辽东半岛大石桥周家铁钴矿控矿构造特征及其区域地质意义

构造作用往往能为成矿流体提供重要的导矿通道,以此对矿床的形成及富集起着关键的控制作用,对其进行深入的研究能为地质找矿提供理论依据。本文对中国东北地区辽宁大石桥市周家铁钴矿开展了详细的地质工作,包括剖面测制、构造解析和岩相学观察等。野外观察及室内岩相学研究指示Fe-Co矿矿体主要赋存于里尔峪组二段变粒岩和浅粒岩中。此外,还有少量铁矿见于古元古代辽吉花岗岩中。构造解析显示周家Fe-Co矿围岩变形包括早期紧闭褶皱、逆冲断层以及断层相关褶皱和晚期布丁构造、倾竖褶皱。通过野外岩脉穿切关系并综合前人年代学资料,可以将周家铁钴矿形成过程分为三个阶段,早期发生原始地层变形,即为S_(0)发生变形形成S_(1)和F_(1)阶段;中期逆冲断层及紧闭褶皱等产于强烈造山期的构造要素为周家铁钴矿在古元古代的富集成矿提供了重要的构造条件;周家铁钴矿最终构造样式为倾竖褶皱和布丁状铁矿体,形成于晚期古元古代造山后的抬升剥蚀。

Improving maize residue cover estimation with the combined use of optical and SAR remote sensing images

Conservation tillage is an important conservation measure for arable land in modern agricultural pro-duction,which plays an essential role in protecting black soil and improving the quality of arable land.The estimation of maize residue cover(MRC)can be used to obtain the spatial distribution characteristics of conservation tillage,which is essential for government departments to promote conservation tillage technology and understand the implementation of it.In this paper the southern part of the Songnen Plain was used as the study area,and Sentinel-2 MSI images and Sentinel-1 SAR images were used as data sources to correlate the spectral indices and radar backscatter coefficients with the field sampling data in the study area.The MRC estimation model of the study area was constructed using the Random Forest(RF)model,the Multiple Linear Stepwise Regression(MLSR)model,and Back Propagation Neural Network(BPNN)model,respectively.The results of the study showed that the correlation coefficients of normalized difference tillage index(NDTI),simple tillage index(STI),normalized difference index(NDI5),NDI7,shortwave infrared normalized difference residue index(SINDRI),normalized difference senescent vegetation index(NDSVI),normalized difference residue index 2(NDRI2),NDRI3,NDRI4,NDR15,NDRI6,NDRI7,NDR18,NDRI9,and MRC in the study area were greater than 0.4,and the correlation coefficients were higher for NDTI and STI,which reached 0.861 and 0.860,respectively.The correlation coefficient between W and MRC was 0.56 and between VH and MRC was 0.594.We used MLSR,RF,and BPNN methods in combination with Sentinel-2 MSI images and Sentinel-1 SAR images for MRC estimation.The synergistic use of Sentinel-2 MSI images and Sentinel-1 SAR images helped to improve the accuracy of the MRC estimation models and the correlation coefficient R2 of all three models to greater than 0.8.Based on the statistical analysis of remote sensing estimation results,we found that the average value of the MRC of the maize growing areas in Changchun,Siping,and eastern Songyuan in November 2020 was 66%,and 2%of farmland in the study area had a MRC of less than 30%.

Serum levels of microRNAs can specifically predict liver injury of chronic hepatitis B

