ChIP-cloning analysis uncovers centromere-specific retrotransposons in Brassica nigra and reveals their rapid diversification in Brassica allotetraploids.

Centromeres are indispensable functional units of chromosomes. The evolutionary mechanisms underlying the rapid evolution of centromeric repeats, especially those following polyploidy, remain unknown. In this study, we isolated centromeric sequences of Brassica nigra, a model diploid progenitor (B genome) of the allopolyploid species B. juncea (AB genome) and B. carinata (BC genome) by chromatin immunoprecipitation of nucleosomes containing the centromere-specific histone CENH3. Sequence analysis detected no centromeric satellite DNAs, and most B. nigra centromeric repeats were found to originate from Tyl/copia-class retrotransposons. In cytological analyses, six of the seven analyzed repeat clusters had no FISH signals in A or C genomes of the related diploid species B. rapa and B. oleracea. Notably, five repeat clusters had FISH signals in both A and B subgenomes in the tetraploid B. juncea. In the tetraploid B. carinata, only CL23 displayed three pairs of signals in terminal or interstitial regions of the C-derived chromosome, and no evidence of colonization of CLs onto C-subgenome centromeres was found in B. carinata. This observation suggests that centromeric repeats spread and proliferated between genomes after polyploidization. CL3 and CRB are likely ancient centromeric sequences arising prior to the divergence of diploid Brassica which have detected signals across the genus. And in allotetraploids B. juncea and B. carinata, the FISH signal intensity of CL3 and CRB differed among subgenomes. We discussed possible mechanisms for centromeric repeat divergence during Brassica speciation and polyploid evolution, thus providing insights into centromeric repeat establishment and targeting.

Attractiveness-related recognition bias captures the memory of the beholder.

Earlier electroencephalographic studies have compared attractive and unattractive faces and between faces with other objects, such as flowers, without revealing if a recognition memory bias toward faces and flowers exists or whether humans exhibit enhanced specific components toward all attractive objects or only toward attractive faces. For objects with similar degrees of attractiveness, we sought to determine if the N170, P1, and N250 reflect upon the attractiveness of faces and flowers and demonstrated by comparing event-related potentials of humans' different perceptual mechanisms recognizing high attractive faces and high attractive flowers. The repeated high attractive faces tended to elicit a larger N170. Simultaneously, the P1 was preferentially associated with the repeated high attractive flowers, but both indicated that the repetitive enhancement effect only occurred on repeated attractive faces. Thus, differences existed in the perceptual mechanisms for processing repeated high attractive faces and repeated high attractive flowers. However, there was no significant difference in N250 between repeated faces and repeated flowers or between high attractive faces and high attractive flowers. Consequently, high attractive faces and high attractive flowers capture the beholder's memory bias in different processing stages. The N170 and P1 components are affected by attractiveness, thereby demonstrating the differences between human perceptual mechanisms in recognizing high attractive faces and objects.

Minimally invasive procedure for diagnosis and treatment of vallecular cysts in children: review of 156 cases.

PURPOSE: Vallecular cyst is an uncommon but potentially life-threatening disease. The aim of this study was to review the presentation, evaluation, and treatment of vallecular cysts in children. METHODS: Medical records of 156 patients treated for vallecular cysts between 2013 and 2016 were retrospectively reviewed. The patients were divided into four age groups for comparison of clinical data: A, < 1 month; B, 1-6 months; C, 7-12 months; and D, > 1 year. RESULTS: The median age of all patients (98 males and 58 females) was 12.1 months (range 1 day-11 years), including 21, 86, 21, and 28 patients in group A, B, C, and D, respectively. A diagnosis of vallecular cysts was made for 135 patients using a combination of flexible laryngoscopy and ultrasound, and ten patients (all in group A) required pre-surgery ventilation support. The most common symptoms were wheezing (59.6%) and stridor (36.5%). Ten patients experienced difficulty with intubation. Endoscopic-assisted transoral coblation marsupialization was performed for all patients, combined with supraglottoplasty for 41 out of 68 patients with concurrent laryngomalacia. Patients in group D had a longer operation time and higher incidence of intraoperative bleeding, two of whom experienced post-operation recurrence, and symptoms resolved after a second operation in both cases. CONCLUSIONS: Flexible laryngoscopy and ultrasound are recommended for a diagnosis in suspected cases of vallecular cysts. Coblation marsupialization has advantages of minor damage, low recurrence rate, and suitability for all age groups.

