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Water resource is an important factor restricting social-economic development. Hebei Province is one of the regions suffering from severe water shortage in China. Based on the Water Resources Assessment and Planning model, population growth, economic growth, water-saving, and integrated scenarios were established. The water demand and supply in Hebei Province in 2025 and 2035 were forecasted in this study. The research results show that agriculture is the main unmet water demand sector. In the absence of large-scale population inflows, the local population growth has little impact on the changes in water supply-demand. Economic development is one of the main factors affecting water balance. The water-saving scenario has the greatest impact on water supply-demand. Compared to population and economic growth scenarios, the simulation results of water demand and unmet water demand were the smallest. Under an integrated scenario, the current situation of water shortage in Hebei has been greatly improved, but there is still a demand shortage of 44.12 × 10 8 m3 in 2030. It is necessary to take measures to improve the carrying capacity of water resources in various regions of Hebei Province and narrow the regional gap. This study provided a reference for the rational utilization of water resources.

A retrospective cohort study.To evaluate the efficacy and safety of midline lumbar fusion (MIDLF) for lumbosacral fusion compared to posterior lumbar interbody fusion (PLIF).Patients undergone posterior lumbosacral fusion surgery were divided into a MIDLF group (n = 37) and a PLIF group (n = 42). The follow-up time was at least 12 months. The operation data, recovery condition, complications, clinical outcomes, and status of implants and fusion were compared between the two groups.The MIDLF group experienced significantly less blood loss, lower postoperative creatine kinase levels and total drainage volume, earlier time to ambulation, and less hospital stay times after surgery compared to the PLIF group (P0.05). The mean postoperative back pain visual analog scale scores in the MIDLF group were significantly lower than the PLIF group (P0.05). The improvement in Oswestry Disability Index scores during three-month follow-up displayed a significant difference between the two groups (P0.05). The fusion rate tended to be higher in the MIDLF group, however, the difference was not significant(P0.05). The was no significant difference in respect of screw loosening and cage subsidence rate. There were two cases of complications both occurring in the PLIF group.MIDLF is safe and effective for lumbosacral fusion and in line with the concept of enhanced recovery after surgery.

Yuetian Wang,1,&ast; Chun Liu,2,&ast; Huiling Liu,3 Haoyong Fu,1 Chunde Li,1 Lei Yang,3,4 Haolin Sun1 1Department of Orthopedics, Peking University First Hospital, Beijing, People’s Republic of China; 2Medical Research Centre, Changzhou Second People’s Hospital Affiliated to Nanjing Medical University, Jiangsu, People’s Republic of China; 3Institute of Orthopedics, Department of Orthopedics, Soochow University, Suzhou, People’s Republic of China; 4Center for Health Sciences and Engineering (CHSE), School of Health Sciences and Biomedical Engineering, Hebei University of Technology, Tianjin, People’s Republic of China&ast;These authors contributed equally to this workCorrespondence: Lei Yang; Haolin Sun, Tel +86 13681146156, Email ylei@hebut.edu.cn; sunhaolin@vip.163.comPurpose: To evaluate the effect of cement augmentation of cortical bone trajectory (CBT) screws using a novel calcium phosphate–based nanocomposite (CPN).Material and Methods: CBT screws were placed into cadaveric lumbar vertebrae. Depending on the material used for augmentation, they were divided into the following three groups: CPN, polymethylmethacrylate (PMMA), and control. Radiological imaging was used to evaluate the cement dispersion. Biomechanical tests were conducted to measure the stability of CBT screws. A rat cranial defect model was used to evaluate biodegradation and osseointegration of the CPN.Results: After cement augmentation, the CPN tended to disperse into the distal part of the screws, whereas PMMA remained limited to the proximal part of the screws (P < 0.05). As for cement morphology, the CPN tended to form a concentrated mass, whereas PMMA arranged itself as a scattered cement cloud, but the difference was not significant (P > 0.05). The axial pullout test showed that the average maximal pullout force (Fmax) of CPN-augmented CBT screws was similar to that of the PMMA group (CPN, 1639.56 ± 358.21 N vs PMMA, 1778.45 ± 399.83 N; P = 0.745) and was significantly greater than that of the control group (1019.01 ± 371.98 N; P < 0.05). The average torque value in the CPN group was higher than that in the control group (CPN, 1.51 ± 0.78 N∙m vs control, 0.97 ± 0.58 N∙m) and lower than that in the PMMA group (1.93 ± 0.81 N∙m), but there were no statistically significant differences (P > 0.05). The CPN could be biodegraded and gradually replaced by newly formed bone tissue after 12 weeks in a rat cranial defect model.Conclusion: The biocompatible CPN could be a valuable augmentation material to enhance CBT screw stability.Keywords: cement augmentation, CBT screws, osteoporotic spine, PMMA, CPN

