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  • Author: Hui Zhang x
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Abstract

Objective

Problem-solving should be a fundamental component of nursing education because it is a core ability for professional nurses. For more effective learning, nursing students must understand the relationship between self-directed learning readiness and problem-solving ability. The aim of this study was to investigate the relationships among self-directed learning readiness, problem-solving ability, and academic self-efficacy among undergraduate nursing students.

Methods

From November to December 2016, research was conducted among 500 nursing undergraduate students in Tianjin, China, using a self-directed learning readiness scale, an academic self-efficacy scale, a questionnaire related to problem-solving, and self-designed demographics. The response rate was 85.8%.

Results

For Chinese nursing students, self-directed learning readiness and academic self-efficacy reached a medium-to-high level, while problem-solving abilities were at a low level. There were significant positive correlations among the students’ self-directed learning readiness, academic self-efficacy, and problem-solving ability. Furthermore, academic self-efficacy demonstrated a mediating effect on the relationship between the students’ self-directed learning readiness and problem-solving ability.

Conclusions

To enhance students’ problem-solving ability, nursing educators should pay more attention to the positive impact of self-directed learning readiness and self-efficacy in nursing students’ education.

Abstract

Background. Penumbra characteristics play a significant role in dose delivery accuracy for radiation therapy. For treatment planning, penumbra width and radiation field offset strongly influence target dose conformity and organ at risk sparing.

Methods. In this study, we present an analytical and numerical approach for evaluation of the rounded leaf end effect on penumbra characteristics. Based on the rule of half-value layer, algorithms for leaf position calculation and radiation field offset correction were developed, which were advantageous particularly in dealing with large radius leaf end. Computer simulation was performed based on the Monte Carlo codes of EGSnrc/BEAMnrc, with groups of leaf end radii and source sizes. Data processing technique of curve fitting was employed for deriving penumbra width and radiation field offset.

Results. Results showed that penumbra width increased with source size. Penumbra width curves for large radius leaf end were U-shaped. This observation was probably related to the fact that radiation beams penetrated through the proximal and distal leaf sides. In contrast, source size had negligible impact on radiation field offset. Radiation field offsets were found to be constant both for analytical method and numerical simulation. However, the overall resulting values of radiation field offset obtained by analytical method were slightly smaller compared with Monte Carlo simulation.

Conclusions. The method we proposed could provide insight into the investigation of rounded leaf end effects on penumbra characteristics. Penumbra width and radiation field offset calibration should be carefully performed to commission multileaf collimator for intensity modulated radiotherapy.

Abstract

Aiming at the problem of recommendation systems, this paper proposes a fuzzy clustering algorithm based on particle swarm optimization. This algorithm can find the best solution, using the capacity of global search in PSO algorithm with a powerful global and defining a proportion factor, which can adjust the position and reduce the search space automatically. Then using mutation particles it replaces the particles flying out the solution space by new particles during the searching process. In order to check the performance of the proposed algorithm, by testing with typical ZDT1, ZDT2, ZDT3 functions, the experimental results show that the improved method not only has a better ability to converge to the global point, but can also efficiently avoid premature convergence.

Abstract

Background: Study of antiangiogenic drugs is one of the cutting-edge fields in new antitumor drug development. However, system studies on Vaccaria segetalis extract as an inhibitor of tumor-induced neovascularization have not been published yet. In the current study, we performed a preliminary investigation of the antiangiogenic effect of Vaccaria segetalis extract on angiogenesis.

Objective: We studied the inhibitory effect of Vaccaria segetalis extract on neovascularization.

Methods: The effects of Vaccaria segetalis extract on in vitro proliferation, migration, and tube formation of human mammary endothelial cells (HMECs) were determined by 3 - (4,5) - dimethylthiahiazo (-z-y1) - 3, 5 -diphenytetrazoliumromide (MTT) assay and Matrigel plug assay. The antiangiogenic effect of Vaccaria segetalis extract was observed on the chick chorioallantoic-membrane (CAM) angiogenesis model. The CD31 expression on HMECs was detected by immunohistochemical staining. The therapeutic effect of Vaccaria segetalis extract on the metastasis of Lewis lung cancer was also observed in the mouse model.