AIM： To investigate whether circulating microRNAs （miRNAs） can serve as molecular markers to predict liver injury resulted from chronic hepatitis B （CHB）. METHODS： The profiles of serum miRNA expression were first generated with serum samples collected from 10 patients with CHB and 10 healthy donors （Ctrls） by microarray analysis. The levels of several miRNAs were further quantitated by real-time reverse transcription polymerase chain reaction with serum samples from another 24 CHB patients and 24 Ctrls. Serum samples of 20 patients with nonalcohlic steatohepatitis （NASH） were also included for comparison. The comparison in the levels of miRNAs between groups （CHB, NASH and Ctrl） was analyzed with Mann-Whitney U-test. The cor- relation between miRNAs and clinical pathoparameters was analyzed using Spearman correlation analysis or canonical correlation analysis. The receiver-operator characteristic （ROC） curves were also generated to de- termine the specificity and sensitivity of each individual miRNA in distinguishing patients with CriB from Ctrls. RESULTS： miRNA profile analysis showed that 34 miR- NAs were differentially expressed between CriB and Ctrl subjects, in which 12 were up-regulated and 22 down-regulated in CriB subject （fold change 〉 2.0 and P 〈 0.01）. The median levels of miR-122, -572, -575 and -638 were significantly higher （P 〈 1.00 × 10-5） while miR-744 significantly lower （P 〈 1.0× 10-6） in Crib compared with the Ctrl. The levels of miR-122, -572 and -638 were also higher （P 〈 1.00×10-3） while the level of miR-744 lower in CriB （P 〈 0.05） than in NASH, although the difference between them was not as significant as that between CHB and Ctrl. ROC curve analysis revealed that the levels of miR-122, -572, -575, -638 and -744 in serum were sensitive and specific enough to distinguish CriB, NASH and Ctrl. Multivariate analysis further showed that the levels of these miRNAs were correlated with the liver function parameters. Most significantly, it was the scatter plot of principal component with the levels of these miRNAs, but not the parameters of liver function, which clearly distinguished CriB, NASH and Ctrl subjects. CONCLUSION： Serum levels of miR-122, -572, -575, -638 and -744 are deregulated in patients with CHB or NASH. The levels of these miRNAs may serve as po- tential biomarkers for liver injury caused by CHB and NASH.

No expenditure difference among patients with liver cancer at stageⅠ-ⅣV:Findings from a multicenter cross-sectional study in China

Objective:The number of liver cancer patients in China accounts for more than half of the world.However,China currently lacks national,multicenter economic burden data,and meanwhile,measuring the differences among different subgroups will be informative to formulate corresponding policies in liver cancer control.Thus,the aim of the study was to measure the economic burden of liver cancer by various subgroups.Methods:A hospital-based,multicenter and cross-sectional survey was conducted during 2012・2014,covering 39 hospitals and 21 project sites in 13 provinces across China.The questionnaire covers clinical information,sociology,expenditure,and related variables.All expenditure data were reported in Chinese Yuan(CNY)using 2014 values.Results:A total of 2,223 liver cancer patients were enrolled,of whom 59.61%were late-stage cases(III-IV),and 53.8%were hepatocellular carcinoma.The average total expenditure per liver cancer patient was estimated as 53,220 CNY,including 48,612 CNY of medical expenditures(91.3%)and 4,608 CNY of non-medical expenditures(8.7%).The average total expenditures in stage I,H,m and stage IV were 52,817 CNY,50,877 CNY,50,678 CNY and 54,089 CNY(P>0.05),respectively.Non-medical expenditures including additional meals,additional nutrition care,transportation,accommodation and hired informal nursing were 1,453 CNY,839 CNY,946 CNY,679 CNY and 200 CNY,respectively.The one-year out-of-pocket expenditure of a newly diagnosed patient was 24,953 CNY,and 77.2%of the patients suffered an unmanageable financial burden.Multivariate analysis showed that overall expenditure differed in almost all subgroups(P<0.05),except for sex,clinical stage,and pathologic type.Conclusions:There was no difference in treatment expenditure for liver cancer patients at different clinical stages,which suggests that maintaining efforts on treatment efficacy improvement is important but not enough.To fiirtherly reduce the overall economic burden from liver cancer,more effort should be given to primary and secondary prevention strategies.

Clonal variations in nutritional components of Pinus koreansis seeds collected from seed orchards in Northeastern China

