Mapping soil organic matter in cultivated land based on multi-year composite images on monthly time scales

Rapid and accurate acquisition of soil organic matter(SOM)information in cultivated land is important for sustainable agricultural development and carbon balance management.This study proposed a novel approach to predict SOM with high accuracy using multiyear synthetic remote sensing variables on a monthly scale.We obtained 12 monthly synthetic Sentinel-2 images covering the study area from 2016 to 2021 through the Google Earth Engine(GEE)platform,and reflectance bands and vegetation indices were extracted from these composite images.Then the random forest(RF),support vector machine(SVM)and gradient boosting regression tree(GBRT)models were tested to investigate the difference in SOM prediction accuracy under different combinations of monthly synthetic variables.Results showed that firstly,all monthly synthetic spectral bands of Sentinel-2 showed a significant correlation with SOM(P<0.05)for the months of January,March,April,October,and November.Secondly,in terms of single-monthly composite variables,the prediction accuracy was relatively poor,with the highest R^(2)value of 0.36 being observed in January.When monthly synthetic environmental variables were grouped in accordance with the four quarters of the year,the first quarter and the fourth quarter showed good performance,and any combination of three quarters was similar in estimation accuracy.The overall best performance was observed when all monthly synthetic variables were incorporated into the models.Thirdly,among the three models compared,the RF model was consistently more accurate than the SVM and GBRT models,achieving an R^(2)value of 0.56.Except for band 12 in December,the importance of the remaining bands did not exhibit significant differences.This research offers a new attempt to map SOM with high accuracy and fine spatial resolution based on monthly synthetic Sentinel-2 images.

“磨玻璃影”特征的早期肺腺癌中MPP成分的突变特征分析及ZNF469基因的探索

背景与目的目前,肺癌依然是我国发病率和死亡率最高的恶性肿瘤。而在早期肺腺癌(lung adenocarcinoma,LUAD)中,微乳头(micropapillary,MPP)成分尤其常见,且通常表现出高侵袭性,其与早期转移、淋巴浸润的风险以及患者的5年生存率显著相关。本研究旨在探究以磨玻璃影(ground-glass opacities,GGOs)为特征的早期LUAD中MPP成分和非MPP成分的异同,寻找MPP成分所特有的突变特征,并分析锌指蛋白家族的ZNF469基因与早期LUAD预后以及免疫浸润的关系。方法收集31例LUAD恶性肺结节,采用显微解剖法将其分为成对的MPP和非MPP成分。对早期恶性肺结节组分进行全外显子组测序(whole-exome sequencing,WES),利用maftools、非负矩阵分解(Nonnegative Matrix Factorization,NMF)法、Sigminer等方法进行突变特征分析,以揭示侵袭性LUAD中MPP组分相比于其他肿瘤组织所特有的基因组突变特征。利用癌症基因组图谱(The Cancer Genome Atlas,TCGA)的LUAD数据库中ZNF469的表达情况,探讨其与肺癌预后的关系;利用GeneMANIA数据库以及基因本体(Gene Ontology,GO)、京都基因与基因组百科全书(Kyoto Encyclopedia of Genes and Genomes,KEGG)富集分析探索LUAD中与ZNF469相关基因的互作网络及信号通路;利用TIMER和TISIDB数据库分析ZNF469表达与LUAD中免疫细胞浸润水平的相关性。结果MPP成分具有较多的基因组变异,相比于非MPP成分的肿瘤组织,癌症体细胞突变目录(Catalogue of Somatic Mutations in Cancer,COSMIC)的13号突变特征(胞苷脱氨酶家族,APOBEC)是MPP成分所特有的,这提示其参与了MPP成分对LUAD早期侵袭过程的促进作用;并且APOBEC特征高的MPP样本具有更高的肿瘤突变负荷(tumor mutational burden,TMB),提示这些患者更能从免疫治疗中获益。LUAD中突变ZNF469的表达高于正常组织,与LUAD患者的不良预后有关。基因互作网络分析以及GO和KEGG富集分析发现,COL6A1、COL1A1、COL1A2、TGFB2、MMP2、COL8A2、C2CD4C等与ZNF469具有相互作用,且主要与编码胶原蛋白、参与细胞外基质构成有关。ZNF469表达与肿瘤的免疫浸润呈正相关。结论本研究揭示了中国人群侵袭性LUAD中MPP成分的特有突变特征,并发现突变ZNF469的高表达影响LUAD预后与免疫浸润,推测ZNF469可作为LUAD潜在的诊断及预后生物标志物。

