Explore the vast range of titles available.

Complex environments, such as underground pipe galleries, subway tunnels, and bridge piles, seriously affect the construction of underground passages. Reducing the disruption of the surrounding environment and road traffic during the construction of underground passages in urban transportation hubs is very important for underground passages. Overcoming these difficulties is a problem that we constantly strive to solve. In this paper, we innovatively propose an open-shield construction method (OSM) without a support structure. It simplifies the construction process, is very adaptable to low soil cover depth and complex construction environments, and has minimal impact on traffic disruption during construction. We first analyze the main problems in the construction of urban underground passages and then elaborate on the OSM in detail. Then, an example of an actual project is used to explain the requirements for prefabricated pipe segments and the waterproof structure. Finally, the effect of applying this method is evaluated by using numerical simulation technology and actual monitoring data. This method provides practical engineering application references for the construction of urban underground passages.

The disposal of agricultural waste ash is a great ecological challenge. This study analyzed the basic properties of corn straw ash and soybean straw ash, encompassing the identification of key oxides, the assessment of particle size distribution, and the performance of thermogravimetric analysis. This study also evaluated the potential of corn straw ash and soybean straw ash to replace cement in mortar and concrete through laboratory tests. The findings indicated that the strength activity index of corn straw ash was higher than soybean straw ash. Furthermore, when these ashes were used as cement replacements, the compressive strength of concrete decreased. Notably, concrete containing corn straw ash exhibited greater strength than concrete with the same substitution amount of soybean straw ash. Specifically, at a 5% substitution level, the compressive strengths of corn straw ash concrete and soybean straw ash concrete were 31.5 and 30.5 MPa, respectively. Additionally, soybean straw ash concrete demonstrated superior resistance to water penetration compared to corn straw ash concrete. Both corn straw ash and soybean straw ash exhibited the potential to enhance the early crack resistance of concrete.

Long non-coding RNA (lncRNA) PMS2L2 has been reported to participate in endotoxin-induced inflammatory responses. As these types of responses can promote osteoarthritis (OA), it was of interest to ascertain if PMS2L2 may be involved in OA. To explore any potential participation of PMS2L2 in OA, synovial fluid was extracted from both OA patients and healthy controls (n = 62 each) and PMS2L2 expression of each sample determined by RT-qPCR. In addition, as miR-34a has a potential binding site on PMS2L2, hypothetical interactions between PMS2L2 and miR-34a in chondrocytes were analyzed by performing over-expression experiments. Furthermore, the role of PMS2L2 and miR-34a in the regulation of chondrocyte proliferation was analyzed using CCK-8 and BrdU assays. The results showed that PMS2L2 expression in OA patient synovial fluid was lower compared to that in control group fluid, and the extent of this reduction was related to disease stage. In in vitro studies, it was seen that endotoxin treatment of chondrocytes led to decreased PMS2L2 expression. It was found that PMS2L2 over-expression caused increased miR-34a expression in OA patient chondrocytes but not in cells from healthy controls. In contrast, miR-34a over-expression in either cell population did not affect PMS2L2 expression. Lastly, over-expression of both PMS2L2 and miR-34a led to inhibited chondrocyte proliferation. Of note, a combined over-expression of PMS2L2 and miR-34a resulted in stronger effects on proliferation compared to that from either single over-expression. Based on the findings that PMS2L2 is down-regulated during ongoing states of OA, and that changes in PMS2L2 expression can lead to increases in chondrocyte expression of miR-34a - resulting in inhibition of chondrocyte proliferation in OA. From these findings, one may conclude that finding means to regulate PMS2L2 could be a promising new target in the development of regimens for the treatment of OA.

Building deformations are not only closely related to the distance from the building to metro-station excavation but also related to the relative positions of the building and metro-station excavation. Building deformations can be predicted using ground surface settlement profiles. Based on typical geological parameters of Nanjing metro-station excavation, ground surface settlements were numerically simulated by auxiliary planes perpendicular and parallel to the excavation and by angled auxiliary planes at the excavation corner. Results show that the ground surface settlement profiles in auxiliary planes are closely related to the relative positions of the auxiliary planes and the metro-station excavation. Partitioning of ground surface settlements was proposed according to the three types of ground surface settlement profiles; furthermore, bending deformation and torsional deformation regularities of surrounding buildings were analyzed, and an estimation method for building settlements was developed. Finally, field-monitored settlement data of 21 buildings in different zones were compared with the estimated settlement data, and the application of the settlement estimation method to different types of foundations was analyzed. The results of this study can serve as reference for metro-station deep excavation construction and protection of surrounding buildings.

A large underground transportation hub is located on the west side of the Nanjing Youth Olympic Center, which is close to the embankment of the Yangtze River. The near-surface primarily comprises newly deposited soft soil of considerable thickness; the lower part is a riverbed-phase sandy soil containing two confined aquifers. The foundation pit requires deep excavation and has unusual shapes of “pit in pit” and “pit leaning pit.” For the convenience and safety of excavation, the piezometric head of the upper confined aquifer, where the pit bottom is located, reached 1 m below the bottom plane through precipitation, while that of the lower confined aquifer also dewatered down to a safe water level to avoid an uplift problem. After considering the engineering geological conditions, the function and shape of the foundation pits, we divided the soil layers of the foundation pits into two areas (the NW area and the SE area) and proposed the support scheme correspondingly. The numerical simulation results and completed construction safely verified the feasibility of the support scheme.

