Shenzhen Municipal People's Government

Abstract Capacitive‐type strain sensors based on hydrogel ionic conductors have undergone rapid development benefited from their robust structure, drift‐free sensing, higher sensitivity, and precision. However, the unsatisfactory electro‐mechanical stability of the conventional hydrogel conductors, which are normally vulnerable to large deformation and severe mechanical impacts, remains a challenge. In addition, there is not enough research regarding the adhesiveness and mechanical properties of the dielectric layer, which is also critical for the mechanical adaptability of the whole device. Here, a dynamically super‐tough capacitive‐type strain sensor based on energy‐dissipative dual‐crosslinked hydrogel conductors and an organogel dielectric with high adhesive strength is developed. Combining with the mechanical advantages of the hydro/organo‐gels, the capacitive strain sensor exhibits high stretchability and superior linear dependence of sensitivity with a gauge factor of ≈0.8% at 100% strain. Moreover, the sensor displayed ultrastability against various severe mechanical stimuli that can even survive unprecedentedly from extremely catastrophic car run‐over by 20 times. With these synergistic mechanical advantages, the capacitive strain sensor is successfully applied as a highly‐reliable wearable sensing system to monitor diverse faint physiological signals and large‐range human motions.

Forest fire recognition is important to the protection of forest resources. To effectively monitor forest fires, it is necessary to deploy multiple monitors from different angles. However, most of the traditional recognition models can only recognize single-source images. The neglection of multi-view images leads to a high false positive/negative rate. To improve the accuracy of forest fire recognition, this paper proposes a graph neural network (GNN) model based on the feature similarity of multi-view images. Specifically, the correlations (nodes) between multi-view images and library images were established to convert the input features of graph nodes into the correlation features between different images. Based on feature relationships, the image features in the library were updated to estimate the node similarity in the GNN model, improving the image recognition rate of our model. Furthermore, a fire area feature extraction method was designed based on image segmentation, aiming to simplify the complex preprocessing of images, and effectively extract the key features from images. By setting the threshold in the hue-saturation-value (HSV) color space, the fire area was extracted from the images, and the dynamic features were extracted from the continuous frames of the fire area. Experimental results show that our method recognized forest fires more effectively than the baselines, improving the recognition accuracy by 4%. In addition, the multi-source forest fire data experiment also confirms that our method could adapt to different forest fire scenes, and boast a strong generalization ability and anti-interference ability.

Calcium silicate hydrate (CSH) is a potential new material for effective heavy metal adsorption, but the high manufacturing costs and difficult reusability have restricted its large-scale application. Herein, we report a green and facile strategy to prepare amorphous and hierarchically structured CSH-based nanocomposites from steel slag for heavy metal removal. The obtained flowerlike CSH-based materials showed fast adsorption rates and superior adsorption capacities for all employed heavy metal ions (Cu(II), Pb(II), and Zn(II)), with maximum adsorption capacities of approximately 244, 273, and 508 mg/g, respectively. The adsorption kinetics were all well fitted to the pseudo-second-order model, and the adsorption equilibrium fitted the Langmuir model. The excellent adsorption performance could be attributed to the release of Ca2+ and OH– from the CSH nanosheets. Moreover, as a case study, the obtained CSH–Cu(II) after absorption can be converted and reused as an photocatalyst by simply heating at 300 °C, which shows an excellent degradation efficiency of ∼90% for methylene blue within 150 min under simulated sunlight irradiation. This work lays the foundation for the development of an environmentally friendly route of "solid waste → adsorbent → catalyst", which will be of great significance for solid waste utilization as well as water purification.

