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Medium- and low-permeability reservoirs are important in oilfield development. However, due to their characteristics of poor pore permeability and high heterogeneity, the development of suitable technologies has been very difficult. In this study, an in situ emulsifying/ultra-low-interfacial-tension cyclic flooding system has been developed for low- and medium-permeability reservoirs. Based on the hydrophilic-lipophilic balance (HLB) value method, an emulsifying surfactant ASD with Span 80 (sorbitan monooleate) as the main component has been identified as highly promising through screening. At mass fractions of surfactant ASD between 0.2% and 0.6%, the extent of water separation from the emulsion is greatly reduced, and the W/O emulsion can effectively improve the mobility ratio and increase the sweep volume. The surfactant SA synthesized in our laboratory reduces the interfacial tension of crude oil to 10−4 mN m−1. Laboratory core flooding experiments have shown that multiple rounds of alternating injection with aqueous solutions of surfactants ASD and SA can improve oil recovery by 22.25%. Upon injecting a low-viscosity aqueous solution of surfactant ASD, it emulsifies crude oil in situ under reservoir conditions, solving the problems of difficult polymer injection and insufficient spread. Our work provides useful insights for the development of low- and medium-permeability reservoirs. [ABSTRACT FROM AUTHOR]

Objective To analyse the trend of COPD patients' inpatient costs and its influencing factors in the context of the reform of DRG, and to provide reference for the reasonable control of COPD inpatient costs. Methods ITSA were used to analyse the trend of COPD patients' inpatient costs in a tertiary general hospital from 2018 to 2022, and univariate analysis, stepwise regression analysis and RFM were used to analyse the factors influencing the inpatient costs and the degree of significance of COPD patients' inpatient costs after the official operation of the DRG. Results The results of ITSA showed that the overall inpatient costs of COPD patients decreased significantly and by an average of 1.82% per month during the DRG operation stage; the integrated medical service fee, drug fee, and consumable fee all showed a decreasing trend during the DRG operation stage, by an average of 1.06%, 1.67%, and 4. 98% per month, respectively, but the proportion of the integrated medical service fee increased compared with that before the DRG reform by 7.18%; The stepwise regression results showed that the number of hospital days (β = 0.584), admission status (β = 0.294), whether surgery (β = 0.125), whether traditional Chinese medicine (β = 0.084), and drug share ratio (β = 0.099) had a statistically significant impact on COPD hospitalisation costs (P < 0.05); and the results of the Random Forest model analysis showed that hospital days, admission status, drug share ratio were the most important factors influencing COPD hospitalisation costs, status, and medication ratio were the key factors affecting COPD hospitalisation costs. Conclusion DRG can effectively promote medical institutions to strengthen cost management and reduce the economic burden of disease. Hospitals should further reduce the cost of COPD and the economic burden of patients by reducing the number of inpatient days, strengthening the management of critically ill patients, and promoting the rational use of drugs. [ABSTRACT FROM AUTHOR]

To investigate the association between mtDNA genetic information and the risk of SF, individuals were conducted in the drinking water endemic fluorosis area in northern China, sequenced the whole genome of mtDNA, identified the SNPs and SNVs, analyzed the haplogroups, and diagnosed SF, and then, the effect of mtDNA genetic information on the risk of SF was evaluated. We find that, D5 haplogroup and its specific SNPs reduced the risk, while the D4 haplogroup and its specific SNPs increased the risk of SF. The number of SNVs in coding regions of mitochondrial respiratory chain (MRC) is different between the controls and cases. This suggests that D5 haplogroup may play a protective role in the risk of SF, while the opposite is observed for the D4 haplogroup, this may relate to their specific SNPs. And SNVs that encode the MRC complex may also be associated with the risk of SF. [ABSTRACT FROM AUTHOR]

Limited studies have demonstrated that inorganic arsenic exposure is positively associated with serum vitamin D levels, although the correlation between urinary arsenic species and serum vitamin D has not been investigated in areas of water-borne arsenicosis. A cross-sectional study of 762 participants was conducted in Wenshui Country, Shanxi Province, a water-borne arsenicosis area. The results showed a positive relationship between urinary arsenic species (inorganic arsenic (iAs), methylarsonic acid (MMAV), dimethylarsinic acid (DMAV) and serum 25(OH)D. Log-binomial regression analysis indicated a 0.4% increase in the risk of vitamin D excess for every 1-unit increment in the Box–Cox transformed urinary DMAV after adjustment for covariates. After stratifying populations by inorganic arsenic methylation metabolic capacity, serum 25(OH)D levels in the populations with iAs% above the median and primary methylation index (PMI) below the median increased by 0.064 ng/mL (95% CI: 0.032 to 0.096) for every one-unit increase in the Box–Cox transformed total arsenic (tAs) levels. Serum 25(OH)D levels increased by 0.592 ng/mL (95% CI: 0.041 to 1.143) for every one-unit rise in the Box–Cox transformed iAs levels in people with skin hyperkeratosis. Overall, our findings support a positive relationship between urinary arsenic species and serum 25(OH)D. It was recommended that those residing in regions with water-borne arsenicosis should take moderate vitamin D supplements to avoid vitamin D poisoning. [ABSTRACT FROM AUTHOR]