肺腺癌中免疫微环境特征与EGFR突变状态的相关性研究

背景与目的在全球范围内肺癌发病率和死亡率一直居高不下,而肺腺癌是其中最主要的一个组织亚型,表皮生长因子受体(epidermal growth factor receptor,EGFR)突变是肺腺癌的一个重要驱动基因突变。近年来以程序性死亡受体1(programmed cell death 1,PD-1)及程序性死亡配体1(programmed cell death ligand 1,PD-L1)抑制剂为代表的免疫检查点抑制剂(immune checkpoint inhibitors,ICIs)治疗在部分肺癌患者中疗效显著。有研究表明EGFR突变的患者对免疫治疗的获益程度有限,本研究旨在讨论肺腺癌患者中EGFR突变状态与各类免疫细胞浸润数量、空间分布的关系。方法本研究纳入62例接受手术的肺腺癌患者。通过对手术切除的肿瘤组织进行不同区域多点采样,最终获取了223份肿瘤组织样本。通过基因检测获取了每份肿瘤组织的EGFR突变情况,包括突变丰度(variant allele frequency,VAF)以及突变亚型等信息。对肿瘤组织进行苏木精-伊红(hematoxylin-eosin,HE)染色、免疫组化染色、多重荧光免疫组化染色,并通过计算免疫组化评分获取各类免疫细胞在肿瘤组织中的浸润情况以及三级淋巴结构(tertiary lymphoid structure,TLS)的分布情况。结果与野生型患者相比,EGFR突变肺腺癌患者肿瘤组织中CD68^(+)巨噬细胞以及组织相容性复合物(major histocompatibility complex,MHC)II类抗原呈递细胞浸润更多,且MHC II类抗原呈递细胞空间分布的异质性较大,而CD56^(+)自然杀伤细胞以及CD8^(+)T细胞等浸润更低。EGFR VAF高的肿瘤组织与更低的CD3^(+)T细胞、CD20^(+)B细胞、CD56^(+)自然杀伤细胞、CD68^(+)巨噬细胞、CD8^(+)T细胞等细胞浸润相关,其中只有CD3^(+)T细胞分布的空间异质性较小。对于中国人群常见的两种EGFR突变亚型,EGFR外显子19缺失突变相较于EGFR外显子21 L858R突变肿瘤组织中有更低的免疫细胞浸润,但CD3^(+)T细胞、CD56^(+)自然杀伤细胞、CD68^(+)巨噬细胞以及CD8^(+)T细胞等免疫细胞分布的空间异质性更高。预后分析发现,CD3^(+)T细胞、CD20^(+)B细胞浸润程度高、TLS形成数量多以及CD8^(+)T细胞高分布异质性的EGFR突变患者拥有更长的无病生存期。结论EGFR突变肺腺癌具有独特的低免疫细胞浸润的“非炎性”肿瘤微环境,不同突变亚型以及VAF的肿瘤微环境之间也表现出异质性,这些差异不仅体现在免疫细胞的浸润数量上,也体现在免疫细胞的空间分布情况。因此对EGFR突变肺腺癌的免疫微环境进行进一步更深入的研究对未来提高EGFR突变肺腺癌患者的免疫治疗疗效具有重大意义。

Geometry and tectonic deformation of the seismogenic structure for the 8 August 2017 M_S 7.0 Jiuzhaigou earthquake sequence,northern Sichuan, China

