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Objective: This study aimed to investigate the dynamic changes in the platelets of patients with severe heatstroke and the impact of these changes on the occurrence of disseminated intravascular coagulation (DIC) and prognosis in them. Methods: This retrospective cohort study conducted at two tertiary hospitals recruited 264 patients with severe heatstroke. Logistic regression was used to analyze the association between platelet counts and DIC. The receiver operating characteristic (ROC) curve was used to evaluate the predictive performance of platelets count for DIC occurrence. We used mediation effect to analysis the role of DIC as a mediating variable to mediate the relationship between platelet count decrease after 24 hours and death. Results: There were 214 patients with lower platelet counts compared to admission (107 × 109/L[69,168] vs.171 × 109/L[126,215], p < 0.001). The DIC patients had lower platelet counts than the non-DIC patients when measured in the emergency department and after 24 hours. The platelet count decrease after 24 hours was a risk factor for DIC (odds ratio [OR] = 2.710, 95% confidence interval [CI] = 1.069–6.869). The results of the ROC curve revealed that the predictive performance of the platelet count after 24 hours (area under the curve [AUC] = 0.8685, 95% CI = 0.8173–0.9197) was significantly better than that of the platelet count measured in the emergency department (AUC = 0.7080, 95% CI = 0.6345–0.7815). Mediation analyses showed that PLT decrease after 24 hours did not directly lead to death, but can indirectly cause death by inducing the development of DIC. Conclusions: Decreased platelet count is an independent risk factor for DIC in patients with severe heatstroke. Although the platelet counts measured in the emergency department and after 24 hours show a good predictive performance for DIC occurrence, the prediction performance of the latter is better. [ABSTRACT FROM AUTHOR]

Although there has been an increasing number of studies investigate portfolio optimization from different perspectives, few attempts could be found that focus on the development trend and hotspots of this research area. Therefore, it motivates us to comprehensively investigate the development of portfolio optimization research and give some deep insights into this knowledge domain. In this paper, some bibliometric methods are utilized to analyse the status quo and emerging trends of portfolio optimization research on various aspects such as authors, countries and journals. Besides, 'theories', 'models' and 'algorithms', especially heuristic algorithms are identified as the hotspots in the given periods. Furthermore, the evolutionary analysis tends to presents the dynamic changes of the cutting-edge concepts of this research area in the time dimension. It is found that more portfolio optimization studies were at an exploration stage from mean-variance analysis to consideration of multiple constraints. However, heuristic algorithms have become the driving force of portfolio optimization research in recent years. Multi-disciplinary analyses and applications are also the main trends of portfolio optimization research. By analysing the dynamic changes and multi-dimensional evolution in recent decades, we contribute to presenting some deep insights of the portfolio optimization research directly, which assists researchers especially beginners to comprehensively learn this research field. [ABSTRACT FROM AUTHOR]

Identifying the spatiotemporal dynamics of the water body in Dongting Lake, the second largest freshwater lake in China, is crucial for water resource management. In this study, the variations of the water body were comprehensively analyzed based on remote sensing images and in situ measurements from 2000 to 2019. Four breakpoint detection approaches were integrated to analyze the change trends and explore the related driving forces behind the changes. The results showed that significant intra– and inter–annual fluctuations of the water body were found from 2000 to 2019. The water area and volume decreased at rates of 1.26 km2/a and 16.65 × 106 m3/a, respectively. During the entire study period, the outflow at Chenglingji station (CLJ), the inflow from three outlets of the Yangtze River (Inflow2), and the inundation conditions during the last period (Arealag) made the largest relative contributions to the water area variation (around 25%, 27% and 24%, respectively). A breakpoint was detected around 2004, corresponding to the operation period of the Three Gorges Dam (TGD). The regulation of TGD profoundly affected the hydrological characteristics at the three outlets and CLJ, and may have indirectly caused the water area to expand by 2.41 km2/a during the dry seasons between 2004 and 2019. These results provide valuable insight into how natural and anthropogenic factors affect water body variation and may offer a practical reference for the local government to adjust management strategies. [ABSTRACT FROM AUTHOR]

