To save 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 saving content to .
To save 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 saving to your Kindle.
Note you can select to save to either the @free.kindle.com or @kindle.com variations.
‘@free.kindle.com’ emails are free but can only be saved 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.
The differential impact of depression across different periods in life on mortality remains inconclusive. We aimed to examine the association of depression that occurs at different age with all-cause mortality, and to explore the roles of dementia, as well as genetic and early-life environmental factors, in this association.
From the Swedish Twin Registry, 44,919 twin individuals were followed for up to 18 years. Depression was ascertained using the National Patient Registry and categorized as early-life (<45 years), midlife (45–64 years), and late-life (≥65 years) depression according to the age of the first diagnosis. Deaths were identified through the Cause of Death Register. Generalized estimating equation, generalized structural equation, and conditional logistic regression were used for unmatched, mediation, and co-twin matched analyses, respectively.
In unmatched analyses, the multivariate-adjusted odds ratios (ORs) and 95% confidence intervals (CIs) of mortality were 1.71 (1.46–2.00) for depression at any age, 1.72 (1.36–2.17) for early-life, 1.51 (1.19–1.90) for midlife, and 4.10 (2.02–8.34) for late-life depression. Mortality was significantly higher in individuals with late-life depression than those with earlier-life depression (p < 0.05). The mediation analysis showed that 59.83% of the depression-mortality association was mediated by dementia. No significant difference in ORs between the unmatched and co-twin matched analyses was observed (p = 0.09).
Depression is associated with an increased risk of all-cause mortality, and dementia mediates approximately 60% of the impact of depression on mortality in late life. Genetic and early-life environmental factors may not play a significant role in the depression-mortality association.
Most medical diagnostic tests are expensive, involve slow turnaround times from centralized laboratories and require highly specialized equipment with seasoned technicians to carry out the assay. To facilitate realization of precision medicine at the point of care, we have developed a mixed-scale nanosensor chip featuring high surface area pillar arrays where solid-phase reactions can be performed to detect and identify nucleic acid targets found in diseased patients. Products formed can be identified and detected using a polymer nanofluidic channel. To guide delivery of this platform, we discuss the operation of various components of the device and simulations (COMSOL) used to guide the design by investigating parameters such as pillar array loading, and hydrodynamic and electrokinetic flows. The fabrication of the nanosensor is discussed, which was performed using a silicon (Si) master patterned with a combination of focused ion beam milling and photolithography with deep reactive ion etching. The mixed-scale patterns were transferred into a thermoplastic via thermal nanoimprint lithography, which facilitated fabrication of the nanosensor chip making it appropriate for in vitro diagnostics. The results from COMSOL were experimentally verified for hydrodynamic flow using Rhodamine B as a fluorescent tracer and electrokinetic flow using single fluorescently labelled oligonucleotides (single-stranded DNAs, ssDNAs).
Several amino acids can stimulate milk synthesis in mammary epithelial cells (MEC); however, the regulatory role of isoleucine (Ile) and underlying molecular mechanism remain poorly understood. In this study, we aimed to evaluate the regulatory effects of Ile on milk protein and fat synthesis in MEC and reveal the mediation mechanism of Brahma-related gene 1 (BRG1) on this regulation. Ile dose dependently affected milk protein and fat synthesis, mechanistic target of rapamycin (mTOR) phosphorylation, sterol regulatory element binding protein 1c (SREBP-1c) expression and maturation, and BRG1 protein expression in bovine MEC. Phosphatidylinositol 3 kinase (PI3K) inhibition by LY294002 treatment blocked the stimulation of Ile on BRG1 expression. BRG1 knockdown and gene activation experiments showed that it mediated the stimulation of Ile on milk protein and fat synthesis, mTOR phosphorylation, and SREBP-1c expression and maturation in MEC. ChIP-PCR analysis detected that BRG1 bound to the promoters of mTOR and SREBP-1c, and ChIP-qPCR further detected that these bindings were increased by Ile stimulation. In addition, BRG1 positively regulated the binding of H3K27ac to these two promoters, while it negatively affected the binding of H3K27me3 to these promoters. BRG1 knockdown blocked the stimulation of Ile on these two gene expressions. The expression of BRG1 was higher in mouse mammary gland in the lactating period, compared with that in the puberty or dry period. Taken together, these experimental data reveal that Ile stimulates milk protein and fat synthesis in MEC via the PI3K-BRG1-mTOR/SREBP-1c pathway.
