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Eutrophication is a common phenomenon in aquatic ecosystems caused by human disturbance and is regarded as one of the major threats to biodiversity in rivers throughout the world. However, no consistent pattern explains the relationship between eutrophication and biodiversity in rivers. In the present work, we explored fieldwork in connection to the influence of eutrophication on biodiversity in nine streams in a boreal river ecosystem in China. We aimed to test the intermediate disturbance hypothesis (IDH) in our model, which predicts that biodiversity reaches its maximum at intermediate disturbance. We used total phosphorus (TP) as a direct indicator of eutrophication and divided TP concentration into five levels of eutrophication, which represented anthropogenic disturbance of varied intensity. The results obtained from periphyton, macroinvertebrate, and fish assemblages showed that species richness was higher at intermediate eutrophication levels, and the pattern was not impacted by other factors. Our findings may provide important insights into the influence of anthropogenic disturbance on biodiversity in stream ecosystems. [ABSTRACT FROM AUTHOR]

Using undrained triaxial shear tests, this study investigates the mechanical properties of fine-grained materials (silty clay and sand) which are extensively used for China's Qinghai–Tibet Railway (QTR) under different confining pressures (σ3) and freezing temperatures (T). The results show that a reduction in T causes an increase in the shear strength and elastic modulus of all the materials tested in the present study. In addition, the freezing of the silty clay has no significant effect on the type of soil behaviour (strain-hardening), whereas the freezing of the sand changes its strain-hardening behaviour to strain-softening. Supposing that the deviatoric stress–strain curves of the silty clay and sand can be divided into two segments due to a reverse bending point, it was assumed that the first segment follows a hyperbolic function. Meanwhile, the second segment is also a hyperbola, with the reverse bending point as the origin and the residual strength as the asymptote. Accordingly, a nonlinear relation constitutive model that considers σ3 and T is derived. All model parameters are identified. The reasonability of the new model was verified using the test results of the materials. A comparison of the predicted and test results shows that this model can well simulate the deviatoric stress–strain response in the failure process of the tested materials. In particular, it can reflect the residual deviatoric stress after the materials' failure. [ABSTRACT FROM AUTHOR]

In the cold regions of China, coarse-grained materials are frequently encountered or used as backfilling materials in infrastructure construction, such as dams, highways, railways, and mineral engineering structures. Effects of confining pressure (0.2, 0.5, and 1 MPa) and frozen temperature (−2, −5, −10, and −15°C) on the stress-strain response and elastic modulus were investigated using triaxial compression tests. Moreover, the microscale structures of a coarse-grained material were obtained by X-ray computed tomography. The coarse-grained material specimens exhibited strain-softening and significant dilatancy behaviors during shearing. A modified model considering microstructures of the material was proposed to describe these phenomena. The predicted values coincided well with the experimental results obtained in this study and other literatures. The sensitivity analysis of parameters indicated that the model can simulate the initial hardening and post-peak strain-softening behavior of soils. And the transition of volume strain from contraction to dilatancy can also be described using this model. The results obtained in this study can provide a helpful reference for the analysis of frozen coarse-grained materials in geotechnical engineering. [ABSTRACT FROM AUTHOR]

Objective: To report the first case series of robotic single-site (RSS) surgery via the da Vinci Si Surgical System for mature cyst teratoma cystectomy in China.Materials and Methods: The study was devised as a retrospective study in a single medical center. Five patients with mature cyst teratomas requested a minimally invasive surgical treatment. These patients were treated with RSS surgery for mature cyst teratoma between January 2014 and January 2015. RSS mature cyst teratoma cystectomies were performed with the da Vinci single-site platform in the Hainan branch of PLA General Hospital. Data regarding patient characteristics, surgical approach, and perioperative clinical outcomes were collected and analyzed in a retrospective study.Results: All RSS procedures were completed successfully in the five patients. No instrument failure was noted during the procedures. The median operating time was 65 minutes (range 45-100 minutes). The median docking time was 20 minutes (range 18-28 minutes). No instrument failure was noted during any surgical procedures. The median blood loss was 30 mL (range 10-70 mL). No patient had massive intraoperative bleeding nor required a transfusion. No extra trocar was placed during the surgery. None of the patients had bladder or rectal injury. The median length of stay in hospital was 2.8 days. All patients were followed up until 6 months postoperatively, and no surgical complication occurred.Conclusion: RSS mature cyst teratoma cystectomy using the wristed semirigid instrumentation is feasible. Randomized controlled trials with a larger number of patients and longer postoperative follow-up should be conducted to further evaluate the effect of this therapeutic strategy. [ABSTRACT FROM AUTHOR]