The network theory is having an important role in tourism research, which provides a useful lens for understanding the structures and interrelations among tourism destinations. This paper analyzes the structure of China's inbound tourist flow network (ITFN) in a dynamic view, from three levels: the global, the meso, and the individual, meanwhile the correlation between network structure and tourism performance is verified. The interpretation of ITFN structure has been divided into three meanings: the global-level metrics identify the holistic topology, the meso-level metrics are used to understand collaboration, and the individual-level metrics work for competitiveness assessing. China's case shows the ITFN has a small-world characteristic but gradually becomes weak, the collaboration clusters become more, and the difference of competitiveness among regions has amplified. Moreover, the small-world nature and individual competitiveness have positive impacts on tourism performance, but the correlation between performance and clustering coefficient is significantly negative. [ABSTRACT FROM AUTHOR]

Objective: The aim of the study was to evaluate the dynamic changes of angle of progression (AoP) before the onset of labor and their correlation with labor outcome and to investigate the effect of visual feedback using transperineal ultrasound on maternal pushing.Methods: We recruited a group of low-risk nulliparous women with singleton pregnancy at term. We measured AoP at rest, during pelvic floor contraction and Valsalva maneuver (before and after visual feedback). We compared AoP between women who delivered vaginally (VD) and those who underwent a cesarean section (CS). We also assessed the correlation between AoP and labor durations.Results: Overall, 222 women were included in the study; 129 (58.1%) had spontaneous VD, 35 (15.8%) had instrumental delivery, and 58 (26.1%) underwent CS. In comparison with rest, AoP decreased at PFMC (p < .001) and increased at first Valsalva (p < .001). AoP increased further significantly at Valsalva after visual feedback (p < .001). Women with VD had wider AoP at rest (p = .020), during Valsalva maneuver before (p = .024), and after visual feedback (p = .037). At cox regression analysis, wider AoP was associated with shorter first, second, and active second stages.Conclusion: Wider AoP at rest and under Valsalva is associated with vaginal delivery, the shorter interval to delivery, and shorter labor duration in nulliparous women at term. The accuracy of AoP in the prediction of cesarean delivery is modest and is unlikely to be clinically applicable in isolation for the prediction of the mode of delivery. [ABSTRACT FROM AUTHOR]

Metabolism, transformation and dynamic changes of DNJ, 2-O-α-D-Gal-DNJ, fagomine, isofagomine and 4-O-β-d-Glc-fagomine from mulberry leaves in silkworms at different instars were observed. UPLC-Q/TOF-MS and UPLC-TQ/MS methods were adopted for qualitative and quantitative analysis respectively. Three species mulberry leaves were used to feed the silkworm as controls. By analyzing and comparing the content changes of DNJ, fagomine and their derivatives in silkworms and silkworm excrement at different instar, we revealed the dynamic changes, confirmed the enrichment effect of the polyhydroxy alkaloids by silkworm, and inferred the conversion process behind this effect. The experimental results indicated that DNJ and its derivatives turned into some intermediate substances in the metabolic process, and finally they converted back and the content increased. Fagomine and its derivatives interconverted into each other in the process, 4-O-β-d-Glc-fagomine transformed into fagomine, while fagomine transformed into isofagomine. [ABSTRACT FROM AUTHOR]

Optimizing the distribution of vegetable production requires knowing where vegetables are currently produced and understanding the factors driving structural changes in vegetable production. Revised Gini coefficient and Moran's Index are used to examine the spatial and temporal changes of vegetable production in China. A spatial Durbin model is applied to investigate the driving forces of these dynamic changes. The results show that: vegetable production in China has become more geographically concentrated in Huang-Huai-Hai region and Yangtze River Basin; Both comparative advantage and New Economic Geography-type mechanisms were drivers of the dynamic changes of vegetable production. Rural labor, road density (low-grade) and urban population growth have significant positive effects on vegetable production, while no significant effects of the climate factors is found. Furthermore, evidence of the existence of the spatial spillover effect was found in vegetable production. More specifically, rural labor and road density (low-grade) have positive externalities on vegetable production in neighboring provinces. [ABSTRACT FROM AUTHOR]

