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Background: Male infertility is a global health issue. The more causative genes related to human male infertility should be further explored. The essential role of Zcwpw1 in male mouse fertility has been established and the role of ZCWPW1 in human reproduction needs further investigation to verify. Methods: An infertile man with oligoasthenoteratozoospermia phenotype and his parents were recruited from West China Second University Hospital, Sichuan University. A total of 200 healthy Han Chinese volunteers without any evidence of infertility were recruited as normal controls, while an additional 150 infertile individuals were included to assess the prevalence of ZCWPW1 variants in a sporadic male sterile population. The causative gene variant was identified by Whole-exome sequencing and Sanger sequencing. The phenotype of the oligoasthenoteratozoospermia was determined by Papanicolaou staining, immunofluorescence staining and electron microscope. In-vitro experiments, western blot and in-silicon analysis were applied to assess the pathogenicity of the identified variant. Additionally, we examined the influence of the variant on the DNA fragmentation and DNA repair capability by Sperm Chromatin Dispersion and Neutral Comet Assay. Results: The proband exhibits a phenotype of oligoasthenoteratozoospermia, his spermatozoa show head defects by semen examination, Papanicolaou staining and electron microscope assays. Whole-exome sequencing and Sanger sequencing found the proband carries a homozygous ZCWPW1 variant (c.1064C > T, p. P355L). Immunofluorescence analysis shows a significant decrease in ZCWPW1 expression in the proband's sperm. By exogenous expression with ZCWPW1 mutant plasmid in vitro, the obvious declined expression of ZCWPW1 with the mutation is validated in HEK293T. After being treated by hydroxyurea, MUT-ZCWPW1 transfected cells and empty vector transfected cells have a higher level of γ-H2AX, increased tail DNA and reduced H3K9ac level than WT-ZCWPW1 transfected cells. Furthermore, the Sperm Chromatin Dispersion assay revealed the proband's spermatozoa have high DNA fragmentation. Conclusions: It is the first report that a novel homozygous missense mutation in ZCWPW1 caused human male infertility with sperm head defects and high DNA fragmentation. This finding enriches the gene variant spectrum and etiology of oligoasthenoteratozoospermia. [ABSTRACT FROM AUTHOR]

Achieving sustainable development is an issue of global concern. Accounting for the gross ecosystem product (GEP) value can specifically quantify the value of ecosystems for people, which is conducive to the formulation of sustainable management decisions. We have improved the GEP framework accounting method for the first time and evaluated the ecosystem service value of 36 cities in three provinces in the northeast (TPN) of China from 2000 to 2019, which provides decision‐making references for the sustainable development of TPN. The main accounting results and policy recommendations are as follows: (1) The ecological value of Northeast China is in an upward stage—GEP has increased from 3.1 trillion yuan in 2000 to 4.5 trillion yuan in 2019, with climate regulation and water conservation functions being the main driving factors for GEP. (2) Based on the dual analysis of GEP and gross domestic product (GDP), there is still high room for improvement in most cities in the TPN region. While ensuring the protection of ecosystem services, cities can convert ecological value into economic value through carbon trading, water rights trading, ecological compensation, and other methods based on ecological characteristics, which is conducive to the sustainable development of GDP and GEP in the TPN region in the future. (3) The cold and hot spot analysis of GEP also provides decision‐making basis for the planning of future ecosystem service protection areas in the TPN region. [ABSTRACT FROM AUTHOR]

The measurement of the relative differential cross sections of the neutron-deuteron ( n - d) elastic scattering, i.e., the 2 H(n, el) 2 H reaction, for 12 neutron energies from 13.56 MeV to 52.48 MeV has been carried out at the Back-n White Neutron Source of the China Spallation Neutron Source (CSNS). By detection of the recoil deuterons using the light charged particle detector array (LPDA) system, the relative differential cross sections of the neutrons in the center-of-mass frame were obtained and then compared with previous measurements, the theoretical calculations performed using the Nijmegen I nucleon-nucleon potential in the Faddeev formalism, and the evaluated from libraries including the ENDF-B/VIII.0, JEFF-3.3, JENDL-4.0, CENDL-3.2, and FENDL-3.2. The present work was the first measurement relative differential cross sections of the n-d scattering for the 30 MeV < E n ≤ 60 MeV neutron energy range using a white neutron source. [ABSTRACT FROM AUTHOR]