Chronic activity of hepatitis B is thought to involve aberrant immune tolerance of unknown mechanism. In this study, we examined the role of CD4(+)CD25(+)Foxp3(+) regulatory T cells in disease activity and viral clearance in hepatitis B. Patients with chronic active hepatitis B (CAH) and asymptomatic HBV carriers (AsC) exhibited a significantly high frequency of CD4(+)CD25(+)Foxp3(+) T cells as opposed to that of controls and resolved HBV infection. These CD4(+)CD25(+) T cells expressed an elevated level of Foxp3 and displayed increased inhibitory activity towards both CD4(+)CD25(-) and CD8(+) effector cells. They were found to accumulate in liver biopsy tissue of CAH patients as opposed to controls. The frequency of CD4(+)CD25(+)Foxp3(+) T cells correlated positively with hepatitis B envelope (HBe) antigen status and serum HBV DNA copy numbers and had a converse relationship with HBe antibody status in patients with CAH and AsC. It was evident that in these patients, the increased frequency of CD4(+)CD25(+)Foxp3(+) T cells was associated with serum levels of transforming growth factor-beta known to promote peripheral conversion of CD4(+)CD25(-) T cells to CD4(+)CD25(+)Foxp3(+) regulatory T cells. The findings provide new insights into the role of CD4(+)CD25(+)Foxp3(+) regulatory T cells in chronic activity and viral clearance in chronic hepatitis B.

AIM: To determine the therapeutic efficacy of resveratrol on ulcerative colitis (UC) and its underlying mechanisms. METHODS: The mouse UC model was developed using 5% dextran sulfate sodium. Mice were randomly divided into four groups: normal control, UC model group, resveratrol low-dose group (RLD; 50 mg/kg per day), and resveratrol high-dose group (RHD; 100 mg/kg per day). RESULTS: The results showed that RLD regulates Treg/Th17 balance mainly through reducing the number of Th17 cells, whereas RHD regulates Treg/Th17 balance through both downregulating the number of Th17 cells and upregulating the number of Treg cells. Resveratrol can also regulate the level of plasma and intestinal mucosal cytokines including interleukin (IL)-10, transforming growth factor-β1, IL-6, and IL-17. The expressions of hypoxia inducible factor (HIF)-1α, mammalian target of rapamycin (mTOR), and signal transducer and activator of transcription 3 were significantly decreased in the intestinal tissues of mice treated with resveratrol. CONCLUSION: The therapeutic efficacy of resveratrol in UC is dose dependent and closely associated with the regulation of Treg/Th17 balance and the HIF-1α/mTOR signaling pathway.

Solid amine adsorbents are among the most promising CO2 adsorption technologies for biogas upgrading due to their high selectivity toward CO2, low energy consumption, and easy regeneration. However, in most cases, these adsorbents undergo severe chemical inactivation due to urea formation when regenerated under a realistic CO2 atmosphere. Herein, we demonstrated a facile and efficient synthesis route, involving the synthesis of nano-Al2O3 support derived from coal fly ash with a CO2 flow as the precipitant and the preparation of polyethylenimine (PEI)-impregnated Al2O3-supported adsorbent. The optimal 55%PEI@2%Al2O3 adsorbent showed a high CO2 uptake of 139 mg·g–1 owing to the superior pore structure of synthesized nano-Al2O3 support and exhibited stable cyclic stability with a mere 0.29% decay per cycle even under the realistic regenerated CO2 atmosphere. The stabilizing mechanism of PEI@nano-Al2O3 adsorbent was systematically demonstrated, namely, the cross-linking reaction between the amidogen of a PEI molecule and nano-Al2O3 support, owing to the abundant Lewis acid sites of nano-Al2O3. This cross-linking process promoted the conversion of primary amines into secondary amines in the PEI molecule and thus significantly enhanced the cyclic stability of PEI@nano-Al2O3 adsorbents by markedly inhibiting the formation of urea compounds. Therefore, this facile and efficient strategy for PEI@nano-Al2O3 adsorbents with anti-urea properties, which can avoid active amine content dilution from PEI chemical modification, is promising for practical biogas upgrading and various CO2 separation processes.

Abstract Chronic obstructive pulmonary disease (COPD) is an intractable disease involving a sticky mucus layer and nanoagents with mucus‐penetrating capability offer a new way to deliver drugs. However, drug release from nanovehicles requires optimization to enhance the therapeutic effects of COPD therapy. Herein, black phosphorus quantum dots (BPQDs) are combined with PEGylated chitosan nanospheres containing the antibiotic amikacin (termed PEG@CS/BPQDs‐AM NPs). As a drug‐delivery system, the hydrophilicity of PEG and positive charge of CS facilitate the penetration of nanovehicles through the mucus layer. The nanovehicles then adhere to the mucous membrane. Furthermore, the BPQDs degrade rapidly into nontoxic PO 4 3− and acidic H + , thereby promoting the dissociation of PEGylated CS nanospheres, accelerating the release of AM, decreasing the vitality of biofilms for ease of eradication. Our results reveal that drug delivery mediated by BPQDs is a feasible and desirable strategy for precision medicine and promising for the clinical therapy of COPD.

