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Urban cover-collapse sinkholes pose a significant global challenge due to their destructive impacts. Previous studies have identified groundwater fluctuations, subsurface soil conditions, pipeline leakage, precipitation, and subterranean construction activities as key contributors to these phenomena. However, unique geological settings across different urban environments lead to variations in the primary factors influencing sinkhole formation. This study focuses on Shanghai, a city notable for its extensive urbanization and rich historical context, to explore the dynamics of sinkholes within urbanized areas worldwide. We employ spatial analysis and statistical methods to examine data on sinkholes recorded in the past two decades in Shanghai, correlating these events with the city's shallow sand layer, ground elevation, and proximity to surface water. Our goal is to identify the dominant factors governing sinkhole occurrence in Shanghai and to lay the groundwork for their effective scientific management and prevention. Key findings indicate that most sinkholes in the area are associated with a thin shallow sand layer, low to moderate ground elevations, and the absence of nearby rivers. Additionally, many sinkholes correlate with subterranean voids within the confined aquifer beneath the cohesive soil layer. The lack of historical river channels, obscured by urban development, also indirectly contributes to sinkhole formation. We recommend enhancing urban river management and drainage systems to mitigate potential damage from water accumulation. [ABSTRACT FROM AUTHOR]

In this work, a new composite photocatalyst was synthesized by flower-like Bi2O3 and two-dimensional multilayer V2C using a facile hydrothermal method. Compared with the pristine sample, the specific surface area of Bi2O3/V2C MXene composite is significantly increased, which is favourable to improve the photocatalytic efficiency. The analysis of the UV-vis absorption spectrum and band gap energy shows that the construction of heterojunction broadens the light response range, improves the light absorption capacity, and obtains a narrower band gap than any of the single component, which is beneficial to the utilization of light. PL, TPC and EIS analysis revealed that Bi2O3/V2C MXene composite had stronger carrier mobility, which further confirmed that the photocatalytic oxidation performance of the system was the dominant reason in the photocatalytic NO pollutant removal process. This study provides a new idea for better understanding the two-dimensional MXene material-based photocatalyst and improving the NO removal efficiency. [ABSTRACT FROM AUTHOR]

Anisotropic permeability is of great significance for assessing the consolidation and drainage mode of soil layers in reclamation areas, as well as for preventing and controlling ground settlement after project construction. This paper analyzes the anisotropic permeability of the inland and nearshore soil layers in Chongming East Shoal, Shanghai, and the formation mechanism of anisotropic permeability through permeability and scanning electron microscope (SEM) tests. The results highlight that compared with dredger fill and sandy silt, the horizontal permeability coefficient of underlying soft clay (USC) is significantly higher than its vertical permeability coefficient, which is more significant in nearshore USC. Interestingly, the upper clay (21.5 m) in the thickest clay layer shows greater anisotropic permeability than the lower clay (41.5 m). Due to the instability of seepage channels, the USC anisotropic permeability increases in a fluctuating manner as the hydraulic gradient increases. Microstructural parameters are used to reveal the mechanism of anisotropic permeability, which shows that a simple soil skeleton and structure, strong particle orientation, decreased particle abundance, increased particle roundness, decreased particle contact area, and increased pore area all contribute to the enhancement of permeability. Moreover, micro-parameters have been proposed to evaluate anisotropic permeability in terms of the effective seepage-pore area. This approach addresses the constraint of water films on the permeability efficiency of USC particles. [ABSTRACT FROM AUTHOR]

Land subsidence has to be controlled under global climate change and sea level rising for coastal megacities. Land subsidence caused by lowering groundwater level during underground excavation has become a dominant influence factor for land subsidence during urbanization and city renewal. How to manage the land subsidence induced by foundation pit dewatering (FPD) on an urban scale was urgent. Shanghai was selected as the research background. A subsidence and drawdown double control (SDDC) partition was established. The position of three times excavation depth (3H) horizontally away from the foundation boundary in the plane was defined as the boundary between dewatering subsidence and excavation settlement. Land subsidence of 3H (LS-3H) and groundwater drawdown on 3H (GD-3H) were defined as the evaluating and controlling indicators. An FPD conceptual model was summarized by the estimating and investigating of foundation pit information and numerical simulations were performed. A total of 6540 FPD scenarios were simulated for the LS-3H and GD-3H. Multi-factor regression analysis was conducted to obtain relations between the GD-3H and the shape, area, depth, and curtain depth of foundation pit on the basis of the numerical simulations. The regression models can be used to estimate the GD-3H and compared with the threshold specified by land subsidence prevention and control (LSPC) law, which can provide a reference for similar cases. [ABSTRACT FROM AUTHOR]