Synthesis of two new gem-fluoronitro containing tetranitroadamantanes and property comparison with their nitro and gem-dinitro analogues.

Two new fluorinated tetranitroadamantanes, 2,6-difluoro-2,4,4,6-tetranitroadamantane and 2,4,6,8-tetrafluoro-2,4,6,8-tetranitroadamantane, were synthesized. 2,6-Difluoro-2,4,4,6-tetranitroadamantane was prepared from 4,4-dinitroadamantane-2,6-dione by a three-step route with an overall yield of 40%. It has a slightly higher crystal density (1.787 g cm-3) than its analogue 2,2,4,4,6,6-tetranitroadamantane (1.777 g cm-3). 2,4,6,8-Tetrafluoro-2,4,6,8-tetranitroadamantane was prepared from 4,8-dihydroxyadamantane-2,6-dione by an eight-step route with an overall yield of 8%. It is notable that the replacement of one nitro group in the gem-dinitro functionality with fluorine might slightly reduce the detonation performance but improve the density and inherent steric hindrance, which makes it possible to introduce more nitro functionalities on the adamantane backbone.

Karyotypes and Distribution of Tandem Repeat Sequences in Brassica nigra Determined by Fluorescence in situ Hybridization.

Whole-genome shotgun reads were analyzed to determine the repeat sequence composition in the genome of black mustard, Brassica nigra (L.) Koch. The analysis showed that satellite DNA sequences are very abundant in the black mustard genome. The distribution pattern of 7 new tandem repeats (BnSAT13, BnSAT28, BnSAT68, BnSAT76, BnSAT114, BnSAT180, and BnSAT200) on black mustard chromosomes was visualized using fluorescence in situ hybridization (FISH). The FISH signals of BnSAT13 and BnSAT76 provided useful cytogenetic markers; their position and fluorescence intensity allowed for unambiguous identification of all 8 somatic metaphase chromosomes. A karyotype showing the location and fluorescence intensity of these tandem repeat sequences together with the position of rDNAs and centromeric retrotransposons of Brassica (CRB) was constructed. The establishment of the FISH-based karyotype in B. nigra provides valuable information that can be used in detailed analyses of B. nigra accessions and derived allopolyploid Brassica species containing the B genome.

Acid/Phosphide-Induced Radical Route to Alkyl and Alkenyl Sulfides and Phosphonothioates from Sodium Arylsulfinates in Water.

A newly developed aqueous system with acid and phosphide was introduced in which odorless and stable sodium arylsulfinates can in situ generate arylsulfenyl radicals. These radicals have high reactivity to react with alkynes, alkenes, and H-phosphine oxides for the synthesis of alkyl and alkenyl sulfides and phosphonothioates. The control experiments and quantum calculations are also performed to gain insights into the generation mechanism of arylsulfenyl radicals. Notably, the chemistry is free of thiol odors, organic solvents, and metals.

Absorption mechanism of oxymatrine in cultured Madin-Darby canine kidney cell monolayers.