Study Design: This is a broad, narrative review of the literature. Objective: In this review, we describe recent biomechanics studies on cement-augmented pedicle screws for osteoporotic spines to determine which factors influence the effect of cement augmentation. Methods: A search of Medline was performed, combining the search terms “pedicle screw” and (“augmentation” OR “cement”). Articles published in the past 5 years dealing with biomechanical testing were included. Results: Several factors have been identified to impact the effect of cement augmentation in osteoporotic spines. These include the type of augmentation material, the volume of injected cement, the timing of augmentation, the severity of osteoporosis, the design of the pedicle screw, and the specific augmenting technique, among others. Conclusions: This review elaborates the biomechanics of cement-augmented pedicle screws, determines which factors influence the augmentation effect, and identifies the risk factors of cement leakage in osteoporotic bone, which might offer some guidance when using this technique in clinical practice. Further, we provide information about newly designed screws and recently developed augmentation materials that provide higher screw stability as well as fewer cement-related complications.

Study Design A biomechanical study. Objective To evaluate the efficacy and feasibility of cement-augmented cortical bone trajectory (CBT) screw fixation. Methods Forty-nine CBT screws were inserted into lumbar vertebrae guided by three-dimensionally printed templates, and then injected with 0, .5, or 1.0 mL of polymethylmethacrylate. The screw placement accuracy, cement dispersion, and cement leakage rate were evaluated radiologically. Biomechanical tests were performed to measure the axial pull-out strength and torque value. Results Overall, 83.67% of the screws were inserted without pedicle perforation. In the 1.0 mL group, cement dispersed into the pedicle zone and formed a concentrated mass more often than in the .5 mL group, but not significantly more often (P > .05). The total cement leakage rate was 18.75%. Compared with the control group, the torque value was slightly higher in the .5 mL group (P = .735) and significantly higher in the 1.0 mL group (P = .026). However, there was no significant difference between the .5 and 1.0 mL groups (P = .431). The maximal pull-out force (Fmax) was increased by 52.85% and 72.73% in the .5 and 1.0 mL groups, respectively, compared with the control group (P < .05). However, the difference was not significant between the 2 cemented groups (P = .985). Conclusions Cement augmentation is a useful method for increasing CBT screw stability in osteoporotic spines. The cement injection volume is recommended to be 1 mL for each screw, and the cement should disperse into the vertebral body than the pedicle zones.

Optical beams carrying orbital angular momentum (OAM) have received much attention due to the prospects of their use in terahertz communications, biomedical engineering, and imaging. Here we propose an antenna design for the generation of multiple beams carrying OAM with different topological states at the same frequency. The proposed OAM generator is based on a compact set of microstrip ring-shaped resonators. An analytical solution for the radiated field of a single circular ring resonator antenna is derived involving the cavity model and the magnetic current approach. To verify our theoretical description, the numerical full-wave simulation is performed for an actual size OAM generator with the use of the ANSYS HFSS electromagnetic solver, and an antenna prototype operating in the microwave band is fabricated and tested. Conditions of the antenna operation in the combined OAM and mode-division multiplexing (OAM-MDM) regimes are discussed. Obtained results prove that the proposed antenna can be used as a compact and low-cost generator of multiple beams with different OAM states.

Groundwater is an important water source to consider when ensuring the safety of urban water supply. Groundwater contaminated by bacteria poses a potential health risk to the drinking water supply. This study focuses on the water supply of Liuzhou City, a famous industrial city in China. Analyses of the concentrations, spatial distribution, and pollution sources of bacteria in the groundwater were conducted based on samples collected from 27 wells during the wet and dry seasons in 2018. The total colony counts and total coliform were high during both the wet and dry seasons, posing a severe threat to the emergency water supply security for more than one million people in the city. The groundwater in Liuzhou City is generally contaminated by bacteria, with higher pollution levels in the northern urban-rural fringe and central urban areas. Domestic pollution is the main sources of groundwater bacteria. In addition, bacterially contaminated rivers (Liujiang River) passing through the urban area likely transfer bacteria to the groundwater due to the circulation of the groundwater and surface river water. Controlling the bacterial pollution of groundwater in this region requires adherence to a long-term management plan.