To reveal the geometry of the seismogenic structure of the Aug. 8, 2017 M_S 7.0 Jiuzhaigou earthquake in northern Sichuan,data from the regional seismic network from the time of the main event to Oct. 31, 2017 were used to relocate the earthquake sequence by the tomoDD program, and the focal mechanism solutions and centroid depths of the M_L ≥ 3.5 events in the sequence were determined using the CAP waveform inversion method. Further, the segmental tectonic deformation characteristics of the seismogenic faults were analyzed preliminarily by using strain rosettes and areal strains(As). The results indicate:(1) The relocated M_S 7.0 Jiuzhaigou earthquake sequence displays a narrow ～ 38 km long NNW-SSE-trending zone between the NW-striking Tazang Fault and the nearly NSstriking Minjiang Fault, two branches of the East Kunlun Fault Zone. The spatial distribution of the sequence is narrow and deep for the southern segment, and relatively wide and shallow for the northern segment. The initial rupture depth of the mainshock is 12.5 km, the dominant depth range of the aftershock sequence is between 0 and 10 km with an average depth of 6.7 km. The mainshock epicenter is located in the middle of the aftershock region, showing a bilateral rupture behavior. The centroid depths of 32 M_L ≥ 3.5 events range from 3 to 12 km with a mean of about 7.3 km, consistent with the predominant focal depth of the whole sequence.(2) The geometric structure of the seismogenic fault on the southern section of the aftershock area(south of the mainshock) is relatively simple, with overall strike of ～150° and dip angle ～75°, but the dip angle and dip-orientation exhibit some variation along the segment. The seismogenic structure on the northern segment is more complicated; several faults, including the Minjiang Fault, may be responsible for the aftershock activities. The overall strike of this section is ～159° and dip angle is ～59°, illustrating a certain clockwise rotation and a smaller dip angle than the southern segment. The differences between the two segments demonstrate variation of the geometric structure along the seismogenic faults.(3) The focal mechanism solutions of 32 M_L ≥ 3.5 events in the earthquake sequence have obvious segmental characteristics. Strike-slip earthquakes are dominant on the southern segment, while 50% of events on the northern segment are thrusting and oblique thrusting earthquakes, revealing significant differences in the kinematic features of the seismogenic faults between the two segments.(4) The strain rosettes for the mainshock and the entire sequence of 31 M_L ≥ 3.5 aftershocks correspond to strike-slip type with NWW-SEE compressional white lobes and NNE-SSW extensional black lobes of nearly similar size. The strain rosette and As value of the entire sequence of 22 M_L ≥ 3.5 events on the southern segment are the same as those of the M_S 7.0 mainshock,indicating that the tectonic deformation here is strike-slip. However, the strain rosette of the entire sequence of 10 M_L ≥ 3.5 events on the northern segment show prominent white compressional lobes and small black extensional lobes, and the related As value is up to 0.52,indicating that the tectonic deformation of this segment is oblique thrusting with a certain strike-slip component. Differences between the two segments all reveal distinctly obvious segmental characteristics of the tectonic deformation of the seismogenic faults for the Jiuzhaigou earthquake sequence.

A New Species of Odorous Frog Genus Odorrana(Anura,Ranidae) from Southern Guizhou Province,China

