Experimental investigation on pyrolysis products and pore structure characteristics of organic-rich shale heated by supercritical carbon dioxide

The efficient pyrolysis and conversion of organic matter in organic-rich shale,as well as the effective recovery of pyrolysis shale oil and gas,play a vital role in alleviating energy pressure.The state of carbon dioxide(CO_(2))in the pyrolysis environment of shale reservoirs is the supercritical state.Its unique supercritical fluid properties not only effectively heat organic matter,displace pyrolysis products and change shale pore structure,but also achieve carbon storage to a certain extent.Shale samples were made into powder and three sizes of cores,and nitrogen(N_(2))and supercritical carbon dioxide(ScCO_(2))pyrolysis experiments were performed at different final pyrolysis temperatures.The properties and mineral characteristics of the pyrolysis products were studied based on gas chromatography analysis,Xray diffraction tests,and mass spectrometry analysis.Besides,the pore structure characteristics at different regions of cores before and after pyrolysis were analyzed using N_(2) adsorption tests to clarify the impact of fracturing degree on the pyrolysis effect.The results indicate that the optimal pyrolysis temperature of Longkou shale is about 430℃.Compared with N_(2),the oil yield of ScCO_(2) pyrolysis is higher.The pyrolysis oil obtained by ScCO_(2) extraction has more intermediate fractions and higher relative molecular weight.The ScCO_(2) can effectively improve the pore diameter of shale and its effect is better than that of N_(2).The micropores are produced in shale after pyrolysis,and the macropores only are generated in ScCO_(2) pyrolysis environments with temperatures greater than 430℃.The pore structure has different development characteristics at different pyrolysis temperatures,which are mainly affected by the pressure holding of volatile matter and products blocking.Compared to the surface of the core,the pore development effect inside the core is better.With the decrease in core size,the pore diameter,specific surface area,and pore volume of cores all increase after pyrolysis.

Enhanced recovery of tight reservoirs after fracturing by natural gas huff-n-puff: Underlying mechanisms and influential factors

Tight oil resources are abundant in the world.It is very important to strengthen the research on the development theory and technology of tight oil reservoirs for ensuring national energy security.Natural gas huff-n-puff can effectively improve the oil recovery of tight oil reservoirs.However,the pore-scale oil production characteristics and the mechanisms of natural gas huff-n-puff in matrix-fracture cores are poorly understood.The influence degree of important factors on oil recovery is not clear and the interactions between factors are rarely considered.In this paper,the oil production characteristics and mechanisms of natural gas huff-n-puff in tight cores with different fracture lengths were quantitatively analyzed by combining nuclear magnetic resonance(NMR)with numerical simulation technology.The influencing factors and their interactions were evaluated by the response surface method(RSM).The results show that tight cores mainly consist of medium pores(0.1–1μm)and small pores(0.01–0.1μm).The fracture mainly increases the proportion of macro-pores(1–10μm)and medium pores.In the natural gas huff-n-puff process,crude oil from macro-pores(1–10μm)and medium pores is mainly developed,and the contribution percentage of crude oil in medium pores to oil recovery is the largest,up to 98.28%.The position of gas–oil contact(GOC)moves deeper as the number of huff-n-puff cycles increases.The contents of CH_(4) and CO_(2) in the oil phase remain at a high level within the GOC,while between the GOC and the component sweep front,the contents of CH_(4) and CO_(2) in the oil phase decrease with the increase in dimensionless distance.The gas component sweep volume is increasing with the increase in fracture length.Moreover,the injected natural gas mainly extracts C_(3)–C_(10) components from crude oil.The reduction law of crude oil viscosity is consistent with the migration laws of CH_(4) components along the path.Compared with soaking time and gas diffusion coefficient,the injection pressure is the most significant factor underlying the recovery of natural gas huff-n-puff in tight cores.Besides the influence of single-factor,the interaction effects of gas injection pressure and diffusion also should be considered to determine the huff-n-puff parameters in the field implementation of natural gas huff-n-puff in tight reservoirs after fracturing.