Abstract The multiple possible pathways of high‐valent cobalt catalyzed C−H activation/annulation of 2‐benzamidopyridine 1‐oxide with terminal alkyne were investigated in this combined theoretical and experimental study. The calculated results indicated that Co III catalyzed C−H activation occurs via a concerted‐metalation deprotonation (CMD) process and that the subsequent annulation involves the Co IV intermediate generated through a proton‐coupled electron transfer (PCET) process in DMSO solvent or through an intermolecular single electron transfer (SET) process in trifluoroethanol (TFE) solvent. Moreover, the theoretical calculations also revealed that Co III is the actual catalyst, and the solvent controls the chemoselectivity in the annulation stage, triggering a switch between five‐ and six‐membered ring products. Kinetic isotope effect (KIE), electron paramagnetic resonance (EPR), and TEMPO inhibition experiments were performed to confirm the computational results. The mechanistic insights should be valuable for understanding the PCET and SET processes involved in transition metal‐catalyzed C−H functionalizations. magnified image

Abstract The decarbonisation of the iron and steel industry, contributing approximately 8% of current global anthropogenic CO 2 emissions, is challenged by the persistently growing global steel demand and limitations of techno-economically feasible options for low-carbon steelmaking. Here we explore the inherent potential of recovering energy and re-using materials from waste streams, high-temperature slag, and re-investing the revenues for carbon capture and storage. In a pathway based on energy recovery and resource recycling of glassy blast furnace slag and crystalline steel slag, we show that a reduction of 28.5 ± 5.7% CO 2 emissions to the sectoral 2 °C target requirements in the iron and steel industry could be realized in 2050 under strong decarbonization policy consistent with low warming targets. The technological schemes applied to engineer this high-potential pathway could generate a revenue of US$35 ± 16 and US$40 ± 18 billion globally in 2035 and 2050, respectively. If this revenue is used for carbon capture and storage implementation, equivalent CO 2 emission to the 2 °C sectoral target requirements is expected to be reduced before 2050, without any external investments.

Abstract Amine-functionalized adsorbents offer substantial potential for CO 2 capture owing to their selectivity and diverse application scenarios. However, their effectiveness is hindered by low efficiency and unstable cyclic performance. Here we introduce an amine-support system designed to achieve efficient and stable CO 2 capture. Through atom-level design, each polyethyleneimine (PEI) molecule is precisely impregnated into the cage-like pore of MIL–101(Cr), forming stable composites via strong coordination with unsaturated Cr acid sites within the crystal lattice. The resulting adsorbent demonstrates a low regeneration energy (39.6 kJ/mol CO2 ), excellent cyclic stability (0.18% decay per cycle under dry CO 2 regeneration), high CO 2 adsorption capacity (4.0 mmol/g), and rapid adsorption kinetics (15 min for saturation at 30 °C). These properties stem from the unique electron-level interaction between the amine and the support, effectively preventing carbamate products’ dehydration. This work presents a feasible and promising cost-effective and sustainable CO 2 capture strategy.

BACKGROUND: Severe acute respiratory syndrome (SARS) is a novel infectious disease. No information is currently available on host-specific immunity against the SARS coronavirus (CoV), and detailed characteristics of the epidemiology of SARS CoV infection have not been identified. METHODS: ELISA was used to detect antibody to SARS CoV. Reverse-transcriptase polymerase chain reaction was used to detect SARS CoV RNA. T cells in peripheral blood of patients were quantified by flow cytometry. RESULTS: Of 36 patients with probable SARS CoV infection, 30 (83.3%) were positive for IgG antibody to SARS CoV; in contrast, only 3 of 48 patients with suspected SARS CoV infection, 0 of 112 patients with fever but without SARS, and 0 of 96 healthy control individuals were positive for it. IgG antibody to SARS CoV was first detected between day 5 and day 47 after onset of illness (mean +/- SD, 18.7+/-10.4). CONCLUSION: Detection of antibody to SARS CoV is useful in the diagnosis of SARS; however, at the incubation and initial phases of the illness, serological assay is of little value, because of late seroconversion in most patients.

