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Engineered biomaterials provide unique functions to overcome the bottlenecks seen in biomedicine. Hence, a technique for rapid and routine tests of collagen is required, in which the test items commonly include molecular weight, crosslinking degree, purity, and sterilization induced structural change. Among them, the crosslinking degree mainly influences collagen properties. In this study, second harmonic generation (SHG) and coherent anti-Stokes Raman scattering (CARS) microscopy are used in combination to explore the collagen structure at molecular and macromolecular scales. These measured parameters are applied for the classification and quantification among the different collagen scaffolds, which were verified by other conventional methods. It is demonstrated that the crosslinking status can be analyzed from SHG images and presented as the coherency of collagen organization that is correlated with the mechanical properties. Also, the comparative analyses of SHG signal and relative CARS signal of amide III band at 1,240 cm−1 to δCH2 band at 1,450 cm−1 of these samples provide information regarding the variation of the molecular structure during a crosslinking process, thus serving as nonlinear optical signatures to indicate a successful crosslinking.
Based on a cohort from the Chinese Longitudinal Healthy Longevity Survey (CLHLS), we aimed to evaluate the relationship between sleep duration and the incidence of cognitive impairment among older Chinese adults.
We conducted a prospective analysis based on 3692 participants from the CLHLS at baseline (in 2011), and as a 3-year follow-up (till 2014), 531 participants (14.4%) had cognitive impairment, which was defined as a Mini-Mental State Examination score <24. Sleep duration was classified into three groups: short (≤5 hours/day), normal (>5 but <10 hours), and long (≥10 hours/day). A logistic regression model was used to examine the association between baseline sleep duration and cognitive impairment after adjusting for sociodemographic data, living habits, and health conditions.
Five hundred sixty-two participants (15.2%) were in the short-duration group, and 608 participants (16.5%) were in the long-duration group. After adjusting for multiple potential confounders, compared with normal sleep duration, long sleep duration was associated with the incidence of cognitive impairment (OR = 1.309, 95% CI: 1.019–1.683), especially among men (OR = 1.527, 95% CI: 1.041–2.240) and those having a primary and above education level (OR = 1.559, 95% CI: 1.029–2.361). No significant association was observed between short sleep duration and cognitive impairment (OR = 0.860, 95% CI: 0.646–1.145).
Excessive sleep may increase the risk of cognitive impairment in older individuals. It may be a suggestive sign of early neurodegeneration and may be a useful clinical tool to identify those at a higher risk of progressing to cognitive impairment.
The purpose of this study was to construct a glycyrrhetinic acid (GA)-mediated, breakable, intracellular, nanoscale drug-delivery carrier via amide and esterification reactions. The structures were identified by Fourier-transformed infrared (FTIR) and 1H-nuclear magnetic resonance (1H-NMR) spectrophotometry. The compatibility and safety of the carrier were evaluated using hemolysis and cytotoxicity tests. The GA-copolymer micelle was prepared using the solvent evaporation method. FTIR and 1H-NMR detection demonstrated the successful construction of the polymer. No hemolysis occurred in any concentration of polymer within 3 h, and the hemolysis rate was less than 5%. 3-(4,5-dimethyl-thiazol-2-yl)-2,5-diphenyl-tetrazolium bromide (MTT) experimental results showed that the novel polymer reduced the cell survival rate and had significant cytotoxic effects. The blank nanoparticles were liquid with light blue opalescence. Transmission electron microscopy revealed that the empty micelles were uniform spheres, with an average size of 62 nm and a zeta potential of −13 mV. The novel GA-mediated polymeric carrier material developed here has the potential to effectively kill human SMMC-7721 cancer cells within 3 days when the dose is above 500 ug/mL.