Taurine (Tau) has many profound physiological functions, but its role and molecular mechanism in muscle cells are still not fully understood. In this study, we investigated the role and underlying molecular mechanism of Tau on protein synthesis and proliferation of C2C12 myoblast cells. Cells were treated with Tau (0, 60, 120, 180 and 240 μM) for 24 h. Tau dose-dependently promoted protein synthesis, cell proliferation, mechanistic target of rapamycin protein (mTOR) phosphorylation and also AT-rich interaction domain 4B (ARID4B) expression, with the best stimulatory effects at 120 μM. LY 294002 treatment showed that Tau promoted ARID4B expression in a phosphoinositide 3-kinase (PI3K)-dependent manner. ARID4B knockdown (by small interfering RNA transfection for 24 h) prevented Tau from stimulating protein synthesis and cell proliferation, whereas ARID4B gene activation (using the CRISPR/dCas9 technology) had stimulatory effects. ARID4B knockdown abolished Tau signalling to mRNA expression and protein phosphorylation of mTOR, whereas ARID4B gene activation had stimulatory effects. Chromatin immunoprecipitation (ChIP)-PCR identified that all of ARID4B, H3K27ac and H3K27me3 bound to the −4368 to –4591 bp site in the mTOR promoter, and ChIP-quantitative PCR (qPCR) further detected that Tau stimulated ARID4B binding to this site. ARID4B knockdown or gene activation did not affect H3K27me3 binding to the mTOR promoter but decreased or increased H3K27ac binding, respectively. Furthermore, ARID4B knockdown abolished the stimulation of Tau on H3K27ac binding to the mTOR promoter. In summary, these data uncover that Tau promotes protein synthesis and proliferation of C2C12 myoblast cells through the PI3K-ARID4B-mTOR pathway, providing a deep understanding of how Tau regulates anabolism in muscle cells.
As the corona virus disease 2019 (COVID-19) pandemic continues around the world, understanding the transmission characteristics of COVID-19 is vital for prevention and control. We conducted the first study aiming to estimate and compare the relative risk of secondary attack rates (SARs) of COVID-19 in different contact environments. Until 26 July 2021, epidemiological studies and cluster epidemic reports of COVID-19 were retrieved from SCI, Embase, PubMed, CNKI, Wanfang and CBM in English and Chinese, respectively. Relative risks (RRs) were estimated in pairwise comparisons of SARs between different contact environments using the frequentist NMA framework, and the ranking of risks in these environments was calculated using the surface under the cumulative ranking curve (SUCRA). Subgroup analysis was performed by regions. Thirty-two studies with 68 260 participants were identified. Compared with meal or gathering, transportation (RR 10.55, 95% confidence interval (CI) 1.43–77.85), medical care (RR 11.68, 95% CI 1.58–86.61) and work or study places (RR 10.15, 95% CI 1.40–73.38) had lower risk ratios for SARs. Overall, the SUCRA rankings from the highest to the lowest were household (95.3%), meal or gathering (81.4%), public places (58.9%), daily conversation (50.1%), transportation (30.8%), medical care (18.2%) and work or study places (15.3%). Household SARs were significantly higher than other environments in the subgroup of mainland China and sensitive analysis without small sample studies (<100). In light of the risks, stratified personal protection and public health measures need to be in place accordingly, so as close contacts categorising and management.
As a new management reform adapting the development of the times, electronic human resource management (E-HRM) covers all possible integration mechanisms and contents between HRM and Information Technologies. E-HRM promotes employees' subject status with the network characteristics of openness and cooperation. Taking the theory of work adjustment as the instruction, this research studies the adaptive process induced by reconstructing the sense of matching when employees experience the reform, along with the influence of E-HRM on employee's initiative behavior from the perspective of job crafting. In total, 706 employees and their supervisors were investigated with matched questionnaire survey. The results show that: (1) E-HRM can stimulate employees' personal initiative behavior; (2) task crating, relational crafting and cognitive crafting as three dimensions of employees' job crafting, mediate the effect of E-HRM on personal initiative behavior and (3) the self-development motivation of employees' internet use plays a positive moderating role, steering self-oriented job crafting in the positive direction which conforms to the organizations' expectation.