The vertical–horizontal curtain system (VH curtain) is sometimes utilized in foundation pit dewatering under complex hydrogeological conditions. However, the working mechanism of this system when the horizontal curtain is semi-permeable and cannot completely cut off the bottom aquifer remains unknown. A transparent soil physical model test was performed to reveal the water control mechanism of the VH curtain system with a semi-permeable horizontal curtain. A multi-point inert tracer with a high-speed camera was used to photograph the seepage process. The seepage mode was revealed via a model test. With the Shanghai deep tunnel project as background, a numerical simulation was performed to understand the utilization of the VH curtain. The influence of horizontal curtain position, horizontal curtain thickness, horizontal curtain hydraulic conductivity, and VH curtain combination form on the seepage path around the foundation pit and on the drawdown of water level inside and outside the pit were studied. Results provide a basis for the engineering application of the VH curtain pumping well system. [ABSTRACT FROM AUTHOR]

Background Heterotopic gastric mucosa in the upper esophagus (HGMUE) is reported to be related to gastroesophageal reflux disease (GERD). This study investigated the prevalence of GERD and the use of salivary pepsin to diagnose gastroesophageal reflux, especially proximal reflux, in HGMUE patients. Methods One hundred and fifty-three HGMUE patients and 50 healthy volunteers were studied. All subjects took a reflux symptom index questionnaire (RSI); underwent endoscopy, barium esophagogram, high-resolution manometry (HRM), and 24-hour multichannel intraluminal impedance-pH-metry (MII-pH); and salivary pepsin test. Results Ninety-five (62.1%) HGMUE patients but no control subjects were diagnosed with GERD. The salivary pepsin concentration, RSI score, DeMeester score, acid exposure time (AET), total reflux episodes, proximal acidic reflux episodes, and proximal weakly acidic reflux episodes were significantly higher in the HGMUE group than in the control group (P  < 0.05). The salivary pepsin test showed a sensitivity of 85.9% and specificity of 56.9% for diagnosing GERD using the optimal cut-off value of 75 ng/mL. One hundred and seven (69.9%) and 46 (30.1%) HGMUE patients were categorized as pepsin (+) and pepsin (−), respectively when 75 ng/mL was used as a cut-off value. Male sex, RSI, AET, and proximal acid reflux episodes were positive predictive factors for the occurrence of pepsin (+) in HGMUE patients. Conclusions GERD, especially GERD with proximal acid reflux and related symptoms, was common in HGMUE patients. The salivary pepsin test could be an additional useful test for testing reflux in HGMUE patients, but it will not replace the MII-pH. [ABSTRACT FROM AUTHOR]

Groundwater level has to be lowered during deep excavation. A vertical curtain is usually adopted to control the drawdown inside and outside a foundation pit in a built-up area. However, the cost and working difficulty increases substantially with the rise in depth of vertical curtains. In the manuscript, a man-made horizontal seepage reducing body (HSRB) was introduced to shorten the vertical curtain depth and control drawdown. With the No. 4 shaft foundation pit of Guangyuan Project, Shanghai as background, HSRB was proposed in foundation pit dewatering. Microbially induced carbonate precipitation grouting technology was recommended to form an environment-friendly HSRB. Numerical method was used to simulate and understand the influence of position, thickness, and hydraulic conductivity of HSRB on groundwater level. The non-separated HSRB was better than the separate HSRB. Decreasing HSRB hydraulic conductivity was better than increasing HSRB depth. Four seepage modes were summarized considering vertical curtain penetration conditions into multi-aquifer, and the fifth seepage mode was formed for vertical curtain using man-made HSRB, which can be referred by similar engineering applications. [ABSTRACT FROM AUTHOR]

Purpose: Although laparoscopic Nissen fundoplication (LNF) is a kind of minimally invasive surgery, some transition time may still be required to allow the fundoplicated stomach to adapt to the new anatomical position. We observed transient delayed gastric emptying (DGE) post-LNF in our preliminary study. This study aimed to investigate the occurrence rate and development of transient DGE post-LNF. Methods: Patients who underwent LNF for gastroesophageal reflux disease (GERD) at our institution were recruited consecutively. They were treated with standardized LNF and prospectively followed up for 2 months. Proper diet guidance and/or pharmacologic therapy were given during these 2 months. GERD Health-Related Quality of Life (GERD-HRQL), DGE symptoms, and DGE status were evaluated preoperatively and postoperatively. Results: Fifty-one patients underwent LNF and completed a 2-month follow-up. LNF succeeded in all patients. Prior to LNF, no DGE was identified. At the 1-month follow-up, LNF led to a significant reduction in the GERD-HRQL total score but a significantly increased DGE score. Endoscopically, DGE was identified in forty-seven (n = 47, 92.2%) patients. At the 2-month follow-up, the GERD-HRQL scores continued to show decreases compared to the 1 month. The DGE score returned to the baseline value. Endoscopically, no DGE was identified in any patients (n = 0, 0.0%). Conclusions: Transient DGE is a very common one-month post-LNF but can recover quickly in the second month following LNF. [ABSTRACT FROM AUTHOR]

