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 firstname.lastname@example.org
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.
This article designs a frog-inspired swimming robot based on pneumatic muscles. The musculoskeletal characteristics of the frog are refined and used as the basis for the design of the robot joint structure and movement mode. The posture adjustment module, joint water seal, and power system are designed to meet the robot’s motion requirements, and the structure optimization design of the robot is completed by combining simulation analysis. The body length of the robot is about 710 mm, and the overall mass is 10 kg. Combining the structural characteristics of the robot, the control system is built to realize the frog-like motion. The robot’s propulsion speed is about 0.6 m/s, the propulsion distance reaches 2.4 m, the turning angle is 30°, and the turning radius is 0.6 m. The prototype experiment verifies the rationality of the frog-inspired swimming robot structure design and the reliability of the control system and water seal.
Preterm birth is the leading cause of perinatal mortality and morbidity. Some prospective cohort studies suggested that fish and shellfish consumption may affect the incidence of preterm birth. However, conflicting evidence exists on the relationship between fish and shellfish consumption and preterm birth. This retrospective study was conducted in Lanzhou, China, between 2010 and 2012. A total of 10,179 women were interviewed after delivery to collect information on their past intake of fish and shellfish using food frequency questionnaire. Clinical data including birth outcomes and maternal complications were extracted from medical records of the participants. Logistic regression models were used to estimate odds ratios and 95% confidence intervals to examine the association between fish and shellfish consumption and preterm birth and its clinical subtypes. Fish and shellfish consumption was associated with reduced risk of preterm birth (OR=0.65, 95%CI:0.56-0.77). Increasing frequency of fish and shellfish consumption, compared with no fish and shellfish consumption, were associated with decreasing odds of preterm birth: for ≤ 1 time/ week, OR = 0.74 (95% CI: 0.63-0.89); for ≥2 times a week, OR = 0.57 (95% CI:0.48-0.68). The P for trend was 0.023. Besides, increasing weekly total amount of fish and shellfish consumption, compared with no fish and shellfish consumption, were also associated with decreasing odds of preterm birth: for <350 g/week, OR = 0.67 (95% CI: 0.57-0.78); for ≥350 g/week, OR = 0.57 (95% CI:0.43-0.74). The P for trend was 0.011. Significant trend effect was also seen between fish and shellfish consumption and very preterm birth (P for trend =0.001) and spontaneous preterm birth (P for trend =0.003). Interaction was observed between total fish and shellfish consumption with maternal age (P for interaction=0.041) and pre-pregnancy BMI underweight (P for interaction=0.012). Maternal fish and shellfish consumption was associated with lower incidence of preterm birth. The findings support for the protective role of fish and shellfish consumption in preventing preterm birth and recommend for the national guideline of ≥350 g/week of fish and shellfish consumption among pregnant women.
High dietary fiber intake has been associated with a lower risk of diabetes, but the association of dietary fiber with prediabetes is only speculative, especially in China, where the supportive data from prospective studies is lacking. This study aimed to examine the association between dietary fiber intake and risk of incident prediabetes among Chinese adults. We performed a prospective analysis in 18,085 participants of the TCLSIH cohort study who were free of diabetes, prediabetes, cancer, and cardiovascular disease at baseline. Dietary data were collected using a validated 100-item food frequency questionnaire. Prediabetes was defined based on the American Diabetes Association diagnostic criteria. Cox proportional hazard models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs). During 63,175 person-years of follow-up, 4,139 cases of incident prediabetes occurred. The multivariable HRs (95% CIs) of prediabetes for the highest versus lowest quartiles were 0.85 (0.75, 0.98) (P for trend =0.02) for total dietary fiber, 0.84 (0.74, 0.95) (P for trend <0.01) for soluble fiber, and 1.05 (0.93, 1.19) (P for trend =0.38) for insoluble fiber. Fiber from fruits, but not from cereals, beans, and vegetables was inversely associated with prediabetes. Our results indicate that intakes of total dietary fiber, soluble fiber, and fiber derived from fruit sources were associated with a lower risk of prediabetes.