The purpose of the current study was to investigate associations between spicy food intake and serum lipids levels in Chinese rural population.
Information on spicy food flavour and intake frequency was obtained using a two-item questionnaire survey. Dietary data were collected using a validated thirteen-item FFQ. Fasting blood samples were collected and measured for total cholesterol (TC), TAG, HDL-cholesterol and LDL-cholesterol. Multivariate linear and logistic regression models were employed to examine the relationship between spicy food and serum lipids levels according to the spicy food flavour and intake frequency, respectively.
A cross-sectional study in Henan Province.
38 238 participants aged 18–79 years old.
Spicy flavour and intake frequency were consistently associated with decreased TC and non-HDL-cholesterol levels but mildly associated with elevated TAG levels. Each level increment in spicy flavour was inversely associated with high TC (OR: 0·91; 95 % CI 0·88, 0·93) and high non-HDL-cholesterol (OR: 0·88; 95 % CI 0·85, 0·91) but positively associated with high TAG (OR: 1·04; 95 % CI 1·01, 1·07). Similarly, 1-d increment in spicy food intake frequency was also inversely associated with high TC (OR: 0·92; 95 % CI 0·91, 0·94) and high non-HDL-cholesterol (OR: 0·91; 95 % CI 0·89, 0·93) but positively associated with high TAG (OR: 1·04; 95 % CI 1·02, 1·06).
Spicy food intake was mildly associated with increased risk of abnormal TAG level, significantly associated with decreased risk of abnormal TC and non-HDL levels. Spicy food intake may be contribute to the management of lipid levels.
The coronavirus disease 2019 (COVID-19) epidemic is spreading globally. Studies revealed that obesity may affect the progression and prognosis of COVID-19 patients. The aim of the meta-analysis is to identify the prevalence and impact of obesity on COVID-19. Studies on obese COVID-19 patients were obtained by searching PubMed, Cochrane Library databases and Web of Science databases, up to date to 5 June 2020. And the prevalence rate and the odds ratio (OR) of obesity with 95% confidence interval (CI) were used as comprehensive indicators for analysis using a random-effects model. A total of 6081 patients in 11 studies were included. The prevalence of obesity in patients with COVID-19 was 30% (95% CI 21–39%). Obese patients were 1.79 times more likely to develop severe COVID-19 than non-obese patients (OR 1.79, 95% CI 1.52–2.11, P < 0.0001, I2 = 0%). However obesity was not associated with death in COVID-19 patients (OR 1.05, 95% CI 0.65–1.71, P = 0.84, I2 = 66.6%). In dose−response analysis, it was estimated that COVID-19 patients had a 16% increased risk of invasive mechanical ventilation (OR 1.16, 95% CI 1.10–1.23, P < 0.0001) and a 20% increased risk of admission to ICU (OR 1.20, 95% CI 1.11–1.30, P < 0.0001) per 5 kg/m2 increase in BMI. In conclusion, obesity in COVID-19 patients is associated with severity, but not mortality.
The associations between sugar-sweetened beverage (SSB) and artificially sweetened beverage (ASB) consumption and the risk of metabolic syndrome (MetS) remain controversial. A quantitative assessment of dose–response associations has not been reported. This study aims to assess the associations between the risk of MetS and SSB, ASB, and total sweetened beverage (TSB, the combination of SSB and ASB) consumption by reviewing population-based epidemiological studies.
We searched PubMed, Embase and Web of Science databases prior to 4 November 2019, for relevant studies investigating the SSB–MetS and ASB–MetS associations. A random effects model was used to estimate pooled relative risks (RR) and 95 % CI. Dose–response association was assessed using a restricted cubic splines model.
We identified seventeen articles (twenty-four studies, including 93 095 participants and 20 749 MetS patients).