The Keziletage pluton which plays an important role in studying the nature of continental lithosphere and restraining the tectonic evolution of the Southern TianShan orogenic belts is located in the middle of the Keziletage synclinorium, a secondary tectonic unit of the South TianShan syncline fold belt. Emplacement mechanism of the Keziletage pluton in Xinjiang is studied through detailed analyses of magnetic fabrics. Data from 28 sampling sites within the pluton show that the value of the average susceptibility (Km) is high. The corrected anisotropy degree (Pj) is less than 1.2, which can be an indicator of flow magnetic fabrics. The shape parameter (T) of magnetic susceptibility ellipsoid displays that the Keziletage pluton is dominated by oblate compression fabric. Although the magnetic fabrics show NE-SW compression as a whole, the magnetic lineations are little over magnetic foliations. We suggest that the collision of Tarim blocks to YiLi-mid TianShan micro-plate became much weaker during the emplacement when the regional tectonic setting was changing to extension environment.

This research studies the mechanical behavior of a weak intercalated layer with in situ large-scale shear tests. The in situ samples were prepared from the rock mass of the Masanfeng cut slope, which is located in the city of Maanshan, China. From the measured shear stress shear deformation relationships under different normal stresses, the shear deformation behavior and shear constitutive models of the weak intercalated layer were studied, and the strength parameters at different limit conditions were calculated. The constitutive function for normal deformation was derived from test results of the normal deformation.

Analysis and research results show that the sliding plane of Jiudingshan landslide is along the weak intercalated layer (clay-filled) in the limestone and the sliding block is separated by the tension crack on the slope crest. The earlier study results show that for the rough, ups and downs structural plane, when i is greater than 2.0, the shear strength of the structural surface is intensely close to the strength of the filling. By the earlier theory, this failure must be through the clay filling. In this study, the failure is back-analyzed and the shear strength of the infilling is tested by the laboratory direct shear tests for which samples were retrieved in the field. The failure cannot be explained by the laboratory results of shear strength parameters. To simulate the field conditions, the real strength parameters of sliding surface are measured by the in situ shear tests for the weak intercalated layer. By the in situ tests, it is shown that the failure initiates along the contacts between the clay infilling and the limestone boundaries, but not through the clay itself. Though the contact surface is the interface of the clay–limestone, the cohesion is not 0 and it is not negligible too.

Background Necrotizing enterocolitis (NEC) is the leading cause of death among preterm infants born at < 30 weeks’ gestation. The incidence of NEC is reduced when infants are fed human milk. However, in many neonatal intensive care units (NICUs), it is standard practice to freeze and/or pasteurize human milk, which deactivates bioactive components that may offer additional protective benefits. Indeed, our pilot study showed that one feed of fresh mother’s own milk per day was safe, feasible, and can reduce morbidity in preterm infants. To further evaluate the benefits of fresh human milk in the NICU, a randomized controlled trial is needed. Methods Our prospective multicenter, double-blinded, randomized, controlled trial will include infants born at < 30 weeks’ gestation and admitted to one of 29 tertiary NICUs in China. Infants in the intervention (fresh human milk) group ( n  = 1549) will receive at least two feeds of fresh human milk (i.e., within 4 h of expression) per day from the time of enrollment until 32 weeks’ corrected age or discharge to home. Infants in the control group (n = 1549) will receive previously frozen human milk following the current standard protocols. Following informed consent, enrolled infants will be randomly allocated to the control or fresh human milk groups. The primary outcome is the composite outcome mortality or NEC ≥ stage 2 at 32 weeks’ corrected age, and the secondary outcomes are mortality, NEC ≥ stage 2, NEC needing surgery, late-onset sepsis, retinopathy of prematurity (ROP), bronchopulmonary dysplasia (BPD), weight gain, change in weight, increase in length, increase in head circumference, time to full enteral feeds, and finally, the number and type of critical incident reports, including feeding errors. Discussion Our double-blinded, randomized, controlled trial aims to examine whether fresh human milk can improve infant outcomes. The results of this study will impact both Chinese and international medical practice and feeding policy for preterm infants. In addition, data from our study will inform changes in health policy in NICUs across China, such that mothers are encouraged to enter the NICU and express fresh milk for their infants. Trial registration Chinese Clinical Trial Registry; #ChiCTR1900020577; registered January 1, 2019; http://www.chictr.org.cn/showprojen.aspx?proj=34276

Bosten Lake is located in Yanqi Basin of Xinjiang. A working area in the southeast of China is influenced by the regulation of Bosten Lake, and the transitional zone of climate in the north and south of Xinjiang, forming a climate of large evaporation, dry and little rain, and groundwater is a very important fresh water resource. In order to find out the composition of groundwater resources in the working area, the groundwater steady flow model is established by using the data of borehole, well, pumping test and so on, and the groundwater resources in this area are evaluated. The groundwater exploitation mode in the simulated area is evaluated. The results show that: the exploitable groundwater resources in the simulated area is about 22.045 million m 3 /a. Changing the mode of agricultural water use under the existing groundwater equilibrium condition can effectively reduce the waste of groundwater resources.