Contribution of moderate overall coal-bearing basin uplift to tight sand gas accumulation:case study of the Xujiahe Formation in the Sichuan Basin and the Upper Paleozoic in the Ordos Basin,China

Tight sand gas is an important unconventional gas resource occurring widely in different petroleum basins. In coal-bearing formations of the Upper Triassic in the Sichuan Basin and the Carboniferous and Permian in the Ordos Basin, coal measure strata and tight sandstone constitute widely distributed source-reservoir assemblages and form the basic conditions for the formation of large tight sand gas fields. Similar to most tight gas basins in North America, the Sichuan, and Ordos Basins, all experienced overall moderate uplift and denudation in Meso- Cenozoic after earlier deep burial. Coal seam adsorption principles and actual coal sample simulation experiment results show that in the course of strata uplift, pressure drops and desorption occurs in coal measure strata, resulting in the discharge of substantial free gas. This ac- counts for 28 %-42 % of total gas expulsion from source rocks. At the same time, the free gases formerly stored in the pores of coal measure source rocks were also dis- charged at a large scale due to volumetric expansion re- sulting from strata uplift and pressure drop. Based on experimental data, the gas totally discharged in the uplift period of Upper Paleozoic in the Ordos Basin, and Upper Triassic Xujiahe Formation in the Sichuan Basin is calcu- lated as （3-6） × 10^5 m^3/km^2. Geological evidence for gasaccumulation in the uplift period is found in the gas reservoir analysis of the above two basins. Firstly, natural gas discharged in the uplift period has a lighter carbon isotope ratio and lower maturity than that formed in the burial period, belonging to that generated at the early stage of source rock maturity, and is absorbed and stored in coal measure strata. Secondly, physical simulation experiment results at high-temperature and high-salinity inclusions, and almost actual geologic conditions confirm that sub- stantial gas charging and accumulation occurred in the uplift period of the coal measure strata of the two basins. Diffusive flow is the main mode for gas accumulation in the uplift period, which probably reached 56 × 10^12 m^3 in the uplift period of the Xujiahe Formation of the Sichuan Basin, compensating for the diffusive loss of gas in the gas reservoirs, and has an important contribution to the formation of large gas fields. The above insight has promoted the gas resource extent and potential of the coal measure tight sand uplift area; therefore, we need to reassess the areas formerly believed unfavorable where the uplift scale is large, so as to get better resource potential and exploration prospects.

Regional brain structural abnormality in ischemic stroke patients:a voxel-based morphometry study

Our previous study used regional homogeneity analysis and found that activity in some brain areas of patients with ischemic stroke changed significantly. In the current study, we examined structural changes in these brain regions by taking structural magnetic resonance imaging scans of 11 ischemic stroke patients and 15 healthy participants, and analyzing the data using voxel-based morphometry. Compared with healthy participants, patients exhibited higher gray matter density in the left inferior occipital gyrus and right anterior white matter tract. In contrast, gray matter density in the right cerebellum, left precentral gyrus, right middle frontal gyrus, and left middle temporal gyrus was less in ischemic stroke patients. The changes of gray matter density in the middle frontal gyrus were negatively associated with the clin- ical rating scales of the Fugl-Meyer Motor Assessment （r = -0.609, P = 0.047） and the left middle temporal gyrus was negatively correlated with the clinical rating scales of the nervous functional deficiency scale （r = -0.737, P = 0.010）. Our findings call objectively identify the functional abnormality in some brain regions of ischemic stroke patients.

美伐他汀降低β-淀粉样蛋白神经毒性的体外研究

目的通过美伐他汀降低β-淀粉样蛋白(Aβ)神经毒性,从机制角度探讨他汀类药物辅助治疗阿尔茨海默病的可能性。方法在实验室培养神经细胞,并加入美伐他汀,观察美伐他汀是否具有活化AMPK的能力,并观察在给予美伐他汀的同时,Aβ导致的过磷酸化现象是否得到抑制。结果在样品中加入美伐他汀时,人神经上皮瘤细胞(SK-N-MC)神经细胞数降低情况改善。Western blot检测结果发现,美伐他汀作用24 h后,SK-N-MC神经细胞AMPK磷酸化。结论美伐他汀可能通过提高AMPK活性,对抗Aβ导致的神经毒性,并进一步抑制蛋白质过磷酸化,发挥保护神经的作用。

Changes of resting cerebral activities in subacute ischemic stroke patients

This study aimed to detect the difference in resting cerebral activities between ischemic stroke pa- tients and healthy participants, define the abnormal site, and provide new evidence for pathological mechanisms, clinical diagnosis, prognosis prediction and efficacy evaluation of ischemic stroke. At present, the majority of functional magnetic resonance imaging studies focus on the motor dysfunc- tion and the acute stage of ischemic stroke. This study recruited 15 right-handed ischemic stroke patients at subacute stage （15 days to 11.5 weeks） and 15 age-matched healthy participants. A rest- ing-state functional magnetic resonance imaging scan was performed on each subject to detect cerebral activity. Regional homogeneity analysis was used to investigate the difference in cerebral activities between ischemic stroke patients and healthy participants. The results showed that the ischemic stroke patients had lower regional homogeneity in anterior cingulate and left cerebrum and higher regional homogeneity in cerebellum, left precuneus and left frontal lobe, compared with healthy participants. The experimental findings demonstrate that the areas in which regional homogeneity was different between ischemic stroke patients and healthy participants are in the cerebellum, left precuneus, left triangle inferior frontal gyrus, left inferior temporal gyrus and anterior cingulate. These locations, related to the motor, sensory and emotion areas, are likely po- tential targets for the neural regeneration of subacute ischemic stroke patients.