The aim of the present study was to compare the rate of preterm birth (PTB) and growth from birth to 18 years between twins conceived by in vitro fertilization (IVF) and twins conceived by spontaneous conception (SC) in mainland China. The retrospective cohort study included 1164 twins resulting from IVF and 25,654 twins conceived spontaneously, of which 494 from IVF and 6338 from SC were opposite-sex twins. PTB and low birth weight (LBW), and growth, including length/height and weight, were compared between the two groups at five stages: infancy (0 year), toddler period (1–2 years), preschool (3–5 years), primary or elementary school (6–11 years), and adolescence (10–18 years). Few statistically significant differences were found for LBW and growth between the two groups after adjusting for PTB and other confounders. Twins born by IVF faced an increased risk of PTB compared with those born by SC (adjusted odds ratio [aOR] 8.21, 95% confidence interval [CI] [3.19, 21.13], p < .001 in all twins and aOR 10.12, 95% CI [2.32, 44.04], p = .002 in opposite-sex twins). Twins born by IVF experienced a similar growth at five stages (0–18 years old) when compared with those born by SC. PTB risk, however, is significantly higher for twins conceived by IVF than those conceived by SC.
Across Eurasia, horse transport transformed ancient societies. Although evidence for chariotry is well dated, the origins of horse riding are less clear. Techniques to distinguish chariotry from riding in archaeological samples rely on elements not typically recovered from many steppe contexts. Here, the authors examine horse remains of Mongolia's Deer Stone-Khirigsuur (DSK) Complex, comparing them with ancient and modern East Asian horses used for both types of transport. DSK horses demonstrate unique dentition damage that could result from steppe chariotry, but may also indicate riding with a shallow rein angle at a fast gait. A key role for chariots in Late Bronze Age Mongolia helps explain the trajectory of horse use in early East Asia.
Chronic inflammation exerts pleiotropic effects in the etiology and progression of chronic obstructive pulmonary disease (COPD). Glucosamine is widely used in many countries and may have anti-inflammatory properties. We aimed to prospectively evaluate the association of regular glucosamine use with incident COPD risk and explore whether such association could be modified by smoking in the UK Biobank cohort, which recruited more than half a million participants aged 40–69 years from across the UK between 2006 and 2010. Cox proportional hazards models with adjustment for potential confounding factors were used to calculate hazard ratios (HRs) as well as 95% confidence intervals (95% CIs) for the risk of incident COPD. During a median follow-up of 8.96 years (interquartile range 8.29 to 9.53 years), 9016 new-onset events of COPD were documented. We found that regular use of glucosamine was associated with a significantly lower risk of incident COPD with multivariable adjusted HR of 0.80 (95% CI, 0.75 to 0.85; P<0.001). When subgroup analyses were performed by smoking status, the adjusted HRs for the association of regular glucosamine use with incident COPD were 0.84 (0.73 to 0.96), 0.84 (0.77 to 0.92), and 0.71 (0.62 to 0.80) among never smokers, former smokers and current smokers, respectively. No significant interaction was observed between glucosamine use and smoking status (P for interaction=0.078). Incident COPD could be reduced by 14% to 84% through a combination of regular glucosamine use and smoking cessation
The present study aimed to explore the association between dietary patterns in abdominal obesity obtained by reduced-rank regression (RRR) with visceral fat index (VFI) as a dependent variable and dyslipidemia in rural adults in Henan, China. A total of 29538 people aged 18-79 were selected from the Henan Rural Cohort Study. RRR analysis was used to identify dietary patterns; logistic regression analysis and restricted cubic spline regression models were applied to analyze the association between dietary patterns in abdominal obesity and dyslipidemia. VFI was used as a mediator to estimate the mediation effect. The crude prevalence of dyslipidemia in rural Henan was 34.2%. The dietary pattern in abdominal obesity was characterized by high carbohydrate and red meat intake and low consumption of fresh fruits, vegetables, milk, and dairy products. After full adjustment, the highest quartile of dietary pattern scores was significantly associated with an increased risk of dyslipidemia (OR: 1.33, 95% CI: 1.23-1.44, P-trend<0.001), there was a non-linear dose-response relationship between them (Poverall-association<0.001, Pnon-lin-association=0.022). The result was similar in dose-response between the dietary pattern scores and VFI. The indirect effect partially mediated by VFI was significant (OR: 1.07, 95% CI: 1.06-1.08). VIF explained approximately 53.3% of the odds of dyslipidemia related to the dietary pattern. Abdominal obesity dietary pattern scores positively affected VFI and dyslipidemia; there was a dose-response in both relationships. Dyslipidemia progression increased with higher abdominal obesity dietary pattern scores. In addition, VFI played a partial mediating role in relationship between abdominal obesity dietary pattern and dyslipidemia.
