Development of a nomogram for predicting liver transplantation prognosis in hepatocellular carcinoma

BACKGROUND At present,liver transplantation(LT)is one of the best treatments for hepatocellular carcinoma(HCC).Accurately predicting the survival status after LT can significantly improve the survival rate after LT,and ensure the best way to make rational use of liver organs.AIM To develop a model for predicting prognosis after LT in patients with HCC.METHODS Clinical data and follow-up information of 160 patients with HCC who underwent LT were collected and evaluated.The expression levels of alphafetoprotein(AFP),des-gamma-carboxy prothrombin,Golgi protein 73,cytokeratin-18 epitopes M30 and M65 were measured using a fully automated chemiluminescence analyzer.The best cutoff value of biomarkers was determined using the Youden index.Cox regression analysis was used to identify the independent risk factors.A forest model was constructed using the random forest method.We evaluated the accuracy of the nomogram using the area under the curve,using the calibration curve to assess consistency.A decision curve analysis(DCA)was used to evaluate the clinical utility of the nomograms.RESULTS The total tumor diameter(TTD),vascular invasion(VI),AFP,and cytokeratin-18 epitopes M30(CK18-M30)were identified as important risk factors for outcome after LT.The nomogram had a higher predictive accuracy than the Milan,University of California,San Francisco,and Hangzhou criteria.The calibration curve analyses indicated a good fit.The survival and recurrence-free survival(RFS)of high-risk groups were significantly lower than those of low-and middle-risk groups(P<0.001).The DCA shows that the model has better clinical practicability.CONCLUSION The study developed a predictive nomogram based on TTD,VI,AFP,and CK18-M30 that could accurately predict overall survival and RFS after LT.It can screen for patients with better postoperative prognosis,and improve longterm survival for LT patients.

Application and Effect Evaluation of the Integrated“5A and 3+3”Management Model in the Safe Medication Use for Chemotherapy Patients

Objective:To explore the application and effect evaluation of the integrated“5A and 3+3”management model in ensuring safe medication use for chemotherapy patients.Methods:A total of 100 intravenous chemotherapy patients admitted to the oncology department of Shaanxi Provincial People’s Hospital were randomly divided into two groups using a random number list method.Both groups received conventional nursing management during chemotherapy,while the study group additionally received the integrated“5A and 3+3”safety management model.The nursing intervention effects between the two groups were compared.Results:After the intervention,the study group showed higher levels of self-management ability,compliance,and nursing satisfaction compared to the control group.The overall incidence of adverse events during hospitalization was lower in the study group,with statistically significant differences(P<0.05).The knowledge scores of medical staff in the study group,related to the prevention and treatment of chemotherapy drug side effects,daily symptom management,and daily life management,were higher than those in the control group,with statistically significant differences(P<0.05).Conclusion:Implementing the integrated“5A and 3+3”model in the safe medication management of intravenous chemotherapy patients can effectively enhance patients’self-management abilities and compliance,improve medical staff’s ability to safely administer chemotherapy drugs,reduce adverse events caused by chemotherapy,and increase patient satisfaction.

Development of homozygous tetraploid potato and whole genome doubling-induced the enrichment of H3K27ac and potentially enhanced resistance to cold-induced sweetening in tubers

Polyploid plants typically display advantages on some agronomically important traits over their diploid counterparts.Extensive studies have shown genetic,transcriptomic,and epigenetic dynamics upon polyploidization in multiple plant species.However,few studies have unveiled those alternations imposed only by ploidy level,without any interference from heterozygosity.Cultivated potato is highly heterozygous.Thus,in this study,we developed two homozygous autotetraploid lines and one homozygous diploid line in parallel from a homozygous diploid potato.We confirmed their ploidy levels using chloroplast counting and karyotyping.Oligo-FISH and genome re-sequencing validated that these potato lines are nearly homozygous.We investigated variations in phenotypes,transcription,and histone modifications between two ploidies.Both autotetraploid lines produced larger but fewer tubers than the diploid line.Interestingly,each autotetraploid line displayed ploidy-related differential expression for various genes.We also discovered a genomewide enrichment of H3K27ac in genic regions upon whole-genome doubling(WGD).However,such enrichment was not associated with the differential gene expression between two ploidies.The tetraploid lines may exhibit better resistance to cold-induced sweetening(CIS)than the diploid line in tubers,potentially regulated through the expression of CIS-related key genes,which seems to be associated with the levels of H3K4me3 in cold-stored tubers.These findings will help to understand the impacts of autotetraploidization on dynamics of phenotypes,transcription,and histone modifications,as well as on CIS-related genes in response to cold storage.