The pooled RR for the risk of MetS were 1·51 (95 % CI 1·34, 1·69), 1·56 (1·32, 1·83) and 1·44 (1·19, 1·75) in high consumption group of TSB, SSB and ASB, respectively; and 1·20 (1·13, 1·28), 1·19 (1·11, 1·28) and 1·31 (1·05, 1·65) per 250 ml/d increase in TSB, SSB and ASB consumption, respectively. Additionally, we found evidence of non-linear, TSB–MetS and SSB–MetS dose–response associations and a linear ASB–MetS dose–response association.
TSB, SSB and ASB consumption was associated with the risk of MetS. The present findings provide evidence that supports reducing intake of these beverages to lower the TSB-, SSB- and ASB-related risk of MetS.
We analyzed characteristics of tornado-related injuries and medical impact on a county-level hospital in China in June 23, 2016. The objective of this study was to describe and analyze local government rescue responses following the tornado.
County hospital medical records of 288 tornado-related injury patients were collected. Descriptive analyses to study injury characteristics and associated risk factors were performed.
Of the studied population, 84% of the wounded were older than 45 years. Only 30 (10.4%) people were sent to the hospital for treatment within 3 hours following the disaster. Heavy objects or collapsing houses accounted for 191 (66.3%) of the documented injuries. The proportion of people with resulting brain injuries was 46.2% of the entire injured population, and the incidence of lower extremity injuries was 27.8%. A total of 89.6% of the wounded had skin and soft tissue injuries. Multiple injuries were found in 129 (44.8%) people and 156 had a single injury (54.2%), and 3 cases with acute stress disorder were admitted to the hospital.
Preparation plans, including tornado warnings, prevention, and rescue, are a basic requirement for the mitigation of tornado-related injuries. Protection awareness of tornado disasters is also critical to ensure injury prevention.
To study injury patterns and medical rescue operations related to tornadoes that occur in rural areas, this study investigated the data pertaining to the 2017 Chifeng tornado (China).
Medical records of 52 tornado-related patients were investigated. Data were collected from 3 local hospitals that received all the tornado victims.
A total of 148 injuries were diagnosed. Tornado-related injuries were mainly caused by collapsed houses (51.9%) and direct physical trauma caused by the tornado (38.5%). Most injuries occurred outdoors (63.5%). The head (20.3%) and thorax (14.8%) were most 2 frequent anatomical injury sites. Soft-tissue injuries (43.9%) and contusions and lacerations (37.3%) were the 2 most common injury types. On evaluating the Abbreviated Injury Scale scores, a score of 1 was the most common (66.2%), and a score of 6 was not recorded.
A trailing phenomenon in the distribution of time to admission among the victims of a particular tornado in China was observed. The delivery is timely compared with nondisaster situation. There was a statistically significant difference of injury causes between outdoor and indoor patients. Helmets should be used by potential tornado victims. Basement units capable of functioning as shelters should be built in villages.
Anatase phase NOx/S6+–TiO2 (x= 0, 1) film with high solar-driven activity has been successfully prepared via electro-assisted oxidation processes. The morphological and structural properties of the film were characterized by scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, and X-ray diffraction, while the optical property was detected by UV-vis-NIR absorption spectroscopy. The results showed that the NOx/S6+–TiO2 film was composed of “flower-like” microvoids structure and displayed broad and strong optical absorption at around 544 and 1500 nm. Transient photocurrent response, photoluminescence spectroscopy, and electrochemical impedance spectroscopy indicated that the generation and separation of photogenerated charges were significantly enhanced under simulated solar irradiation. The NOx/S6+–TiO2 film exhibited excellent photoelectrocatalytic activity for the degradation of methyl orange (MO), and the decoloration rate and TOC removal respectively reached 98.97 and 59.44% at 20 min under solar irradiation. The film still had good stability after reusing ten times. Furthermore, a possible mechanism of photoelectrocatalysis was suggested in MO degradation by using NOx/S6+–TiO2 film.
This study was performed to explore the clinical features of Kawasaki disease shock syndrome and analyse the association between the left ventricular ejection fraction and Kawasaki disease shock syndrome.
We retrospectively reviewed the medical records of all consecutive inpatients with Kawasaki disease at Wenzhou Medical University Second Affiliated Hospital and Yuying Children’s Hospital in Wenzhou, China from January 2009 to December 2016. We compared the clinical characteristics, laboratory data, and left ventricular ejection fraction between patients with and without Kawasaki disease shock syndrome and analysed the effect of the left ventricular ejection fraction on Kawasaki disease shock syndrome under different clinical conditions of Kawasaki disease.