Inhalation of hydrogen gas reduces liver injury during major hepatotectomy in swine

AIM： To study the effect of H2 gas on liver injury in massive hepatectomy using the Intermittent Pringle maneuver in swine. METHODS： Male Bama pigs （n = 14） treated with ketamine hydrochloride and Sumianxin Ⅱ as induc- tion drugs followed by inhalation anesthesia with 2% isoflurane, underwent 70% hepatotectomy with loss of bleeding less than 50 mL, and with hepatic pedicle occlusion for 20 min, were divided into two groups： Hydrogen-group （n = 7）, the pigs with inhalation of 2% hydrogen by the tracheal intubation during major hepa- totectomy; Contrast-group （n= 7）, underwent 70% hepatotectomy without inhalation of hydrogen. Hemo- dynamic changes and plasma concentrations of alanine aminotransferase （ALT）, aspartate aminotransferase （AST）, hyaluronic acid （HA）, tumor necrosis factor-α （TNF-α）, interleukin-6 （IL-6）, and malondialdehyde （MDA） in liver tissue were measured at pre-operation, post-hepatotectomy （PH） 1 h and 3 h. The apoptosis and proliferating cell nuclear antigen （PCNA） expres- sion in liver remnant were evaluated at PH 3 h. Then we compared the two groups by these marks to evalu- ate the effect of the hydrogen in the liver injury during major hepatotectomy with the Pringle Maneuver in the swine. RESULTS： There were no significant differences in body weight, blood loss and removal liver weight be- tween the two groups. There was no significant differ- ence in changes of portal vein pressure between two groups at pre-operation, PH 30 min, but in hydrogen gas treated-group it slightly decrease and lower than its in Contrast-group at PH 3 h, although there were no significant difference （P = 0.655）. ALT and AST in Hydrogen-group was significantly lower comparing to Contrast-group （P = 0.036, P = 0.011, vs P = 0.032, P = 0.013） at PH 1 h and 3 h, although the two groups all increased. The MDA level increased between the two group at PH i h and 3 h. In the hydrogen gas treated- group, the MDA level was not significantly significant at pre-operation and significantly low at PH 1 h and 3 h comparing to Contrast-group （P = 0.0005, P = 0.0004）. In Hydrogen-group, the HA level was also significantly low to Contrast-group （P = 0.0005, P = 0.0005） al- though the two groups all increased at PH 1 h and 3 h. The expression of cluster of differentiation molecule 31 molecules Hydrogen-group was low to Contrast-group. However, PCNA index （%） was not statistically signifi- cant between the two groups （P = 0.802）. Micropho- tometric evaluation of apoptotic index （AI） in terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling-stained tissue after hepatotectomy for 3h, the AI% level in the hydrogen was significantly low to Contrast-group （P = 0.012）. There were no significant difference between Hydrogen-group and Contrast- group at pre-operation （P = 0.653, P = 0.423）, but after massive hepatotectomy, the TNF-α and IL-6 levels increase, and its in Hydrogen-group was significantly low compared with Contrast-group （P = 0.022, P = 0.013, vs P = 0.016, P= 0.012）, respectively. Hydro- gen-gas inhalation reduce levels of these markers and relieved morphological liver injury and apoptosis.CONCLUSION： H2 gas attenuates markedly ischemia and portal hyperperfusion injury in pigs with massive hepatotectomy, possibly by the reduction of inflamma- tion and oxidative stress, maybe a potential agent for treatment in clinic.

Relationship between self-directed learning readiness, learning attitude, and self-efficacy of nursing undergraduates

Objective: The purposes of this study were to analyze the influencing factors of self-directed learning readiness(SDLR) of nursing undergraduates and explore the impacts of learning attitude and self-efficacy on nursing undergraduates.Methods: A total of 500 nursing undergraduates were investigated in Tianjin, with the Chinese version of SDLR scale, learning attitude questionnaire of nursing college students, academic self-efficacy scale, and the general information questionnaire.Result: The score of SDLR was 149.99±15.73. Multiple stepwise regressions indicated that academic self-efficacy, learning attitude, attitudes to major of nursing, and level of learning difficulties were major influential factors and explained 48.1% of the variance in SDLR of nursing interns.Conclusions: The score of SDLR of nursing undergraduates is not promising. It is imperative to correct students' learning attitude, improve self-efficacy, and adopt appropriate teaching model to improve SDLR.