Selenium,Type-2 Diabetes,and the Possible Protective Role of Vitamin D

Diabetes is a pervasive and serious global health issue.According to the International Diabetes Federation report,463 million adults worldwide were living with diabetes in 2019,and this number is projected to reach 700 million in 2045^([1]).

Development of a diagnostic nomogram for alpha-fetoproteinnegative hepatocellular carcinoma based on serological biomarkers

BACKGROUND Hepatocellular carcinoma(HCC)is the third leading cause of cancer-related death worldwide.Serum biomarkers play an important role in the early diagnosis and prognosis of HCC.Because a certain percentage of HCC patients are negative for alpha-fetoprotein(AFP),the diagnosis of AFP-negative HCC is essential to improve the detection rate of HCC.AIM To establish an effective model for diagnosing AFP-negative HCC based on serum tumour biomarkers.METHODS A total of 180 HCC patients were enrolled in this study.The expression levels of GP73,des-γ-carboxyprothrombin(DCP),CK18-M65,and CK18-M30 were detected by a fully automated chemiluminescence analyser.The variables were selected by logistic regression analysis.Several models were constructed using stepwise backward logistic regression.The performance of the models was compared using the C statistic,integrated discrimination improvement,net reclassification improvement,and calibration curves.The clinical utility of the nomogram was assessed using decision curve analysis(DCA).RESULTS The results showed that the expression levels of GP73,DCP,CK18-M65,and CK18-M30 were significantly greater in AFP-negative HCC patients than in healthy controls(P<0.001).Multivariate logistic regression analysis revealed that GP73,DCP,and CK18-M65 were independent factors for diagnosing AFP-negative HCC.By comparing the diagnostic performance of multiple models,we included GP73 and CK18-M65 as the model variables,and the model had good discrimination ability(area under the curve=0.946)and good goodness of fit.The DCA curves indicated the good clinical utility of the nomogram.CONCLUSION Our study identified GP73 and CK18-M65 as serum biomarkers with certain application value in the diagnosis of AFP-negative HCC.The diagnostic nomogram based on CK18-M65 combined with GP73 demonstrated good performance and effectively identified high-risk groups of patients with HCC.

Effect of Six Bacterial Strains on the Activity of Second Instar Larvae and Egg Hatching of Meloidogyne incognita

[Objectives]The paper was to screen effective biocontrol strains against Meloidogyne incognita.[Methods]The effect of six bacterial strains sourced from the research group s strain library on the activity of second instar larvae of M.incognita,as well as on egg hatching,was evaluated.[Results]The treatment of fermentation supernatant derived from the X-2 strain exhibited a pronounced lethal effect on M.incognita,with a corrected mortality rate reaching 97%within 72 h.Additionally,this treatment significantly inhibited egg hatching,achieving an inhibition rate of 94.69%at a 20-fold dilution.The strain was identified as Bacillus velezensis,belonging to the genus Bacillus,and was designated as RKN1111.[Conclusions]This study presents alternative strains and a theoretical framework for the biological control of M.incognita.