In total, 1147 patients were diagnosed with Kawasaki disease. Of these 1147 patients, 17 were diagnosed with Kawasaki disease shock syndrome; 68 patients admitted to the hospital at the same time, ±2 weeks, with Kawasaki disease but without Kawasaki disease shock syndrome served as the control group. Compared with the control group, the Kawasaki disease shock syndrome group had a significantly higher incidence of coronary artery lesions, cardiac troponin I concentration, N-terminal prohormone of brain natriuretic peptide concentration, neutrophil count and ratio, alanine aminotransferase concentration, aspartate aminotransferase concentration, and C-reactive protein concentration and a significantly lower platelet count, serum albumin concentration, and left ventricular ejection fraction. A low left ventricular ejection fraction was associated with Kawasaki disease shock syndrome under different conditions of Kawasaki disease.
Among patients with Kawasaki disease, cardiac injury is more likely in those with Kawasaki disease shock syndrome than without, and a low left ventricular ejection fraction may be associated with the development of Kawasaki disease shock syndrome.
We sought to examine the potential modifiers in the association between long-term low-dose folic acid supplementation and the reduction of serum total homocysteine (tHcy) among hypertensive patients, using data from the China Stroke Primary Prevention Trial (CSPPT). This analysis included 16 867 participants who had complete data on tHcy measurements at both the baseline and exit visit. After a median treatment period of 4·5 years, folic acid treatment significantly reduced the tHcy levels by 1·6 μmol/l (95 % CI 1·4, 1·8). More importantly, after adjustment for baseline tHcy and other important covariates, a greater degree of tHcy reduction was observed in certain subgroups: males, the methylenetetrahydrofolate reductase (MTHFR) 677TT genotype, higher baseline tHcy levels (≥12·5 (median) v. <12·5 μmol/l), lower folate levels (<8·0 (median) v. ≥8·0 ng/ml), estimated glomerular filtration rate (eGFR) <60 ml/min per 1·73 m2 (v. 60–<90 and ≥90 ml/min per 1·73 m2), ever smokers and concomitant use of diuretics (P for all interactions <0·05). The degree of tHcy reduction associated with long-term folic acid supplementation can be significantly affected by sex, MTHFR C677T genotypes, baseline folate, tHcy, eGFR levels and smoking status.
Pine wilt disease, which is caused by the pine wood nematode (PWN), Bursaphelenchus xylophilus, has caused huge damage to pine forests around the world. In this study, we analysed the PWN transcriptome to investigate the expression of genes related to the associated bacterial species Pseudomonas fluorescens and found that the gene adh-1 encoding alcohol dehydrogenase (ADH) was upregulated. The open reading frame of adh-1, which encoded a protein of 352 amino acid residues, was cloned from B. xylophilus. Recombinant ADH with a relative molecular weight of 39 kDa, was present mainly in inclusion bodies and was overexpressed in Escherichia coli BL21 (DE3) and purified after refolding. The biochemical assay revealed that recombinant ADH could catalyse the dehydrogen reaction of eight tested alcohols including ethanol in the presence of NAD+. Quantitative real-time RT-PCR analysis indicated that ethanol upregulated adh-1 expression in PWN. Results of RNA interference and inhibition of ADH treatment indicated that downregulating expression of adh-1 or inhibition of ADH could reduce ethanol tolerance and the vitality and reproduction ability of B. xylophilus, suggesting that adh-1 is involved in pathogenicity of PWN.
We applied laser THz emission spectroscopy to study the effects of monolayer graphene on the THz emission from InAs. THz emission from graphene/InAs varies linearly with the laser excitation power in the low-intensity excitation regime. We found that unlike in graphene/SI-InP junctions, graphene and O2 adsorbates on graphene have no significant effect on the THz emission from graphene/InAs junctions because the THz radiation mechanism in InAs is by the photo-Dember effect, whereas for SI-InP is by the surge current effect. There is also a slight enhancement in the THz emission from both bare InAs and graphene/InAs by UV illumination, which is probably due to the additional photoexcited carriers by UV that somehow enhances the photo-Dember field.