Assessment of recoverable oil and gas resources by in-situ conversion of shale——Case study of extracting the Chang 7_(3) shale in the Ordos Basin

The purpose of this study is to investigate the entire evolution process of shales with various total organic contents(TOC)in order to build models for quantitative evaluation of oil and gas yields and establish methods for assessing recoverable oil and gas resources from in-situ conversion of organic matters in shale.Thermal simulation experiments under in-situ conversion conditions were conducted on Chang 7_(3) shales from the Ordos Basin in a semi-open system with large capacity.The results showed that TOC and R_(o) were the key factors affecting the in-situ transformation potential of shale.The remaining oil and gas yields increased linearly with TOC but inconsistently with R_(o).R_(o) ranged 0.75%—1.25%and 1.05%—2.3%,respectively,corresponding to the main oil generation stage and gas generation stage of shale in-situ transformation.Thus a model to evaluate the remaining oil/gas yield with TOC and R_(o) was obtained.The TOC of shale suitable for in-situ conversion should be greater than 6%,whereas its R_(o) should be less than 1.0%.Shales with 0.75%(R_(o))could obtain the best economic benefit.The results provided a theoretical basis and evaluation methodology for predicting the hydrocarbon resources from in-situ conversion of shale and for the identification of the optimum“sweet spots”.The assessment of the Chang 7_(3) shale in the Ordos Basin indicated that the recoverable oil and gas resources from in-situ conversion of organic matters in shale are substantial,with oil and gas resources reaching approximately 450×10^(8) t and 30×10^(12)m^(3),respectively,from an area of 4.27×10^(4) km^(2).

Effect of miR-467b on atherosclerosis of rats

Objective:To observe the effect of miR-467 b on the atherosclerosis(AS) of rats with apolipoprotein E(ApoE) gene knockout(ApoE^(-/-)).Methods:ApoE^(-/-) rats were fed with high fat and high cholesterol diet and were randomly divided into group A,group B and group C,with10 rats in each group.Group A:rats were injected with ApoE agonist through the caudal vein;Group B:rats were injected with ApoE antagonist through the caudal vein;Group C:as negative control group.Enzyme oxidation method was used to detect the blood lipid levels of rats.Western blotting method was used to detect the aortic lipoprotein lipase(LPL) cxprcssion IcvcLs of rats.HE staining and oil rod o staining were performed to observe the AS lesions and lipid accumulation state.Results:Compared with Group C,blood lipid level,aortic intima and aortic sinus lipid accumulation area ratio,aortic sinus lesion area and LPL expression level in Group A significantly reduced:while blood lipid level,aortic intima and aortic sinus lipid accumulation area ratio,aortic sinus lesion area,and LPL expression level in Group B significantly increased,with the statistical difference(P<0.05).Conclusions:miR-467 b can alleviate the AS lesions of ApoE^(-/-) rats,and its inhibiting effect on AS may be related to LPL expression.

Long-term follow-up of auditory performance and speech perception and effects of age on cochlear implantation in children with pre-lingual deafness

Background: The development of auditory and speech perception ability of children with hearing loss is affected by many factors after they undergo cochlear implantation (CI). Age at CI (CI age) appears to play an important role among these factors. This study aimed to evaluate the development of auditory and speech perception ability and explore the impact of CI age on children with pre-lingual deafness present before 3 years of age. Methods: Two hundred and seventy-eight children with pre-lingual deafness (176 boys and 102 girls) were included in this study, and the CI age ranged from 6 to 36 months (mean age, 19 months). Categorical auditory performance (CAP) was assessed to evaluate auditory ability, and the speech intelligibility rating was used to evaluate speech intelligibility. The evaluations were performed before CI and 1, 3, 6, 12, 18, 24, 36, 48, and 60 months after CI. Results: The auditory ability of the pre-lingually hearing-impaired children showed the fastest development within 6 months after CI (k = 0.524, t = 30.992, P < 0.05);then, the progress started to decelerate (k = 0.14, t = 3.704, P < 0.05) and entered a plateau at the 24th month (k = 0.03, t = 1.908, P < 0.05). Speech intelligibility showed the fastest improvement between the 12th and 24th months after CI (k = 0.138, t = 5.365, P < 0.05);then, the progress started to decelerate (k = 0.026, t = 1.465, P < 0.05) and entered a plateau at the 48th month (k = 0.012, t = 1.542, P < 0.05). The CI age had no statistical significant effect on the auditory and speech abilities starting at 2 years after CI (P > 0.05). The optimal cutoff age for CI was 15 months. Conclusions: Within 5 years after CI, the auditory and speech ability of young hearing-impaired children continuously improved, although speech development lagged behind that of hearing. An earlier CI age is recommended;the optimal cutoff age for CI is at 15 months.