In nonlinear dynamics, there are three classic routes to chaos, namely the period-doubling route, the Ruelle–Takens–Newhouse route and the intermittency route. The first two routes have previously been observed in self-excited thermoacoustic systems, but the third has not. In this experimental study, we present evidence of the intermittency route to chaos in the self-excited regime of a prototypical thermoacoustic system – a laminar flame-driven Rijke tube. We identify the intermittency to be of type II from the Pomeau–Manneville scenario through an analysis of (i) the probability distribution of the quiescent epochs between successive bursts of chaos, (ii) the first return map, and (iii) the recurrence plot. By establishing the last of the three classic routes to chaos, this study strengthens the universality of how strange attractors arise in self-excited thermoacoustic systems, paving the way for the application of generic suppression strategies based on chaos control.
To estimate the current evidence regarding the association between gestational acrylamide (AA) exposure and offspring’s growth.
Systematic review and meta-analysis.
A systematic literature search for relevant publications was conducted using PubMed, Medline, Embase, Web of Science databases from inception to 26 April 2019. The standardised mean difference (SMD) or OR with 95 % CI was selected as the effect sizes and was calculated using a random effects model.
Five cohort studies including 54 728 participants were identified. Offspring’s birth weight was significantly lower in high AA exposure group than in low AA exposure group (SMD –0·05, 95 % CI –0·09, –0·02, P = 0·005). There was also an association between maternal AA exposure and small for gestational age (OR 1·14, 95 % CI 1·06, 1·23, P < 0·001). In addition, pooled ORs suggested that children had a high risk of developing overweight/obesity in the future in maternal high AA exposure group (OR 1·14, 95 % CI 1·08, 1·21, P < 0·001 at age 3; OR 1·13, 95 % CI 1·07, 1·19, P < 0·001 at age 5; OR 1·09, 95 % CI 1·02, 1·16, P = 0·020 at age 8).
These findings have important implications for conducting health education, providing guidance on maternal diet and developing an appropriate dietary strategy for pregnant women to reduce dietary AA exposure.
Executive dysfunction is one of the main cognitive theories of autism spectrum disorder (ASD). Despite evidence of deficits in executive functions in individuals with ASD, little is known about executive dysfunctions as candidate cognitive endophenotypes for ASD. In this study, we investigated executive functions in youths with ASD, their unaffected siblings and typically developing controls (TDC).
We recruited 240 youths with a clinical diagnosis of ASD (aged 6–18 years), 147 unaffected siblings of ASD youths, and 240 TDC youths. TDC youths were recruited based on the age and sex distribution of the ASD youths. Participants were assessed using the verbal Digit Span test and four executive function tasks from the Cambridge Neuropsychological Test Automated Battery, including Intra-dimensional/Extra-dimensional Shift (I/ED), Spatial Span (SSP), Spatial Working Memory (SWM), and Stocking of Cambridge (SoC).
ASD youths, relative to TDC, performed significantly worse in executive function tasks assessing verbal working memory (forward and backward digit span), set-shifting (I/ED), visuospatial working memory (SSP, SWM), and planning/problem solving (SoC). Furthermore, unaffected siblings, relative to TDC, performed worse in forward and backward digit recalls and made more errors in SWM. These results were independent of the effects of age, sex, IQ, and symptoms of attention-deficit/hyperactivity disorder.
Our findings support impaired executive functions in youths with ASD. However, unaffected siblings were mostly unimpaired except in the areas of verbal and spatial working memory, which may be potential cognitive endophenotypes for ASD.
The aim of this study was to investigate the combined effect of n-3 fatty acids (EPA and DHA, at an EPA:DHA ratio of 150:500) and phytosterol esters (PS) on non-alcoholic fatty liver disease (NAFLD) patients. We conducted a randomised, double-blind, placebo-controlled trial. Ninety-six NAFLD subjects were randomly assigned to the following groups: the PS group (receiving 3·3 g/d PS); the FO group (receiving 450 mg EPA + 1500 mg DHA/d); the PS + FO combination group (receiving 3·3 g/d PS and 450 mg EPA + 1500 mg DHA/d) and the PO group (a placebo group). The baseline clinical characteristics of the four groups were similar. The primary outcome was liver:spleen attenuation ratio (L:S ratio). The percentage increase in liver–spleen attenuation (≤1) in the PS + FO group was 36 % (P = 0·083), higher than those in the other three groups (PS group, 11 %, P = 0·519; FO group, 18 %, P = 0·071; PO group, 15 %, P = 0·436). Compared with baseline, transforming growth factor-β (TGF-β) was significantly decreased in the three study groups at the end of the trial (PS, P = 0·000; FO, P = 0·002; PS + FO, P = 0·001) and TNF-α was significantly decreased in the FO group (P = 0·036), PS + FO group (P = 0·005) and PO group (P = 0·032) at the end of the intervention. Notably, TGF-β was reduced significantly more in the PS + FO group than in the PO group (P = 0·032). The TAG and total cholesterol levels of the PS + FO group were reduced by 11·57 and 9·55 %, respectively. In conclusion, co-supplementation of PS and EPA + DHA could increase the effectiveness of treatment for hepatic steatosis.
