321 research outputs found
Off-hour admission and mortality risk for 28 specific diseases: A systematic review and meta-analysis of 251 cohorts
Background: A considerable amount of studies have examined the relationship between off-hours (weekends and nights) admission and mortality risk for various diseases, but the results remain equivocal. Methods and Results: Through a search of EMBASE, PUBMED, Web of Science, and Cochrane Database of Systematic Reviews, we identified cohort studies that evaluated the association between off-hour admission and mortality risk for disease. In a random effects meta-analysis of 140 identified articles (251 cohorts), off-hour admission was strongly associated with increased mortality for aortic aneurysm (odds ratio [OR], 1.52; 95% confidence interval, 1.30-1.77), breast cancer (1.50, 1.21-1.86), leukemia (1.45, 1.17-1.79), respiratory neoplasm (1.32, 1.20-1.26), pancreatic cancer (1.32, 1.12-1.56), malignant neoplasm of genitourinary organs (1.27, 1.08-1.49), colorectal cancer (1.26, 1.07-1.49), pulmonary embolism (1.20, 1.13-1.28), arrhythmia and cardiac arrest (1.19, 1.09-1.29), and lymphoma (1.19, 1.06-1.34). Weaker (OR<1.19) but statistically significant association was noted for renal failure, traumatic brain injury, heart failure, intracerebral hemorrhage, subarachnoid hemorrhage, stroke, gastrointestinal bleeding, myocardial infarction, chronic obstructive pulmonary disease, and bloodstream infections. No association was found for hip fracture, pneumonia, intestinal obstruction, aspiration pneumonia, peptic ulcer, trauma, diverticulitis, and neonatal mortality. Overall, Off-hour admission was associated with increased mortality for 28 diseases combined (OR, 1.11; 95% confidence interval, 1.10-1.13).Conclusions: Off-hour admission is associated with increased mortality risk, and the associations varied substantially for different diseases. Specialists, nurses, as well as hospital administrators and health policy makers can take these findings into consideration to improve the quality and continuity of medical services
Experimental Study on Plugging Behavior of Degradable Fibers and Particulates within Acid-etched Fracture
As proven from field practices in North America and Northwest China, temporary plugging and diverting acid fracturing is an indispensable technology to enhance stimulation effect and hydrocarbon production of complex carbonate reservoirs. It\u27s well-known that the key to the success of this technology lies in creating a temporary plugging within the previously created fractures. Consequently, many scholars have conducted laboratory experiments to investigate the plugging behavior of fibers and particulates. However, the current devices nearly have certain limitations in simulating temporary plugging experiments. Aiming at this problem, this paper introduced the fracture temporary plugging evaluation system with large fracture size, and high-pressure resistance, which can meet the requirement of temporary plugging experiment. In addition, 3D printing technology was used to reproduce the roughness of acid-etched fracture surface, improving the experimental accuracy. Based on the device, a series of experiments were performed to study the effect of carrier fluids type, the injection rate, the fracture width, and the fracture morphology on plugging behavior of fibers and particulates. Experimental results show that the plugging effect of HPG fracturing fluid is better than that of slick water. Moreover, the effect of temporary plugging deteriorates with the decrease of injection rate, which can be attributed to the fact that high injection rate increases the probability of bridging and plugging. When it comes to the fracture width, only fibers have favorable plugging effect under the condition of 2 mm fracture width. However, a single type of temporary plugging agent (only fibers or particulates) cannot achieve effective plugging under the condition of 4 mm fracture width. The combination of fibers and particulates can obtain favorable plugging effect. When the fracture width increases to 6 mm, it\u27s difficult to obtain favorable plugging effect if the diameter of particulates is less than 50% of fracture width. Hence, it is recommended to add big particulates whose diameters are at least 50% of the fracture width to improve the plugging effect. Moreover, the fracture surface morphology affects the formation time of temporary plugging, but does not affect whether temporary plugging is formed or not. This study deepens the understanding the plugging behavior of fibers and particulates within acid-etched fracture and provides fundamental for field treatment design
Enhancement of the Wettability and Lubrication of Shale Rock via Nanoemulsions