From four Korean pine （Pinus koraiensis） orchards, 60 clones were selected and analyzed for the fatty acid and amino acid components of the seeds to reveal the variations and correlations of the seed characteristics among the clonal source orchards and clones. The nutri- tional components of the seeds of the P. koraiensis trees exhibited rich genetic variation; the variation coefficient of the fatty acids was 2.24-66.83 %, while the variation coefficient of the amino acids was 14.70-38.88 %. Rela- tively high genetic-improvement potential exists for the nutritional components of the seeds. The phenotypic dif- ferentiation of the fatty acid and amino acid components reveals that variation within the population （85.18 %） was the primary source for the variation of the fatty acid components; variation among the orchards （63.08 %） was the primary source of the variation of the amino acid components. Data drawn from various clonal source orchards all showed that the seed characteristics were highly controlled by heritability （h2 〉 80 %）, and the seed characteristics of the P. koraiensis trees exhibited a similar genetic gain trend. The principal components were ana- lyzed to obtain the comprehensive principal component value for each clonal seed orchard. Twelve clones were selected based on a clonal selection rate of 20 %. Corre- lation and multiple stepwise-regression analyses were conducted, considering different location conditions, to reveal the stable correlations between the seed character- istics to facilitate improvements of the seed yield of P. koraiensis trees and the clonal selection. Species of real characteristics in P. koraiensis were controlled by higher heritability. Genetic gain was obtained by selecting of superior clones.

Improved Computational Model of Grid Cells Based on Column Structure

To simulate the firing pattern of biological grid cells,this paper presents an improved computational model of grid cells based on column structure.In this model,the displacement along different directions is processed by modulus operation,and the obtained remainder is associated with firing rate of grid cell.Compared with the original model,the improved parts include that:the base of modulus operation is changed,and the firing rate in firing field is encoded by Gaussian-like function.Simulation validates that the firing pattern generated by the improved computational model is more consistent with biological characteristic than original model.Besides,the firing pattern is badly influenced by the cumulative positioning error,but the computational model can also generate the regularly hexagonal firing pattern when the real-time positioning results are modified.

Conducting qi and regulating the spirit needling method for insomnia: A randomized controlled trial

Objective:To evaluate the clinical effect differences between conducting qi and regulating the spirit needling method and regular needling method.Methods:Sixty-nine patients of insomnia were randomly divided into an observation group(35 cases)and a control group(34 cases).Bǎihuì(百会GV20),Sìshéncōng(四神聪EX-HN1),Hégǔ(合谷LI4),Tàichōng(太冲LR3),Zúsānlǐ(足三里ST36)and Sānyīnjiāo(三阴交SP6)were selected in the two groups.The patients in the observation group were treated with needling method for conducting qi and regulating the spirit.The patients in the control group were treated with the regular needling method.The treatment was given once every other day,both groups were treated for 12 times.Pittsburgh Sleep Quality Index(PSQI)and Epworth Sleepiness Scale(ESS)were observed before and after the treatment and the clinical effect was evaluated.Results:After treatment,the total score and the score of each item of PSQI as well as the result of ESS were all improved after the treatment in the two groups(all P<0.05).The improvements in the total score of PSQI and the result of ESS in the observation group were better than the control group(both P<0.05).The total effective rate was 88.57%(31/35)in the observation group,significantly superior to 76.47%(26/34)in the control group(P<0.05).Conclusion:The conducting qi and regulating the spirit needling method achieves a better effect on insomnia as compared with the regular needling method.This method achieves a remarkable improvement in sleep latency,sleep quality and daytime sleepiness.

Effects of ZnO nanoparticles on perfluorooctane sulfonate induced thyroid-disrupting on zebrafish larvae

Perfluorooctane sulfonate（PFOS） and ZnO nanoparticles（nano-ZnO） are widely distributed in the environment.However,the potential toxicity of co-exposure to PFOS and nano-ZnO remains to be fully elucidated.The test investigated the effects of co-exposure to PFOS and nano-ZnO on the hypothalamic–pituitary–thyroid（HPT） axis in zebrafish.Zebrafish embryos were exposed to a combination of PFOS（0.2,0.4,0.8 mg/L） and nano-ZnO（50 mg/L）from their early stages of life（0–14 days）.The whole-body content of TH and the expression of genes and proteins related to the HPT axis were analyzed.The co-exposure decreased the body length and increased the malformation rates compared with exposure to PFOS alone.Co-exposure also increased the triiodothyronine（T3） levels,whereas the thyroxine（T4）content remained unchanged.Compared with the exposure to PFOS alone,exposure to both PFOS（0.8 mg/L） and nano-ZnO（50 mg/L） significantly up-regulated the expression of corticotropin-releasing factor,sodium/iodidesymporter,iodothyronine deiodinases and thyroid receptors and significantly down-regulated the expression of thyroid-stimulating hormone,thyroglobulin（TG）,transthyretin（TTR） and thyroid receptors.The protein expression levels of TG and TTR were also significantly down-regulated in the co-exposure groups.In addition,the expression of the thyroid peroxidase gene was unchanged in all groups.The results demonstrated that PFOS and nano-ZnO co-exposure could cause more serious thyroid-disrupting effects in zebrafish than exposure to PFOS alone.Our results also provide insight into the mechanism of disruption of the thyroid status by PFOS and nano-ZnO.