Salidroside Ameliorates Vascular Endothelial Cell Senescence through Downregulation of KLF4

Salidroside is extensively used as a herbal medicine worldwide, and it has been shown to protect against disruption of endothelial homeostasis and act as an anti-aging agent. The present study aimed to investigate the ameliorative effects of salidroside on homocysteine (Hcy)-induced cell senescence in human umbilical vein endothelial cells (HUVECs) that were mediated via inhibition of Krüppel-like factor 4 (KLF4). An endothelial cell senescence model was induced by Hcy. The cell viability, activities of telomerase and lactate dehydrogenase (LDH), and the level of reactive oxygen species were determined using commercial kits. The expression levels of KLF4, p53 and p21 were determined via western blot analysis, whereas the mRNA expression levels of KLF4 were detected by reverse transcription-quantitative PCR. Small interfering RNA-mediated knockdown of KLF4 was found to reverse Hcy-induced cell senescence. Hcy treatment led to an accelerated cell senescence, as evidenced by decreases in both cell viability and telomerase activity, whereas increases were noted in the leakage of LDH and the level of reactive oxygen species, in addition to an up-regulation of the protein levels of p53 and p21, and up-regulation of KLF4 at both the mRNA and protein level. Treatment with salidroside ameliorated Hcy-induced cell senescence in a dose-dependent manner. Taken together, these results suggested that Hcy may induce cell senescence through upregulation of KLF4, and this may be reversed by treatment with salidroside. Therefore, salidroside was shown to inhibit Hcy-induced cell senescence through KLF4 inhibition.

Synthesis and Evaluation of a Water-Swelling Polymer Plugging Agent SWL-1

In this paper, to solve the problems of low water absorption and weak pressure bearing capacity of current plugging materials, acrylic acid (AA), acrylamide (AM), and sodium allyl sulfonate (SAS) are used as monomers, and soluble starch is used as grafting. Material, the use of free radical aqueous solution method to synthesize the plugging agent SWL-1 with good water absorption and strong salt resistance. The monomer ratio is set as n (AA):n (AM):n (SAS) = 5:2:1, the experimental synthesis temperature is 70°C, and the orthogonal experiment is used to determine the experimental synthesis conditions as AA neutralization degree 80%, The amount of initiator is 0.60%, the amount of crosslinking agent is 0.50%, the ratio of monomer to starch is 7:1, and the amount of calcium carbonate is 13%. The comprehensive evaluation of the performance of the plugging agent SWL-1 shows that the water absorption performance at 60°C is the best 268.78 g/g, and the water absorption performance in 8% NaCl, 0.9% CaCl2 and composite brine is 21.5 g/g, 12.5 g/g and 24.9 g/g, indicating good resistance to sodium and calcium, the water retention rate is still higher than 30% after 15 days at 160°C. The sand bed plugging test found that the maximum pressure of SWL-1 was 7 MPa, and the crack plugging test found that when the crack width was 1 mm, 2 mm, and 3 mm, the maximum compressive strength of SWL-1 was 10 MPa. The acid solubility test showed that the maximum pressure was 10 MPa. The highest rate is 86.38%.

水溶液环境下Phe→Mg(Ⅱ)配合物对映异构的理论研究

采用密度泛函理论的M06-2X和MN15方法,结合处理溶剂效应的SMD模型方法,研究了在水溶液环境下苯丙氨酸二价镁配合物(Phe→Mg(Ⅱ))的对映异构.研究发现:Phe→Mg(Ⅱ)的对映异构可在质子以羰基O为桥、以羰基O和氨基N联合为桥和只以氨基N为桥迁移的3个反应通道上实现.计算结果表明:质子只以氨基N为桥迁移的反应通道最具优势,在只考虑水的极性作用时速度决定步骤的自由能垒为212.3 kJ·mol^(-1),在水的极性和水分子(簇)的共同作用下该自由能垒降至108.1~111.5 kJ·mol^(-1).在水溶液环境下Phe→Mg(Ⅱ)的对映异构过程比较缓慢,苯丙氨酸二价镁可短期用于生命体同补苯丙氨酸和金属镁.