Ground-based Multi-Axis Differential Optical Absorption Spectroscopy (Max-DOAS) measurements of nitrogen dioxide (NO 2) were continuously obtained from January to November 2019 in northeastern China (NEC). Seasonal variations in the mean NO 2 vertical column densities (VCDs) were apparent, with a maximum of 2.9 × 1016 molecules cm−2 in the winter due to enhanced NO 2 emissions from coal-fired winter heating, a longer photochemical lifetime and atmospheric transport. Daily maximum and minimum NO 2 VCDs were observed, independent of the season, at around 11:00 and 13:00 local time, respectively, and the most obvious increases and decreases occurred in the winter and autumn, respectively. The mean diurnal NO 2 VCDs at 11:00 increased to at 08:00 by 1.6, 5.8, and 6.7 × 1015 molecules cm−2 in the summer, autumn and winter, respectively, due to increased NO 2 emissions, and then decreased by 2.8, 4.2, and 5.1 × 1015 molecules cm−2 at 13:00 in the spring, summer, and autumn, respectively. This was due to strong solar radiation and increased planetary boundary layer height. There was no obvious weekend effect, and the NO 2 VCDs only decreased by about 10% on the weekends. We evaluated the contributions of emissions and transport in the different seasons to the NO 2 VCDs using a generalized additive model, where the contributions of local emissions to the total in the spring, summer, autumn, and winter were 89 ± 12%, 92 ± 11%, 86 ± 12%, and 72 ± 16%, respectively. The contribution of regional transport reached 26% in the winter, and this high contribution value was mainly correlated with the northeast wind, which was due to the transport channel of air pollutants along the Changbai Mountains in NEC. The NO 2 /SO 2 ratio was used to identify NO 2 from industrial sources and vehicle exhaust. The contribution of industrial NO 2 VCD sources was >66.3 ± 16% in Shenyang due to the large amount of coal combustion from heavy industrial activity, which emitted large amounts of NO 2. Our results suggest that air quality management in Shenyang should consider reductions in local NO 2 emissions from industrial sources along with regional cooperative control. [Display omitted] • NO 2 vertical column densities (VCDs) peaked in winter due to enhanced heating emissions. • NO 2 VCDs showed an uptrend from 08:00 to 11:00 and had a slight decrease at noon. • NO 2 was mainly sourced from local industrial NO 2 emissions in Shenyang. • Regional transport from the northeastern direction contributed 26% to NO 2 in winter. [ABSTRACT FROM AUTHOR]

Abstract: Measurements of cross sections of the 95Mo(n, α)92Zr reaction at E n=4.0, 5.0 and 6.0MeV were carried out at the 4.5MV Van de Graaff of Peking University, China. A twin gridded ionization chamber and two large-area 95Mo samples were adopted. Fast neutrons were produced through the D(d, n)3He reaction by using a deuterium gas target. A small 238U fission chamber was employed for absolute neutron flux determination. Present data are compared with existing evaluations and measurement. [Copyright &y& Elsevier]

Abstract: Cross sections of the 147Sm(n, α)144Nd reaction were measured at En=5.0 and 6.0MeV. A twin gridded ionization chamber was used as a charged particle detector and two large area 147Sm2O3 samples placed back to back were employed. Experiments were performed at the 4.5MV Van de Graaff accelerator of Peking University. Neutrons were produced through the D(d, n)3He reaction with a deuterium gas target. Absolute neutron flux was determined by a small 238U fission chamber. Present cross-section data are compared with existing results of evaluations and measurements. [Copyright &y& Elsevier]

Studies the trace element characteristics in the diopsides of peridotite xenoliths at the Cenozoic Hannuoba basalts in northern China. Overall depletion and heterogeneity of the continental mantle beneath northern China Craton; Indicators of the partial melting of the xenoliths; Formation of xenoliths by mantle deformation.