Accuracy of baseline low-dose computed tomography lung cancer screening: a systematic review and meta-analysis

Background:Screening using low-dose computed tomography(LDCT)is a more effective approach and has the potential to detect lung cancer more accurately.We aimed to conduct a meta-analysis to estimate the accuracy of population-based screening studies primarily assessing baseline LDCT screening for lung cancer.Methods:MEDLINE,Excerpta Medica Database,and Web of Science were searched for articles published up to April 10,2022.According to the inclusion and exclusion criteria,the data of true positives,false-positives,false negatives,and true negatives in the screening test were extracted.Quality Assessment of Diagnostic Accuracy Studies-2 was used to evaluate the quality of the literature.A bivariate random effects model was used to estimate pooled sensitivity and specificity.The area under the curve(AUC)was calculated by using hierarchical summary receiver-operating characteristics analysis.Heterogeneity between studies was measured using the Higgins I 2 statistic,and publication bias was evaluated using a Deeks’funnel plot and linear regression test.Results:A total of 49 studies with 157,762 individuals were identified for the final qualitative synthesis;most of them were from Europe and America(38 studies),ten were from Asia,and one was from Oceania.The recruitment period was 1992 to 2018,and most of the subjects were 40 to 75 years old.The analysis showed that the AUC of lung cancer screening by LDCT was 0.98(95%CI:0.96-0.99),and the overall sensitivity and specificity were 0.97(95%CI:0.94-0.98)and 0.87(95%CI:0.82-0.91),respectively.The funnel plot and test results showed that there was no significant publication bias among the included studies.Conclusions:Baseline LDCT has high sensitivity and specificity as a screening technique for lung cancer.However,long-term follow-up of the whole study population(including those with a negative baseline screening result)should be performed to enhance the accuracy of LDCT screening.

中国农田土壤动物长期监测样地科学调查监测的实施方法

我国农田土壤动物面临严峻的多样性丧失问题,建设监测样地并开展长期监测是解决该问题的重要途径,但至今国内外仍缺乏农田土壤动物长期监测样地科学调查监测的实施方法。依据BCI 50 ha大型固定样地建设规范,参照我国已建成的森林和农田土壤动物大型固定样地监测经验,本文提出了农田土壤动物长期监测样地科学调查监测的实施方法。首先,需要明确科学问题,确定科学调查监测应遵守的基本原则。其次,需要规范长期调查监测涉及的专业术语,依据研究目的和实际情况选择地点和样地,参照建设规范和农田特征建立农田土壤动物大型固定样地。第三,以研究农田土壤动物多样性为核心,揭示土壤动物在农田生态系统健康和功能中的作用,有选择性地开展4类27项科学指标的长期监测工作,要求按照统一的、规范化的工作流程开展野外调查和室内实验。最后,要科学规范地完成标本的鉴定描述和保存保管,研发体现农田土壤动物特征的数据库和管理信息系统。希望本文的研究结果能推动我国乃至世界范围的规范化样地建设和标准化网络监测,为我国农田土壤动物评估与保护提供长期可靠的数据支撑。

High Spicy Food Intake and Risk of Cancer： A Meta-analysis of Case-control Studies