Nanoemulsions have been widely used as additives for drilling fluids in recent years. With the development of nanotechnology, multifunctional nanomaterials have been added to nanoemulsions. The improvement of wettability of the surfaces, alteration of oil-wet on shale rock surfaces, and environmentally friendly conditions are considered as the future development directions of nanoemulsions. In this work, a novel nanoemulsion was prepared by using hydrocarbon-based polyoxyethylene ether, oil (hydrocarbon), distilled water, and formation crude oil as the main raw materials. The shale rocks before and after immersion with as-prepared nanoemulsion were characterized by contact angle measurement, atomic force microscope (AFM), and Fourier transform infrared spectroscopy (FTIR). It is clearly observed that the nanoemulsion greatly improved the wettability of the sandstone and rock surface by forming a layer of active agent film on the surface of the rock. The as-prepared nanoemulsion had good ability to curb the anticollapse and lubricate and protect the oil and gas layer
Mammalian splicing divergence is shaped by drift, buffering in trans, and a scaling law
Alternative splicing is ubiquitous, but the mechanisms underlying its pattern of evolutionary divergence across mammalian tissues are still underexplored. Here, we investigated the cis-regulatory divergences and their relationship with tissue-dependent trans-regulation in multiple tissues of an F1 hybrid between two mouse species. Large splicing changes between tissues are highly conserved and likely reflect functional tissue-dependent regulation. In particular, micro-exons frequently exhibit this pattern with high inclusion levels in the brain. Cis-divergence of splicing appears to be largely non-adaptive. Although divergence is in general associated with higher densities of sequence variants in regulatory regions, events with high usage of the dominant isoform apparently tolerate more mutations, explaining why their exon sequences are highly conserved but their intronic splicing site flanking regions are not. Moreover, we demonstrate that non-adaptive mutations are often masked in tissues where accurate splicing likely is more important, and experimentally attribute such buffering effect to trans-regulatory splicing efficiency
Relationship between metabolic syndrome and its components and cardiovascular disease in middle-aged and elderly Chinese population:a national cross-sectional survey
OBJECTIVES: To assess the relationship between metabolic syndrome (MetS) and its components and cardiovascular disease (CVD) according to different criteria of MetS, as well as whether the estimated association between MetS and CVD was affected by different definitions of MetS among the Chinese population. DESIGN: Population-based, cross-sectional study. SETTING: Data were from a large-scale national stroke screening survey, China National Stroke Screening and Prevention Project. PARTICIPANTS: A nationally representative sample of 109 551 Chinese adults aged ≥40 years in 2014-2015 were included. PRIMARY OUTCOME MEASURES: CVD conditions (stroke, coronary heart disease (CHD) and atrial fibrillation (AF)) diagnosed by clinicians were self-reported. RESULTS: ORs after adjusting for CHD, stroke, AF and CVD in those with MetS using the National Cholesterol Education Program Adult Treatment Panel III (NCEP ATP III) criterion were 1.56 (95% CI 1.48 to 1.63), 1.23 (95% CI 1.17 to 1.30), 1.14 (95% CI 1.08 to 1.21) and 1.40 (95% CI 1.35 to 1.45); 1.51 (95% CI 1.44 to 1.58), 1.20 (95% CI 1.14 to 1.26), 1.09 (95% CI 1.04 to 1.15) and 1.34 (95% CI 1.29 to 1.38) with the American Heart Association/National Heart, Lung, and Blood Institute criterion; and 1.41 (95% CI 1.35 to 1.48), 1.24 (95% CI 1.19 to 1.30), 1.12 (95% CI 1.06 to 1.18) and 1.31 (95% CI 1.27 to 1.35) with the International Diabetes Federation criterion, respectively. Elevated blood pressures were all highly related to the prevalence of stroke and AF, and reduced high-density lipoprotein-cholesterol was associated with a higher OR for CHD than other individual components of MetS. CONCLUSIONS: MetS is significantly associated with CVD, and the prevalence of CVD was more evident when MetS was defined according to the NCEP ATP III criterion. Developing effective public health strategies for the prevention, detection and treatment of MetS should be an urgent priority to reduce the burden of CVD in China
Association between exposure to noise and risk of hypertension: A meta-analysis of observational epidemiological studies
Background and Objective: An increasing amount of original studies suggested that exposure to noise could be associated with the risk of hypertension, but the results remain inconsistent and inconclusive. We aimed to synthesize available epidemiological evidence about the relationship between various types of noise and hypertension, and to explore the potential dose-response relationship between them in an up-to-date meta-analysis. Methods: We conducted a literature search of PubMed and Embase from these databases’ inception through December 2016 to identify observational epidemiological studies examining the association between noise and risk of hypertension. A Random-effects model was used to combine the results of included studies. Dose-response meta-analysis was conducted