Patients with severe mental disorders in low-resource settings have limited access to services, resulting in overwhelming caregiving burden for families. In extreme cases, this has led to the long-term restraining of patients in their homes. China underwent a nationwide initiative to unlock patients and provide continued treatment. This study aims to quantify household economic burden in families after unlocking and treatment, and to identify factors associated with increased burden due to schizophrenia.
A total of 264 subjects were enrolled from three geographically diverse provinces in 2012. Subjects were patients with schizophrenia who were previously put under restraints and had participated in the ‘unlocking and treatment’ intervention. The primary outcome was the current household economic burden, obtained from past year financial information collected through on-site interview. Patient disease characteristics, treatment, outcomes and family caregiving burden were collected as well. Univariate and multivariate linear regression were used to construct risk factor models for indirect economic burden.
After participating in the intervention, 85% of patients continued to receive mental health services, 70% used medication as prescribed and 80% were never relocked. Family members reported significantly decreased caregiving burden after receiving the intervention. Mean direct and indirect household economic burdens were CNY963 (US$31.7) and CNY11 724 (US$1670) per year, respectively, while family total income was on average CNY12 108 (US$1913) per year. Greater disease severity and poorer patient psychosocial function at time of study were found to be independent factors related to increased indirect burden.
The ‘unlocking and treatment’ intervention has improved the lives of patients and families. Indirect burden due to disease is still a major economic issue that needs to be addressed, potentially through improving treatment and patient functioning. Our findings contribute to the unravelling and eventual elimination of chronic restraining of mentally ill patients in low-resource settings.
In self-excited combustion systems, the application of open-loop forcing is known to be an effective strategy for controlling periodic thermoacoustic oscillations, but it is not known whether and under what conditions such a strategy would work on thermoacoustic oscillations that are not simply periodic. In this study, we experimentally examine the effect of periodic acoustic forcing on a prototypical thermoacoustic system consisting of a ducted laminar premixed flame oscillating quasiperiodically on an ergodic
torus at two incommensurate natural frequencies,
. Compared with that of a classical period-1 system, complete synchronization of this
system is found to occur via a more intricate route involving three sequential steps: as the forcing amplitude,
, increases at a fixed forcing frequency,
, the system transitions first (i) to ergodic
quasiperiodicity; then (ii) to resonant
quasiperiodicity as the weaker of the two natural modes,
, synchronizes first, leading to partial synchronization; and finally (iii) to a
limit cycle as the remaining natural mode,
, also synchronizes, leading to complete synchronization. The minimum
required for partial and complete synchronization decreases as
, resulting in two primary Arnold tongues. However, when forced at an amplitude above that required for complete synchronization, the system can transition out of
. The optimal control strategy is to apply off-resonance forcing at a frequency around the weaker natural mode (
) and at an amplitude just sufficient to cause
, because this produces the largest reduction in thermoacoustic amplitude via asynchronous quenching. Analysis of the Rayleigh index shows that this reduction is physically caused by a disruption of the positive coupling between the unsteady heat release rate of the flame and the
acoustic modes. If the forcing is applied near the stronger natural mode (
), however, resonant amplification can occur. We then phenomenologically model this
thermoacoustic system as two reactively coupled van der Pol oscillators subjected to external sinusoidal forcing, and find that many of its synchronization features – such as the three-step route to
, the double Arnold tongues, asynchronous quenching and resonant amplification – can be qualitatively reproduced. This shows that these features are not limited to our particular system, but are universal features of forced self-excited oscillators. This study extends the applicability of open-loop control from classical period-1 systems with just a single time scale to ergodic
quasiperiodic systems with two incommensurate time scales.