Background: Shoulder pain is a common musculoskeletal disorder in Chinese population, which affects more than 1,3 billion individuals. To the best of our knowledge, there has been no available Chinese-language version of measurements of shoulder pain and disability so far. Moreover, the Constant-Murley score (CMS) questionnaire is a universally recognized patient-reported questionnaire for clinical practice and research. The present study was designed to evaluate a Chinese translational version of CMS and subsequently assess its reliability and validity.Methods: The Chinese translational version of CMS was formulated by means of forward-backward translation. Meanwhile, a final review was carried out by an expert committee, followed by conducting a test of the pre-final version. Therefore, the reliability and validity of the Chinese translational version of CMS could be assessed using the internal consistency, construct validity, factor analysis, reliability and floor and ceiling effects. Specifically, the reliability was assessed by testing the internal consistency (Cronbach's α) and test-retest reliability (intraclass coefficient correlation [ICC]), while the construct validity was evaluated via comparison between the Chinese translational version of CMS with visual analog scale (VAS) score and the 36-Item Short Form Health Survey (SF-36, Spearman correlation).Results: The questionnaire was verified to be acceptable after distribution among 120 subjects with unilateral shoulder pain. Factor analysis had revealed a two-factor and 10-item solution. Moreover, the assessment results indicated that the Chinese translational version of CMS questionnaire harbored good internal consistency (Cronbach's α = 0.739) and test-retest reliability (ICC = 0.827). In addition, the Chinese translational version of CMS was moderately correlated with VAS score (r = 0.497) and SF-36 (r = 0.135). No obvious floor and ceiling effects were observed in the Chinese translational version of CMS questionnaire.Conclusion: Chinese translational version of CMS exhibited good reliability, which is relatively acceptable and is likely to be widely used in this population. [ABSTRACT FROM AUTHOR]

With the rapid development of high-speed railways (HSRs) in seasonally frozen regions in China in recent years, there is an increasing need for better understanding of how the construction materials behave. In particular, the dynamic behaviours of coarse-grained materials (CGMs) used for China's HSRs subjected to combined actions of cyclic loading and freeze-thaw (F-T) cycles has attracted much attention. In this study, a series of cyclic triaxial tests were performed to investigate the characteristics of CGMs considering the effects of number of F-T cycles (N FT), confining pressures (σ 3), dynamic stress amplitude (σ ¯ d), and fines content (FC). Representative test results of accumulative axial strain (ε acc), resilient modulus (M r), dynamic shear modulus (G d) and damping ratio (D) are then presented and discussed. Empirical models are proposed and validated for predicting the evolution of ε acc and M r for CGMs under the cyclic loading. In addition, the evolution models of G d and D were established, which can be used for computing the response of CGMs under various influencing factors. Overall, this study provides further insights into the cyclic behaviours of CGMs in seasonally frozen regions. • Cyclic triaxial tests were carried out on prepared thawed coarse-grained materials. • Effects of freeze-thaw cycles, confining pressure, dynamic stress amplitude, and fines content were discussed. • Models for accumulative strain, resilient modulus, dynamic shear modulus and damping ratio were proposed and validated. [ABSTRACT FROM AUTHOR]

Background: Shoulder pain is a common musculoskeletal disorder in Chinese population, which affects more than 1,3 billion individuals. To the best of our knowledge, there has been no available Chinese-language version of measurements of shoulder pain and disability so far. Moreover, the Constant-Murley score (CMS) questionnaire is a universally recognized patient-reported questionnaire for clinical practice and research. The present study was designed to evaluate a Chinese translational version of CMS and subsequently assess its reliability and validity., Methods: The Chinese translational version of CMS was formulated by means of forward-backward translation. Meanwhile, a final review was carried out by an expert committee, followed by conducting a test of the pre-final version. Therefore, the reliability and validity of the Chinese translational version of CMS could be assessed using the internal consistency, construct validity, factor analysis, reliability and floor and ceiling effects. Specifically, the reliability was assessed by testing the internal consistency (Cronbach's α) and test-retest reliability (intraclass coefficient correlation [ICC]), while the construct validity was evaluated via comparison between the Chinese translational version of CMS with visual analog scale (VAS) score and the 36-Item Short Form Health Survey (SF-36, Spearman correlation)., Results: The questionnaire was verified to be acceptable after distribution among 120 subjects with unilateral shoulder pain. Factor analysis had revealed a two-factor and 10-item solution. Moreover, the assessment results indicated that the Chinese translational version of CMS questionnaire harbored good internal consistency (Cronbach's α = 0.739) and test-retest reliability (ICC = 0.827). In addition, the Chinese translational version of CMS was moderately correlated with VAS score (r = 0.497) and SF-36 (r = 0.135). No obvious floor and ceiling effects were observed in the Chinese translational version of CMS questionnaire., Conclusion: Chinese translational version of CMS exhibited good reliability, which is relatively acceptable and is likely to be widely used in this population.