BACKGROUND: Baicalin is a bioactive ingredient extracted from the root of Scutellariae radix, which is used to treat ulcerative colitis (UC). OBJECTIVE: We investigated the activity of baicalin on lipopolysaccharide-stimulated RAW264.7 cells and 2,4,6-trinitrobenzene sulfonic acid-induced rats, including the attenuation of oxidant stress and apoptosis. MATERIALS AND METHODS: The severity of colitis was assessed by disease activity index. The activities of catalase (CAT), glutathione peroxidase (GSH-PX), superoxide dismutase (SOD), and the content of malondialdehyde (MDA) were determined by their corresponding kits. The terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) was performed to study whether experimental colitis was associated with intestinal epithelial cell (IEC) apoptosis and the effect of baicalin on IEC apoptosis. Western blot analysis and immunocytochemistry assay were applied to determine the protein expressions. The reactive oxygen species (ROS) level in the colon of UC rats treated with baicalin was determined by ROS assay kit. RESULTS: Baicalin remarkably upregulated the activities of CAT, GSH-PX, and SOD and decreased the content of MDA in a dose-dependent manner in vitro and in vivo. The TUNEL-positive cells in rats treated baicalin were remarkably reduced. Both Western blot analysis and immunocytochemistry assay indicated that baicalin significantly decreased the expressions of transforming growth factor beta-1, Bax protein and upregulated the expression of Bcl-2 protein. In addition, the expressions of total and cleaved caspase-3, total and cleaved caspase-9 protein, Fas, and FasL in vitro were downregulated by the treatment with baicalin. Baicalin of different doses reduced the generation of ROS in UC rats. CONCLUSION: Taken together, these evidences provide scientific basics for the application of baicalin in the treatment of UC and suggest that baicalin exerts its effect via suppression of oxidant stress and apoptosis. SUMMARY: Baicalin remarkably upregulated the activities of catalase, glutathione peroxidase, and superoxide dismutase and decreased the content of MDA, both in vivo and in vitroThe terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling-positive cells in rats treated baicalin remarkably reduced in a concentration-dependent mannerWestern blot analysis and immunocytochemistry assay indicated that baicalin significantly decreased the expressions of transforming growth factor beta-1, Bax protein, and upregulated the expression of Bcl-2 proteinThe expressions of total and cleaved caspase-3, total and cleaved caspase-9 protein, Fas, and FasL in vitro were downregulated by the treatment with baicalin. Abbreviations used: UC: Ulcerative colitis, LPS: Lipopolysaccharide, TNBS: 2,4,6-trinitrobenzene sulfonic acid, DAI: Disease activity index, CAT: Catalase, GSH-PX: Glutathione peroxidase, SOD: Superoxide dismutase, MDA: Malondialdehyde, TUNEL: Terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling, ROS: Reactive oxygen species, IEC: Intestinal epithelial cell, SD: Sprague-Dawley, HE: H and E, DNTB: 5,5'-dithiobis-2-nitrobenzoic acid, TBA: Thiobarbituric acid, TBARS: Thiobarbituric acid-reactive substances, S.D: Standard deviation, and PBS: Phosphate-buffered saline.