Ovarian cancer is a type of common gynecological tumors with high incidence and poor survival. The anticancer effects of the traditional Chinese medicine Solanum lyratum Thunb (SLT) have been intensively investigated in various cancers but in ovarian cancer is rare. The current study is aimed at investigating the effect of SLT on ovarian cancer cells. Lactate dehydrogenase (LDH) and MTT assays indicated that SLT concentrations of 0.25 and 0.5 μg/mL were not cytotoxic and had significant inhibitory effects on the cell viabilities of A2780 and SKOV3 cells, hence were used for subsequent experiments. Flow cytometric and western blot analysis revealed that SLT effectively suppressed ovarian cancer cell proliferation via inducing cell cycle arrest and increasing apoptosis. Cell cycle and apoptosis-related protein expressions were also regulated in SLT-treated cells. Moreover, DCFH-DA and western blot assays demonstrated that SLT enhanced ROS accumulation and subsequently activated the p53 signaling pathway. However, SLT-regulated ovarian cancer cell proliferation, apoptosis, migration, invasion, and EMT were significantly reversed by an ROS inhibitor (NAC, N-acetyl-L-cysteine). Furthermore, A2780 and SKOV3 cells cocultured with M0 macrophages showed that SLT activated the polarization of M0 macrophages to M1 macrophages and inhibited the polarization to M2 macrophages, with the increased percentage of CD86+ cells and decreased percentage of CD206+ cells were detected. In summary, this study illustrated the anticancer effects of SLT on ovarian cancer cells, suggesting that SLT may have the potential to provide basic evidence for the discovery of antiovarian cancer agents. [ABSTRACT FROM AUTHOR]

Summary: The asymptotic stabilization problem is studied for a cascade connection of passive switched nonlinear systems and a passive switched nonlinear system in this paper. When each subsystem is asymptotically zero state detectable and passive on active time intervals, asymptotic stabilization is achieved via co‐design of switching laws and controllers without damping injection. First, an output‐feedback controller is designed to asymptotically stabilize a cascade connection of two passive switched systems if outputs are measurable. Second, when the output of the first switched system is noisy or unmeasurable, a sampled integral stabilization (SIS) technique is employed to investigate asymptotical stabilization of a cascade connection by measuring only the storage function of the second switched system. Finally, as a special case of a cascade connection, the SIS technique is used to stabilize a passive switched system without damping injection. Under this circumstance, the controller is designed by sampling the integral of the passive output. The two‐link robot manipulator is provided to illustrate the effectiveness of the SIS technique. [ABSTRACT FROM AUTHOR]

Abstract: Local strict QSR‐dissipativity of a switched nonlinear system is studied using the linearization technique in this paper. We obtain local strict QSR‐dissipativity of a switched system even if each subsystem is not locally strictly QSR dissipative by designing a switching law. The derived dissipative sufficient condition is characterized by a modified Lyapunov‐Metzler inequality that can be simplified as an LMI by assuming specific forms. Two special forms of local strict QSR‐dissipativity, local input state strict passivity and local L2‐gain, are considered. When the approximate errors of a switched affine system satisfy certain conditions, local strict passivity can be drawn from its linearization. Finally, a numerical example is given to illustrate how to apply the proposed method to achieve passivity of switched nonlinear systems. [ABSTRACT FROM AUTHOR]

In this study, finite‐time passivity of switched non‐linear systems is developed. First, a finite‐time passivity concept is proposed using multiple storage functions. Second, a switching law is designed to make a switched non‐linear system finite‐time passive. Third, on the basis of the proposed concept, finite‐time passivity properties are investigated. On the one hand, finite‐time passivity can induce finite‐time stability. On the other hand, finite‐time passivity is preserved under the feedback interconnection and parallel interconnection. Furthermore, the merging switching signal technique is employed to make an interconnected system finite‐time passive. Finally, an example is provided to demonstrate the effectiveness of the obtained results. [ABSTRACT FROM AUTHOR]