Context Oxymatrine (OMT) is beneficial to human health by exerting various biological effects. Objective To investigate the absorption mechanism of OMT and discover absorption enhancers using Madin-Darby canine kidney (MDCK) cell monolayers. Materials and methods Concentration effects on the transport of OMT were measured in the range of 1.0 × 10(-5)-1.0 × 10(-3) M in 2 h. Then, the effect of time, direction, temperature and pH on the transport of OMT at 10(-4) M was studied. Moreover, Papp of OMT was determined in the absence/presence of cyclosporine and surfactants at 100 µM to further confirm the relative transport mechanism. Results The Papp AP→BL ranged from (3.040 ± 0.23) × 10(-6) to (3.697 ± 0.19) × 10(-6 )cm/s as the concentration varied from 10(-5) to 10(-3) M. OMT showed similar Papp at 4 and 37 °C (p > 0.05). Increasing the apical pH 7.4 and 8.0 resulted in Papp versus pH 5.0 (p < 0.01). Furthermore, in the presence of cyclosporine and surfactants including sodium citrate, sodium dodecyl sulphate (SDS) and deoxysodium cholate, Papp was (0.318 ± 0.033) × 10(-5), (0.464 ± 0.048) × 10(-5), (0.897 ± 0.115) × 10(-5) and (1.341 ± 0.122) × 10(-5 )cm/s, respectively. In the presence of surfactants, Papp significantly increased up to 1.5-4.3-fold (p < 0.05). Discussion and conclusion OMT transport across MDCK cell monolayers was by passive diffusion. Sodium citrate, SDS and deoxysodium cholate serve as excellent absorption enhancers which are useful for the related research improving the oral bioavailability of OMT.

HIV-infected female sex workers' high risk behavior and attitude changes in Kaiyuan City, Yunnan Province, China.

OBJECTIVE: To investigate the attitude and sexual behavior status and change among HIV positive female workers in entertainment sites in Kaiyuan city, Yunnan province, China. The key information should be applied in the integrated intervention program in future. METHODS: A cohort survey among HIV positive female workers was conducted during 12 months, between 2010 and 2012. All the risk sexual behavior and attitude were collected for assessment for the potential secondary transmission to sexual partners. RESULTS: Of 99 HIV positive women who sell sex in Kaiyuan city, 99 participated in the survey at baseline, 80, 80, 75, and 75 at 3-, 6-, 9-, and 12-month follow-ups. The percentage of participants who reported consistently used condoms in the last one month ranged between 94.5% and 95.5%. The client volume in the last one month, income per sex and age group were significant related with non-insistent condom use with their clients. CONCLUSION: It was suggested that integrated intervention program package should include 100 percent condom use promotion for the HIV positive FSW with all sexual partners, and also, include socially support involved.

[Development of national neglect norm for urban primary school students of China].

OBJECTIVE: To develop the national neglect norms for urban primary school students in China. METHODS: According to multi-stage stratified cluster sampling principle, 24 cities of 13 provinces (municipalities) in China were selected during December 1 to 31, 2008. A total of 1491 students in grade 1 - 3 and 2236 students in grade 4 - 6 were selected. Questionnaire was designed by authors and the final norms were determined through several statistical analysis methods, such as item analysis method, factor analysis method, reliability analysis method. The reliability analysis and validity analysis were used to test the stability and reliability of the norms. The evaluation criteria of the scale was determined by the percentile method, then the initial development of the norm was completed. RESULTS: The two questionnaires of grade 1 - 3 and grade 4 - 6 students consisted of 55 and 57 items, respectively, whose item loadings were ranged from 0.301 to 0.687 and 0.321 to 0.730, which met the statistical requirements. For grade 1 - 3 students, the scale's total Cronbach α coefficients was 0.914, the total split-half reliability coefficients was 0.896, the Cronbach α coefficients of four level was above 0.737 except medical and social neglect, split-half reliability was ranged from 0.461 to 0.757; for grade 4-6 students, the scale's total Cronbach α coefficients was 0.916, split-half reliability was 0.883, except social neglect, the Cronbach α coefficients of other level was ranged 0.457 to 0.856, split-half reliability was ranged from 0.500 to 0.798. The total neglect cut-off score of the two scales grade 1-3 and 4-6 were 125 and 155, respectively. CONCLUSION: The structure of two norms was reasonable. The scales have good stability and reliability.

Theoretical investigations on structure, density, detonation properties, and sensitivity of the derivatives of PYX.