to examine the potential dose-response relationship. Results: Thirty-two studies (five cohort studies, one case-control study, and twenty-six cross-section Studies) involving 264,678 participants were eligible for inclusion. Pooled result showed that living or working in environment with noise exposure was significantly associated with increase risk of hypertension (OR 1.62; 95% CI: 1.40 to 1.88). We found no evidence of a curve linear association between noise and risk of hypertension. Dose-response analysis suggested that, for an increment of per 10 dB(A) of noise, the combined odds ratio of hypertension was 1.06 (95% CI: 1.04 to 1.08). Conclusions: Integrated epidemiological evidence supports the hypothesis that exposure to noise may be a risk factor of hypertension, and there is a positive dose-response association between them
Pressure Pulsation Signal Analysis for Centrifugal Compressor Blade Crack Determination
Blade is a key piece of component for centrifugal compressor. But blade crack could usually occur as blade suffers from the effect of centrifugal forces, gas pressure, friction force, and so on. It could lead to blade failure and centrifugal compressor closing down. Therefore, it is important for blade crack early warning. It is difficult to determine blade crack as the information is weak. In this research, a pressure pulsation (PP) sensor installed in vicinity to the crack area is used to determine blade crack according to blade vibration transfer process analysis. As it cannot show the blade crack information clearly, signal analysis and empirical mode decomposition (EMD) are investigated for feature extraction and early warning. Firstly, signal filter is carried on PP signal around blade passing frequency (BPF) based on working process analysis. Then, envelope analysis is carried on to filter the BPF. In the end, EMD is carried on to determine the characteristic frequency (CF) for blade crack. Dynamic strain sensor is installed on the blade to determine the crack CF. Simulation and experimental investigation are carried on to verify the effectiveness of this method. The results show that this method can be helpful for blade crack classification for centrifugal compressors
Development of a New Multifunctional Cationic Surfactant System with Corrosion Inhibiting Ability
Is carrot consumption associated with a decreased risk of lung cancer? A meta-analysis of observational studies
Findings of epidemiological studies regarding the association between carrot consumption and lung cancer risk remain inconsistent. The present study aimed to summarise the current epidemiological evidence concerning carrot intake and lung cancer risk with a meta-analysis. We conducted a meta-analysis of case–control and prospective cohort studies, and searched PubMed and Embase databases from their inception to April 2018 without restriction by language. We also reviewed reference lists from included articles. Prospective cohort or case–control studies reporting OR or relative risk with the corresponding 95 % CI of the risk lung cancer for the highest compared with the lowest category of carrot intake. A total of eighteen eligible studies (seventeen case–control studies and one prospective cohort study) were included, involving 202 969 individuals and 5517 patients with lung cancer. The pooled OR of eighteen studies for lung cancer was 0·58 (95%CI 0·45, 0·74) by comparing the highest category with the lowest category of carrot consumption. Based on subgroup analyses for the types of lung cancer, we pooled that squamous cell carcinoma (OR 0·52, 95 % CI 0·19, 1·45), small-cell carcinoma (OR 0·43, 95 % CI 0·12, 1·59), adenocarcinoma (OR 0·34, 95 % CI 0·15, 0·79), large-cell carcinoma (OR 0·40, 95 % CI 0·10, 1·57), squamous and small-cell carcinoma (OR 0·85, 95 % CI 0·45, 1·62), adenocarcinoma and large-cell carcinoma (OR 0·20, 95 % CI 0·02, 1·70) and mixed types (OR 0·61, 95 % CI 0·46, 0·81). Exclusion of any single study did not materially alter the pooled OR. Integrated epidemiological evidence from observational studies supported the hypothesis that carrot consumption may decrease the risk of lung cancer, especially for adenocarcinoma
A tri-layer structure consisting of novel heptacobaltate clusters and single cobalt centers bridged by 5-tert-butyl isophthalate
A 2D tri-layer compound {[Co(8)(tbip)(6)(H(2)O)(9)(OH)(4)]center dot 12(H(2)O)}(n) (1) (H(2)tbip = 5-tert-butyl isophthalic acid) consisting of novel heptacobaltate clusters and single cobalt centers bridged by tbip(2-) ligands has been hydrothermally synthesized. The complex represents a rare example of a homometallic coordination polymer built up from both heptanuclear metal clusters and single metal centers simultaneously. The magnetic investigation reveals that the complex exhibits the overall predominance of antiferromagnetic coupling between magnetic centers.National Natural Science Foundation of China[20771024, 21051003]; Natural Science Foundation of Fujian Province[2008I0013
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