Search

The difficulty of crop germination in drought-prone areas during the sowing period is a worldwide problem for subsurface drip irrigation (SDI). Alternate row/bed planting (AP), in which the corn seeds were planted beneath a furrow, was applied to improve the corn germination and yield in Beijing, the North China Plain. Field experiments were conducted to assess the impacts of three furrow depths (FDs), 0 cm (H0), 10 cm (H10) and 15 cm (H15), and two cultivation management practices, backfilling the furrow after germination (BF) and not (NBF), on soil water content and temperature, corn germination and yield by SDI in 2018 and 2019. The results showed that the soil water content around the seeds (θseed) increased with increasing FD, while the soil temperature decreased with increasing FD. BF slightly increased the soil temperature, with an average growing degree days of 26–34 ℃ at a depth of 0–25 cm. The seed germination time was shortened by 3–5 days, and the emergence rate was improved following the increase in FD. The H15 treatment achieved the maximum emergence rate of 91.8% on average for two years, which was 7–17% higher than those of the H0 and H10 treatments. A Binary quadratic regression equation was adopted to fit the response of the emergence rate to θseed after preemergence irrigation and the average soil temperature during the period from sowing to the emergence stage (STseedVE). The fitting equation indicated that the θseed of 28–30% and the STseedVE of 25–27.5 ℃ together could give an emergence rate over 90% by SDI. The H15-BF treatment obtained the highest grain yield of 13.1 Mg ha−1 on average for 2 years, which was 5–24% higher than those of the other treatments. The yield between H15-NBF and H15-BF showed an insignificant difference. There were statistically significant (p < 0.05) effects of FD on the emergence rate and grain yield. In conclusion, the model of AP with an FD of 15 cm is suitable for SDI corn in the North China Plain. [ABSTRACT FROM AUTHOR]

The state of class consciousness of working-class children in China has received scant attention in the scholarly literature. This study examines the class consciousness of rural migrant children as they are about to join their migrant parents and become "China's new workers." Qualitative investigations were conducted in two primary schools in Beijing. Focus group and individual interviews were held with 87 fifth- and sixth-grade migrant children in the two case schools and 324 valid student questionnaires were collected. The findings reveal that migrant children are aware of the unequal class relationships suffered by migrant workers; however, their interpretations of class-based injustices exhibit false consciousness, shadowed by individualism, meritocracy and the duality of images. Family and school may play vital roles in shaping migrant children's class consciousness. [ABSTRACT FROM AUTHOR]

Duchenne muscular dystrophy (DMD) and Becker muscular dystrophy (BMD) are X-linked recessive neuromuscular disorders caused by mutations in DMD. A high-quality database of DMD/BMD is essential not only for clinical practice but also for fundamental research. Here, we aimed to build the largest Chinese national dystrophinopathy database using the National Rare Diseases Registry System of China. Peking Union Medical College Hospital (PUMCH) was the National Rare Diseases Center of China. This research involved 2013 patients with dystrophinopathies, whose diagnoses were confirmed; they were registered and followed up at PUMCH from March 2011 to December 2018. Family history, clinical signs, and treatment data were reported for patients with DMD and BMD at different rates. All six serum biochemical indexes could accurately distinguish between DMD and BMD patients. Copy number variations were the most frequent mutation type (79.2% in DMD and 84.3% in BMD), of which large deletions accounted for 88.4 and 88.6%, large duplications accounted for 11.6 and 11.4% in DMD and BMD, respectively. An exon deletion hotspot, located in exons 45–54, was observed in DMD, and intron 44 was the most frequent deletion starting point (26.5%). Duplication and single nucleotide variations appeared to be uniformly distributed among all exons. Eleven patients were identified to have ultrarare mutation types. Eleven other patients suffered from two separate mutations simultaneously, some of which may have taken place via dependent mechanisms. Thus, we have established the largest hospital-based Chinese dystrophinopathy database via the National Rare Diseases Registry System. This study provides valuable information for further diagnostic and therapeutic studies of dystrophinopathy. [ABSTRACT FROM AUTHOR]