Municipal sewage sludge is abundant and rich in phosphorus, making it a promising alternative phosphorus reserve. A good knowledge of the phosphorus transformation during pyrolysis will underlie the industrial phosphorus recycling and reclamation of sewage sludge. This work first advanced a novel calcium oxide (CaO)-enhancement phosphorus-recycling technique based on pyrolysis of sewage sludge, by regulating the transformation of phosphorus in sewage sludge during pyrolysis through the CaO addition. The obtained results indicated that CaO addition promoted the formation of hydroxylapatite, which is a desirable phosphorus species for plant growth. The factors of pyrolysis temperature and inherent composition of sewage sludge both influenced the fraction of hydroxylapatite during pyrolysis. An increase in pyrolysis temperature and a sludge with a high content of ash and a low content of volatile matters potentially promoted the transformation of P from organic phosphorus to the inorganic species during pyrolysis with the addition of CaO, particularly for the formation of hydroxylapatite. Increasing CaO addition significantly increased the fraction of hydroxylapatite in the obtained char, and the maximum content of 25 wt % hydroxylapatite over total phosphorus was attained. This enhanced transformation of hydroxylapatite may be potentially attributed to the interaction between CaO and the polyphosphate with the aid of the inherent minerals that appeared to benefit the immobilization of phosphorus during sludge pyrolysis. As the formation of hydroxylapatite was enhanced, this facile technology of CaO-enhancement sewage sludge pyrolysis could be used for the direct recycling of P as well as the disposal of sewage sludge.

This paper compares the field performance of non-vegetated and vegetated three-layer landfill cover systems utilising construction waste but without geomembrane at the Shenzhen Xiaping landfill site in humid climates over a monitoring period of 54 months. The top layer of each cover system was constructed using coarse-grained completely decomposed granite (CDG). The middle and bottom layers were compacted with coarse recycled concrete (CRC) and fine-grained CDG, respectively. Numerical analyses were also carried out. During the 54-month monitoring period, the cumulative rainfall recorded was 9800 mm. Retained pore water pressure in the vegetated cover was close to that in the non-vegetated cover after the heaviest rainfall recorded in Shenzhen during the monitoring period. The pore water pressure retained in the vegetated cover can be higher than that in the non-vegetated cover due to the increased saturated water permeability (k s ) induced by plant growth over 3 years. Surface runoff and water storage capacity in the vegetated cover were about five times and 9% higher than those in the non-vegetated cover, respectively. However, the long-term behaviour of the cover system in respect of these two aspects was influenced by the increase of k s due to the growth of grass roots. The middle CRC layer diverted infiltrated water by up to 51% of total rainfall. The measured average annual percolation of the non-vegetated and vegetated covers was about 23 mm and 21 mm, respectively. The measured data are supported by numerical analyses and they meet the US recommended criterion.

Composite box girders with corrugated steel webs and trusses is a new type of advanced bridge structure proposed recently. This kind of structure consists of a top concrete slab, corrugated steel webs and two bottom concrete-filled steel tubes connected by trusses. The resistance to torsion and overturning of this kind of structure is larger than that of composite bridges with a single concrete-filled steel tube. This kind of structure is able to satisfy the requirement of rapid construction, environment protection and cost effectiveness. Two composite box girder bridges with corrugated steel webs and trusses have been or are being constructed in China. This paper presents the design of these two bridges in detail, which will provide valuable engineering experience for the further promotion of this kind of new bridge structure. Experimental research has been carried out to study the flexural behavior and the flexural capacity of this kind of new bridge structure. The test results show that when the test beam is at the elastic stage, the cross-section can be viewed as a plane section if only the strains of the concrete top slab and the bottom steel tubes are considered. The test beam shows good ductility throughout the whole loading process.

OBJECTIVE: Adequate bowel preparation is essential for a successful colonoscopy; clinical studies suggest reinforced education can improve the preparation process. However, there have been no trials to compare WeChat directions (the most widely used social media app in China) with those of the short message service (SMS). This study was aimed to assess the effect of WeChat and SMS on the bowel preparation quality. PARTICIPANTS AND METHODS: This was a single-center, prospective, endoscopically blinded, randomized, controlled study. Patients in reinforced education groups received additional reminder messages by WeChat and SMS 2 days before colonoscopy. The primary outcome was bowel preparation quality evaluated by the Boston bowel preparation scale (BBPS) score and the rate of adequacy (BBPS score ≥6). Secondary outcomes included polyp detection rate, adenoma detection rate, and mean total adenomas detected. Patient tolerance level and subjective feelings were also evaluated. RESULTS: The total BBPS score and the percentage of adequacy were significantly higher in the reinforced education groups compared with the control (WeChat vs. control, P<0.001; SMS vs. control, P<0.001). Moreover, statistically significant differences between the two interventions were found in the total BBPS score but not in the rate of adequacy (P=0.007 and 0.561, respectively). The detection of adenomas, using multiplicity detection rate, advanced adenoma detection rate, and mean total adenomas detected, was much higher in the intervention groups (P=0.039, 0.037, and 0.019, respectively). CONCLUSION: WeChat was superior to SMS for bowel preparation, although both of them may help improving the detection of adenomas.