Few studies have investigated gender differences in dietary intake. The objective of this cross-sectional study was to examine gender differences in dietary patterns and their association with the prevalence of metabolic syndrome. The food intakes of 3794 subjects enrolled by a two-stage cluster stratified sampling method were collected using a valid semi-quantitative food frequency questionnaire (FFQ). Metabolic syndrome (MetS) was defined according to the International Diabetes Federation (IDF) and its prevalence was 35.70% in the sample (37.67% in men and 24.67% in women). Dietary patterns were identified using factor analysis combined with cluster analysis and multiple group confirmatory factor analysis was used to assess the factorial invariance between gender groups. The dominating dietary pattern for men was the "balanced" dietary pattern (32.65%) and that for women was the "high-salt and energy" dietary pattern (34.42%). For men, the "animal and fried food" dietary pattern was related to higher risk of MetS (odds ratio: 1.27; 95% CI: 1.01-1.60), after adjustment for age, marital status, socioeconomic status and lifestyle factors. For women, the "high-salt and energy" dietary pattern was related to higher risk of MetS (odds ratio: 2.27; 95% CI: 1.24-4.14). We observed gender differences in dietary patterns and their association with the prevalence of MetS. For men, the "animal and fried food" dietary pattern was associated with enhancive likelihood of MetS. For women, it was the "high-salt and energy" dietary pattern.

Background: A key limitation of conventional ultrasound (US) includes poor differentiation of benign from malignant thyroid nodules. Contrast-enhanced US (CEUS) and acoustic radiation force impulse (ARFI) could provide better characterization of focal thyroid nodules; however, no studies have compared their efficacies., Objective: To evaluate the diagnostic efficacy of conventional US,CEUS, ARFI, and their combined use in differentiating focal solid thyroid nodules., Methods: One-hundred-forty-six Chinese patients with 175 thyroid nodules (119 benign and 56 malignant) were prospectively enrolled. Each patients underwent conventional US, CEUS and ARFI, respectively. The diagnostic performance of the conventional US, CEUS, ARFI, combined use of either CEUS or ARFI and combined use of the three modalities were assessed and compared using Pathological diagnosis (histological/cytological) as the reference method., Results: There were no significant differences between individual groups (CEUS vs US, P = 0.279, ARFI vs US, P = 0.372, CEUS vs ARFI, P = 0.849), combined use of US and CEUS or combined use of US and ARFI yielded significant difference compared to US. (combination of US & CEUS vs US, P = 0.021; combination of US & ARFI vs US, P = 0.036). The combination of three modalities significantly improved the diagnostic accuracy compared with either combination of conventional US and CEUS or combination of conventional US and ARFI (P = 0.045 and P  = 0.027, respectively)., Conclusions: CEUS and ARFI can be used as an additional tool in the diagnostic work up of thyroid nodules. The combination of CEUS with ARFI can significantly improve the diagnostic accuracy.

Background and Aims: Pinus kwangtungensis is a five-needled pine, inhabiting isolated mountain tops, cliffs or slopes in the montane areas of southern China and northern Vietnam. Global warming and long-term deforestation in southern China threaten its existence and genetic integrity, and this species is listed as vulnerable in the China Species Red List. However, the level and distribution of genetic diversity in this vulnerable species are completely unknown. In this paper, the genetic diversity and structure are examined using paternally inherited plastid markers to shed light on its evolutionary history and to provide a genetic perspective for its conservation., Methods: By means of direct sequencing, a new polymorphic fragment containing a minisatellite site was identified within the plastid genome of P. kwangtungensis. Using the minisatellite site along with five SNPs (one indel and four substitutions) within the same fragment, the population genetic structure and pollen flow were analysed in 17 populations of P. kwangtungensis in southern China., Key Results: Analysis of 227 individuals from 17 populations revealed ten haplotypes at the minisatellite site. The haplotype diversity at species level was relatively high (0.629). Genetic diversity of each population ranged from 0 to 0.779, and the western populations harboured more genetic variation than the eastern and Hainan populations, although the former appeared to have experienced a bottleneck in recent history. Population subdivision based on this site was high (F(ST) = 0.540 under IAM; R(ST) = 0.677 under SMM). Three major clusters (eastern, western and Hainan) were identified based on a neighbor-joining dendrogram generated from genetic distances among the populations. The genetic structures inferred from all the polymorphic sites and the SNPs were in concordance with that from the minisatellite site., Conclusions: The results suggest that there are at least three refugia for P. kwangtungensis and that populations in these refugia should be treated as separate evolutionarily significant units or conservation units. The high diversities in the western populations suggest that these were much larger in the past (e.g. glacial stages) and that the shrinking population size might have been caused by recent events (e.g. deforestation, global warming, etc.). The western populations should be given priority for conservation due to their higher genetic diversity and limited population sizes. It is concluded that the newly found minisatellite may serve as a novel and applicable molecular marker for unravelling evolutionary processes in P. kwangtungensis.