Ovine babesiosis is one of the most important tick-borne haemoparasitic diseases of small ruminants. The ovine parasite Babesia sp. Xinjiang is widespread in China. In this study, recombinant full-length XJrRAP-1aα2 (rhoptry-associated protein 1aα2) and C-terminal XJrRAP-1aα2 CT of Babesia sp. Xinjiang were expressed and used to evaluate their diagnostic potential for Babesia sp. Xinjiang infections by indirect enzyme-linked immunosorbent assay (ELISA). Purified XJrRAP-1aα2 was tested for reactivity with sera from animals experimentally infected with Babesia sp. Xinjiang and other haemoparasites using Western blotting and ELISA. The results showed no cross-reactivities between XJrRAP-1aα2 CT and sera from animals infected by other pathogens. High level of antibodies against RAP-1a usually lasted 10 weeks post-infection (wpi). A total of 3690 serum samples from small ruminants in 23 provinces located in 59 different regions of China were tested by ELISA. The results indicated that the average positive rate was 30·43%, and the infections were found in all of the investigated provinces. This is the first report on the expression and potential use of a recombinant XJrRAP-1aα2 CT antigen for the development of serological assays for the diagnosis of ovine babesiosis, caused by Babesia sp. Xinjiang.
Seven-band grouper (Hyporthodus septemfasciatus) is a commercial rocky reef fish in East Asia that has been regarded as a promising species for aquaculture. To investigate the broodstock contributions to offspring for the sustainability of fry production, 62 individuals of H. septemfasciatus from two broodstocks and one offspring population were analysed using fluorescent-AFLP. A total of 602 bands were amplified and 70.10% of them were polymorphic. The numbers of polymorphic loci were 308 (Pbroodstock I = 55.50%) and 356 (Pbroodstock II = 63.12%) in the two broodstocks, and 294 (Poffspring = 52.88%) in the offspring, respectively. The average values of Shannon diversity index (I) and expected heterozygosity (H) were higher in the broodstock (Ibroodstock I = 0.281, Ibroodstock II = 0.244, Hbroodstock I = 0.185, Hbroodstock II = 0.161) than those in the offspring (Ioffspring = 0.243, Hoffspring = 0.161). AMOVA and FST analyses showed that significant genetic differentiation between broodstock and offspring populations, and limited effective broodstock population size has contributed to the offspring. Both STRUCTURE and Principal Coordinates Analysis (PCoA) also showed the three populations composed of two stocks and most offspring individuals (95.0%) only originated from 44.0% of the individuals of broodstock I, which may have negative effects on sustainable fry production. Therefore, genetic variation between broodstock and offspring should be monitored, and large effective size of broodstock should be employed to ensure the success of commercial breeding programmes. Our data provide a useful genetic basis for future planning of sustainable culture and management of H. septemfasciatus.