“Ecological conservation and high-quality development of the Yellow River Basin” is one of the fundamental national strategies related to national food security and ecological security in China. Evaluating the impact of land use/cover change (LUCC) on soil erosion is valuable to improving regional ecological environments and sustainable development. This study focused on the Yellow River Basin and used remote sensing data, the soil wind erosion modulus (SWEM) calculated with the revised wind erosion equation (RWEQ), to analyze the impact of regional scale LUCC from 1990 to 2018 on soil wind erosion. The main conclusions are as follows: (1) The total area of cultivated land, grass land, and unused land decreased, with a total reduction of 11,038.86 km²; total areas of forest land and built-up areas increased, increased by 2746.61 and 8356.77 km2, respectively, with differences within the region in these LUCC trends at different periods. From 1990 to 2000, the area of cultivated land increased by 1958.36 km2 and built-up land area increased by 1331.90 km2. The areas of forestland, grass land, water area, and unused land decreased. From 2000 to 2010, the area of cultivated land and grass land decreased by 4553.77 and 2351.39 km², respectively, whereas the areas of forestland and built-up land significantly increased. From 2010 to 2018, the area of cultivated land and grass land continued to decrease, and the area of built-up land continued to increase. (2) Since the 1990s, the SWEM has generally declined (Slope1990–2018 = −0.38 t/(ha·a)). Total amount of wind erosion in 2018 decreased by more than 50% compared with the amount in 1990. During this period, the intensity of wind erosion first increased and then decreased. In terms of the SWEM, 90.63% of the study area showed a decrease. (3) From 1990 to 2018, LUCC reduced the total amount of soil wind erosion by 15.57 million tons. From 1990 to 2000, the conversion of grass land/forest land to cultivated land and the expansion of desert resulted in a significant increase in soil wind erosion. From 2000 to 2018, the amount of soil wind erosion decreased at a rate of about 1.22 million tons/year, and the total amount of soil wind erosion decreased by 17.8921 million tons. During this period, the contribution rate of ecological programs (e.g., conversion of cultivated land to forest land and grass land, ecological engineering construction projects, etc.) to reduction of regional soil wind erosion was 59.13%, indicating that ecological programs have a positive role in reducing soil wind erosion intensity. The sustainable development of the ecological environment of the Yellow River Basin should be continued through strengthening ecological restoration and protection, to further consolidate gains made in this fragile ecosystem. This study provides scientific and technological support and relevant policy recommendations for the sustainable development of the Yellow River ecosystem under global change.

Coal resource utilization and environmental protection is a critical global issue. This study aims to address the need for geochemical maps of harmful trace elements (HTEs) in Chinese coalfields and to extract scientific information from these maps. Based on data extracted from the Trace Elements in Coal of China database, geochemical maps of As, Cd, Cr, F, Hg, Ni, Pb, and Se in Chinese coalfields were generated, for the first time, using the ArcGIS platform. Differences in regional HTE concentrations were attributed to multiple factors, including the type of coal-forming environment, terrigenous debris, and groundwater effect. However, on a national scale, the spatial distribution pattern of HTEs in coal is affected by the abundance of elements in the earth's crust. Herein, the enrichment anomaly of HTEs in coal were found to be significantly correlated with fault locations, and hydrothermal fluid action was characterized as the primary causal factor. HTE abundance in coal is the result of geochemical cycles in the earth's crust. Additionally, stratum fracture zones may serve as conduits and material sources for the migration of HTEs from deep layers to shallow layers, including coal seams. This study provides an essential reference for extensive map applications and coal environmental management while advancing our understanding of the spatial distribution patterns of chemical elements in coal.