As a biological affinity chromatographic method, cell membrane chromatography (CMC) using a silica stationary phase covered with specific cell membrane has been used in screening active components. The innovation of this work is that the bioactive cell membrane and the chromatographic packing are mixed and absorbed for the first time to form the pre-column. The pre-column was placed in front of a C18 column to create dynamic CMC online high-performance liquid chromatography (HPLC) system. The retention behavior and dynamic changes of pharmaceuticals were studied for this system. The results indicate that the retention time of the drug was increased and the symmetry factor reached the analytical level after the addition of the dynamic cell membrane pre-column. Therefore, the dynamic CMC coupled with HPLC system may be a potentially rapid and efficient drug analysis approach for the interaction of drug molecule and receptor on red blood cell membranes. [ABSTRACT FROM AUTHOR]

Wild strawberries are grown widely in southern Shaanxi (China), but information about their sensory and chemical characteristics is scant. In this work, exploratory research was conducted to correlate the results of instrumental analyses of the aroma compounds in wild strawberry wine and their sensory perception. Headspace solid-phase micro extraction (HS-SPME) was used for the pretreatment, and gas chromatography-mass spectrometry (GC-MS) was to analyze the aroma compounds. A total of 78 volatile compounds were identified, including 25 alcohols, 25 esters, four acids, five ketones, four aldehydes, nine terpenes, five phenols, and one styrene, but only 74 could be quantified. Odor activity values (OAVs) were determined for 21 odor-active compounds. Six were identified as the characteristic aroma substances for the wild strawberries from a principal component analysis (PCA) of the composition, in particular methyl 2-methylbutyrate, ethyl 2-methylbutyrate, ethyl 3-methylbutyrate, (E)-3-hexen-1-ol, 1-octen-3-ol, and phenylacetaldehyde. Sensory evaluation by a trained panel using descriptive analysis also revealed that sweetness was the main attribute in wild strawberry and its wines, and differences in varietal flavors were also observed. Wild strawberry wine is proved to exhibit a high quality of its fruit flavor, and thus winemaking is a performable practice for wild strawberry. [ABSTRACT FROM AUTHOR]

Wild strawberries are grown widely in southern Shaanxi (China), but information about their sensory and chemical characteristics is scant. In this work, exploratory research was conducted to correlate the results of instrumental analyses of the aroma compounds in wild strawberry wine and their sensory perception. Headspace solid-phase micro extraction (HS-SPME) was used for the pretreatment, and gas chromatography-mass spectrometry (GC-MS) was to analyze the aroma compounds. A total of 78 volatile compounds were identified, including 25 alcohols, 25 esters, four acids, five ketones, four aldehydes, nine terpenes, five phenols, and one styrene, but only 74 could be quantified. Odor activity values (OAVs) were determined for 21 odor-active compounds. Six were identified as the characteristic aroma substances for the wild strawberries from a principal component analysis (PCA) of the composition, in particular methyl 2-methylbutyrate, ethyl 2-methylbutyrate, ethyl 3-methylbutyrate, (E)-3-hexen-1-ol, 1-octen-3-ol, and phenylacetaldehyde. Sensory evaluation by a trained panel using descriptive analysis also revealed that sweetness was the main attribute in wild strawberry and its wines, and differences in varietal flavors were also observed. Wild strawberry wine is proved to exhibit a high quality of its fruit flavor, and thus winemaking is a performable practice for wild strawberry. [ABSTRACT FROM AUTHOR]