Obstacle avoidance is an important issue in robotics. In this paper, the particle
swarm optimization (PSO) algorithm, which is inspired by the collective
behaviors of birds, has been designed for solving the obstacle avoidance
problem. Some animals that travel to the different places at a specific time of
the year are called migrants. The migrants also represent the particles of PSO
for defining the walking paths in this work. Migrants consider not only the
collective behaviors, but also geomagnetic fields during their migration in
nature. Therefore, in order to improve the performance and the convergence speed
of the PSO algorithm, concepts from the migrant navigation method have been
adopted for use in the proposed hybrid particle swarm optimization (H-PSO)
algorithm. Moreover, the potential field navigation method and the designed
fuzzy logic controller have been combined in H-PSO, which provided a good
performance in the simulation and the experimental results. Finally, the
Federation of International Robot-soccer Association (FIRA) HuroCup Obstacle Run
Event has been chosen for validating the feasibility and the practicability of
the proposed method in real time. The designed adult-sized humanoid robot also
performed well in the 2015 FIRA HuroCup Obstacle Run Event through utilizing the
Previous studies have suggested that vitamin E (VE) may affect bone health, but the findings have been inconclusive. We examined the relationship between VE status (in both diet and serum) and bone mineral density (BMD) among Chinese adults. This community-based study included 3203 adults (2178 women and 1025 men) aged 40–75 years from Guangzhou, People’s Republic of China. General and dietary intake information were collected using structured questionnaire interviews. The serum α-tocopherol (TF) level was quantified by reversed-phase HPLC. The BMD of the whole body, the lumbar spine and left hip sites (total, neck, trochanter, intertrochanter and Ward’s triangle) were measured using dual-energy X-ray absorptiometry. In women, the dietary intake of VE was significantly and positively associated with BMD at the lumbar spine, total hip, intertrochanter and femur neck sites after adjusting for covariates (Ptrend: 0·001–0·017). Women in quartile 3 of VE intake typically had the highest BMD; the covariate-adjusted mean BMD were 2·5, 3·06, 3·41 and 3·54 % higher, respectively, in quartile 3 (v. 1) at the four above-mentioned sites. Similar positive associations were observed between cholesterol-adjusted serum α-TF levels and BMD at each of the studied bone sites (Ptrend: 0·001–0·022). The covariate-adjusted mean BMD were 1·24–4·83 % greater in quartile 4 (v. 1) in women. However, no significant associations were seen between the VE levels (dietary or serum) and the BMD at any site in men. In conclusion, greater consumption and higher serum levels of VE are associated with greater BMD in Chinese women but not in Chinese men.
The association between serum carotenoids and the metabolic syndrome (MetS) remains uncertain, and little is known about this relationship in the Chinese population. The present study examined the association between serum carotenoid concentrations and the MetS in Chinese adults. We conducted a community-based cross-sectional study in which 2148 subjects (1547 women and 601 men) aged 50–75 years were recruited in urban Guangzhou, China. Dietary data and other covariates were collected during face-to-face interviews. Blood pressure, waist circumference, blood lipids, glucose and serum carotenoids (α-, β-carotene, β-cryptoxanthin, lycopene and lutein/zeaxanthin) were examined. We found dose–response inverse relationships between individual serum carotenoid concentrations and total carotenoids and the prevalence of the MetS after adjusting for potential confounders (P for trend < 0·001). The OR of the MetS for the highest (v. lowest) quartile were 0·31 (95 % CI 0·20, 0·47) for α-carotene, 0·23 (95 % CI 0·15, 0·36) for β-carotene, 0·44 (95 % CI 0·29, 0·67) for β-cryptoxanthin, 0·39 (95 % CI 0·26, 0·58) for lycopene, 0·28 (95 % CI 0·18, 0·44) for lutein+zeaxanthin and 0·19 (95 % CI 0·12, 0·30) for total carotenoids. Higher concentrations of each individual carotenoid and total carotenoids were significantly associated with a decrease in the number of abnormal MetS components (P for trend < 0·001–0·023). Higher serum carotenoid levels were associated with a lower prevalence of the MetS and fewer abnormal MetS components in middle-aged and elderly Chinese adults.
Early identification of patients with bipolar disorder during their first depressive episode is beneficial to the outcome of the disorder and treatment, but traditionally this has been a great challenge to clinicians. Recently, brain-derived neurotrophic factor (BDNF) has been suggested to be involved in the pathophysiology of bipolar disorder and major depressive disorder (MDD), but it is not clear whether BDNF levels can be used to predict bipolar disorder among patients in their first major depressive episode.
To explore whether BDNF levels can differentiate between MDD and bipolar disorder in the first depressive episode.
A total of 203 patients with a first major depressive episode as well as 167 healthy controls were recruited. After 3 years of bi-annual follow-up, 164 patients with a major depressive episode completed the study, and of these, 21 were identified as having bipolar disorder and 143 patients were diagnosed as having MDD. BDNF gene expression and plasma levels at baseline were compared among the bipolar disorder, MDD and healthy control groups. Logistic regression and decision tree methods were applied to determine the best model for predicting bipolar disorder at the first depressive episode.