Effectiveness of the flipped classroom on the development of self-directed learning in nursing education:a meta-analysis

Objectives: To examine the best practice evidence of the effectiveness of the flipped classroom（FC） as a burgeoning teaching model on the development of self-directed learning in nursing education.Data sources: The relevant randomized controlled trial（RCT） and non-RCT comparative studies were searched from multiple electronic databases including PubMed, Embase, Web of Science, Cumulative Index to Nursing and Allied Health Literature（CINAHL）, Cochrane Central Register of Controlled Trials（CENTRAL）, Wanfang Data, China National Knowledge Infrastructure（CNKI）, and Chinese Science and Technology Periodical Database（VIP） from inception to June 2017.Review methods: The data were independently assessed and extracted for eligibility by two reviewers. The quality of included studies was assessed by another two reviewers using a standardized form and evaluated by using the Cochrane Collaboration’s risk of bias tool. The self-directed learning scores（continuous outcomes） were analyzed by using the 95% confidence intervals（Cls） with the standard deviation average（SMD） or weighted mean difference（WMD）. The heterogeneity was assessed using Cochran’s I;statistic.Results: A total of 12 studies, which encompassed 1440 nursing students（intervention group = 685, control group = 755）, were eligible for inclusion in this review. Of 12 included studies, the quality level of one included study was A and of the others was B. The pooled effect size showed that compared with traditional teaching models, the FC could improve nursing students’ selfdirected learning skill, as measured by the Self-Directed Learning Readiness Scale（SDLRS）, Self-Directed Learning Readiness Scale for Nursing Education（SDLRSNE）, Self-Regulated Learning Scale（SRL）, Autonomous Learning Competencies scale（ALC）, and Competencies of Autonomous Learning of Nursing Students（CALNS）. Overall scores and subgroup analyses with the SRL were all in favor of the FC.Conclusions: The result of this meta-analysis indicated that FCs could improve the effect of self-directed learning in nursing education.Future studies with more RCTs using the same measurement tools are needed to draw more authoritative conclusions.

Reliability and validity of the Chinese version of the new fear of hypoglycemia scale: FH-15

Objective:This study aimed to evaluate the reliability and validity of the Chinese version of the Fear of Hypoglycemia scale with 15 items(FH-15).Methods:After obtaining the original author's authorization,the English version of the FH-15 scale was translated,back translated,and culturally debugged to obtain the Chinese version of FH-15.A convenient sampling method was used to extract patients with type 2 diabetes from four tertiary hospitals in Tianjin.A total of 408 patients with type 2 diabetes were investigated in the hospital to test the reliability and validity of Chinese version FH-15 scale.Results:The content validity index of the scale was 0.92,and the content validity index of each item was 0.8-1.0.The exploratory factor analysis extracted three common factors(fear,avoidance,and interference),which contained 15 items,and the cumulative variance contribution rate was 71.245%.The confirmatory factor analysis results showed that the model fit was better at 1.981 x2/df,GFI=0.901,CGI=0.962,TLI=0.952,and RMSEA=0.070.The cut-off value for the total hypoglycemia fear scale was 30.5.The Cronbach'sαcoefficient of the three dimensions of the scale was 0.918,the Cronbach'sαcoefficient of each dimension is 0.876-0.916,the test-retest reliability was 0.903,and the test-retest reliability of each factor was 0.733-0.930.Conclusion:The Chinese version of the FH-15 scale can be considered reliable and valid.The item expression is concise,clear,and easy to understand.It is suitable for clinical practice as an initial screening tool to identify and evaluate the severity of fear of hypoglycemia in patients with type 2 diabetes.