Challenges and advances in genome mining of ribosomally synthesized and post-translationally modified peptides (RiPPs)

Ribosomally synthesized and post-translationally modified peptides(RiPPs)are a class of cyclic or linear peptidic natural products with remarkable structural and functional diversity.Recent advances in genomics and synthetic biology,are facilitating us to discover a large number of new ribosomal natural products,including lanthipeptides,lasso peptides,sactipeptides,thiopeptides,microviridins,cyanobactins,linear thiazole/oxazole-containing peptides and so on.In this review,we summarize bioinformatic strategies that have been developed to identify and prioritize biosynthetic gene clusters(BGCs)encoding RiPPs,and the genome mining-guided discovery of novel RiPPs.We also prospectively provide a vision of what genomics-guided discovery of RiPPs may look like in the future,especially the discovery of RiPPs from dominant but uncultivated microbes,which will be promoted by the combinational use of synthetic biology and metagenome mining strategies.

Scientific and technological progress in the microbial exploration of the hadal zone

The hadal zone is the deepest point in the ocean with a depth that exceeds 6000 m. Exploration of the biological communities in hadal zone began in the 1950s (the first wave of hadal exploration) and substantial advances have been made since the turn of the twenty-first century (the second wave of hadal exploration), resulting in a focus on the hadal sphere as a research hotspot because of its unique physical and chemical conditions. A variety of prokaryotes are found in the hadal zone. The mechanisms used by these prokaryotes to manage the high hydrostatic pressures and acquire energy from the environment are of substantial interest. Moreover, the symbioses between microbes and hadal animals have barely been studied. In addition, equipment has been developed that can now mimic hadal environments in the laboratory and allow cultivation of microbes under simulated in situ pressure. This review provides a brief summary of recent progress in the mechanisms by which microbes adapt to high hydrostatic pressures, manage limited energy resources and coexist with animals in the hadal zone, as well as technical developments in the exploration of hadal microbial life.

A highly sensitive,dual-signal assay based on rhodamine B covered silver nanoparticles for carbamate pesticides

A highly sensitive sensor for determination of carbamate pesticides based rhodamine B（RB） modified silver nanoparticle（RB-AgNPs） was developed.Compared with the classical method,it combined colorimetric with fluorescence for detecting carbamate pesticides in complex solutions.Carbamate pesticides can inhibit the activity of acetylcholinesterase（AChE）,thus preventing the generation of thiocholine.On the other hand,thioncholine can transform the yellow RB-AgNPs solutions gray color and unquenches the fluorescence of RB simultaneously.Once the activity of AChE was inhibited by the pesticide,the color of the RB-AgNPs solution remains yellow and the fluorescence of RB molecules remains quenched.Under optimized experimental conditions,carbaryl was detected in a concentration range from 0.1 ng/L to 8.0ng/L with a detection limit of 0.023 ng/L（it was detected by fluorescence spectra）.This simple method is suitable for determination of carbamate pesticides in complex samples,such as tomato,apple and river water.

Characteristics of Mandarin Open-set Word Recognition Development among Chinese Children with Cochlear Implants

Background： Cochlear implants （Cls） can improve speech recognition for children with severe congenital hearing loss, and open-set word recognition is an important efficacy measure. This study examined Mandarin open-set word recognition development among Chinese children with Cls and normal hearing （NH）. Methods： This study included 457 children with CIs and 131 children with NH, who completed the Mandarin lexical neighborhood test. The results for children at 1-8 years alter receiving their Cls were compared to those from the children with NH using linear regression analysis and analysis of variance. Results： Recognition of disyllabic easy words, disyllabic hard words, monosyllabic easy words, and monosyllabic hard words increased with time after CI implantation. Scores for cases with implantation before 3 years old were significantly better than those for implantation after 3 years old. There were significant differences in open-set word recognition between the CI and NH groups. For implantation before 2 years, there was no significant difference in recognition at the ages of 6-7 years, compared to 3-year-old children with NH, or at the age of 10 years, compared to 6-year-old children with NH. For implantation before 3 years, there was no significant difference in recognition at the ages of 8 9 years, compared to 3-year-old children with NH, or at the age of 10 years, compared to 6-year-old children with NH. For implantation after 3 years, there was a significant difference in recognition at the age of 13 years, compared to 3-year-old children with NH. Conclusions： Mandarin open-set word recognition increased with time after CI implantation, and the age at implantation had a significant effect on long-term speech recognition. Chinese children with Cls had delayed but similar development of recognition, compared to norrnal children. Early CI implantation can shorten the gap between children with Cls and normal children.