We describe Odorrana liboensis sp.nov.,a new species from the Maolan National Nature Reserve,Libo County,Guizhou Province,China.Phylogenetic analyses based on DNA sequences of the mitochondrial 12 S rRNA,16 S rRNA,and ND2 genes supported the new species as an independent lineage,closely related to O.lipuensis.The uncorrected genetic distances between the 12 S rRNA and16 S rRNA in the new species and its closest congener,O.lipuensis,were 6.06%and 5.19%,respectively.The new species is distinguished from its congeners by a combination of the following morphological characters:(1)having medium body size,with the snout-vent length(SVL)of adult females approximately 1.2 times as long as males at 56.9±1.0(55.8-58.2 mm,n=9)in females and 48.7±1.2(47.1-49.9 mm,n=5)in males;(2)head length greater than width in males and females;(3)tympanum distinctly visible,greater than one-half the diameter of the eye;(4)eyes big and prominent,width of upper eyelid(UEW)approximately3/4 of eye diameter(ED);(5)dorsolateral folds absent;(6)two metacarpal tubercles;(7)relative finger lengths:Ⅱ<Ⅰ<Ⅳ<Ⅲ;(8)subarticular tubercles on fingers prominent:1,1,2,2;(9)one metatarsal tubercle;(10)tibiotarsal articulation reaching to between the eye and nostril when the leg is stretched forward;(11)toes with entire webbing to disks;(12)subarticular tubercles on toes prominent:1,1,2,3,2;(13)dorsal surfaces of limbs with distinct brownish-black bands;(14)smooth,grass-green dorsum with irregular brown mottling;(15)venter smooth,lacking black spots;and(16)lacking pectoral spinules,lacking vocal sacs,and light white nuptial pad present on finger I in males.The new species is currently only known from the type locality.

Effects of Replacing Maize Silage with Silage Sweet Sorghum on Milk Production and Blood Biochemical Indexes of Dairy Cows

In order to study the effects of replacing different proportions of silage maize with silage sweet sorghum treated by different fermentation methods on the production performance and blood biochemical indexes of dairy cows,25 Chinese Holstein lactating cows were randomly divided into 5 groups,5 in each group.The control check (CK) was fed the basal diet;for the experimental group 1 and the experimental group 2,50% of the silage maize in the basal diet was replaced with the additive silage sweet sorghum and the conventional silage sweet sorghum,respectively;and as to the experimental group 3 and the experimental group 4,all the silage maize in the basal diet was replaced with additive silage sweet sorghum and conventional silage sweet sorghum,respectively.The preliminary trial period was 7 d,and the trial period was 35 d.The results showed that the experimental group 1 and the experimental group 3 had the dry matter intake significantly higher than that of the experimental group 2,the experimental group 4 and the CK ( P <0.05).The daily milk yields of the experimental group 1 and the experimental group 2 were significantly lower than that of the CK ( P <0.05),and the experimental group 3 and the experimental group 4 were significantly lower than the experimental group 1 and the experimental group 2 ( P <0.05).The milk protein percentage of the experimental group 2 was extremely significantly higher than that of the experimental group 4 ( P <0.01).The experimental group 1,the experimental group 2 and the experimental group 3 showed the blood glucose levels extremely significantly higher than that in the CK ( P <0.01).The blood urea nitrogen contents in the experimental group 2 and the experimental group 4 were significantly higher than those in the experimental group 1 and the CK ( P <0.01).There were no significant differences in other blood biochemical indexes between various groups ( P >0.05).It is feasible to use silage sweet sorghum to feed dairy cows,but the proportion should not be too large,and attention should be paid to the energy and nitrogen balance of the diet.

Limited Heredity Diversity of the Critically Endangered Guizhou Golden Monkeys

Guizhou golden monkey(Rhinopithecus brelichi)was a unique,endangered and endemic primate species in Guizhou Province.It was an isolated population caused by habitat loss and fragmentation due to the human disturbance in the recently 30 years in China,only distributed in Fanjingshan National Natural Reserve,Guizhou Province.To know the background with demonic population structure,we sequenced 867 bp of the mitochondrial DNA D-loop from 312 fresh fecal samples,results showed there 11 haplotypes among these samples,h was 0.517,πwas 0.00413.It indicated that this species had the lowest genetic diversity among four golden monkeys in China and need strengthen the conversation concern for this species immediately.