Mafic granulite and pyroxenite xenoliths from Cenozoic alkaline basalts at Hannuoba, Hebei Province, North China have been selected for a systematic geochemical and Sr–Nd–Pb isotopic study, which provides a unique opportunity to explore nature of the lower crust and the interaction between the continental crust and lithospheric mantle beneath an Archean craton. The major, compatible and incompatible elements and radiogenic isotopes of these xenoliths suggest great chemical heterogeneity of the lower crust beneath the Hannuoba region. Petrological and geochemical evidences indicate a clear cumulate origin, and most likely, they are related to basaltic underplating in different geological episodes. However, the Sr–Nd–Pb isotopic compositions of the xenoliths reveal a profound enriched source signature (EM I) with some influence of EM II, which implies that some portion of pre-existing, old metasomatized subcontinental lithospheric mantle could have played an important role in their genesis. It is suggested that the interaction between continental crust and subcontinental mantle as manifested by basaltic underplating would be closely related to regional tectonic episodes and geodynamic processes in the deep part of subcontinental lithospheric mantle. [Copyright &y& Elsevier]

The Multi-purpose Time Projection Chamber (MTPC) is a gas-filled detector designed to measure cross sections of neutron-induced light-charged particle emission and fission reactions at the Back-streaming white neutron facility (Back-n) at the China Spallation Neutron Source. A prototype MTPC has been constructed with a drift volume, a resistive Micromegas charge amplification structure, and a high-density pixelated anode readout plane with 1519 hexagonal pads. Test measurements have been performed using a four-component alpha source. Alpha-particle track reconstruction is performed to obtain the deposited energy and length information of the trajectory. The performance test and characterization of the detector have served as the basis for the optimized design of the MTPC, which is currently undergoing commissioning at Back-n. [ABSTRACT FROM AUTHOR]

Bactrocera minax is a disastrous pest of citrus crops in China. Numerous studies focused on the molecular mechanism of odorant perception of B. minax , but the molecular mechanism of odorant degradation remains unclear. Glutathione S -transferases (GSTs) are considered as a class of odorant-degrading enzymes involved in degrading odorant molecules in insects' olfactory system. Here, we identified a delta-class GST gene, BminGSTd3, from B. minax. It was predominantly expressed in adult's olfactory organ antennae. The bacterially expressed recombinant BminGSTd3 was able to catalyze the conjugation of glutathione (GSH) with 2, 4-dinitrochlorobenzene (CDNB). Spectrophotometric analysis showed that undecanol can inhibit catalytic activities of BminGSTd3. Metabolic assays exhibited that undecanol can be depleted by BminGSTd3. Undecanol is believed to be an important B. minax sex pheromone component. The other components of the pheromone remain unclear. To understand how BminGSTd3 specifically recognizes undecanol, a 3D model of BminGSTd3 was constructed by homology modeling. Molecular docking based on this model revealed that E64 and S65 are the key amino acids recognizing undecanol, and this was proven by site-directed mutagenesis and intrinsic fluorescence assays. We suggest that BminGSTd3 is an undecanol metabolizing GST in B.minax , and E64 and S65 may serve as the key binding sites. [ABSTRACT FROM AUTHOR]