Fengqiao Experience, as a model of China’s grassroots social governance practice, had played an important role in resolving various civil disputes. In recent years, in the face of a surge in the intellectual property disputes, in order to optimize the business environment that values intellectual property, various measures have been taken across the country, including establishing online mediation platforms such as Fengqiao E Station. How to maintain healthy market competition and regulate the rules about business rights protection is a topic that urgently needs to be studied and resolved in the field of intellectual property protection currently. This paper used the results of online surveys conducted on wjx.cn and mikecrm.com for workers in different industries, to summarize the challenges faced by online mediation of intellectual property disputes and experience accumulated in practice, such as Hong Kong’s facilitative mediation model. The paper takes Guangzhou as an example, to put forward effective measures to resolve the problem and provide references for intellectual property protection in the Greater Bay Area.

Harmful trace elements in coal have caused serious damage to the environment and human health. Understanding their spatial distribution is helpful for environmental health assessment and for their effective control and utilization. To further explore the geospatial distribution of harmful trace elements found in Chinese coals, this work constructed the Trace Elements in Chinese Coals Database Management System (TECC), and analysed the spatial distribution of harmful trace elements by applying spatial data algorithms and visual technology of WebGIS. The main results are as follows: (1) The mean concentrations of 25 harmful trace elements (Ag, As, B, Ba, Be, Cd, Cl, Co, Cr, Cu, F, Hg, Mn, Mo, Ni, P, Pb, Sb, Se, Sn, Th, Tl, U, V, Zn) in Chinese coals are provided, using the "reserve-concentration" weighted calculation method; (2) Using As, Hg, F, and U as examples, the spatial distribution of harmful trace elements in Chinese coalfields is visually displayed; (3) Harmful trace elements are extremely unevenly distributed in Chinese coalfields; they are mainly concentrated in south China, especially in the southwest region, and some elements may also be concentrated in coals from northwest, northeast, and north China. The enrichment of harmful trace elements in Chinese coals is the result of a combination of multiple factors, such as the nature of the region the coal is sourced from, sedimentary facies, coal-forming plants, and magmatic hydrothermal processes. This work can serve as a reference for the study of harmful trace elements in coal, including assessment of their environmental and health impacts.

To construct a transgenic cell sheet of cartilage-derived morphogenetic protein 1 (CDMP1) by adenovirus vector in vitro and to identify its biological activity.The bone mesenchymal stem cells (BMSCs) were isolated from bone marrow of 1-month-old rabbit, and cultured in vitro. The 3rd-6th generation of BMSCs were used for experiment. The experiment was divided into 3 groups: BMSCs transfected by adenovirus (Ad)-cytomegalovirus (CMV)-human CDMP1 (hCDMP1)-internal ribosome entry site (IRES)-enhanced green fluorescent protein (EGFP) in group A, BMSCs transfected by Ad-CMV-EGFP in group B, and untransfected BMSCs in group C. The expression of green fluorescence was observed in 3 groups under fluorescent inverted microscope. MTT assay was used to detect the proliferation of the cells. The cell sheet was obtained by means of temperature-responsive culture dish for 14 days. The morphological and HE staining observations of the cell sheet were carried out. RT-PCR and Western blot were used to detect the expressions of hCDMP1 and collagen type II at gene and protein levels, while alcian blue staining was used to detect the expression of glycosaminoglycans (GAG).Bright green fluorescence was observed in transfected cells at 72 hours under fluorescent inverted microscope, and the transfection efficiency was up to 90%. MTT assay showed approximate S-shaped growth curves in 3 groups, showing no significant difference in the absorbance (A) value among 3 groups within 9 days (P0.05). The three-dimensional cell sheets were successfully harvested in vitro. The RT-PCR and Western blot showed that there were positive expressions of hCDMPl and collagen type II in group A and negative expression in other 2 groups. HE staining and alcian blue staining showed that there were rich fibrous tissues, mass extracellular matrix, and dark blue metachromatic granules in group A, but there was less fibrous tissues and no specific blue metachromatic granules in other 2 groups; and the positive expression area was significantly lower and gray scale of GAG was significantly higher in group A than that in groups B and C (P0.05).A transgenic cell sheet of exogenous recombinant hCDMP1 by adenovirus vector can express collagen type II and GAG, so it has chondrogenic capacity. This technology that overcomes limitations in traditional tissue engineering, such as low cell-attachment efficiency and inflammatory reaction, may be a new tissue engineering approach for hard tissue reconstruction and is hopeful to build a large density of tissue engineered cartilage.