Background: The term "uterine smooth muscle tumor of uncertain malignant potential" (STUMP) indicates a rare tumor that cannot be classified as a benign leiomyoma or malignant leiomyosarcoma. In this study, we assessed the clinical characteristics, fertility, and oncologic outcomes of patients diagnosed as STUMP in 14 years. In addition, we analyzed the risk factors for recurrence in patients with STUMP. Methods: Medical records of STUMP patients at Peking Union Medical College Hospital (PUMCH) between January 2005 and June 2019 were reviewed and analyzed. Disease-free survival, age of diagnosis, tumor size, surgical procedure, pathology and immunohistochemistry, clinical characteristics, recurrence rate, and reproductive outcomes in the follow-up period were assessed. Univariate and multivariate analyses were performed to determine the prognostic factors. Results: The median age was 42 years old (range: 21–63). Total hysterectomy with or without bilateral salpingo-oophorectomy was performed in 29/67 cases (43.3%), and myomectomy was performed in 38/67 cases (56.7%). Ten patients experienced recurrences, and all but two recurrences occurred within 5 years after the initial surgery. Only two of these recurrences were leiomyosarcoma. There were no deaths in the median follow-up period of 48.4 (range 2.6–170.2) months. There were no remarkable differences in location of tumor between the myomectomy and hysterectomy groups, but the patients in the myomectomy group were younger than those in the hysterectomy group. In univariate and multivariate analysis, mitosis on pathology was the only independent risk factor for recurrence. Expression of Ki-67, p53, and p16 was significantly higher in patients with recurrence. Seven of the 35 patients who attempted to conceive had successful pregnancies. Conclusions: The prognosis of STUMP was favorable and tumors with more than 10 mitoses per 10 high power field should be monitored closely. The surgical procedure was not an independent risk factor of recurrence, and myomectomy may be an acceptable option for patients wishing to preserve fertility. [ABSTRACT FROM AUTHOR]

To evaluate the diagnostic, surgical, and oncological outcomes of patients with growing teratoma syndrome (GTS). Patients diagnosed with ovarian immature teratoma (IMT) between 1980 and 2018 at Peking Union Medical College Hospital (PUMCH) were evaluated for the development of GTS. Their clinical characteristics, surgical and pathological data, and oncological outcomes were collected. Between 1980 and 2018, 175 cases of IMT were referred to PUMCH. Thirty-five patients subsequently developed GTS with a crude rate of approximately 20%. The median interval between the initial diagnosis of IMT and the first occurrence of GTS was 18.5 months (range, 6–78 months). Residual disease (P < 0.001) and gliomatosis peritonei (GP) at initial surgery (P = 0.023) were independent risk factors for GTS development. Fertility-sparing surgery for GTS was performed in 27 patients and four patients achieved five singleton pregnancies. The median follow-up time was 73 months (range, 11–401 months). Eleven patients developed at least one recurrence. Residual disease after GTS surgery was associated with GTS recurrence (P = 0.001). By the end of follow-up, 27 patients were alive without disease and the other eight patients were alive with disease. The presence of residual disease and GP at initial surgery are risk factors for GTS. Complete surgical resection is the cornerstone for treatment of GTS. The presence of residual disease after surgery for GTS is a risk factor for GTS recurrence. Fertility-sparing surgery should be performed because spontaneous pregnancy is possible. The overall prognosis of GTS is excellent. • The incidence of GTS in ovarian immature teratoma is 20%. • Residual disease and gliomatosis peritonei are independent risk factors for development of GTS. • Residual disease after surgery for GTS is a risk factor for GTS recurrence. • Fertility-sparing surgery should be performed in GTS as spontaneous pregnancy is possible. • Overall prognosis of GTS is excellent. [ABSTRACT FROM AUTHOR]

Multi-source looped district cooling (MLDC) systems exhibit promising application potential owing to their ability to utilize various renewable energy resources. The load dispatch for multiple sources is considered a critical factor during operation owing to its effects on the energy and hydraulic performance. However, few studies have investigated the behavior of energy and hydraulic performance under different load dispatch ratios (LDR s). In addition, straightforward methods for determining the optimal load dispatch of MLDC systems have not been introduced. This study investigated the relationship between the load dispatch and operating performance and proposed a fundamental method to achieve optimal load dispatch for MLDC systems and overcome the existing challenges. A double-source looped district cooling system was selected as the case study, and its Modelica model was developed. Subsequently, we investigated the relationship between the LDR s and operating performance, and verified the existence of an optimal LDR (LDR opt), which achieves the best hydraulic performance and lowest energy consumption. Finally, a dataset constructed using a hybrid optimization algorithm was employed to develop a multi-variable data-driven model for predicting LDR opt under various load conditions. This study provides a valuable framework and recommendations for further investigation of the optimal control of MLDC systems. • The Modelica model of an MLDC system in Beijing was developed and validated. • The hydraulic and energy performances under different load dispatch ratios was investigated. • The existence of the LDR opt for the MLDC system was verified. • A multi-variable linear prediction model of LDR opt was developed. [ABSTRACT FROM AUTHOR]