Effects of in-situ stress on the stability of a roadway excavated through a coal seam

Roadways excavated through a coal seam can exert an adverse effect on roadway stability. To investigate the effects of in-situ stress on roadway stability, numerical models were built and high horizontal stresses at varying orientations were applied. The results indicate that stress concentrations, roadway deformation and failure increase in magnitude and extent as the excavation angle with respect to the maximum horizontal stress increases. In addition, the stress adjacent to the coal-rock interface sharply varies in space and evolves with time; coal is much more vulnerable to deformation and failure than rock.The results provide insights into the layout of roadways excavated through a coal seam. Roadways should be designed parallel or at a narrow angle to the maximum horizontal stress. The concentrated stress at the top corner of the face-end should be reduced in advance, and the coal seam should be reinforced immediately after excavation.

Bone Loss Induced by Simulated Microgravity,Ionizing Radiation and/or Ultradian Rhythms in the Hindlimbs of Rats

Objective To better understand the pathological causes of bone loss in a space environment, including microgravity, ionizing radiation, and ultradian rhythms.Methods Sprague Dawley （SD） rats were randomly divided into a baseline group, a control group, a hindlimb suspension group, a radiation group, a ultradian rhythms group and a combined-three-factor group. After four weeks of hindlimb suspension followed by X-ray exposure and/or ultradian rhythms, biomechanical properties, bone mineral density, histological analysis, microstructure parameters, and bone turnover markers were detected to evaluate bone loss in hindlimbs of rats.Results Simulated microgravity or combined-three factors treatment led to a significant decrease in the biomechanical properties of bones, reduction in bone mineral density, and deterioration of trabecular parameters. Ionizing radiation exposure also showed adverse impact while ultradian rhythms had no significant effect on these outcomes. Decrease in the concentration of the turnover markers bone alkaline phosphatase （bALP）, osteocalcin （OCN）, and tartrate-resistant acid phosphatase-5b （TRAP-Sb） in serum was in line with the changes in trabecular parameters.Conclusion Simulated microgravity is the main contributor of bone loss. Radiation also results in deleterious effects but ultradian rhythms has no significant effect. Combined-three factors treatment do not exacerbate bone loss when compared to simulated microgravity treatment alone.

Establishment of a rhesus monkey model of middle cerebral artery ischemia and reperfusion using a microcatheter embolization method

Nonhuman primates are closest to humans in terms of lineage, and middle cerebral artery ischemia/reperfusion responses of nonhuman primates are most similar to ischemic stroke in humans. Therefore, nonhuman primates could be utilized to simulate the process of ischemic stroke in the human. Few studies, however, have reported the use of endovascular technology to establish a rhesus monkey stroke model. In the present study, seven adult, male, rhesus monkeys were selected and, following anesthesia, a microcatheter was inserted into one side of the middle cerebral artery via the femoral artery to block blood flow, thereby resulting in middle cerebral artery occlusion. After 2 hours, the microcatheter was withdrawn to restore the middle cerebral artery blood flow and to establish ischemia/reperfusion. Results from angiography and magnetic resonance angiography confirmed occlusion and reopening of the middle cerebral artery. Magnetic resonance imaging revealed the existence of ischemic brain lesions, and neurological examination showed sustained functional deficits following surgery. The rhesus monkey middle cerebral artery ischemia/reperfusion models established by microcatheter embolization had the advantage of non-craniotomy invasion and reproducibility. The scope and degree of ischemic damage using this model was controllable. Therefore, this nonhuman primate model is an ideal model for cerebral ischemia and reperfusion.

A novel large animal model of recurrent migraine established by repeated administration of inflammatory soup into the dura mater of the rhesus monkey