The -NH(2), -NO(2), -N(3), -NHNO(2), and -ONO(2) substitution derivatives of PYX (2,6-bis(picrylamino)-3,5-dinitropyridine) were studied at the B3LYP/6-31G** level of density functional theory. The sublimation enthalpies and heats of formation (HOFs) in gas phase and solid state of these compounds were calculated. The theoretical predicted density (ρ), detonation pressure (P), and detonation velocity (D) showed that these derivatives have better detonation performance than PYX. The effects of substituent groups on HOF, ρ, P, and D were discussed. The order of contribution of various groups to P and D was -ONO(2) > -NO(2) > -NHNO(2) > -N(3) > -NH(2). Sensitivity was evaluated using the frontier orbital energies, bond orders, bond dissociation enthalpies (BDEs), and characteristic heights (h(50)). The trigger bonds in the pyrolysis process for these PYX derivatives may be Ring-NO(2), NH-NO(2), or O-NO(2) varying with the substituents. The h(50) of most compounds are larger than that of CL-20, and those of -NH(2), -NO(2), and most -ONO(2) derivatives are larger than that of RDX. The BDEs of the trigger bonds of all but the -ONO(2) derivatives are sufficiently large. Taking both detonation performance and sensitivity into consideration, some derivatives of PYX may be good candidates of explosives.

[Development of national neglect norms for children aged 3 to 6 years in rural areas of China].

OBJECTIVE: To develop the national neglect norms for rural children aged 3 to 6 years, which are suitable for Chinese situations. METHODS: According to the multi-stage stratified cluster sampling principle, 84 towns of 10 provinces or municipalities were selected in China. Children aged 3 to 6 years were surveyed in November 2010, the sample of analysis were 3240 (of whom males were 49.6% (1608/3240) and the Han nationality were 93.3% (3023/3240)). Questionnaire was designed by authors and deleted items that did not meet the requirements through several statistical analysis methods, such as item analysis method, factor analysis method, reliability analysis method. The reliability analysis and validity analysis were used to test the stability and reliability of the norm. The evaluation criteria of the scale was determined by the percentile method, then the initial development of the norm completed. RESULTS: After deleting inappropriate items by statistical processing, finally, the scale consisted of 57 items, and included 6 neglected dimensions (physical neglect, emotional neglect, educational neglect, safe neglect, medical neglect and social neglect). Its item loadings ranged from 0.359 to 0.789, which met the statistical requirements. The scale's total Cronbach α coefficients 0.904, the total split-half reliability coefficients were 0.820, the 6 neglect dimensions' Cronbach α coefficients ranged from 0.620 to 0.815, the 6 neglect dimensions' split-half reliability coefficients ranged from -0.034 to 0.789, the scale's parallel reliability were 0.785 and it's re-test reliability were 0.613. After construct validity, external validity and content validity testing, the result showed that this scale could effectively reflect the real neglected status of children investigated. The total neglect cut-off score of this scale were 121. CONCLUSION: The scale has good stability and reliability. And it adapts Chinese conditions and it's convenient to operate.

[The status of child neglect among rural areas children aged 0 - 6 years in China].

OBJECTIVE: To explore the status of child neglect among rural areas children aged 0 - 6 years in China. METHODS: A total of 7411 rural children aged 0 - 6 years old who were composed of two age groups (3315 children aged 0 - 2 years old and 4096 children aged 3 - 6 years old) were multistage stratified randomly sampled from 84 villages which were representative of 10 provinces of China, in accordance with sex and age in November 2010. To identify the child neglect based on the Neglect Norms for Children Aged 0 to 2 and 3 to 6 Years Old in Rural Areas of China, SPSS 13.0 was employed for analyzing neglect frequency and degree for every group of different age, sex and neglect type (including physical, emotional, educational, medical, safety and social neglects). χ(2) test and analysis of variance were also used. RESULTS: The degree of child neglect for the children aged 0 - 2 years old was 45.01 ± 7.56, the neglect frequency was 54.9% (1819/3315); the degree of child neglect for the children aged 3 - 6 years old was 44.42 ± 7.57, the neglect frequency was 53.8% (2203/4096). The neglect frequency of children aged 0, 1, 2 years old were 58.5% (654/1117), 52.2% (597/1144), 53.9% (568/1054) (P < 0.05). For children aged 3 - 6 years old, the degrees of emotional and safety neglect for males (44.60 ± 7.86, 36.82 ± 9.03) were higher than females (44.03 ± 7.72, 36.25 ± 9.05) (P < 0.05); and the frequencies of emotional and social neglect for males (16.8% (349/2072), 28.3% (586/2072)) were also higher than females (14.1% (286/2024), 24.8% (503/2024)) (P < 0.05). All children of two age groups suffered neglect mainly on one of the six neglect types (incidences were 20.6% (683/3315) and 22.7% (931/4096)). For 0-2 age groups, the higher neglect frequencies happened in the single-parent family and the remarried family (62.5% (15/24) and 63.2% (12/19)), but for children aged 3 - 6 years old groups, it happened in the single-parent family (60.0%, 27/45). CONCLUSION: Degree and frequency of child neglect among children aged 0 to 6 years old in the rural areas of China are high, and we should find out risk factors and provide efficient prevention measures.