Incorporation of source contributions to improve the accuracy of soil heavy metal mapping using small sample sizes at a county scale

Estimating heavy metal(HM) distribution with high precision is the key to effectively preventing Chinese medicinal plants from being polluted by the native soil. A total of 44 surface soil samples were gathered to detect the concentrations of eight HMs(As, Hg, Cu, Cr, Ni, Zn, Pb, and Cd) in the herb growing area of Luanping County, northeastern Hebei Province, China. An absolute principal component score-multiple linear regression(APCS-MLR) model was used to quantify pollution source contributions to soil HMs. Furthermore, the source contribution rates and environmental data of each sampling point were simultaneously incorporated into a stepwise linear regression model to identify the crucial indicators for predicting soil HM spatial distributions. Results showed that 88% of Cu, 72% of Cr, and 72% of Ni came from natural sources;50% of Zn, 49% of Pb, and 59% of Cd were mainly caused by agricultural activities;and 44% of As and 56% of Hg originated from industrial activities. When three-type(natural, agricultural, and industrial) source contribution rates and environmental data were simultaneously incorporated into the stepwise linear regression model, the fitting accuracy was significantly improved and the model could explain 31%–86% of the total variance in soil HM concentrations. This study introduced three-type source contributions of each sampling point based on APCS-MLR analysis as new covariates to improve soil HM estimation precision, thus providing a new approach for predicting the spatial distribution of HMs using small sample sizes at the county scale.

Controlled fluorescent switch based on a cation grease/brake rotor system of pillar[5]arene

In recent years,molecular shuttles,motors,pumps,and elevators,etc.could specifically respond external physical or chemical stimuli including light,temperature,pH,redox,solvent and chemical additive to change the structure and function,showing great potential in materials and biological applications[1,2].

Frequent detection of genetic aberrations reveals novel pathogenesis and treatment modalities in systemic juvenile xanthogranuloma

Juvenile xanthogranuloma(JXG),the most common form of non-Langerhans cell histiocytosis(non-LCH),is generally confined to the skin during infancy and early childhood.^(1)JXG rarely involves extracutaneous tissues or systemic organs,resulting in high morbidity and mortality rates.Clonality in JXG has been verified by histopathological and genetic analyses,which have shown it to be tumorous rather than a reactive disorder of JXG.^(2)However,the exact etiopathogenesis of JXG remains unclear.

零工平台模式下电子绩效监控对零工工作者持续价值共创行为的影响

零工经济是共创经济形式,持续价值共创行为是零工平台企业持续发展的基础。然而,零工平台企业中的哪些因素会对持续价值共创产生影响却鲜有研究。基于社会交换理论,本研究探讨电子绩效监控对持续价值共创行为的影响机理,并考察心理契约的中介作用以及顾客反馈的调节作用。通过对各大出行平台392名零工从业者进行问卷调查,结果表明:发展型电子绩效监控通过正向影响关系型心理契约、负向影响交易型心理契约来正向影响持续价值共创行为;预防型电子绩效监控通过负向影响关系型心理契约、正向影响交易型心理契约来负向影响持续价值共创行为;顾客反馈增强了关系型心理契约与持续价值共创行为的关系,同时也增强了关系型心理契约在电子绩效监控与持续价值共创行为之间的中介作用。研究揭示了不同电子绩效监控感知对持续价值共创的影响机制,为零工平台组织优化监控设计提供了启示。

Molecular phylogeny and historical biogeography of the cave fish genus Sinocyclocheilus(Cypriniformes:Cyprinidae)in southwest China