Several animal models of migraine have been established, and those based on trigeminovascular system activation are widely accepted. How- ever, most of these models have been established on lower animals, such as rodents, and involve only a single administration of a noxious stimulus. In this study, an inflammatory soup （10 μL）, consisting of prostaglandin E2 （0.2 mM）, serotonin （2 mM）, bradykinin （2 raM） and histamine （2 raM）, was injected into the dura mater of conscious rhesus monkeys through an indwelling catheter. The infusion started on day 8 and was repeated every 3 days, for a total of six administrations, to induce neurogenic inflammation. We performed behavioral assessments and measured the expression of the oncogene c-fos, neuronal nitric oxide synthase （nNOS） and calcitonin gene related peptide （CGRP） ill the trigeminal system and in multiple brain regions involved in pain processing by immunohistochemical staining. Compared with monkeys in the control group, three of the four animals in the inflammatory soup group displayed decreased motor behaviors, and two showed increased ipsilateral nose and mouth secretions during the stimulus period. Higher expression levels of c-fos, nNOS and CGRP were found in various brain areas of experimental animals compared with controls, including the trigeminal nucleus caudalis, thalamus, hypothalamus, midbrain, pons and other areas involved in pain perception. These results suggest that repeated inflammatory soup stimulation of the dura activates the trigeminovascular system and produces migraine-like pathological changes and abnormal behaviors in conscious rhesus monkeys.

The Phoebe genome sheds light on the evolution of magnoliids

Lauraceae includes the genus Phoebe,and the family is linked to the evolution of magnoliids.We sequenced the genome of Phoebe bournei Nanmu.The assembled genome size was 989.19 Mb,with a contig N50 value of 2.05 Mb.A total of 28,198 protein-coding genes were annotated in P.bournei.Whole-genome duplication(WGD)analysis showed that Lauraceae has experienced two WGD events;the older WGD event occurred just before the divergence of Lauraceae and Magnoliales,and the more recent WGD was shared by all lineages of Lauraceae.The phylogenetic tree showed that magnoliids form a sister clade to monocots and eudicots.We also identified 63 MADS-box genes,including AGL12-like genes that may be related to the regulation of P.bournei roots and FIN219-like genes encoding GH3 proteins,which are involved in photomorphogenesis.SAUR50-like genes involved in light signal-mediated pedicel or stem development were also identified.Four ATMYB46-and three PtrEPSP-homologous genes related to lignin biosynthesis were identified.These genes may be associated with the formation of straight trunks in P.bournei.Overall,the P.bournei reference genome provides insight into the origin,evolution,and diversification of Phoebe and other magnoliids.

Climate change and water security in the northern slope of the Tianshan Mountains

Water security is under threat worldwide from climate change. A warming climate would accelerate evaporationand cryosphere melting, leading to reduced water availability and unpredictable water supply. However, thewater crisis in the Northern Slope of Tianshan Mountains(NSTM) faces dual challenges because water demandsforfast-growing urban areas have put heavy pressure on water resources. The mountain-oasis-desert system featuresglacier-fed rivers that sustain intensive water use in the oasis and end in the desert as fragile terminal lakes.The complex balance between water conservation and economic development is subtle. This paper investigateschanges in hydroclimatic variables and water security-related issues on the NSTM. The spatiotemporal variationsin glaciers, climatic variables, rivers, lakes and reservoirs, groundwater, surface water, human water use, andstreamflow were analyzed for the past four decades. The results show that temperature in the NSTM exhibitedan apparent upward trend with a more significant warming rate in the higher altitude regions. Glacier massloss and shrinkage was strong. The average annual streamflow increased from 1980-1989 to 2006–2011 at mosthydrological stations. The monthly dynamics of surface water area showed notable variability at both inter-annual and seasonal scales, revealing the impacts of both natural and anthropogenic drivers on surface wateravailability in the region. The terrestrial water storage anomaly showed a decreasing trend, which might berelated to groundwater pumping for irrigation. Human water use for agriculture and industry grew with theincrease in cultivated land area and gross domestic product (GDP). The increased agricultural water use wasstrongly associated with the expansion of oases. It is unclear whether water availability would remain high underfuture climatic and hydrological uncertainties, posing challenges to water management. In the context of rapidurban growth and climate change, balancing water for humans and nature is vital in achieving the SustainableDevelopment Goals (SDGs) in NSTM. This study provides a baseline understanding of the interplay among water,climate change, and socio-economic development in NSTM. It would also shed light on wise water managementunder environmental changes for other rapidly developing mountain-oasis-desert systems worldwide.