[Effect of special oral care mode on periodontal health in adolescent orthodontic patients].

PURPOSE: To investigate the effect of special oral care mode on periodontal health of adolescent orthodontic patients. METHODS: From January 2019 to January 2020, one hundred adolescent orthodontic patients who received treatment in our hospital were randomly divided into experimental group and control group according to the principle of completely random number table, with 50 cases in each group. Patients in the control group were given routine oral care, while those in the experimental group were given special oral care; three months later, the periodontal health status of the two groups were compared using SPSS 21.0 software package. RESULTS: There was no significant difference in PLI and GI between the two groups before treatment (P＞0.05). After treatment, PLI and GI in the experimental group were significantly lower than those in the control group(P＜0.01). There was no significance difference in SBI and EDI before treatment between the two groups(P＞0.05). After treatment, SBI and EDI in the experimental group were significantly lower than those in the control group(P＜0.01). There was no significant difference in the scores of periodontal health knowledge before treatment between the two groups(P＞0.05). After treatment, the scores of the two groups were significantly increased(P＜0.01), and the scores of the experimental group were significantly higher than those of the control group (P＜0.01). The patients' satisfaction in the experimental group was significantly higher than that in the control group (90.00% vs 72.00%, P=0.022). CONCLUSIONS: Special oral care mode can significantly improve periodontal health status of adolescent orthodontic patients.

Looking for high energy density compounds applicable for propellant among the derivatives of DPO with -N3, -ONO2, and -NNO2 groups.

The derivatives of DPO (2,5-dipicryl-1,3,4-oxadiazole) are optimized to obtain their molecular geometries and electronic structures at the DFT-B3LYP/6-31G* level. The bond length is focused to primarily predict thermal stability and the pyrolysis mechanism of the title compounds. Detonation properties are evaluated using the modified Kamlet-Jacobs equations based on the calculated densities and heats of formation. It is found that there are good linear relationships between density, detonation velocity, detonation pressure, and the number of azido, nitrate, and nitramine groups. According to the largest exothermic principle, the relative specific impulse is investigated by calculating the enthalpy of combustion (ΔH(comb)) and the total heat capacity (C(p,gases)). It is found that the introduction of -N(3), -ONO(2), and -NNO(2) groups could increase the specific impulses and II-4, II-5, and III-5 are potential candidates for High Energy Density Materials (HEDMs). The effect of the azido, nitrate, and nitramine groups on the structure and the properties is discussed.

Theoretical prediction of properties of aliphatic polynitrates.

Aliphatic polynitrates are studied using the density functional theory B3LYP method with basis set 6-31G*. The assigned infrared spectrum is obtained and is used to compute the thermodynamic properties based on the frequencies scaled by 0.96 and the principle of statistic thermodynamics. On comparison of the theoretical densities with the experimental ones, the reliability of this theoretical method is tested. Detonation properties are evaluated using the modified Kamlet-Jacobs equations based on the calculated densities and heats of formation. According to the largest exothermic principle, the relative specific impulse (Is) is investigated by calculating the enthalpy of combustion (ΔH(comb)) and the total heat capacity (C(p,gases)). It is found that the introduction of methylene nitrate group could decrease the specific impulses on whole. Moreover, in combination with the energetic properties, xylitol pentanitrate, mannitol hexanitrate, volemitol heptanitrate, and 1,2,3,4,5,6,7,8-octanitrate n-octane are potential candidates for high energy density compounds.