Deficits in event-related potential (ERP) including duration mismatch negativity (MMN) and P3a have been demonstrated widely in chronic schizophrenia (SZ) but inconsistent findings were reported in first-episode patients. Psychotropic medications and diagnosis might contribute to different findings on MMN/P3a ERP in first-episode patients. The present study examined MMN and P3a in first episode drug naïve SZ and bipolar disorder (BPD) patients and explored the relationships among ERPs, neurocognition and global functioning.
Twenty SZ, 24 BPD and 49 age and sex-matched healthy controls were enrolled in this study. Data of clinical symptoms [Positive and Negative Symptoms Scale (PANSS), Young Manic Rating Scale (YMRS), Hamilton Depression Rating Scale (HAMD)], neurocognition [Wechsler Adult Intelligence Scale (WAIS), Cattell's Culture Fair Intelligence Test (CCFT), Delay Matching to Sample (DMS), Rapid Visual Information Processing (RVP)], and functioning [Functioning Assessment Short Test (FAST)] were collected. P3a and MMN were elicited using a passive auditory oddball paradigm.
Significant MMN and P3a deficits and impaired neurocognition were found in both SZ and BPD patients. In SZ, MMN was significantly correlated with FAST (r = 0.48) and CCFT (r = −0.31). In BPD, MMN was significantly correlated with DMS (r = −0.54). For P3a, RVP and FAST scores were significant predictors in SZ, whereas RVP, WAIS and FAST were significant predictors in BPD.
The present study found deficits in MMN, P3a, neurocognition in drug naïve SZ and BPD patients. These deficits appeared to link with levels of higher-order cognition and functioning.
Little is known about the impact of modifiable risk factors on blood pressure (BP) trajectories and their associations with hypertension (HTN). We aimed to identify BP trajectories in normotensive Chinese adults and explore their influencing factors and associations with HTN. We used data from 3,436 adults with at least four BP measurements between 1989 and 2018 in the China Health and Nutrition Survey, an ongoing cohort study. We measured BP using mercury sphygmomanometers with appropriate cuff sizes in all surveys. We used group-based trajectory modeling to identify BP trajectories between 1989 and 2009 and multiple logistic and Cox regression models to analyze their influencing factors and associations with HTN in 2011-2018. We identified five systolic blood pressure (SBP) trajectories, ‘Low-increasing(LI)’, ‘Low–stable(LS)’, ‘Moderate-increasing(MI)’, ‘High-stable(HS)’, and ‘Moderate-decreasing(MD)’; and four diastolic blood pressure (DBP) trajectories classified as ‘Low-increasing(LI)’, ‘Moderate–stable(MS)’, ‘Low-stable(LS)’ and ‘High-increasing(HI)’. People with higher physical activity (PA) levels and lower waist circumferences (WCs) were less likely to be in the SBP LI, MI, HS, and MD groups (P < 0.05). People with higher fruit and vegetable intakes, lower WCs and salt intakes, and higher PA levels were less likely to be in the DBP LI, MS, and HI groups (P < 0.05). Participants in the SBP HS group (hazard ratio [HR] 2.01) or the DBP LI, MS, and HI groups (HRs 1.38, 1.40, 1.71, respectively) had higher risks of HTN (P < 0.05). This study suggests that BP monitoring is necessary to prevent HTN in the Chinese population.