Efficacy and safety of the heated gel mattress for prevention of hypothermia in preterm infants during intra-hospital transport： a meta-analysis

Objective： To evaluate the efficacy and safety of the heated gel mattress for prevention of heat loss on preterm infants with hypothermia during the transport systematically and objectively. Methods： Systematic searches on PubMed, EM- BASE, Cochrane Library, Web of Science, CBM, CNKI, Wanfang and VIP were performed for randomized controlled trials （RCTs） or quasi-RCTs which explored the effects of heated gel mattress on prevention of hypothermia in premature infants relative to conventional alternatives. Studies were screened according to inclusion and exclusion criteria, extracted data and assessed quality. Then, meta-analysis and trial sequential analysis were performed by RevMan 5.3 and TSA vO.9 software developed at the Copenhagen Clinical Trials Center in Denmark, independently. Results： This systematic review included 10 studies which comprised 7 RCTs and 3 quasi-RCTs, encompassing 773 patients. The results of meta-analysis showed that in heated gel mattress group admission temperature on neonatal intensive care unit （SMD, 0.63; 95% CI, 0.40 to 0.87; P = 0.00）, incidence of hypothermia （RR, 0.73; 95% CI, 0.57 to 0.93; P = 0.01） and hyperthermia （RR, 1.82; 95% CI, 1.31 to 2.541 P = 0.00） compared with the control group had significantly statistical difference; however, there was no significant difference in admission temperature on exothermic mattresses or TransWarmer mattress group, mortality, sepsis, retinopathy of prematurity, intraventricular hemorrhage Ⅲ/Ⅳ between two groups, trial sequential analysis confirmed that the pooled results of admission temperature on neonatal intensive care unit and hyperthermia were stable and reliable; but the combination of low-temperature incidence and mortality indicators suggested that the sample size was insufficient. Conclusion： Heated gel mattress is a safe and effective re- warming intervention that can improve body temperature of hypothermic preterm infants during transport, reduce the incidence of hypothermia and does not increase the incidence of morbidity and complications. However, it is recommended that clinical monitoring of body temperature should be performed dynamically to decrease the potential risk of high fever. In addition, due to the limitation of quantity and quality of included studies, its cost-effectiveness and far-reaching influence on long-term follow-up outcomes need further evaluation through clinical multicenter, large sample, and high-quality research.

Regeneration of islet β-cells in tree shrews and rats

Backgroud: Current understanding of injury and regeneration of islet β-cells in diabetes is mainly based on rodent studies. The tree shrew is now generally accepted as being among the closest living relatives of primates, and has been widely used in animal experimentation. However, there are few reports on islet cell composition and regeneration of β-cells in tree shrews.Methods: In this study, we examined the changes in islet cell composition and regeneration of β-cells after streptozotocin(STZ) treatment in tree shrews compared with Sprague-Dawley rats. Injury and regeneration of islet β-cells were observed using hematoxylin and eosin(HE) staining and immunohistochemical staining for insulin, glucagon, somatostatin and PDX-1.Results: Our data showed that in rats islet injury was most obvious on day 3 after injection, and islet morphologies were significantly restored by day 21. Regeneration of islet β-cells was very pronounced in rats, and mainly involved regeneration of centro-acinar cells and transformation of extra-islet ductal cells. In tree shrews, the regeneration of islet β-cells was not as significant. On days 3 and 7, only scattered regenerated cells were observed in the remaining islets. Further, no regeneration of centro-acinar cells was observed.Conclusion: The results suggest that the repair mechanism of islet β-cells in tree shrews is similar to that of humans.