Results: The proliferation and migration of human mammary epithelial cells (HMECs) were inhibited significantly by Vaccaria segetalis extract in a dose-dependent manner (IC50 = 50 μg/mL). Angiogenesis was also inhibited in the Matrigel-plug mouse model and the chick chorioallantoic-membrane model. The Vaccaria segetalis extract treatment reduced the expression of CD31 in HMECs and inhibited the growth and metastasis of Lewis lung carcinoma cells in the mouse model.

Conclusion: The Vaccaria segetalis extract, which can obviously inhibit angiogenesis, could be developed as a promising new antiangiogenic drug.

Abstract

The distribution and extent of heavy metal accumulation in the fluvial sediment of the Beijiang River are described. The potential toxicity of this pollution was quantified using a consensus based sediment quality guidelines (SQGs) method and the Hakanson potential ecological risk index. The concentrations of Hg, As, Cu, Zn, Pb, Ni and Cr were high enough to damage the sediment biota on a frequent basis. The potential ecological risk was much higher in the downstream, urbanized reaches of the river than in the upstream reaches which are still rural, but all sections of the river posed at least a moderate level of ecological risk. Estimates of the economic loss associated with these pollutions were appreciable, and were mainly due to Hg and Cu. The Beijiang River basin is heavily polluted, posing environmental risks for the downstream reaches of the Pearl River, and economic loss to the whole watershed.

Abstract

Objective To realize the characteristics of “zheng” differentiation-treatment for hand, foot and mouth disease (HFMD), a new methodology of syndrome differentiation for different stages of HFMD has been explored.

Methods Total of 2 325 cases with HFMD were recorded by distributing them into exterior syndrome stage, interior syndrome stage, severe syndrome stage and recovered syndrome stage, respectively, and the main symptoms and subsidiary symptoms of different stages of HFMD have been observed. The major and minor pathogenesis of HFMD in different stages were obtained, and compared with the “2010 Guideline for the Diagnosis and Treatment of HFMD”.

Results It was found that the major pathogenesis of exterior stage was defined as “the invation of the wenevil to the defender of the body with the collaterals got involved”, and the minor as “qi deficiency”; in interior stage, “the fury of Gan-Yang” was the main pathogenesis, and “qi in chaos and qi deficiency” was the minor; in severe syndrome stage, “the damage of heart, liver and lung” was the main pathogenesis, and “qi in chaos” was the minor; and the pathogenesis of recovered stage was “qi-yin deficiency”. Compared with the “2010 Guideline for the Diagnosis and Treatment of HFMD”, it showed that “the obstruction of the fei-pi qi by the mixture of shi-re evil” and “the mixture of shi-re” in vivo was quite difficult to be explained in completely different context in the general situation; in the severe stage, the TCM clinical characteristics of syndrome differentiation might lose; in the early acute severe cases, the phenomenon that xin-yang and fei-qi almost ran out was difficult to be observed, then, the line between the severe and the acute severe became vague.

Conclusions The theory of syndrome differentiation by stages of HFMD was reasonable in the actual situation of clinical description on HFMD which was expected to be further tested and widely applied in the “zheng” differentiation-treatment of HFMD in the future.

Abstract

Objective

To explore the effects of self-directed learning readiness and learning attitude on problem-solving ability among Chinese undergraduate nursing students.

Methods

A convenience sampling of 460 undergraduate nursing students was surveyed in Tianjin, China. Students who participated in the study completed a questionnaire that included social demographic questionnaire, Self-directed Learning Readiness Scale, Attitude to Learning Scale, and Social Problem-Solving Inventory. Pearson’s correlation analysis was performed to test the correlations among problem-solving ability, self-directed learning readiness, and learning attitude. Hierarchical linear regression analyses were performed to explore the mediating role of learning attitude.

