30 research outputs found
Laboratory Study on Improving Recovery of Ultra-Heavy Oil Using High-Temperature-Resistant Foam
After multiple rounds of steam huff-and-puff processes, an ultra-heavy oil reservoir is prone to excessive steam injection pressure, large heat loss, small sweep range of steam, and steam channeling, thus severely affecting the effective utilization of the oil reservoir. To solve these problems, one-dimensional and three-dimensional (3D) physical simulation tools were used to study the plugging performance of high-temperature composite foams by adding tanning extract and alkali lignin under the influence of some factors such as the reservoir temperature, salinity of formation water, and injection methods. The ultra-heavy oil used in the experiment comes from Shengli Oilfield. Under the condition of surface degassing, the viscosity of ultra-heavy oil could reach 145169 mPa.s at 60 °C. The experimental results show that the foam can produce a synergistic effect with both gel systems, indicating that the gel increases the stability of the foam. The foam can transfer more gel into the high-permeability formation, which can efficiently control the foam. The 3D physical simulation experiments indicated that both the systems enhance the recovery of heavy oil reservoir and reduce its moisture content significantly using steam injection. The method involving tannin extract foam and steam injection increased the recovery by 20% compared to the foam involving only steam injection. The method involving alkali lignin foam and steam injection increased the recovery by 11%
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Chinese pediatrician beliefs about counseling and medications for parents who smoke: a survey in southern China
Background: Pediatricians play an important role in promoting smoking cessation among the parents of young children as more behavioral counseling and cessation treatment are made available in the Chinese healthcare system. However, beliefs about the effectiveness of these interventions can influence pediatriciansâ recommendations to their patients. This study examined pediatriciansâ beliefs regarding effectiveness of counseling and medications for smoking cessation. Methods: A cross-sectional survey of pediatricians was conducted in thirteen conveniently selected southern Chinese hospitals, during September to December 2013. A self-administered questionnaire was used for data collection. We used chi square tests and multinomial logistic regression analysis to identify factors associated with beliefs regarding effectiveness of counseling and medications for smoking cessation. Results: Beliefs of the respondents (504/550; 92% response rate) were divided regarding the effectiveness of counseling and medications for smoking cessation. Sixty percent believed that physician counseling is effective for smoking cessation; 53% believed pharmacological products (or medications) are effective. Factors that were associated with positive beliefs towards the effectiveness of counseling included: believing about the professional responsibility to discuss smoking cessation, being confident in discussing smoking cessation or SHS exposure reduction with patientsâ parents, believing that health professionals should routinely ask about their patients smoking habits, believing that health professionals should routinely advise their smoking patients to quit smoking, possessing adequate knowledge in quitting smoking, and being able to assess smokers different stages of readiness to quit. Most of the above factors were also associated with the belief that medication is effective for smoking cessation. Conclusions: A substantial proportion of Chinese pediatricians believed that cessation counseling and medications are not effective, which is not supported by current evidence in the field. Several factors including individual, practice level and health system level characteristics were associated with their belief. Training efforts are needed to influence pediatriciansâ beliefs regarding the effectiveness of cessation counseling and medications
Changes of Active Substances in <i>Ganoderma lucidum</i> during Different Growth Periods and Analysis of Their Molecular Mechanism
Ganoderma lucidum, renowned as an essential edible and medicinal mushroom in China, remains shrouded in limited understanding concerning the intrinsic mechanisms governing the accumulation of active components and potential protein expression across its diverse developmental stages. Accordingly, this study employed a meticulous integration of metabolomics and proteomics techniques to scrutinize the dynamic alterations in metabolite accumulation and protein expression in G. lucidum throughout its growth phases. The metabolomics analysis unveiled elevated levels of triterpenoids, steroids, and polyphenolic compounds during the budding stage (BS) of mushroom growth, with prominent compounds including Diplazium and Ganoderenic acids E, H, and I, alongside key steroids such as cholesterol and 4,4-dimethyl-5alpha-cholesta-8,14,24-trien-3beta-ol. Additionally, nutrients such as polysaccharides, flavonoids, and purines exhibited heightened presence during the maturation stage (FS) of ascospores. Proteomic scrutiny demonstrated the modulation of triterpenoid synthesis by the CYP450, HMGR, HMGS, and ERG protein families, all exhibiting a decline as G. lucidum progressed, except for the ARE family, which displayed an upward trajectory. Therefore, BS is recommended as the best harvesting period for G. lucidum. This investigation contributes novel insights into the holistic exploitation of G. lucidum
Influence of power generation period on the oily sludge bio-electrical system
The single-chamber bio-electrical systems can degrade oily sludge in sediments while generating electricity from the microbial fuel cells (MFCs) and their characteristics in energy and environmental effects have attracted wide international attention in recent years. To explore the influence of the power generation period on the oily sludge bio-electrical system, an oily sludge bio-electrical system was constructed. The output voltage, polarization curve, power density curve, crude oil removal rate and microflora were detected during different power generation periods, respectively. The results of this study showed that under the stable power generation period, the power generation and oily sludge degradation performance of MFC are higher than the voltage rise period and voltage attenuation period. Besides, the oily sludge bio-electrical system during the stable period contained more electricity-producing bacteria than the other two periods. The voltage in the stable period of oily sludge bio-electrical system is about 280 mV, the electromotive force is 493.1 mV and the power density is 134.93 mW·mâ3. It lays a foundation for the improvement of degradation of crude oil and power generation performance in oily sludge bio-electrical system.