Effects of parental involvement in infant care in neonatal intensive care units:a meta-analysis

Objective： This meta-analysis aimed to examine the effects of parental involvement in infant care in neonatal intensive care units （NlCUs）. Methods： PubMed, Embase, Cochrane Library, Web of Science, China National Knowledge Infrastructure （CNKI）, Wanfang database, and VIP database were searched till November 2017. Randomized controlled trials （RCTs） and controlled clinical trials （CCTs） examining the effect of parental involvement in the NICU were considered for inclusion. Resulls： We included 10 studies （three RCTs, seven CCTs） with a total of 1,851 participants. The meta-analysis demonstrated that there were no statistically significant differences on nosocomial infection between two groups （risk ratio [RR] = 0.90, 95% CI 0.63-1.30, P = 0.58）. Compared with no parental involvement groups, parental involvement groups showed more weight gain （mean difference [MD] = 1.47, 95% CI 0.65-2.29, P 〈 0.05）, higher breast-feeding rate （RR = 1.38, 95% CI 1.25-1.53, P 〈 0.05）, lower readmission rate （RR = 0.35, 95% CI 0.15-0.80, P 〈 0.05）, and higher satisfaction rate （RR = 1.09, 95% CI 1.02-1.16, P 〈 0.05）.Conclusions： Parentaiinvolvement in the NICU interventions could not increase the rate of nosocomial infection of neonates, but could improve their weight gain, breast-feeding and parental satisfaction and decrease their readmission. However, since the conclusion of this meta-analysis was drawn based on the limited number of high-quality RCTs, more hioh-quality studies should be conducted in the future to confirm its positive intervention effects.

Effects of core stability exercise on rehabilitation in stroke patients with hemiplegia： a meta-analysis

Objective： To evaluate the effects of core stability exercise （CST） on rehabilitation in stroke patients with hemiplegia. Methods： Randomly controlled trials about the effects of CST on rehabilitation in stroke patients with hemiplegia were searched in the database, including PubMed, Embase, Web of Science, Cochrane Library, CNKI, Wanfang, CBM and VIP. Search terms include “core stability training / core stability exercise / core stabilization training / core stabilization exercise/ core strength training / core strength exercise” and “stroke / brain ischemia / cerebral infarction / cerebral hemorrhage / intracranial thrombosis / brain hemorrhage / cerebrovascular disorder /cerebrovascular accident, cerebrovascular disease / hemiplegia / hemiparesis/ stroke rehabilitation”. Study screening, data extraction and quality assessment were conducted by two researchers independently. Data was analyzed using RevMan 5.3 software. Results： Totally 11 studies and 704 patients were included with 352 patients in experiment group and 352 in control group. Results of meta-analysis showed that combination of CST and conventional rehabilitation had better effects on trunk control [MD = 10.44, 95% CI （8.83-12.04）, P 〈 0.001], banlace [MD = 5.6, 95% CI （4.81-6.39）, P 〈 0.001], activities of daily living [MD = 12.06, 95% CI （7.65-16.46）, P 〈 0.001], ambulation functional [MD = 0.72, 95% CI （0.32-1.12）, P 〈 0.001] and walking speed [MD = 3.39, 95% CI （2.03-4.76）, P 〈 0.001] than conventional rehabilitation, but there is no clear difference on walking stride [MD = 2.52, 95% CI （-0.25-5.29）, P = 0.07] between two groups. Conclusion： CST together with conventional rehabilitation can better improve trunk control, banlace, activities of daily living, ambulation functional and walking speed in stroke patients compared with conventional rehabilitation, but can not make the walking stride better significantly. However, since the conclusion of this meta-analysis was drawn based on middle quality RCTs, future high quality researchs should be conducted to confirm its positive intervention effects.

Correlation between time management disposition and ability confidence of chinese nursing students： a meta-analysis

