and the development of the present geomorphology and climate of Central and East Asia. This paper is not a comprehensive review of current thinking but instead synthesises our past decades of work together with a number of new findings. The dating of Late Cenozoic basin sediments and the tectonic geomorphology of the NE Tibetan Plateau demonstrates that the rapid persistent rise of this plateau began ~8 ± 1 Ma followed by stepwise accelerated rise at ~3.6 Ma, 2.6 Ma, 1.8–1.7 Ma, 1.2–0.6 Ma and 0.15 Ma. The Yellow River basin developed at ~1.7 Ma and evolved to its present pattern through stepwise backward-expansion toward its source area in response to the stepwise uplift of the plateau. High-resolution multi-climatic proxy records from the basins and terrace sediments indicate a persistent stepwise accelerated enhancement of the East Asian winter monsoon and drying of the Asian interior coupled with the episodic tectonic uplift since ~8 Ma and later also with the global cooling since ~3.2 Ma, suggesting a major role for tectonic forcing of the cooling.
To investigate the association of regional fat depots with metabolic risk factors in Chinese women.
Total and regional fat depots including android fat and gynoid fat were measured by dual-energy X-ray absorptiometry. Central fat distribution was defined as android:gynoid fat ratio. Metabolic risk factors were defined as elevated TAG, reduced HDL-cholesterol, elevated blood pressure and elevated fasting plasma glucose. Logistic regression analyses were performed to examine the associations of regional fat depots with metabolic risk factors. The odds ratios of metabolic risks were further calculated according to tertiles of android fat and gynoid fat.
Participants were recruited from a community-based cross-sectional study. Face-to-face questionnaires, anthropometric and dual-energy X-ray absorptiometry measures were conducted.
Chinese women (n 609) aged 18–79 years.
Android fat and android:gynoid fat ratio were associated with significantly increased odds (OR = 1·4–3·7; P < 0·01) for almost all risk factors, whereas gynoid fat was independently associated with significantly decreased odds (OR = 0·3–0·6; P < 0·01). The inverse associations of gynoid fat with metabolic risk factors remained after adjusting for android fat. Even if their android fat level was in high, women in the highest tertile of gynoid fat had lower odds of having at least two metabolic risk factors compared with women in the lowest gynoid fat tertile (P for trend < 0·01).
There were opposite associations of android and gynoid fat with metabolic risks in Chinese women. Gynoid fat rather than android fat might be a more important inclusion in metabolic disease risk evaluation in female Asians.
Children in China are experiencing a rapid increase in the prevalence of obesity, which is associated with hypertension. To compare the effect of body fat on blood pressure (BP) with that of the normal physical growth, we compared BP levels in Chinese children with different body fat levels. In the present population-based study, 13 972 children in the highest-skinfold-thickness-quartile group were individually matched to 13 972 children in the lowest-skinfold-thickness-quartile group by height and weight. Similarly, 5103 children in the highest-waist-circumference-quartile group were matched to the same number of children in the lowest-waist-circumference-quartile group. The high- and low-fat groups had similar height and weight but the high-fat group had significantly higher skinfold and waist circumference measurements. The differences in systolic BP (SBP) between the high- and low-skinfold-thickness groups were small: 0·01 (95 % CI − 0·41, 0·44) mmHg in boys and 0·20 (95 % CI − 0·15, 0·54) mmHg in girls. The differences in diastolic BP (DBP) were also small (0·39 and 0·38 mmHg for boys and girls, respectively) but were statistically significant. The differences in both SBP and DBP between the high- and low-waist-circumference groups were small but not statistically significant. For a given body size as measured by height and weight, relative body fat had little impact on BP levels in these children. Fat mass and lean mass may have a similar quantitative impact on BP in healthy-weight children.