Results

The results showed that learning attitude (r=0.338, P<0.01) and self-directed learning readiness (r=0.493, P<0.01) were positively correlated with problem-solving ability. Learning attitude played a partial intermediary role between self-directed learning readiness and problem-solving ability (F=74.227, P<0.01).

Conclusions

It is concluded that nursing educators should pay attention on students’ individual differences and take proper actions to inspire students’ self-directed learning readiness and learning attitude.

Abstract

Introduction: A model of fatty liver in postpartum sheep was established to measure blood paraoxonase 1 (PON1) and other biochemical indicators, which were used to predict fatty liver in sheep.

Material and Methods: Sheep were assigned into two experimental groups: a fatty liver group (T, n = 10) and a healthy control group (C, n = 5). PON1 enzyme activity towards paraoxon as a substrate was quantified spectrophotometrically. The results were analysed by t-test and pearson correlation coefficient. Disease was predicted by binary logistic analysis, and diagnostic thresholds were determined by receiver operatingcharacteristic (ROC) analysis.

Results: The activity of serum PON1 in group T was significantly decreased (P < 0.05) when compared with C group, and liver lipid content and the levels of serum BHBA, NEFA, and TG were significantly increased (P < 0.05). Thresholds were lower than 74.0 U/mL for PON1, higher than 0.97 mmol/L for β-hydroxybutyrate, higher than 1.29 mmol/L for non-esterified fatty acids, higher than 0.24 mmol/L for triglycerides, and lower than 71.35 g/L for total protein.

Conclusion: This study verified that PON1, BHBA, NEFA, TG, and TP could be used to predict the risk of fatty liver in sheep.

Abstract

Introduction: The predictive value of selected parameters in the risk of ketosis and fatty liver in dairy cows was determined.

Material and Methods: In total, 21 control and 17 ketotic Holstein Friesian cows with a β-hydroxybutyrate (BHBA) concentration of 1.20 mmol/L as a cut-off point were selected. The risk prediction thresholds for ketosis were determined by receiver operating characteristic (ROC) curve analysis.

Results: In the ketosis group, paraoxonase-1 (PON-1) activity and concentration of PON-1 and glucose (GLU) were decreased, and aminotransferase (AST) activity as well as BHBA and non-esterified fatty acid (NEFA) contents were increased. The plasma activity and concentration of PON-1 were significantly positively correlated with the level of plasma GLU. The plasma activity and concentration of PON-1 were significantly negatively correlated with the levels of AST and BHBA. According to ROC curve analysis, warning indexes of ketosis were: plasma PON-1 concentration of 46.79 nmol/L, GLU concentration of 3.04 mmol/L, AST concentration of 100 U/L, and NEFA concentration of 0.82 mmol/L.

Conclusion: This study showed that the levels of PON-1, GLU, AST, and NEFA could be used as indicators to predict the risk of ketosis in dairy cows.

Abstract

Introduction

The purpose of this study was to investigate the protective effect of hydrogen-rich saline (HRS) against liver ischaemia-reperfusion combined resection injury.

Material and Methods

Eighteen miniature pigs were randomly divided into three groups: a sham operated group (sham group, laparoscopic liver ischaemia-reperfusion combined resection injury group (IRI group), and a hydrogen-rich saline intervention group (IRI + HRS group). Samples of hepatic tissue and serum were collected at the time of reperfusion and then 3 h, 1 d, and 3 d post reperfusion. Liver function, oxidative stress, autophagy-related mRNA genes, and protein expression were evaluated. Changes in cell and tissue ultrastructure were examined by transmission electron microscopy.

Results

Compared with the sham group, the level of autophagy of hepatocytes increased in the IRI and IRI + HRS groups, corresponding to high oxidative stress and severe liver function injury. Liver function, antioxidant content, autophagy levels, and liver injury were improved after intervention with HRS in the IRI + HRS group compared with the IRI group.

Conclusion

Intervention with hydrogen-rich saline could exert a protective effect against liver ischaemia-reperfusion combined resection injury through the reduction of oxidative stress and hepatocyte autophagy.