补中益气汤协同Siβ-catenin调控Wnt/β-catenin信号通路干预肺腺癌顺铂耐药性的分子机制研究

目的:探讨补中益气汤含药血清协同Siβ-catenin调控Wnt/β-catenin信号通路干预A549/DDP细胞顺铂耐药性的分子机制研究。方法:采用siRNA干扰沉默β-catenin的表达,Western blot检测正常血清组、顺铂组、siCTNNB1-235组、siCTNNB1-510组、siCTNNB1-547组A549/DDP细胞的β-catenin蛋白的相对表达量;干扰β-catenin后,Western blot检测各组A549/DDP细胞β-catenin和Survivin的蛋白表达量,MTT法检测各组A549/DDP细胞对顺铂的IC50,Annexin V/PI染色法检测各组A549/DDP细胞顺铂诱导的凋亡率。结果:相较于正常血清组(1.00),siCTNNB1-235组(0.323±0.021)对β-catenin表达抑制率达67%(P=0.000)。RNAi技术沉默β-catenin后,与正常血清组(1.00)相比,补中益气汤联合顺铂组的Survivin(0.247±0.015)和β-catenin(0.257±0.015)蛋白的表达下调更为明显(P=0.000,P=0.000)。IC50和正常血清组(28.330±1.029)µmol/L相比,单独补中益气汤含药血清(20.350±1.155)µmol/L或单独瞬时转染siCTNNB1-235组(15.577±1.535)µmol/L均可降低A549/DDP细胞顺铂的IC50(P=0.000,P=0.000),2者联合(10.453±0.999)µmol/L使用可进一步降低顺铂的IC50(P=0.000)。与正常血清组(9.130±0.384)%相比,瞬时转染siCTNNB1-235联合顺铂组(64.393±0.244)%和补中益气汤联合顺铂组(70.120±0.400)%的总凋亡率均升高(P=0.000,P=0.000)。结论:补中益气汤含药血清和瞬时转染siβ-catenin在抑制Wnt/β-catenin信号通路改善肺腺癌顺铂耐药性方面具有协同效应,且补中益气汤具有siβ-catenin瞬时转染样效应。

Liver injury changes the biological characters of serum small extracellular vesicles and reprograms hepatic macrophages in mice

BACKGROUND Serum small extracellular vesicles(sEVs)and their small RNA(sRNA)cargoes could be promising biomarkers for the diagnosis of liver injury.However,the dynamic changes in serum sEVs and their sRNA components during liver injury have not been well characterized.Given that hepatic macrophages can quickly clear intravenously injected sEVs,the effect of liver injury-related serum sEVs on hepatic macrophages deserves to be explored.AIM To identify the characteristics of serum sEVs and the sRNAs during liver injury and explore their effects on hepatic macrophages.METHODS To identify serum sEV biomarkers for liver injury,we established a CCL4-induced mouse liver injury model in C57BL/6 mice to simulate acute liver injury(ALI),chronic liver injury(CLI)and recovery.Serum sEVs were obtained and characterized by transmission electron microscopy and nanoparticle tracking analysis.Serum sEV sRNAs were profiled by sRNA sequencing.Differentially expressed microRNAs(miRNAs)were compared to mouse liver-enriched miRNAs and previously reported circulating miRNAs related to human liver diseases.The biological significance was evaluated by Ingenuity Pathway Analysis of altered sEV miRNAs and conditioned cultures of ALI serum sEVs with primary hepatic macrophages.RESULTS We found that both ALI and CLI changed the concentration and morphology of serum sEVs.The proportion of serum sEV miRNAs increased upon liver injury,with the liver as the primary contributor.The altered serum sEV miRNAs based on mouse studies were consistent with human liver disease-related circulating miRNAs.We established serum sEV miRNA signatures for ALI and CLI and a panel of miRNAs(miR-122-5p,miR-192-5p,and miR-22-3p)as a common marker for liver injury.The differential serum sEV miRNAs in ALI contributed mainly to liver steatosis and inflammation,while those in CLI contributed primarily to hepatocellular carcinoma and hyperplasia.ALI serum sEVs decreased both CD86 and CD206 expression in monocyte-derived macrophages but increased CD206 expression in resident macrophages in vitro.CONCLUSION Serum sEVs acquired different concentrations,sizes,morphologies and sRNA contents upon liver injury and could change the phenotype of liver macrophages.Serum sEVs therefore have good diagnostic and therapeutic potential for liver injury.