• Reinforcement learning (RL) is introduced to the large-scale MLDC systems. • Performance gaps between RL control and rule-based control are analyzed. • Time lag of RL control and rule-based control has been investigated. • RL control achieves maximum energy savings of 12.99%. Large-scale multi-source looped district cooling (MLDC) systems are expected to be a promising solution to support decarbonization goals and combat climate change owing to their advanced structure. Differential pressure control is one of the most common methods to improve the energy and hydraulic performance of MLDC systems. Traditional rule-based control (RBC) and model-based control may not be appropriate for large-scale systems because of the need for expert knowledge and accurate models. Reinforcement learning control (RLC) has attracted considerable research attention owing to its efficiency and flexibility. However, very little is known about RLC in large-scale heating, ventilation, and air conditioning (HVAC) systems and complex issues. Therefore, this study employs a reinforcement learning technique to optimize the differential pressure setpoints of multiple cold sources, which can achieve energy savings and fulfill hydraulic head demands simultaneously. In this study, a Modelica model of a large-scale MLDC system in Beijing was developed as a virtual environment. The Modelica-Python co-simulation testbed for RLC was then implemented. The results show that RLC can save up to 12.99% of the annual distribution energy consumption while achieving a good hydraulic performance. As an information base for a variety of stakeholders, this study offers a reinforcement learning solution that can improve the operating performance of large-scale HVAC systems. [ABSTRACT FROM AUTHOR]

In recently years, flood disasters have produced immense economical and ecological damages in worldwide, particularly in the developing cities. The increasing damages contribute to 'vulnerability' that illustrates which areas are vulnerable to what and why. Therefore, researching vulnerability is an essential and invaluable tool for helping the policy makers to identify the vulnerable people and hot-spots in advance, and to design and implement effective preparedness strategies. In this paper, using the example of Beijing, we propose a quantitative model for measuring flood vulnerability based on land-use patterns which is one of the key variables affected flood vulnerability. By combining the flood hazard characteristic 'inundation depth', a series of flood vulnerability maps demonstrate differential flood vulnerability of flood-prone areas at regional level with the approach of remote sensing and GIS techniques. These maps detect and show the distribution characteristics of vulnerable hot-spots and reveal challenges that the public faced when living in the flood-prone areas. [ABSTRACT FROM AUTHOR]

Purpose: To determine the prevalence of and risk factors for myopia in primary school children in Chaoyang District, Beijing. Methods: This cross-sectional prevalence survey was conducted in September to October 2011 in 4 schools randomly chosen from among the 126 primary schools in Chaoyang District. Students were assessed with autorefractometry under cycloplegia and checked with retinoscopy for accuracy. Questionnaires were completed by the students' parents. Results: Myopia was present in 36.7 ± 0.7 % of 4249 students aged 5-14 years old. The prevalence of myopia in girls (38.6 ± 1.1 %) was significantly higher than in boys (35.0 ± 1.0 %) ( p = 0.015) and increased with age ( p < 0.001), with the highest prevalence observed in children aged ≥11 years (67.5 ± 1.8 %). After adjustment, having a myopic parent (aOR 3.10; 95 % CI 2.49-3.86), incorrect reading posture (aOR 2.09; 95 % CI 1.75-2.50), reading a book at a distance of <20 cm (aOR 1.60; 95 % CI 1.16-2.21), studying at home for >3 h daily (aOR 1.50; 95 % CI 1.12-2.01), studying for >1 h continuously (aOR 1.21; 95 % CI 1.02-1.45), and reading extracurricular books that utilize a font larger than that used in textbooks (aOR 0.74; 95 % CI 0.59-0.94) were all significantly associated with myopia. Conclusions: The prevalence of myopia among primary school children in Beijing increased with age, and was significantly higher in girls ≥10 years old. Myopia was significantly associated with parental myopia, reading posture, distance between the eyes and the book being read, font size used in extracurricular reading material, time spent studying at home, and the duration of continuous study time. [ABSTRACT FROM AUTHOR]

Electrochromic (EC) glazing provides a promising solution to actively adjusting the sunlight and radiant heat through windows in response to building visual and thermal environmental requirements, and control strategies play a critical role in the application of EC technology in buildings. However, there is a conflict between the visual and thermal environmental requirements for EC regulation during a cooling season. To solve this problem, this paper developed a predictive control strategy for EC glazing. It was achieved based on two theoretical models which could predict the energy performance of EC glazing at different tint states, including the solar radiation heat transmitted through the glazing and lighting energy consumption. The optimum glazing state was determined based on real-time minimized energy consumption. Study results showed that the predictive control strategy outperformed the rule-based control strategy, with percentage energy saving of an office room in Beijing, China from 8.04% to 12.78% over an entire cooling season. In addition, the paper evaluated the energy-saving of using EC glazing under the predictive control strategy in 28 Chinese cities. The results indicated that EC glazing was highly applicable in most of cities with energy saving from 2.35 kWh/m2 to 5.04 kWh/m2 over an entire cooling season. • A predictive control strategy for EC glazing was developed. • Theoretical models were established to predict the EC glazing energy performances. • Real-time minimized energy consumption determined the optimum EC glazing state. • Balance between the visual and thermal environment requirements was achieved. • The energy-savings of using EC glazing in 28 Chinese cities were assessed. [ABSTRACT FROM AUTHOR]