Epidemiological studies have shown that higher intake of flavonoid is inversely associated with coronary heart disease (CHD) risk. However, which flavonoid subclass could reduce CHD risk has remained controversial. The present meta-analysis of prospective cohort studies aimed to quantitatively assess the associations between flavonoid subclasses and CHD risk. A systematic literature search was implemented from PubMed and Web of Science databases up to Mar. 2021, and eligible studies were identified. Multivariate-adjust relative risks (RRs) with corresponding 95% confidence intervals (CIs) were pooled by using a random-effects model. A restricted cubic spline regression model was performed for non-linear dose-response analysis. A total of 19 independent prospective cohort studies with 894,471 participants and 34,707 events were included. The results showed that dietary intakes of anthocyanins (RR = 0.90; 95% CI: 0.83, 0.98), proanthocyanidins (RR = 0.78; 95% CI: 0.65, 0.94), flavonols (RR = 0.88; 95% CI: 0.79, 0.98), flavones (RR = 0.94; 95% CI: 0.89, 0.99) and isoflavones (RR = 0.90; 95% CI: 0.83, 0.98) were negatively associated with CHD risk. Dose-response analysis showed that increment of 50 mg/d anthocyanins, 100 mg/d proanthocyanidins, 25 mg/d flavonols, 5 mg/d flavones and 0.5 mg/d isoflavones were associated with 5% reduction in CHD risk, respectively. Sensitivity and subgroup analyses were used to further support these associations. The present results indicate that dietary intakes of fruits and vegetables abundant five flavonoid subclasses, namely anthocyanins, proanthocyanidins, flavonols, flavones and isoflavones, are associated with a lower risk of CHD.
Early life exposure to famine was associated with adulthood metabolic syndrome and nonalcoholic fatty liver disease (NAFLD), and NAFLD was also affected by cardiometabolic traits. However, the role of cardiometabolic traits in the associations from famine exposure to NAFLD was largely unknown. This study aimed to investigate whether the relationship between early life famine exposure and adulthood NAFLD risk was mediated by cardiometabolic traits. Overall, 7,578 subjects aged 56.0 ± 3.7 years in the Dongfeng-Tongji cohort were included and classified into late-exposed (1952-1954), middle-exposed (1954-1956), early-childhood-exposed (1956-1958), fetal-exposed (1959-1961), and nonexposed (1962-1966, reference) group according to the birth year. NAFLD was diagnosed by experienced physicians via abdominal B-type ultrasound inspection. Mediation analysis was used to evaluate the mediating effects of cardiometabolic traits. Compared with those nonexposed, after multivariable adjustment, participants in fetal-exposed group (OR: 1.37; 95% CI: 1.08-1.73) had 37% higher risk to develop NAFLD, and the overall childhood-exposed group had marginally significant association with NAFLD (OR: 1.39; 95% CI: 0.99-1.94). Stratification analysis found the famine-NAFLD associations more evident in women and those born in areas severely affected by famine. Mediation analysis showed that cardiometabolic traits such as TC, TyG index, γ-GT, ALP, and ALT mediated 6.7%-22.2% of the relation from famine exposure to higher NAFLD risk. Early life exposure to famine was related to increased adulthood NAFLD risk, and this relationship was partly mediated by cardiometabolic traits.
The findings regarding the associations between red meat, fish and poultry consumption, and the metabolic syndrome (Mets) have been inconclusive, and evidence from Chinese populations is scarce. A cross-sectional study was performed to investigate the associations between red meat, fish and poultry consumption, and the prevalence of the Mets and its components among the residents of Suzhou Industrial Park, Suzhou, China. A total of 4424 participants were eligible for the analysis. A logistic regression model was used to estimate the OR and 95 % CI for the prevalence of the Mets and its components according to red meat, fish and poultry consumption. In addition, the data of our cross-sectional study were meta-analysed under a random effects model along with those of published observational studies to generate the summary relative risks (RR) of the associations between the highest v. lowest categories of red meat, fish and poultry consumption and the Mets and its components. In the cross-sectional study, the multivariable-adjusted OR for the highest v. lowest quartiles of consumption was 1·23 (95 % CI 1·02, 1·48) for red meat, 0·83 (95 % CI 0·72, 0·97) for fish and 0·93 (95 % CI 0·74, 1·18) for poultry. In the meta-analysis, the pooled RR for the highest v. lowest categories of consumption was 1·20 (95 % CI 1·06, 1·35) for red meat, 0·88 (95 % CI 0·81, 0·96) for fish and 0·97 (95 % CI 0·85, 1·10) for poultry. The findings of both cross-sectional studies and meta-analyses indicated that the association between fish consumption and the Mets may be partly driven by the inverse association of fish consumption with elevated TAG and reduced HDL-cholesterol and, to a lesser extent, fasting plasma glucose. No clear pattern of associations was observed between red meat or poultry consumption and the components of the Mets. The current findings add weight to the evidence that the Mets may be positively associated with red meat consumption, inversely associated with fish consumption and neutrally associated with poultry consumption.