The hot water tail-flick test is widely used to measure the degree of nociception experienced by laboratory animals. This study was carried out to optimise interval times for the hot water immersion tail-flick tests in rats.
Ten different intervals from 10 s to 1 h were tested in 60 Sprague–Dawley male rats. At least eight rats were tested for each interval in three consecutive hot water tail-flick tests. Dixon's up-and-down method was also used to find the optimal intervals. The same rats were then divided into two groups. In Group N, naloxone was injected to reverse the prolonged latency times, whereas saline was used in the control Group S.
Intervals of 10 s, 20 s, 30 min and 1 h did not significantly impact latencies, yielding similar results in three consecutive tests (p > 0.05). However, interval times of between 30 s and 20 min, inclusively, caused significantly prolonged latencies in the second and third tests (p < 0.001). Dixon's up-and-down method showed that 95% of the rats had prolonged latencies in hot water tail-flick tests at intervals longer than 32 s. Naloxone reversed prolonged latencies in Group N, whereas the latencies in Group S were further prolonged in 5 min interval tests.
The optimal intervals for hot water tail-flick tests are either shorter than 20 s or longer than 20 min. The prolonged latencies after repetitive tests were attributable to an endocrine opioid.
Using the Delingha 13.7 m telescope with a 9-beam SIS superconducting receiver installed, we carried out mapping of C18O and C17O J = (1 − 0) toward molecular clouds in the central molecular zone (CMZ) and in the halo of our galaxy. From the integrated intensity ratio of C18O to C17O, the isotope ratio 18O/17O ratio can be estimated, which is considered to be one of the most useful tracers of nuclear processing and metal enrichment. Here preliminary results are presented toward Sgr A, Sgr B2, Sgr C, Sgr D, and the 1.°3 complex in the CMZ and M+5.3–0.3 in the halo.
The present study was designed to analyse the usefulness of a modified Calgary score system during differential diagnosis between cardiac syncope and postural orthostatic tachycardia syndrome-associated syncope through a large sample sized clinical investigation. The study included 213 children, including 101 boys and 112 girls, with cardiac syncope or postural orthostatic tachycardia syndrome-associated syncope in the age group of 2–19 years (mean 11.8 ± 2.9 years). A modified Calgary score was created, which was analysed to predict differential diagnoses between cardiac syncope and postural orthostatic tachycardia syndrome-associated syncope using a receiver operating characteristic curve. The median of modified Calgary scores for cardiac syncope was −5.0, which significantly differed from that of postural orthostatic tachycardia syndrome (0.0; p < 0.01). The sensitivity and specificity of a differentiation score of less than −2.5 was 96.3% and 72.7%, respectively. Owing to the fact that the modified Calgary score was an integer, when less than −3.0 the diagnosis could be considered as cardiac syncope. The modified Calgary score could be used to make an initial differential diagnosis between cardiac syncope and postural orthostatic tachycardia syndrome-associated syncope in the clinic.
This study was designed to investigate the value of history taking in identifying children with cardiac syncope, and to improve diagnostic efficiency and accuracy in children with cardiac syncope.
Methods and Results
We compared the characteristics of a group of children and adolescents with cardiac syncope at the Pediatric Syncope Unit of five hospitals in China with those with typical vasovagal syncope. We included a cohort of 275 patients in Pediatric Syncope Unit. A cardiac cause of syncope was established in 31 patients, autonomic-mediated reflex syncope in 214, non-syncopal attacks in 15, and in the remaining 15 the cause of syncope remained unexplained. Cardiac syncope was triggered by exercise, whereas vasovagal syncope by prolonged standing, warm-crowded place, and fear or pain emotion. Syncopal spells occurred at various positions in cardiac syncope. Children who had prodromal symptoms with cardiac syncope were significantly fewer than those with vasovagal syncope. Most children with cardiac syncope had history of abnormal electrocardiogram findings when compared with children suffering from vasovagal syncope. On multivariable analysis, history of abnormal electrocardiogram findings and exercise-triggered syncope were independent predictors of cardiac syncope.
Children and adolescents with a history of abnormal electrocardiogram findings and exercise-related syncope spells were at high risk for cardiac syncope.