Aims: Sphingosine kinase 1 (Sphk1) and the signaling molecule sphingosine‐1‐phosphate (S1P) are known to be key regulators of a variety of important biological processes, such as neovascularization. Nitric oxide (NO) is also known to play a role in vasoactive properties, whether Sphk1/S1P signaling is able to alter angiogenesis in the context of cerebral ischemia‐reperfusion injury (IRI), and whether such activity is linked with NO production, however, remains uncertain. Methods: We used immunofluorescence to detect the expression of Sphk1 and NOS in cerebral epithelial cells (EC) after IR or oxygen‐glucose deprivation (OGDR). Western blotting was used to detect the Sphk1 and NOS protein levels in brain tissues or HBMECs. Adenovirus transfection was used to inhibit Sphk1 and NOS. An NO kit was used to detect NO contents in brain tissues and epithelial cells. Tube formation assays were conducted to measure angiogenesis. Results: We determined that EC used in a model of cerebral IRI expressed Sphk1, and that inhibiting this expression led to decreased expression of two isoforms of NO synthase (eNOS and iNOS), as well as to decrease neovascularization density and NO production following injury. In HBMECs, knocking down Sphk1 markedly reduced NO production owing to reduced eNOS activity, and inhibiting eNOS directly similarly decreased NO production in a manner which could be reversed via exogenously treating cells with S1P. We further found that knocking down Sphk1 reduced HBMEC eNOS expression, in addition to decreasing the adhesion, migration, and tube formation abilities of these cells under OGDR conditions. Conclusions: Based on these results, we therefore postulate that Sphk1/S1P signaling is able to mediate angiogenesis following cerebral IRI via the regulation of eNOS activity and NO production. As such, targeting these pathways may potentially represent a novel means of improving patient prognosis in those suffering from cerebral IRI. [ABSTRACT FROM AUTHOR]

An ultrasensitive enzyme-free electrochemical sandwich DNA biosensor is described for the detection of ssDNA oligonucleotides. A DNA sequence derived from the genom of Helicobacter pylori was selected as a model target DNA. The DNA assay was realized through catching target DNA on capture DNA immobilized gold electrode; then labeling the target DNA with reporter DNA (rpDNA) and initiator DNA (iDNA) co-modified gold nanoparticles (AuNPs). The high density of iDNAs serves as one of the amplification strategies. The iDNA triggers hybridization chain reaction (HCR) between two hairpins. This leads to the formation of a long dsDNA concatamer strand and represents one amplification strategy. The electrochemical probe [Ru(NH3)5L]2+, where L stands for 3-(2-phenanthren-9-ylvinyl)pyridine, intercalated into dsDNA chain. Multiple probe molecules intercalate into one dsDNA chain, serving as one amplification strategy. The electrode was subjected to differential pulse voltammetry for signal acquisition, and the oxidation peak current at −0.28 V was recorded. On each AuNP, 240 iDNA and 25 rpDNA molecules were immobilized. Successful execution of HCR at the DNA-modified AuNPs was confirmed by gel electrophoresis and hydrodynamic diameter measurements. Introduction of HCR significantly enhances the DNA detection signal intensity. The assay has two linear ranges of different slopes, one from 0.01 fM to 0.5 fM; and one from 1 fM to 100 fM. The detection limit is as low as 0.68 aM. Single mismatch DNA can be differentiated from the fully complementary DNA. Conceivably, this highly sensitive and selective assay provides a general method for detection of various kinds of DNA. [ABSTRACT FROM AUTHOR]

Objective: To study the preparation of microcapsules of volatile oil from Ledum palustre and its quality evaluation., Methods: The microcapsules were prepared by complex coacervation with encapsulation efficiency as evaluation index, and the preparation was optimized by orthogonal experimental design., Results: The optimum condition of microcapsules prepared was that 5% gelatin and gum arabic was material, with core material ratio of 1: 2; pH 4.0 and glutaraldehyde in an amount of 1.0 mL. The average encapsulation efficiency of microcapsules of volatile oil from Ledum palustre was 79.62%. Microcapsules was distributed evenly without adhesion through microscopic observation and more than 73% of the microcapsule size distribution between 10 - 14 microm. Microcapsules was spherical and the surface folded by using electron microscope scanning. The test solution and reference solution appeared same spot in the same location compared with the negative control solution., Conclusion: The preparation process is simple, stable and feasible.