Predicting the energy performance of household variable refrigerant flow (VRF) systems in the hot summer and cold winter (HSCW) region in China accurately is particularly challenging due to the frequent defrost operations of the VRF systems during winter. Hence, an improved energy model was developed to determine the energy performance of household VRF systems, taking into account the defrost operations. The energy model was validated by experiments and the energy performance of the VRF system for typical residential buildings in Chongqing, Changsha, Nanjing, and Shanghai was determined based on representative operation modes (full-time-full-space and part-time-part-space modes). The results indicate that the efficiency of the VRF system increases as the outdoor temperature decreases. However, the efficiency of the VRF system decreases as the part-load ratio decreases, which leads to variations in the cooling seasonal performance factor for the representative operation modes and cities. The heating seasonal performance factor is not only influenced by the outdoor temperature and part-load ratio distribution, but also defrost operations. Compared with the part-time-part-space mode of C1 and C2, the annual energy consumption for the C4 mode performs lower from 26.3% to 51.7% for typical residential buildings in the four representative cities. [ABSTRACT FROM AUTHOR]

A Multi-purpose Time Projection Chamber prototype based on a resistive Micromegas technique has been proposed, designed and fabricated at China Spallation Neutron Source to measure the cross sections of neutron-induced light-charged particle emission reactions and fission reactions at the Back-n white neutron source. For the requirements of working stability with high voltage and high granularity of readout, the prototype is fabricated by applying a resistive Micromegas with high-density pixelated anode plane. In order to fully understand the process of charge spreading and signal induction on the anode plane covered by a resistive layer, a simulation method is developed and the energy correction function is then obtained, which can be used in the further energy correction in the experimental data analysis. Measured with a 55Fe X-ray source, the uniformity of gain and avalanche gap are specially analyzed by combining the simulated gas avalanche parameters with fitting of experimental data in which the parallel plate avalanche model is adopted. [ABSTRACT FROM AUTHOR]

Abstract: Squamous cell carcinoma (SCC) is one of the commonest dermatological malignancies. Resveratrol (Res) is one type of polyphenolic compound which was first identified from the roots of Veratrum grandinorum in 1940. The previous studies found that Res can promote apoptosis of a variety of tumor cell, especially SCC cells. However it is rare to study the inhibition mechanism of Res in the animal model. In this study, through the establishment of human cutaneous SCC A431 xenografts in nude mice, we observed Res inhibition effect and investigated the inhibition mechanism by checking the expression of apoptosis-related factors, p53, ERK and survivin. The results showed that the xenograft volume and weight of Res groups were less than those of the control groups (P<0.05), but the net body mass of nude mice of Res groups was not significantly different from the control groups (P>0.05). The apoptotic index of Res groups were significantly higher than the control groups (P<0.05). The protein and mRNA expression of p53 and ERK were statistically positively correlated (P<0.05) and significantly increased in Res high- and medium-dose groups compared with the control groups (P<0.05). Moreover, the protein and mRNA expression of SVV were negatively correlated with p53 (P<0.05) and lower than the control groups (P<0.05). The results demonstrate Res inhibitory effect and indicate that the inhibition mechanism of Res is to upgrade the protein and mRNA expression of p53 and to downgrade the protein and mRNA expression of SVV, thus inducing the apoptosis of tumor cells. [Copyright &y& Elsevier]

The Back-n is a high luminosity white neutron beamline at the China Spallation Neutron Source (CSNS). It started running in 2018 for various nuclear data measurements. A Light charged Particle Detector Array (LPDA) is designed for (n , lcp) reaction experiments, which includes a group of detectors and supporting systems. The Δ E - E telescope, consisting of a Low-Pressure Multi-Wire Proportional Chamber (LPMWPC) and a Si-PIN detector, is the core detector of the LPDA. From the beginning of 2018, several measurements have been performed using the Δ E-E telescopes, and the light charged particles such as 1H, 3H, 4He, and 7Li, were identified successfully. At present, the LPMWPC can identify the protons with energy as low as 0.5 MeV. In the near future, combining with CsI(Tl) crystals, a system consisting of sixteen telescopes with an energy acceptance from 0.5 MeV to 100 MeV (proton) will be constructed for general purpose of (n , lcp) measurements. [ABSTRACT FROM AUTHOR]