Building-integrated photovoltaic (BIPV) windows are an effective way to increase distributed PV capacity in the urban environment. However, the effects of BIPV windows on an annual scale have not been rigorously studied. In this study, we compared their performances with different window-to-wall ratios, canyon aspect ratios, and orientations in three Chinese cities. Our results show that in Beijing, BIPV windows with the southward orientation have the highest potential for power generation of 44.7 kWh/(m2·yr), which is 1.5 times the potential in Shenzhen and Nanjing. Compared to clear windows, BIPV windows are advantageous when the window coverage is greater than 50 % in a shallow canyon. The highest electricity saving ratios are found in Beijing (29.7 %), followed by Shenzhen (26.3 %) and Nanjing (23.3 %). However, the electricity saving ratio decreases by over 10 % in deep canyons. Under future climate forcing, the saving potential of BIPV windows increases slightly in Nanjing and remain stable in Shenzhen and Beijing. The study also found that BIPV windows could increase canyon air temperatures by over 0.2 °C during winter days but slightly cool the canyon in summer. The findings guide BIPV application in the built environment and cast light on the construction of low-carbon neighbourhoods. • BIPV windows generate 1.5 times more power in Beijing than in Shenzhen and Nanjing. • Highest electricity savings in studied neighbourhoods: 26.3% SZ, 23.3% NJ, 29.7% BJ. • BIPV windows slightly improve the outdoor thermal comfort in street canyons. • BIPV windows are energy-efficient for glass curtain walls with high solar access. • Energy saving potential remain stable or slightly increases by 2050s. [ABSTRACT FROM AUTHOR]

Highlights • The first city-level building energy efficiency benchmarking system for China. • A model considering the influence of operation parameters on energy consumption. • A systematic methodology of building energy benchmarking is proposed. • The model is a valuable analysis support tool for building energy managers. Abstract The city-level public building energy efficiency benchmarking system has an important guiding value for building energy-saving work, especially for Beijing, with its high energy-consumption density and both long heating and air-conditioning periods. This paper analyzed the characteristics of large-scale office buildings in Beijing and gives a detailed description of the process of establishing a public building energy efficiency benchmarking system for large-scale office buildings in Beijing, China, including data investigation and verification, Energy Usage Intensity(EUI) calculation, determining independent and dependent variables, developing and testing the benchmarking model, and deriving the benchmarking rating table. Then the first city-level public office building energy efficiency benchmarking system in China is established based on 88 large-scale office buildings in Beijing. The results showed that the model's performance index R2 is 0.667 and gives a good representation. The process has a strong potential for replication for other cities in China and even for a national energy-consumption evaluation system. [ABSTRACT FROM AUTHOR]

Avian metapneumovirus (aMPV) is an important causative agent that causes acute respiratory disease and egg-dropping in chickens and turkeys. Here, we characterized an aMPV subgroup C (aMPV/C) from 320-day-old broiler breeder chickens with severe respiratory diseases in Beijing, China, as evidenced by RT-PCR typing and confirmation of the nucleoprotein (N) gene sequence. The N gene sequence of the aMPV/C strain (designated BJ17) exhibited no deletions or insertions and possessed 94.6% to 99.6% identity to those of published aMPV/C isolates. The phylogenetic tree of the nucleotide sequences constructed using the neighbor-joining clustering method showed that the BJ17 strain formed one cluster with other aMPV/C viruses and formed one subcluster with published Chinese aMPV/C isolates regardless of Muscovy duck or chicken origins. Comparative analysis of the N proteins showed that a unique amino acid residue D at position 110 might be associated with regional distribution due to its occurrence in all the Chinese aMPV/C isolates only. Strain BJ17 was successfully isolated by cultured Vero cell passage and further inoculated in 3-wk-old specific-pathogen-free chickens for the examination of pathogenicity. Animal experimental results showed that BJ17-inoculated chickens had severe respiratory diseases and inflammatory lesions, as demonstrated by pathological changes and aMPV antigen in the nasal turbinate, tracheae, and lung tissues. These results enrich the available information regarding the epidemiology and pathogenicity of aMPV/C in chickens, which may facilitate the development of effective measures against aMPV/C infection in China. [ABSTRACT FROM AUTHOR]