At baseline, patients in the bipolar disorder and MDD groups showed lower BDNF mRNA levels (P<0.001 and P = 0.02 respectively) and plasma levels (P = 0.002 and P = 0.01 respectively) compared with healthy controls. Similarly, BDNF levels in the bipolar disorder group were lower than those in the MDD group. These results showed that the best model for predicting bipolar disorder during a first depressive episode was a combination of BDNF mRNA levels with plasma BDNF levels (receiver operating characteristics (ROC) = 0.80, logistic regression; ROC = 0.84, decision tree).
Our findings suggest that BDNF levels may serve as a potential differential diagnostic biomarker for bipolar disorder in a patient's first depressive episode.
β-amyloid (Aβ)-mediated neuronal apoptosis contributes to the progression of Alzheimer's disease (AD), although the exact mechanism remains unclear. This study aimed to investigate whether Dalesconol B (TL-2), a potent immunosuppressive agent with an unusual carbon skeleton, could inhibit Aβ-induced apoptosis in vitro and in vivo and to explore the underlying mechanisms. Aβ1–42 was injected to bilateral hippocampus of mice to make the AD models in vivo. TL-2 was able to cross the blood-brain barrier and attenuate memory deficits in the AD mice. TL-2 also inhibited Aβ1–42-induced neuronal apoptosis in vitro and in vivo. In addition, TL-2 could activate the AKT/GSK-3β pathway, and inhibition of AKT and activation of GSK-3β partially eliminated the neuroprotective effects of TL-2. Furthermore, TL-2 induced the nuclear translocation of β-catenin and enhanced its transcriptional activity through the AKT/GSK-3β pathway to promote neuronal survival. These results suggest that TL-2 might be a potential drug for AD treatment.
We make a connection between the continuous time and lazy discrete time Markov chains through the comparison of cutoffs and mixing time in total variation distance. For illustration, we consider finite birth and death chains and provide a criterion on cutoffs using eigenvalues of the transition matrix.
A robot mapping procedure using a modified speeded-up robust feature (SURF) is proposed for building persistent maps with visual landmarks in robot simultaneous localization and mapping (SLAM). SURFs are scale-invariant features that automatically recover the scale and orientation of image features in different scenes. However, the SURF method is not originally designed for applications in dynamic environments. The repeatability of the detected SURFs will be reduced owing to the dynamic effect. This study investigated and modified SURF algorithms to improve robustness in representing visual landmarks in robot SLAM systems. Many modifications of the SURF algorithms are proposed in this study including the orientation representation of features, the vector dimension of feature description, and the number of detected features in an image. The concept of sparse representation is also used to describe the environmental map and to reduce the computational complexity when using extended Kalman filter (EKF) for state estimation. Effective procedures of data association and map management for SURFs in SLAM are also designed to improve accuracy in robot state estimation. Experimental works were performed on an actual system with binocular vision sensors to validate the feasibility and effectiveness of the proposed algorithms. The experimental examples include the evaluation of state estimation using EKF SLAM and the implementation of indoor SLAM. In the experiments, the performance of the modified SURF algorithms was compared with the original SURF algorithms. The experimental results confirm that the modified SURF provides better repeatability and better robustness for representing the landmarks in visual SLAM systems.
From the Surface Velocity Program (SVP) drifter current data, a detailed and complete track of strong ocean currents in the north-western Pacific is provided using the bin average method. The focus of this study is on the Kuroshio, the strong western boundary current of the North Pacific flowing northward along the east coast of Taiwan and then turning eastward off southern Japan. With its average flow speed of about 2 knots, the Kuroshio can significantly increase the ship's speed for a “super-slow-steaming” container ship travelling at speeds of 12 knots between the ports of Southeast Asia and Japan. By properly utilizing knowledge of strong ocean currents to follow the Kuroshio on the northbound runs and avoid it on the return trip, considerable fuel can be saved and the transit time can be reduced. In the future, the detailed Kuroshio saving-energy route could be built into electronic chart systems for all navigators and shipping routers.