The Back-n white neutron source at the China Spallation Neutron Source (CSNS) was put into operation in 2018, providing a good platform for the cross-section measurement of neutron induced light charged particle (l c p) emission (n , l c p) reactions. Currently, in order to detect and identify light charged particles produced in (n , l c p) reactions at Back-n, a silicon detector array has been developed as a part of Light-charged Particle Detector Array. Composed of 15 silicon detectors, the array can detect the emitted particles ranging from 19.2°to 160.8°. The energy resolution of each silicon detector unit is better than 1% for 5.499 MeV α particles. Adopting this silicon detector array, several experimental measurements have been completed. Differential cross sections and angle-integrated cross sections in the neutron energy region ranging from the eV to the MeV range are extracted. Compared with previous measurements and evaluations, new results are obtained in the present measurements. These experiments indicate the feasibility of the silicon detector array in (n , l c p) reaction cross-section measurements. [ABSTRACT FROM AUTHOR]

A white neutron source for nuclear data measurement has been built and put into operation on China Spallation Neutron Source (CSNS). We developeda beam monitor for real-time online monitoring of neutron flux on the white neutron source. The beam monitor work simultaneously with other nuclear data measurement detectors to provide neutron flux for data analysis. To minimize beam disturbance and reduce the background generated by the monitor, a structure in which neutron conversion layer and Si detectors are separated is employed: A 6LiF film with a mass thickness of 360 μ g/cm 2 was deposited on a 10 μ m aluminum foil and placed inside the beam line. Eight Si-detectors with a size of 20 × 20 mm2 were placed around the film outside the beam to maximize the reception of secondary particles from the conversion layer and to avoid neutron beam irradiation. The simulation of the beam monitor (layout, counting rate, neutron disturbance, etc.), construction and online performance are described in the paper. Good online performance of the monitor was achieved during the CSNS white neutron source flux calibration experiment in March, 2018: The counting rate for the beam line operating at Ф30 mm and Ф60 mm beam pattern modes was normalized to 100 kW proton beam power, and the result is consistent with the simulation. The total uncertainty of the normalized counting rate is less than 1%. Moreover, the measurement of neutron flux in low energy region below 10 keV of the white neutron source by the monitor is discussed. [ABSTRACT FROM AUTHOR]

Ground-based Multi-Axis Differential Optical Absorption Spectroscopy (Max-DOAS) measurements of nitrogen dioxide (NO 2 ) were continuously obtained from January to November 2019 in northeastern China (NEC). Seasonal variations in the mean NO 2 vertical column densities (VCDs) were apparent, with a maximum of 2.9 × 10 16 molecules cm -2 in the winter due to enhanced NO 2 emissions from coal-fired winter heating, a longer photochemical lifetime and atmospheric transport. Daily maximum and minimum NO 2 VCDs were observed, independent of the season, at around 11:00 and 13:00 local time, respectively, and the most obvious increases and decreases occurred in the winter and autumn, respectively. The mean diurnal NO 2 VCDs at 11:00 increased to at 08:00 by 1.6, 5.8, and 6.7 × 10 15 molecules cm -2 in the summer, autumn and winter, respectively, due to increased NO 2 emissions, and then decreased by 2.8, 4.2, and 5.1 × 10 15 molecules cm -2 at 13:00 in the spring, summer, and autumn, respectively. This was due to strong solar radiation and increased planetary boundary layer height. There was no obvious weekend effect, and the NO 2 VCDs only decreased by about 10% on the weekends. We evaluated the contributions of emissions and transport in the different seasons to the NO 2 VCDs using a generalized additive model, where the contributions of local emissions to the total in the spring, summer, autumn, and winter were 89 ± 12%, 92 ± 11%, 86 ± 12%, and 72 ± 16%, respectively. The contribution of regional transport reached 26% in the winter, and this high contribution value was mainly correlated with the northeast wind, which was due to the transport channel of air pollutants along the Changbai Mountains in NEC. The NO 2 /SO 2 ratio was used to identify NO 2 from industrial sources and vehicle exhaust. The contribution of industrial NO 2 VCD sources was >66.3 ± 16% in Shenyang due to the large amount of coal combustion from heavy industrial activity, which emitted large amounts of NO 2 . Our results suggest that air quality management in Shenyang should consider reductions in local NO 2 emissions from industrial sources along with regional cooperative control., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