HIGHLIGHTS
We explore the influence of power generation periods on the performance of oily sludge SMFC.;
Oily sludge SMFC can effectively degrade crude oil and convert it into electricity.;
Power generation, oil degradation performance and bacterial community morphology, diversity, bacterial composition and relative abundance of oily sludge SMFC during different power generation periods were systematically compared.
Chinese Pediatrician Attitudes and Practices Regarding Child Exposure to Secondhand Smoke (SHS) and Clinical Efforts against SHS Exposure
Background: Secondhand Smoke (SHS) exposure is a leading cause of childhood illness and premature death. Pediatricians play an important role in helping parents to quit smoking and reducing childrenâs SHS exposure. This study examined Chinese pediatriciansâ attitudes and practices regarding childrenâs exposure to SHS and clinical efforts against SHS exposure. Methods: A cross-sectional survey of pediatricians was conducted in thirteen conveniently selected hospitals in southern China, during September to December 2013. Five hundred and four pediatricians completed self-administered questionnaires with a response rate of 92%. Ï2 tests were used to compare categorical variables differences between smokers and non-smokers and other categorical variables. Results: Pediatricians thought that the key barriers to encouraging parents to quit smoking were: lack of professional training (94%), lack of time (84%), resistance to discussions about smoking (77%). 94% of the pediatricians agreed that smoking in enclosed public places should be prohibited and more than 70% agreed that smoking should not be allowed in any indoor places and in cars. Most of the pediatricians thought that their current knowledge on helping people to quit smoking and SHS exposure reduction counseling was insufficient. Conclusions: Many Chinese pediatricians did not have adequate knowledge about smoking and SHS, and many lacked confidence about giving cessation or SHS exposure reduction counseling to smoking parents. Lack of professional training and time were the most important barriers to help parents quit smoking among the Chinese pediatricians. Intensified efforts are called for to provide the necessary professional training and increase pediatriciansâ participation in the training
Pre-Existing HCV Variants Resistant to DAAs and Their Sensitivity to PegIFN/RBV in Chinese HCV Genotype 1b Patients
<div><p>Background</p><p>The efficacy of direct-acting antiviral agents (DAAs) could be attenuated by the presence of resistance-associated variants (RAVs). The aim of this study was to investigate the natural prevalence of RAVs among Chinese HCV genotype 1b patients and analyze the efficacy of pegylated interferon (PegIFN)/ribavirin (RBV) therapy in patients with and without RAVs at baseline.</p><p>Methods</p><p>Direct sequencing of the HCV NS3, NS5A and NS5B regions was performed in baseline serum samples of 117 DAAs-naĂŻve subjects infected with HCV genotype 1b. The efficacy of PegIFN/RBV therapy in patients with and without RAVs at baseline was analyzed by comparing the response rates between patients with RAVs and patients with wild type virus.</p><p>Results</p><p>The incidence of RAVs was 8.00% (8/100) in the NS3 region (T54S, n = 1, 1.00%; R117H, n = 5, 5.00%; S122T, n = 1, 1.00%; S174F, n = 1, 1.00%), 29.91% (32/107) in the NS5A region (L28M, n = 12, 11.21%; R30Q, n = 10, 9.35%; L31M, n = 1, 0.93%; P58S, n = 4, 3.74%; Y93H, n = 8, 7.48%) and 98.15% (106/108) in the NS5B region (L159F, n = 1, 0.93%; C316N, n = 103, 95.37%; A421V, n = 6, 5.56%). The response rates to PegIFN/RBV treatment did not differ between patients with or without RAVs in the NS5A region.</p><p>Conclusions</p><p>Pre-existing RAVs, including key RAVs, were detected in Chinese DAAs-naĂŻve patients infected with HCV genotype 1b. IFN-based therapy could be a good option for patients with RAVs, especially key RAVs, at baseline.</p></div
Morpho-Histology, Endogenous Hormone Dynamics, and Transcriptome Profiling in Dacrydium Pectinatum during Male Cone Development
Dacrydium pectinatum de Laubenfels is a perennial gymnosperm species dominant in tropical montane rain forests. Due to severe damages by excessive deforestation, typhoons, and other external forces, the population of the species has been significantly reduced. Furthermore, its natural regeneration is poor. To better understand the male cone development in D. pectinatum, we examined the morphological and anatomical changes, analyzed the endogenous hormone dynamics, and profiled gene expression. The morpho-histological observations suggest that the development of D. pectinatum male cone can be largely divided into four stages: microspore primordium formation (April to May), microspore sac and pollen mother cell formation (July to November), pollen mother cell division (January), and pollen grain formation (February). The levels of gibberellins (GA), auxin (IAA), abscisic Acid (ABA), cytokinin (CTK), and jasmonic acid (JA) fluctuated during the process of male cone development. The first transcriptome database for a Dacrydium species was generated, revealing >70,000 unigene sequences. Differential expression analyses revealed several floral and hormone biosynthesis and signal transduction genes that could be critical for male cone development. Our study provides new insights on the cone development in D. pectinatum and the foundation for male cone induction with hormones and studies of factors contributing to the species’ low rate of seed germination
Prevalence of NS5A Inhibitor Resistance Mutations in Genotype 1b Patients.
<p>Prevalence of NS5A Inhibitor Resistance Mutations in Genotype 1b Patients.</p
Amplification and Sequencing Primers for HCV NS3, NS5A and NS5B in Genotype 1b Patients.
<p>Amplification and Sequencing Primers for HCV NS3, NS5A and NS5B in Genotype 1b Patients.</p