Objective： To evaluate the correlation between time management disposition and ability confidence of Nursing Students in China through the Pearson correlation coefficient. Methods： Electronic databases including the Cochrane library, PubMed, EMBASE, the Web of Science, CBM, Wanfang, VIP and CNKI were searched from inception to October 2017 to collect literature on the correlation between time manage-ment disposition and ability confidence of Chinese nursing students. The studies were examined according to the inclusion and exclusion criteria. After extracting data and evaluating the quality of the included studies. Meta-analysis was carried out using Stata 12.0 software. Results： A total of 7 articles with 1632 nursing students were included, and the quality of the literature was at medium level. Meta-analysis shown the total score of time management disposition of Chinese nursing students and its three dimensions were related to ability confidence. The summary correlation coefficient between time management disposition and ability confidence was 0.52 （0.43 to 0.59） ; There is a weak correlation between time value and ability confidence （r, 0.33; 95% CI, 0.25 to 0.39）; There was a moderate level of correlation between time control and ability confidence （r, 0.49; 95% CI, 0.43 to 0.54）; There was a moderate level of correlation between time efficacy and ability confidence （0.47, 0.41, 0.53）.And the relevance of nursing time management disposition and behavioral confidence varies with the nursing student＇s area, nursing student＇s diploma, measurement tools and sample size. Conclusion： The time man- agement disposition of Chinese nursing students is moderately related to ability confidence. When there are different in nursing students in the area, nursing diploma, measurement tools and sample size, the relevance is very different. The time management disposition of Chinese nursing students and their ability confidence are mutually reinforcing, and the time management disposition and their ability confidence should be further strengthened in the future.

Selection, Training and Supervision of Breast Cancer Peer Educators： a literature review

Breast cancer is one of the most serious malignant and it seriously affects the quality of life and mental health of the patients. Research shows that peer education can improve breast cancer patients＇ quality of life, treatment compliance, and self-management behavior. Its selection, training and supervision are particularly important due to the core role of peer educators in peer support. This article reviewed the research status and progress in the selection, training and supervision of breast cancer peer educators abroad in order to provide references for further study.

Effects of interventions with mindfulness-breathing-stretching components on physiological and mental function of lung cancer patients: a mata-analysis

Objective:To systematically evaluate the effects of interventions with mindfulness-breathing-stretching components on lung neoplasms.Methods:Multiple electronic databases were used to search for research on the effects of interventions with mindfulness-breathing-stretching components on lung neoplasms.The randomized controlled trails and self-control trails were included.Electronic databases include:Cochrane library,Pub Med,EMBASE,Web of Science,China Biology Medicine disc(CBM),VIP,WANFANG and CNKI.Studies were selected according to certain inclusion and exclusion criteria,and data were analyzed by Rev Man 5.3.Results:10 randomized controlled trials and 5 self-control trails were included.The results of meta-analysis were as follows:There was statistically significant difference between two groups in self-perceived burden,quality of life,sleep quality of patients and caregivers,medical coping modes and catecholamine;there was no statistically significant difference between two groups in psychological pressure,mental well-being,fatigue of patients and caregivers,cortisol,endorphins,immunological indexes and complement regulatory proteins.Conclusion:Compared with conventional treatment and nursing,interventions with mindfulness-breathing-stretching components can decrease improve the state of mind,quality of life,quality of sleep,medical coping style and some hormone indexes.However,because of the heterogeneity of indicators and inadequate included studies,larger sample size and high-quality studies are needed.

A Fast Vision-inertial Odometer Based on Line Midpoint Descriptor

Visual simultaneous localization and mapping(VSLAM) are essential technologies to realize the autonomous movement of vehicles. Visual-inertial odometry(VIO) is often used as the front-end of VSLAM because of its rich information, lightweight, and robustness. This article proposes the FPL-VIO, an optimization-based fast vision-inertial odometer with points and lines. Traditional VIO mostly uses points as landmarks;meanwhile, most of the geometrical structure information is ignored. Therefore, the accuracy will be jeopardized under motion blur and texture-less area. Some researchers improve accuracy by adding lines as landmarks in the system.However, almost all of them use line segment detector(LSD) and line band descriptor(LBD) in line processing, which is very time-consuming. This article first proposes a fast line feature description and matching method based on the midpoint and compares the three line detection algorithms of LSD, fast line detector(FLD), and edge drawing lines(EDLines). Then, the measurement model of the line is introduced in detail. Finally, FPL-VIO is proposed by adding the above method to monocular visual-inertial state estimator(VINSMono), an optimization-based fast vision-inertial odometer with lines described by midpoint and points. Compared with VIO using points and lines(PL-VIO), the line processing efficiency of FPL-VIO is increased by 3-4 times while ensuring the same accuracy.