Modern accumulations of genetic data offer unprecedented opportunities for understanding the systematic classification and origins of specific groups of organisms.The genus Sinocyclocheilus is among the most cave abundant genera in Cyprinidae,with 76 recognized species,belonging to 4 species groups.Recent phylogenetic studies have shown that the classification of species groups within the genus Sinocyclocheilus remains controversial.In this study,we constructed a sequence supermatrix of 26 species from 4 species groups of the genus Sinocyclocheilus using the mitochondrial genome to reveal phylogenetic relationships,historical biogeography and patterns of species diversification in the genus Sinocyclocheilus.Phylogenetic analysis strongly supports the monophyletic groups of the 3 species groups(S.jii,S.cyphotergous,and S.tingi groups)except the S.angularis group.Phylogenetic analysis showed that S.anshuiensis and S.microphthalmus,which were recognized as numbers of S.angularis group,formed a strongly supported independent clade.Therefore,we propose a new species group,the S.microphthalmus group,which contains S.anshuiensis and S.microphthalmus.Biogeographic reconstruction suggests that the living Sinocyclocheilus may have originated in north-central Guangxi at the late Eocene and dispersed outward after a vicariance at 32.31 Million years ago(Ma).Early diversification is focused on the late Oligocene(ca.25 Ma),which is related to the second uplift of the Qinghai−Tibetan Plateau and the lateral extrusion of the Indochina at the Oligocene/Miocene boundary.Our results suggest that 2 uplifts of the Qinghai−Tibetan Plateau and climate change in the Miocene may have influenced the diversification of the Sinocyclocheilus lineage.

LncRNA LINC00525 suppresses p21 expression viamRNA decay and triplex-mediated changes in chromatin structure in lung adenocarcinoma

Background:Emerging evidence suggests that long noncoding RNAs(lncRNAs)play crucial roles in various cancers.In the present study,we aim to investigate the function and molecular mechanism of an up-regulated and survivalassociated lncRNA,LINC00525,in lung adenocarcinoma(LUAD).Methods:The expression level of LINC00525 in tissueswas determined by quantitative reverse transcription polymerase chain reaction(RT-qPCR)and in situ hybridization(ISH).The functional role of LINC00525 in LUAD was investigated using gain-and loss-of-function approaches,both in vivo and in vitro.RNA pull-down,RNA immunoprecipitation(RIP),chromatin immunoprecipitation(ChIP),triplex-capture assay,dual-luciferase assay,gene expression microarray,and bioinformatics analysis were used to investigate the potential underlying mechanisms involved.Results:LINC00525 is highly expressed in LUAD cells and tissues.Survival analysis indicated that upregulation of LINC00525 was associated with poor prognosis in patients with LUAD patients.Knockdown of LINC00525 inhibited cell proliferation and cell cycle progression in vitro.In xenograft models,LINC00525 knockdown suppressed tumor growth and tumorigenesis of tumorbearing mice.Mechanistically,LINC00525 epigenetically suppressed p21 transcription by guiding Enhancer Of Zeste 2 Polycomb Repressive Complex 2 Subunit(EZH2)to the p21 promoter through an formation of RNA-DNA triplex with the p21 promoter,leading to increased trimethylation of lysine 27 on histone 3(H3K27me3)of the p21 promoter.In addition,LINC00525 repressed p21 expression post-transcriptionally by enhancing p21mRNA decay.LINC00525 promoted p21mRNAdecay by competitively binding toRNABindingMotif Single Stranded Interacting Protein 2(RBMS2).Conclusion:Our findings demonstrate that LINC00525 promotes the progression of LUAD by reducing the transcription and stability of p21 mRNA in concert with EZH2 and RBMS2,thus suggesting that LINC00525 may be a potential therapeutic target for clinical intervention in LUAD.

Meiotic nuclear divisions 1(MND1)fuels cell cycle progression by activating a KLF6/E2F1 positive feedback loop in lung adenocarcinoma