This paper investigates the behavior of simply supported prestressed steel–concrete composite beams through experimental and analytical studies. Eight specimens were instrumented and tested in the experimental program considering different parameters. The slip effect between the steel and concrete interface and the increase of the prestressing tendon force with the increase of loading were accounted for in the analytical model. A reduced stiffness method was then proposed for calculating the deflection of prestressed composite beams. Formulas for calculating the yield and ultimate moments were also derived. It was found that including the slip effect on the deflection and yield moment can significantly improve the accuracy of analytical predictions. As the calculated values showed good agreements with the test results, the proposed formulas can be reliably applied to the analysis and design of prestressed steel–concrete composite beams.

The composite box girder bridge with corrugated steel webs and trusses is a recently proposed enhanced composite box girder bridge structure. The shear-lag effect of this kind of structure is studied in detail in this research. Two 8.744 m-long test beams with and without concrete filled in the bottom steel tubes were constructed and tested. The non-uniform distribution of cross-sectional stress in the top concrete slab was captured. The filling of concrete inside the bottom steel tubes is shown not to have a great influence on the shear-lag effect. Numerical parametric studies were carried out to study the influence of various factors on the shear-lag effect of this kind of structure. The numerical results indicate that the magnitude of the shear-lag effect increases with the width-to-span ratio and the suspension ratio. Analytical equations were derived to calculate the shear-lag coefficient for composite box girders with corrugated steel webs and trusses based on the energy variational principle. The experimental and numerical validation indicates that the proposed equations can be well applied in engineering practice.

The composite box girder with corrugated steel webs (CSWs) and trusses is a bridge structure developed on the basis of traditional box girders with CSWs. In this research, experimental, numerical and analytical studies were carried out to investigate the flexural performance of simply supported composite box girders with CSWs. Two 1:5 scale models of a real bridge were fabricated and tested, including one with concrete filled steel tubes and another with hollow steel tubes. The test results show that the two specimens have good ductility and failed in a ductile manner. The concrete filled inside steel tubes reduces the deflection and increases the yield load. The cross sections of the two specimens basically satisfy the “plane section assumption”. Finite element models were also developed for the two specimens and validated based on the experimental results. Afterwards, a parametric study was carried out with the validated finite element models, which shows that the steel ratios and the structure of bottom trusses strongly influences the flexural behavior. At last, a theoretical model is developed to calculate the bending moment of composite beams at the ultimate load.

Abstract The adoption of electric vehicles (EVs) is an important way to reduce air pollution and greenhouse gas emissions. The city of Shenzhen, in southern China, has focused on developing policies to encourage EV implementation over the past decade and now has the most EVs of any city in the world, including the largest e‐bus and e‐taxi fleets. This paper reviews Shenzhen's innovative incentive policies and business models with respect to the potential for other cities and regions to learn from the city's experiences. Subsidies for the purchase and use of EVs, the construction of charging facilities, and the provision of services followed an inverse U‐shaped trend that initially rose to encourage early adoption before decreasing as the market matured. Additional incentives included preferential vehicle licensing, parking privileges, and road access. Furthermore, the city adopted a business model that incentivized cooperation between third‐party financial institutions, EV manufacturers, and charging facility operators to reduce the initial financial burden and risk of EV adoption by pooling purchasing power through leasing and vehicle sharing while disassociating vehicle and battery maintenance. Although Shenzhen's experience has unique aspects that cannot easily be replicated, such as a strong financial position of the government, it offers two important lessons for other cities around the globe: (a) incentivize the whole EV value chain in order to avoid bottlenecks and (b) use innovative business models that mobilize both public and private resources by distributing both risks and rewards. This article is categorized under: Energy and Transport &gt; Economics and Policy Energy and Transport &gt; Economics and Policy Energy Research and Innovation &gt; Climate and Environment