Background: This study aimed to study the dynamic changes of B cell lymphoma/leukaemia 2 (Bcl-2), caspase-3 and heat shock response protein 70 (Hsp70) in blood serum following acute middle cerebral artery occlusion (MCAO) in rats. Methods: Occlusion of the cerebral artery was accomplished via the intraluminal filament, followed by the TTC staining evaluation and neurological deficit score. Meanwhile, the blood serum was extracted at 0.5, 2, 3, 6, 12 and 24 hours and 3 and 7 days after surgery. The serum expression levels of caspase-3, Bcl-2 and Hsp70 were determined using ELISA kits according to the manufacturer's protocols. Expression correlations between Bcl-2 and Hsp70, Bcl-2 and caspase-3 were analysed using correl function. A rats model was successfully established. Results: The expression of all three indexes, including Bcl-2, caspase-3 and Hsp70, was significantly increased after surgery ( p < 0.05) and peaked at 12, 24 and 24 hours, respectively. Up to 7 days after MCAO, the expression levels of these proteins recovered to the control levels. There were positive correlations between the expressions of Bcl-2 and Hsp70, Bcl-2 and caspase-3 ( p < 0.05). Conclusions: The altered expressions of these proteins in the blood serum may result in many symptoms in acute ischaemic stroke individuals. [ABSTRACT FROM AUTHOR]

Wetlands, with their many values and important functions, are precious resources. They have, however, undergone great changes during economic development and population growth. Relying on recent advances in remote sensing and geographic information system (GIS) techniques, this paper probes changes in wetland landscapes on Yinchuan Plain during 1978-2006. A series of remote sensing images was used to identify wetland landscape types. Landscape pattern indices, such as patch number, patch density, landscape shape, and Shannon's diversity, evenness, and contagion indices were calculated with GIS and landscape analysis software. Changes in wetland landscape patterns on Yinchuan Plain were analyzed. The analysis show that the total area of wetlands on Yinchuan Plain decreased from 391,540,239 m2 in 1978 to 267,979,957 m2 in 2006, a significant change over 28 years. The area of rivers and lakes has shrunk, and the area of paddies has increased consistently, with increasing wetland fragmentation and heterogeneity. The number of patches, patch density, and landscape shape index shows that wetland landscape patterns have undergone great changes. The landscape diversity, landscape evenness, and contagion indices indicate that wetland landscapes have become less heterogeneous. We discuss the causes of these changes and the sustainable development of wetland ecosystems. [ABSTRACT FROM AUTHOR]

We examined MR images of the spinal cord from the neutral neck to the fully flexed neck position in Chinese patients with Hirayama's disease (HD). MRI was performed on 25 HD patients and 31 healthy controls in the neutral and fully flexed neck positions. The mean anterior-posterior diameter (APD) and transverse diameter (TD) of the cervical cord at C6 level in the different positions was measured. Localized lower cervical cord atrophy and asymmetric cord flattening in a neutral neck position were highly suggestive of HD. The mean APDs were 5.6±0.7 mm in HD patients and 6.7±0.5 mm in controls (p <0.001). These changes seemed related to longer disease duration, i.e. >18 months. Although displacement forward of the lower cervical spinal cord without significant compression was observed in healthy young people, anterior shifting of posterior dural sac and lower cervical cord compression in flexion were distinctive and pathognomonic features of HD. The mean APDs were 4.3±0.9 mm in HD patients and 6.0±0.5 mm in controls in flexion (p <0.001). Our results may be helpful in diagnosing and assessing this disease. [ABSTRACT FROM AUTHOR]

Objective: The purpose of this study was to visualize and quantify dynamic changes in the cervix and to study factors influencing cervical length. Methods: Eighteen women with a gestational age between 23 and 40 weeks were examined by transvaginal ultrasound during a continuous observation period of 30 minutes. Results: All women delivered at >34 weeks of gestation, fourteen at term. The overall mean difference between the shortest and longest cervical length during the 30-minute recordings (cervical length variation) was 10.9 mm (range 1.6-26.7 mm). In the presence of fetal movements directed at the cervix, peristaltic movement of the bowel or contractions, cervical length variation was larger than in the absence of these conditions (mean 12.7 mm, range 5.2-26.7 mm and mean 6.1 mm, range 1.6-9.4 mm, respectively; p = 0.03). Conclusions: Dynamic changes in cervical length are present at early gestation and long before delivery and can be observed either spontaneously or associated with contractions, fetal movements or peristalsis. These conditions must be considered as pitfalls in cervical length measurement. In critical cases, such as early threatened preterm labor, increases in the frequency and duration of sonographic ultrasound measurements may be helpful to obtain a more reliable estimation of the cervical status. [ABSTRACT FROM AUTHOR]