In this study, tropospheric formaldehyde (HCHO) vertical column densities (VCDs) were measured using multi-axis differential optical absorption spectroscopy (MAX-DOAS) from January to November 2019 in Shenyang, Northeast China. The maximum HCHO VCD value appeared in the summer (1.74 × 10 16 molec/cm 2 ), due to increased photo-oxidation of volatile organic compounds (VOCs). HCHO concentrations increased from 08:00 and peaked near 13:00, which was mainly attributed to the increased release of isoprene from plants and enhanced photolysis at noon. The HCHO VCDs observed by MAX-DOAS and OMI have a good correlation coefficient (R) of 0.78, and the contributions from primary and secondary HCHO sources were distinguished by the multi-linear regression model. The anthropogenic emissions showed unobvious seasonal variations, and the primary HCHO was relatively stable in Shenyang. Secondary HCHO contributed 82.62%, 83.90%, 78.90%, and 41.53% to the total measured ambient HCHO during the winter, spring, summer, and autumn, respectively. We also found a good correlation (R = 0.78) between enhanced vegetation index (EVI) and HCHO VCDs, indicating that the oxidation of biogenic volatile organic compounds (BVOCs) was the main source of HCHO. The ratio of secondary HCHO to nitrogen dioxide (NO 2 ) was used as the tracer to analyze O 3 -NO x -VOC sensitivities. We found that the VOC-limited, VOC-NO x -limited, and NO x -limited regimes made up 93.67%, 6.23%, 0.11% of the overall measurements, respectively. In addition, summertime ozone (O 3 ) sensitivity changed from VOC-limited in the morning to VOC-NO x -limited in the afternoon. Therefore, this study offers information on HCHO sources and corresponding O 3 production sensitivities to support strategic management decisions., (Copyright © 2021 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Abstract: Delayed recovery (DR) is very commonly seen in the patients undergoing laparoscopic radical biliary surgery, we aimed to investigate the potential risk factors of DR in the patients undergoing radical biliary surgery, to provide evidences into the management of DR.Patients who underwent radical biliary surgery from January 1, 2018 to August 31, 2020 were identified. The clinical characteristics and treatment details of DR and no-DR patients were compared and analyzed. Multivariable logistic regression analyses were conducted to identify the potential influencing factors for DR in patients with laparoscopic radical biliary surgery.We included a total of 168 patients with laparoscopic radical biliary surgery, the incidence of postoperative DR was 25%. There were significant differences on the duration of surgery, duration of anesthesia, and use of intraoperative combined sevoflurane inhalation (all P < .05), and there were not significant differences on American Society of Anesthesiologists, New York Heart Association, tumor-lymph node- metastasis, and estimated blood loss between DR group and control group (all P > .05). Multivariable logistic regression analyses indicated that age ≥70 years (odd ratio [OR] 1.454, 95% confidence interval [CI] 1.146-1.904), body mass index ≥25 kg/m2 (OR 1.303, 95% CI 1.102-1.912), alcohol drinking (OR 2.041, 95% CI 1.336-3.085), smoking (OR 1.128, 95% CI 1.007-2.261), duration of surgery ≥220 minutes (OR 1.239, 95% CI 1.039-1.735), duration of anesthesia ≥230 minutes (OR 1.223, 95% CI 1.013-1.926), intraoperative combined sevoflurane inhalation (OR 1.207, 95% CI 1.008-1.764) were the independent risk factors for DR in patients with radical biliary surgery (all P < .05).It is clinically necessary to take early countermeasures against various risk factors to reduce the occurrence of DR, and to improve the prognosis of patients., Competing Interests: The authors have no conflicts of interest to disclose., (Copyright © 2021 the Author(s). Published by Wolters Kluwer Health, Inc.)