Production and characterization of interspecific somatic hybrids between Brassica oleracea var. botrytis and B. nigra and their progenies for the selection of advanced pre-breeding materials.

Somatic hybridization is a potential method for gene transfer from wild relatives to cultivated crops that can overcome sexual incompatibilities of two distantly related species. In this study, interspecific asymmetric somatic hybrids of Brassica oleracea var. botrytis (cauliflower) and Brassica nigra (black mustard) were obtained by protoplast fusion and their backcrossed (BC(3)) and selfed (S(3)) offspring were analyzed. Cytological analysis showed that the B. nigra chromosomes were successively eliminated in the backcrosses with cauliflower. The fertility of the hybrid progenies was quite different due to the asynchronous and abnormal chromosome behavior of pollen mother cells (PMC) during meiosis. Analysis of sequence-related amplified polymorphism (SRAP) showed that all of these hybrids mainly had the DNA banding pattern from the two parents with some alterations. Genetically, the selfed generations were closer to B. nigra, while the backcrossed generations were closer to the cauliflower parent. Analysis of cleaved amplified polymorphic sequences (CAPS) and restriction fragment length polymorphisms (RFLP) showed that all somatic hybrids in this study contained chloroplast (cp) DNA of the donor parent black mustard, while mitochondrial (mt) DNA showed evidence of recombination and variations in the regions analyzed. Furthermore, three BC(3) plants (originated from somatic hybrids 3, 4, 10) with 2-8 B. nigra-derived chromosomes shown by genomic in situ hybridization (GISH) displayed a more cauliflower-like morphology and high resistance to black-rot. These plants were obtained as bridge materials for further analysis and breeding.

Theoretical investigation on structures, densities, detonation properties, and the pyrolysis mechanism of the derivatives of HNS.

The derivatives of 2,2',4,4',6,6'-hexanitrostilbene (HNS) are optimized to obtain their molecular geometries and electronic structures at the DFT-B3LYP/6-31G* level. Detonation properties are evaluated using the modified Kamlet-Jacobs equations based on the calculated densities and heats of formation. It is found that there are good linear relationships between the density, detonation velocity, detonation pressure, and number of nitro, amino, and hydroxy groups. The thermal stability and pyrolysis mechanism of the title compounds are investigated by calculating the bond dissociation energies at the unrestricted B3LYP/6-31G* level. For the nitro and amino derivatives of HNS, the C-NO(2) bond is a trigger bond during the thermolysis initiation process, while for hydroxy derivatives, it is started from the isomerization reaction of the hydrogen transfer in the O-H bond. According to the quantitative standard of energetics and stability, as high-energy density compounds, 2,2',3,3',4,4',5,6,6'-nonanitrostilbene and 2,2',3,3',4,4',5,5',6,6'-decanitrostilbene essentially satisfy this requirement. In addition, we have discussed the effect of the nitro, amino, and hydroxy groups on the structure and properties.

[Pharmacognostical study on Fructus Hordei germinatus, Fructus Oryzae germinatus and Fructus Setariae germinatus].

OBJECTIVE: To establish the standard for quality control of Fructus Hordei germinatus, Fructus Oryzae germinatus and Fructus Setariae germinatus. METHODS: The digital microscope and infrared spectroscopy were used in the pharmacognostical study. RESULTS: Distinguished differences were found on morphological and microscopical features of these three crude drugs. Whereas, their infrared spectrums were basically all the same. CONCLUSION: The study provides a convenient, effect method for the identification of these three medicinal materials.

Effects of berberine on tumor growth and intestinal permeability in HCT116 tumor-bearing mice using polyamines as targets.