Local passivity andH∞control of switched discrete-time nonlinear systems are studied using the linearisation technique in this paper. We first establish LMI-based sufficient conditions under which theconsidered system is locally strictly QSR-dissipative. Then, two special cases of QSR-dissipativity, local passivity andl2gain, are investigated. In view of the derived conditions being all convex in linearised system matrices, local feedback passification andH∞control problems of switched discrete-time nonlinear systems are solved. The efficiency of the proposed method is verified through numerical examples. [ABSTRACT FROM PUBLISHER]

Copyright of Hydrogeology Journal is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Hydrogeology Journal is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Subway foundation pit dewatering may contribute to the regional land subsidence in a built-up area when aquifers are too thick to be cut off by a curtain. The land subsidence induced by subway foundation pit dewatering was divided into local subsidence and areal subsidence. The former was managed by construction organizations, while the latter was managed by a land resource, urban management, and hazard prevention department. The areal subsidence could not be recovered after dewatering because of its vast influence area and contribution to regional land subsidence. The boundary between local subsidence and areal subsidence was defined as the location of three times the foundation pit depth to the foundation pit boundary. The subsidence within the boundary belonged to local subsidence, whereas the subsidence outside the boundary belonged to areal subsidence. With Shanghai as background, the conceptual and mathematical models that considered hydrogeological conditions, curtain depth, and pumping well screens were established, and numerical simulations were performed. When the pumping well screens were enveloped by a diaphragm wall, the best vertical distance of about 1.0-4.0 m was obtained between the screen bottoms and curtain bottom. The decreasing rate of areal subsidence was the highest under the interaction of diaphragm wall and pumping well screens. Further increasing the penetration depth of the diaphragm wall and shortening the length of the pumping well screen were both less efficient. [ABSTRACT FROM AUTHOR]

Managed aquifer recharge is one of the most popular methods for dealing with local water shortage issues, and the bacterial community could be a vital factor influencing groundwater quality during this process. In this study, analysis of variations in groundwater components during artificial recharge revealed three stages at a text site in China. During stage I, total iron and dissolved organic carbon levels are stable basically, dissolved oxygen and SO42− levels have rising trends, NO3− curve varied not obviously. Variation curves show increases in dissolved oxygen, NO3−, SO42− and stabilization in dissolved organic carbon and total iron at stage II. During stage III, dissolved oxygen and NO3− have rising trends, dissolved organic carbon, total iron, and SO42− keep stable. At 25 and 70 days the Simpson and Shannon–Wiener indices show that microbial community richness and population diversity underwent a gradual dynamic change after recharge water arrived. Correlation analysis shows that the Simpson index was mainly affected by dissolved oxygen and NO3−. PCR-DGGE confirmed these findings. Overall, the results revealed that the main bacterial communities reduce total nitrogen, total phosphorous, and chemical oxygen demand, which corresponded to the calculated correlation index. [ABSTRACT FROM AUTHOR]

Copyright of Hydrogeology Journal is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Glioblastoma (GBM) is one of the most common and malignant types of primary cancer in the central nervous system; however, the clinical outcomes of patients with GBM remain poor. Circular RNAs (circRNAs) have been revealed to serve important roles in diverse biological processes, such as regulating cell proliferation, epithelial-mesenchymal transition and tumor development. However, the underlying biological function of circRNA filamin A (circFLNA) and its potential role in GBM remain to be determined. The present study aimed to identify differentially expressed circRNAs in GBM. Reverse transcription-quantitative PCR was used to analyze the expression levels of circFLNA. The results demonstrated that the expression levels of circFLNA were significantly upregulated in clinical GBM samples and GBM cells compared with adjacent healthy brain tissues and normal human astrocytes, respectively. The results of the Cell Counting Kit-8 and Transwell assays revealed that circFLNA knockdown significantly inhibited the proliferative and invasive abilities of GBM cell lines. Moreover, high circFLNA expression levels were associated with a worse prognosis in GBM. MicroRNA (miR)-199-3p was subsequently predicted to be target of circFLNA. The inhibitory effect of miR-199-3p on cell proliferation and invasion was partially reversed following circFLNA knockdown. In conclusion, the findings of the present study identified novel roles for circFLNA in GBM and indicated that the circFLNA/miR-199-3p signaling axis may serve an important role in GBM progression. Therefore, circFLNA may represent a novel target for the diagnosis and treatment of GBM. [ABSTRACT FROM AUTHOR]