The case-control study was designed to investigate the genetic effects of interferon-gamma (IFN-γ) rs2069727 and rs1861494 polymorphisms on ankylosing spondylitis (AS) susceptibility in a Chinese Han population. Blood samples were collected from 108 AS patients and 110 healthy controls. IFN-γ polymorphisms were genotyped by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Hardy-Weinberg equilibrium (HWE) test was performed in control group. Odds ratios (OR) with 95% confidence intervals (95% CI) were calculated using chi-square test to evaluate the association between AS susceptibility and IFN-γ polymorphisms, and the results were adjusted by logistic regressive analysis. The frequency of rs2069727 CC genotype was much higher in cases than that in controls, suggested its significant association with increased AS risk (adjusted OR = 5.899, 95% CI = 1.563-22.261; P = .009). In addition, C allele also showed close association with increased risk of AS (adjusted OR = 2.052, 95% CI = 1.286-1.704, P  = 0 .003). While the genotype and allele frequencies of IFN-γ rs1861494 polymorphism were not significantly different between patients and controls (P  > 0.05 for all), IFN-γ rs2069727 polymorphism is significantly associated with increased AS risk in a Chinese Han Population., (© 2020 The Authors. Journal of Cellular and Molecular Medicine published by Foundation for Cellular and Molecular Medicine and John Wiley & Sons Ltd.)

Importance: Myopia has reached epidemic levels among children in regions of East and Southeast Asia. High myopia is associated with myopic macular degeneration, glaucoma, and retinal detachment., Objective: To determine the incidence of myopia and high myopia based on refraction without cycloplegia among children in primary and junior high schools in China., Design, Setting, and Participants: This observational cohort study was completed in Guangzhou, China. It consisted of a cohort from 19 primary schools, who were followed up from 2010 to 2015, and a cohort from 22 junior high schools, who were followed up from 2010 to 2012. All schools were randomly chosen at rates proportional to the number of schools in each of the city's 11 districts. Students with or without myopia in grade 1 (primary school) or grade 7 (junior high school) were eligible for inclusion. Data analysis occurred from February 2017 to October 2017., Main Outcomes and Measures: Myopia was defined as a spherical equivalent refraction (SER) of -0.50 diopters (D) or less, as measured by subjective refraction without cycloplegia; high myopia was defined as a SER of -6.0 D or less. Annual incidences were defined as the proportion of participants each year found to have myopia or high myopia who did not previously have the condition. Height, weight, axial length (AL), corneal radius of curvature (CRC), and AL/CRC ratio were examined to assess if these measures were associated with future myopia or high myopia., Results: A total of 4741 students with or without myopia in either grade 1 for the primary school cohort (mean [SD] age 7.2 [0.4] years; 932 of 1975 [47.2%] female) or grade 7 for the junior high school cohort (mean [SD] age 13.2 [0.5] years; 1254 of 2670 [47.0%] female) were included. Baseline mean (SD) SER was 0.31 (0.86) D among 1975 students in grade 1 vs -1.60 (2.00) D among 2670 students in grade 7. Baseline prevalence of myopia was 12.0% in grade 1 students (n = 237 of 1969) and 67.4% in grade 7 students (n = 1795 of 2663). The incidence of myopia was 20% to 30% each year throughout both cohorts. The incidence of high myopia was initially less than 1% in the primary school cohort (grade 1: n = 2 of 1825; 0.1% [95% CI, 0.0%-0.3%]), but incidence exceeded 2% in the junior high school cohort (in grade 9: n = 48 of 2044; 2.3% [95% CI, 1.0%-3.7%])., Conclusions and Relevance: The incidence of myopia among Chinese students based on refraction without cycloplegia is among the highest of any cultural or ethnic group. If confirmed with cycloplegic refraction, interventions to prevent myopia onset in Chinese populations should be initiated in primary schools.