Background:Considering the increase in the proportion of lung adenocarcinoma(LUAD)cases among all lung cancers and its considerable contribution to cancer-related deaths worldwide,we sought to identify novel oncogenes to provide potential targets and facilitate a better understanding of the malignant progression of LUAD.Methods:The results from the screening of transcriptome and survival analyses according to the integrated Gene Expression Omnibus(GEO)datasets and The Cancer Genome Atlas(TCGA)data were combined,and a promising risk biomarker called meiotic nuclear divisions 1(MND1)was selectively acquired.Cell viability assays and subcutaneous xenograftmodelswere used to validate the oncogenic role ofMND1 in LUADcell proliferation and tumor growth.Aseries of assays,including mass spectrometry,co-immunoprecipitation(Co-IP),and chromatin immunoprecipitation(ChIP),were performed to explore the underlying mechanism.Results:MND1 up-regulation was identified to be an independent risk factor for overall survival in LUAD patients evaluated by both tissue microarray staining and third party data analysis.In vivo and in vitro assays showed that MND1 promoted LUAD cell proliferation by regulating cell cycle.The results of the Co-IP,ChIP and dual-luciferase reporter assays validated that MND1 competitively bound to tumor suppressor Kruppel-like factor 6(KLF6),and thereby protecting E2F transcription factor 1(E2F1)from KLF6-induced transcriptional repression.Luciferase reporter and ChIP assays found that E2F1 activated MND1 transcription by binding to its promoter in a feedback manner.Conclusions:MND1,KLF6,and E2F1 form a positive feedback loop to regulate cell cycle and confer DDP resistance in LUAD.MND1 is crucial for malignant progression and may be a potential therapeutic target in LUAD patients.

Photodegradation of new herbicide HW-02 in organic solvents

HW-02 is a new organophosphates herbicide which is discovered and developed in China. The kinetics and mechanism of HW-02 photodegradation in the organic solvents were studied at 25°C under the irradiation of ultraviolet light. The results showed that photochemical reaction of HW-02 in organic solvents such as n-hexane, methanol, dimethyl benzene and acetone under UV light could be well described by the first kinetic equation, and the photodegradation efficiency decreased with a order of n-hexane methanol xylene acetone. The photodegradation efficiency constant of HW-02 in n-hexane, methanol, xylene and acetone were 4.951 × 10^-2 , 3.253 × 10^-2 , 2.377 × 10^-2 and 1.628 × 10^-2 min 1 , and the corresponding half-lives were 13.99, 21.20, 29.15 and 42.56 min, respectively. By separation and identification of photoproducts using GC-MS, it could be concluded that HW-02 was photolyzed through ester cleavage, photo-dechlorination and photoisomerization of the molecule itself.

Patient-directed vs.fixed-volume PEG for colonoscopy preparation:a randomized controlled trial

Background:Individualization using different volumes of polyethylene glycol is widely regarded as the optimal solution for bowel preparation,while the patient-directed regimen we propose may serve as a reliable individual solution.This study aimed to assess the efficacy,safety,and satisfaction of bowel preparation with a patient-directed regimen.Methods:Patients in the fixed-volume group ingested the same amount of PEG,while those in patient-directed group ingested different amount according to stool consistency or stool water content.Results:After filtering by exclusion criteria,428 individuals in the fixed-volume group and 103 in the patient-directed group were successfully enrolled and analyzed.Eighty-three(80.6%)individuals in the patient-directed group had a reduced polyethylene glycol volume.There was no significant difference in the bowel preparation efficacy between the two groups(90.0%vs.90.3%,χ^(2)=0.01;p=0.918).Patients in the patient-directed group complained of fewer adverse effects(53.0%vs.36.9%,χ^(2)=8.655;p=0.003),especially vomiting(13.6%vs.1.0%,χ^(2)=13.304;p<0.001).Regarding comfort during bowel preparation,the degree of comfort was not significantly different between groups.Furthermore,the willingness rate for further colonoscopy in the patient-directed group was significantly higher than that in the fixed-volume group(90.3%vs.77.1%,χ^(2)=8.912;p<0.05).Multivariable logistic regression analysis showed that the body mass index served as an independent factor impacting quality of bowel preparation with the patient-directed regimen(OR 1.16,95%CI 1.00–1.34;p=0.043).Conclusions:Without decreasing the bowel preparation efficacy,the patient-directed regimen increased the safety and satisfaction of bowel preparation and is expected to be a regular and individual solution for bowel preparation.Individuals with a lower body mass index are more likely to undertake this new regimen.