Background：Studies on the association between spicy food intake and cancer risk have reported inconsistent results.We quantitatively assessed this association by conducting a meta-analysis based on evidence from case-control studies.Methods：PubMed,EMBASE,and the Cochrane Library were searched for eligible publications.Combined odds ratios （ORs） with their 95% confidence interval （CI） were calculated using a random-or fixed-effects model.The methodological quality of the included articles was assessed using the Newcastle-Ottawa scale （NOS）.All data were analyzed using STATA 1 1.0 software （version 11.0;StataCorp.,College Station,TX,USA）.Subgroup analyses were also performed with stratification by region,sex,number of cases,cancer subtype,source of the control group,and NOS score.Results：A total 39 studies from 28 articles fulfilled the inclusion criteria for the meta-analysis （7884 patients with cancer and 10,142 controls）.Comparison of the highest versus lowest exposure category in each study revealed a significant OR of 1.76 （95% CI =1.35-2.29） in spite of significant heterogeneity （P 〈 0.00l）.In the subgroup analyses,this positive correlation was still found for gastric cancer,different regions,different numbers of cases,different sources of the control group,and high-quality articles （NOS score of≥ 7）.However,no statistically significant association was observed for women,esophageal cancer,gallbladder cancer,or low-quality articles （NOS score of〈7）.No evidence of publication bias was found.Conclusions：Evidence from case-control studies suggested that a higher level of spicy food intake may be associated with an increased incidence of cancer despite significant heterogeneity.More studies are warranted to clarify our understanding of the association between high spicy food intake and the risk of cancer.

The nitritation performance of biofilm reactor for treating domestic wastewater under high dissolved oxygen

The objective of this study was to investigate the nitritation performance in a biofilm reactor for treating domestic wastewater.The reactor was operated in continuous feed mode from phases 1 to 3.The dissolved oxygen（DO）was controlled at 3.5–7 mg/L throughout the experiment.The biofilm reactor showed excellent nitritation performance after the inoculation of nitrifying sludge,with the hydraulic retention time being reduced from 24 to 7 hr.Above 90%nitrite accumulation ratio（NAR）was maintained in phase 1.Afterwards,nitratation occurred with the low NH4^＋–N concentration in the reactor.The improvement of NH4^＋–N concentration to 20–35 mg/L had a limited effect on the recovery of nitritation.However,nitritation recovered rapidly when sequencing batch feed mode was adopted in phase 4,with the effluent NH4^＋-N concentration above 7 mg/L.The improvement of ammonia oxidizing bacteria（AOB）activity and the combined inhibition effect of free ammonia（FA）and free nitrous acid（FNA）on the nitrite oxidizing bacteria（NOB）were two key factors for the rapid recovery of nitritation.Sludge activity was obtained in batch tests.The results of batch tests had a good relationship with the long term operation performance of the biofilm reactor.

Inhibition factors and Kinetic model for ammonium inhibition on the anammox process of the SNAD biofilm

The aim of the present work was to evaluate the anaerobic ammonium oxidation （anammox） activity of simultaneous partial nitrification, anammox and denitrification （SNAD） biofilm with different substrate concentrations and pH values. Kaldnes rings taken from the SNAD biofilm reactor were incubated in batch tests to determine the anammox activity. Haldane model was applied to investigate the ammonium inhibition on anammox process. As for nitrite inhibition, the NH4-N removal rate of anammox process remained 87.4% of the maximum rate with the NO2-N concentration of 100 mg/L. Based on the results of Haldane model, no obvious difference in kinetic coefficients was observed under high or low free ammonia （FA） conditions, indicating that ammonium rather than FA was the true inhibitor for anammox process of SNAD biofilm. With the pH value of 7.0, the rmax, KS and K of ammonium were 0.209 kg NO2-N/kg VSS/day, 9.5 mg/L and 422 rag/L, respectively. The suitable pH ranges for anammox process were B.0 to 9.0. These results indicate that the SNAD biofilm performs excellent tolerance to adverse conditions.

Bimetallic cobalt-nickel coordination polymer electrocatalysts for enhancing oxygen evolution reaction

Coordination polymers(CPs)have great potential to be used in electrocatalysis owing to their designable compositions and structures.It is highly challenging to apply CPs as electrocatalysts for oxygen evolution reaction(OER)on account of insufficient catalytic efficiency and relatively poor stability of current electrocatalysts.Herein,through a mixed-metal strategy,one-dimensional Co_(x)Ni_(1-x)-HIPA with dual active sites was synthesized and studied for OER electrocatalysts.By changing the metal ratio of CoxNi1-x-HIPA,the OER performance was well regulated.The optimized Co_(1/2)Ni_(1/2)-HIPA exhibited minimum reaction activation energy,and represented an overpotential of 367 m V to reach 10 mA/cm^(2) at 25℃.Moreover,an overpotential of 314 m V at 10 m A/cm^(2) was obtained from Co_(1/2)Ni_(1/2)-HIPA at 55℃.This mixed-metal strategy provides a feasible way for adjusting the electronic states of the electrocatalysts to improve the electrocatalytic OER performance.