水平圆盘式大豆单粒精密排种器的设计与试验

为了实现大豆单粒精密播种,设计了一种水平圆盘大豆单粒精密排种器,并对其工作原理进行了分析。依据大豆种子的物理参数,对排种盘的型孔尺寸、直径等参数进行了计算分析,确定型孔尺寸的长、宽和高分别为9、5、9mm。为了得到排种器的最佳性能,以排种器转速、大豆品种为试验因素,以排种合格指数、重播指数、漏播指数为试验指标,利用EDEM软件进行仿真试验,结果表明:当排种器最佳转速为40r/min时,排种合格率均大于96.4%,重播率小于2%,漏播率小于1.7%。在最佳参数下,进行台架试验验证,结果表明:当排种器转速为40r/min时,3个品种的大豆种子的排种合格率均大于96.5%,重播率小于2%,漏播率小于1.7%,能够满足大豆单粒精密播种的要求。

基于异步Dueling DQN和计划时间预测网络的连接优化器

连接顺序选择是查询优化领域中极具挑战性的研究方向,对于数据库管理系统获得良好的查询性能至关重要.然而,传统优化方法和现有智能优化方法均存在着不足,如规划时间过长、容易得到质量较差的连接计划、编码未考虑结构特征、依赖基数估计和代价估计使得连接计划无法反映真实的执行时间等.针对上述问题,提出了一种新型基于异步Dueling DQN(Deep Q-network)和计划时间预测网络的连接优化器:ADP-Join(Asynchronous Dueling DQN and Plan Latency Prediction Network for Join Order Selection).ADP-Join集成了一种新的编码方法,能够区分不同结构的连接计划.ADP-Join设计了计划时间预测网络PLN(Plan Latency Prediction Network)来改善现有基于强化学习优化器的奖励机制.再者,提出异步更新机制改进Dueling DQN模型来提升训练性能和减少训练时间.大量的实验结果表明,在TPC-H和JOB真实数据集上ADP-Join的性能优于现有的智能优化器.

角色认同、内部动机、主观锻炼体验与青少年锻炼行为的关系研究

目的:运用交叉滞后研究设计,探讨青少年角色认同、内部动机、主观锻炼体验与锻炼行为的因果关系。方法:采用《锻炼认同量表》中的角色认同分量表,《因果控制点知觉量表》的内部动机分量表,《主观锻炼体验量表》的积极幸福感和心理困扰分量表,以及《体育活动等级量表》等,对1091名青少年(45.28%男生)进行为期12周、两阶段的纵向问卷调查。结果:对于青少年,角色认同、内部动机、主观锻炼体验和锻炼行为的性别、学段差异显著(各指标男性皆高于女性,初中生皆高于高中生);角色认同、内部动机、主观锻炼体验与锻炼行为皆具有跨时间的稳定正相关;交叉滞后分析显示,角色认同与内部动机、角色认同与锻炼行为分别存在互为因果的关系,且内部动机能够单向预测12周后的锻炼行为和主观锻炼体验,锻炼行为能够单向预测12周后的主观锻炼体验,主观锻炼体验能够单向预测12周后的角色认同。结论:在青少年体育锻炼情境中,角色认同、内部动机、主观锻炼体验和锻炼行为具有性别、学段的非一致性特征;角色认同与内部动机、角色认同与锻炼行为分别存在互促、互抑关系,且内部动机是锻炼行为、主观锻炼体验的原因变量,锻炼行为是主观锻炼体验的原因变量,主观锻炼体验是角色认同的原因变量。