Dietary habits play an important role in the development of obesity and type 2 diabetes. However, evidence on association between diet frequency and type 2 diabetes was limited and inconclusive. We aimed to examine the association between meal frequency and risk of type 2 diabetes. The cohort study used data from China Health and Retirement Longitudinal Study of 8874 community-dwelling people aged over 45 years. Participants were classified as eating two meals per day, three meals per day and four meals per day. Multiple Poisson regression models were used to examine risk of 4-year incident type 2 diabetes among people who ate more or less than three meals per day compared with people who ate three meals per day. We documented 706 type 2 diabetes cases during follow-up. After adjustment for known risk factors for type 2 diabetes, except for BMI, participants who ate four meals per day were at a lower risk of type 2 diabetes than those who ate three meals per day (relative risk(RR) = 0·73 (0·58, 0·92)). After further adjustment for baseline BMI, the association was slightly attenuated but remained statistically significant (RR = 0·76 (0·60, 0·97)). Subgroup analysis showed that the fully adjusted RR of type 2 diabetes for people eating four meals per day were 0·66 (0·48, 0·91) and 0·93 (0·65, 1·34) among those had a BMI < 25 and ≥ 25 kg/m2, respectively. Eating four meals per day, compared with eating three meals per day was associated with lower risk of developing type 2 diabetes in a Chinese population, particularly in those with a BMI < 25 kg/m2.
When a mixture of viscous oil and non-colloidal particles displaces air between two parallel plates, the shear-induced migration of particles leads to the gradual accumulation of particles on the advancing oil–air interface. This particle accumulation results in the fingering of an otherwise stable fluid–fluid interface. While previous works have focused on the resultant instability, one unexplored yet striking feature of the experiments is the self-similarity in the concentration profile of the accumulating particles. In this paper, we rationalise this self-similar behaviour by deriving a depth-averaged particle transport equation based on the suspension balance model, following the theoretical framework of Ramachandran (J. Fluid Mech., vol. 734, 2013, pp. 219–252). The solutions to the particle transport equation are shown to be self-similar with slight deviations, and in excellent agreement with experimental observations. Our results demonstrate that the combination of the shear-induced migration, the advancing fluid–fluid interface and Taylor dispersion yield the self-similar and gradual accumulation of particles.
Nutritional Risk Screening index is a standard tool to assess nutritional risk, but epidemiological data are scarce on controlling nutritional status (CONUT) as a prognostic marker in acute haemorrhagic stroke (AHS). We aimed to explore whether the CONUT may predict a 3-month functional outcome in AHS. In total, 349 Chinese patients with incident AHS were consecutively recruited, and their malnutrition risks were determined using a high CONUT score of ≥ 2. The cohort patients were divided into high-CONUT (≥ 2) and low-CONUT (< 2) groups, and primary outcomes were a poor functional prognosis defined as the modified Rankin Scale (mRS) score of ≥ 3 at post-discharge for 3 months. Odds ratios (OR) with 95 % confidence intervals (CI) for the poor functional prognosis at post-discharge were estimated by using a logistic analysis with additional adjustments for unbalanced variables between the high-CONUT and low-CONUT groups. A total of 328 patients (60·38 ± 12·83 years; 66·77 % male) completed the mRS assessment at post-discharge for 3 months, with 172 patients at malnutrition risk at admission and 104 patients with a poor prognosis. The levels of total cholesterol and total lymphocyte counts were significantly lower in high-CONUT patients than low-CONUT patients (P = 0·012 and < 0·001, respectively). At 3-month post discharge, there was a greater risk for the poor outcome in the high-CONUT compared with the low-CONUT patients at admission (OR: 2·32, 95 % CI: 1·28, 4·17). High-CONUT scores independently predict a 3-month poor prognosis in AHS, which helps to identify those who need additional nutritional managements.
Based on the framework of disjunctive propositional logic, we first provide a syntactic representation for Scott domains. Precisely, we establish a category of consistent disjunctive sequent calculi with consequence relations, and show it is equivalent to that of Scott domains with Scott-continuous functions. Furthermore, we illustrate the approach to solving recursive domain equations by introducing some standard domain constructions, such as lifting and sums. The subsystems relation on consistent finitary disjunctive sequent calculi makes these domain constructions continuous. Solutions to recursive domain equations are given by constructing the least fixed point of a continuous function.