Impact of window and air-conditioner operation behaviour on cooling load in high-rise residential buildings

Space cooling is an important building energy end-use that was found in recent years to be significantly impacted by occupant behaviours.However,the majority of previous studies ignored the interplay between the operation of windows and air conditioners(ACs)on cooling load,particularly in building energy modelling.In addition,studies on the analysis of cooling load characteristics regarding high-rise buildings are insufficient.The vertical effect of high-rise buildings on cooling load remains vague.This study thus aims to examine how window and AC operation behaviours impact the cooling load of high-rise buildings in an urban context demonstrated by a real-life typical 40-floor residential building in Hong Kong.This study investigates window and AC operation behaviours jointly and examines the vertical effect on cooling load by using agent-based building energy modelling(BEM)techniques and initiating stochastic and diverse behaviour modes.A carefully designed questionnaire survey was conducted to help build behaviour modes and validate energy models.Ninety building energy models were established integrating meteorological parameters generated by the computational fluid dynamics(CFD)programme for ten typical floors and nine combinations of window and AC behaviour modes.The results show that comfort-based AC modes and schedule-based window modes yielded the lowest cooling load.Considering the combined effect of AC and window uses,the maximum difference in cooling loads could be 26.8%.Behaviour modes and building height induce up to 32.4%differences in cooling loads.Besides,a deviation between the behaviour modes and height on the cooling load was found.The findings will help develop a thorough energy model inferring occupants’window and AC behaviour modes along with the building height in high-rise residential buildings.The findings indicate that the interaction impact of window and AC behaviour modes and height should be jointly considered in future high-rise building energy modelling,building energy standards,and policymaking.

Dispersion of double-slot in optical microring resonators buffer

In the optical packet switching network, optical buffer is an important device. Microring resonator optical buffers provide good delay performance and flexibility in design. By cascading multiple microring resonators, higher delay-bandwidth product is obtained, but the requirements of high integration and low dispersion are hard to satisfy simultaneously. Double-slot waveguide was proposed to construct highly integrated racetrack microring resonators in this study. Based on dispersion analysis of the thickness of each layer of a waveguide, the structure ofwaveguide was optimized to reach flat and low dispersion. Average dispersions of straight and 3 μm bend waveguides were 5.1 ps/（nm·km） and 4.4 ps/（nm· km）, respectively. Besides, the additional loss from coupling was greatly reduced when applying proper relative displacement between straight and bend waveguides. Theoretical and design basis provided in this paper will help to develop multi-microring optical buffers in the future.

Broadband filter using multi-layer sub-wavelength high-contrast grating structure

This paper proposed a novel broadband filter using multi-layer sub-wavelength high-contrast grating （HCG） structure. This filter has wide bandwidth and good sideband suppression. We simulated and analyzed the effects of different numbers of layers and different grating indexes on filtering performance of the broadband filter. According to the simulated results, we designed a multi- layer HCG broadband filter, which has bandwidth of 843 nm and center wavelength of 1550 nm.

LIMIT CYCLES FOR A CLASS OF NONPOLYNOMIAL PLANAR VECTOR FIELDS (II)

In this paper, the problem of limit cycles for a class of nonpolynomial planar vector felds is investigated. First, based on Liapunov method theory, we obtain some sufcient conditions for determining the origin as the critical point of such nonpolynomial planar vector felds to be the focus or center. Then, using Dulac criterion, we establish some sufcient conditions for the nonexistence of limit cycles of this nonpolynomial planar vector felds. And then, according to Hopf bifurcation theory, we analyze some sufcient conditions for bifurcating limit cycles from the origin. Finally, by transforming the nonpolynomial planar vector felds into the generalized Li′enard planar vector felds, we discuss the existence, uniqueness and stability of limit cycles for the former and latter planar vector felds. Some examples are also given to illustrate the efectiveness of our theoretical results.