The prognosis of colorectal cancer (CRC) is seriously affected by high intestinal mucosal permeability accompanied by increasing tumor load. Berberine, a natural plant-derived product, can protect the intestinal mucosal barrier and suppress tumor growth, but its effects on the intestinal mucosal barrier dysfunction of CRC have not yet been evaluated. Herein, we assessed the effects of berberine on the intestinal mucosal permeability of HCT116 tumor-bearing mice and the underlying mechanism. Berberine (6.25, 12.5, 25 mg/kg) was administered to tumor-bearing mice for 3 weeks by intraperitoneal injection, and saline was given to controls and models. Compared with the control group, tumor-bearing mice had increased intestinal mucosal permeability in the third week. Meanwhile, the body weight decreased by 4%-7%, the concentration of D-lactic acid in plasma increased, and the expressions of ZO1 and Occludin were down-regulated. The intestinal mucosa was impaired. Compared with the model group, berberine inhibited tumor growth in a dose-dependent manner (6.25, 12.5, 25 mg/kg), reduced the permeability of intestinal mucosa, and alleviated intestinal mucosal damage. HPLC showed that berberine decreased the content of polyamines in tumor tissue, whereas increased that in intestinal mucosa tissue. Western blot showed that berberine inhibited the expressions of ODC, C-MYC and HIF-1α, but up-regulated those of OAZ1 and SSAT. In short, berberine may exert antitumor effects by suppressing tumor growth and elevating the intestinal mucosal permeability.

Sleep Duration and Factors Related to Sleep Loss in 3-14-Year-Old Children in Beijing: A Cross-Sectional Survey.

BACKGROUND: It is known that short sleep duration adversely affects children's behavior and physical development. This study aimed to investigate the status of sleep duration in 3-14-year-old children in Beijing and explore the related factors of sleep loss with them. METHODS: In this study, a cross-sectional study of random stratified cluster sampling was conducted on 3-14-year-old children and adolescents in Beijing. According to the proportion of children in each district and school, the final cohort included a total of 11 kindergartens, 7 primary schools, and 8 junior high schools from 7 districts of Beijing. Children of sampled classes were included, and their parents were invited to fill a series of questionnaires including the simplified Chinese version of Pediatric Sleep Questionnaire, Sleep Questionnaire Scale, and Hong Kong-Children Sleep Questionnaire about the performance of the last 6 months. RESULTS: Out of the total 11,420 questionnaires, 9198 questionnaires were valid and effective with the response rate of 80.54%. The age of the investigated children was 8.8 ± 3.8 years, including 4736 males and 4462 females. The daily sleep duration of children in Beijing was 9.7 ± 0.7 h. The prevalence of sleep loss (<9 h/day) of children in Beijing was 11.8%. The daily sleep duration of children aged <6, 6 ≤ age <11, and ≥11 years was 9.7 ± 0.6 h, 9.6 ± 0.6 h, and 9.5 ± 0.8 h, respectively. The sleep duration reduced significantly in children aged ≥11 years as compared to younger children in Beijing which was mainly contributed by the variation tendency of sleep duration on weekdays. The multivariate logistic regression analysis identified factors associated with sleep loss (P < 0.05): male (odds ratio [OR] = 1.32, 95% confidence interval [CI]: 1.15-1.51), age ≥11 years (OR = 2.37, 95% CI: 1.92-2.93), overweight (OR = 1.34, 95% CI: 1.17-1.54), family history of snoring (OR = 1.35, 95% CI: 1.13-1.61) and activities before bedtime with watching TV (OR = 1.24, 95% CI: 1.08-1.43), sports (OR = 1.22, 95% CI: 1.01-1.48), playing cellphone (OR = 1.91, 95% CI: 1.31-2.73) and surfing the Internet (OR = 1.27, 95% CI: 1.06-1.52) and among them age ≥11 years and playing cellphone before bedtime had greater impact on children's short sleep duration than that of other factors. CONCLUSIONS: Sleep loss was common among 3-14-year-old children in Beijing. Sleep duration decreased with age, especially among children over 11 years old. Factors associated with sleep loss covered sociodemographic characteristics, family sleep habits and routine activities before bedtime, and among those variables, age ≥11 years and playing with cellphones before bedtime had a greater impact on sleep duration, indicating that existing sleep loss in 3-14-year-old children could be, at least partly, improved by paying more attention to children aged of 11 years or entering Grade 5 and Grade 6 and to children with a family history of snoring; by reducing the use of electronic products before bedtime, especially cellphones; by managing weight and keeping fit; and by improving the bedtime routine.