•A colorimetric aptasensor for the detection of multiple antibiotics is presented.•The method allows for multiplex antibiotics detection by the naked eye.•This colorimetric aptasensor displays great ...tolerance to high salt concentrations.•The method would promote the practical application via RGB analysis of smartphone.
We devise a novel colorimetric aptasensor for multiplex antibiotics based on an ss-DNA fragment coordinately controlling gold nanoparticles (AuNPs) aggregation. The multifunctional aptamer (Apt) was elaborately designed to be adsorbed on AuNPs surfaces acting as a binding element for antibiotics and a molecular switch. Chloramphenicol (CAP) and tetracycline (TET) were selected as the model antibiotics. When one kind of antibiotics was added, the specifically recognized fragment of Apt can bind to it and dissociated, and the non-specific one coordinately controls AuNPs aggregation under high-salt conditions. Hence, different color changes of AuNPs solution can be used as the signal readout. The aptasensor exhibited remarkable selectivity and sensitivity for separate detection of TET and CAP, and the detection limits are estimated to be 32.9 and 7.0 nM, respectively. The analysis with the absorption spectroscopy and the smartphone are applied to detect antibiotics in real samples with consistent results and desirable recoveries.
Water Sustainability for China and Beyond Liu, Jianguo; Yang, Wu
Science (American Association for the Advancement of Science),
08/2012, Volume:
337, Issue:
6095
Journal Article
Peer reviewed
A water crisis has prompted the Chinese government to develop an ambitious water conservancy plan. However, the plan may not achieve water sustainability and may cause unintended environmental and ...socioeconomic consequences, unless it accounts for complex human-nature interactions (1). Water shortages, for example, force people to find alternatives, such as treatment facilities, whose land and energy requirements aggravate food and energy production, which need large amounts of water. Other nations face similar challenges and share real water from China along international rivers and/or virtual water through trade. Water problems are particularly challenging in China, which has the largest population, fastest-growing economy, rising water demand, relatively scarce water, dated infrastructure, and inadequate governance. We highlight China's water crisis and plan, and then offer recommendations.
The tumor microenvironment is highly complex, and immune escape is currently considered an important hallmark of cancer, largely contributing to tumor progression and metastasis. Named for their ...capability of killing target cells autonomously, natural killer (NK) cells serve as the main effector cells toward cancer in innate immunity and are highly heterogeneous in the microenvironment. Most current treatment options harnessing the tumor microenvironment focus on T cell-immunity, either by promoting activating signals or suppressing inhibitory ones. The limited success achieved by T cell immunotherapy highlights the importance of developing new-generation immunotherapeutics, for example utilizing previously ignored NK cells. Although tumors also evolve to resist NK cell-induced cytotoxicity, cytokine supplement, blockade of suppressive molecules and genetic engineering of NK cells may overcome such resistance with great promise in both solid and hematological malignancies. In this review, we summarized the fundamental characteristics and recent advances of NK cells within tumor immunometabolic microenvironment, and discussed potential application and limitations of emerging NK cell-based therapeutic strategies in the era of presicion medicine.
Extreme hypoxia of tumors represents the most notable barrier against the advance of tumor treatments. Inspired by the biological nature of red blood cells (RBCs) as the primary oxygen supplier in ...mammals, an aggressive man‐made RBC (AmmRBC) is created to combat the hypoxia‐mediated resistance of tumors to photodynamic therapy (PDT). Specifically, the complex formed between hemoglobin and enzyme‐mimicking polydopamine, and polydopamine‐carried photosensitizer is encapsulated inside the biovesicle that is engineered from the recombined RBC membranes. The mean corpuscular hemoglobin of AmmRBCs reaches about tenfold as high as that of natural RBCs. Owing to the same origin of outer membranes, AmmRBCs share excellent biocompatibility with parent RBCs. The introduced polydopamine plays the role of the antioxidative enzymes existing inside RBCs to effectively prevent the oxygen‐carrying hemoglobin from the oxidation damage during the circulation. This biomimetic engineering can accumulate in tumors, permit in situ efficient oxygen supply, and impose strong PDT efficacy toward the extremely hypoxic tumor with complete tumor elimination. The man‐made pseudo‐RBC shows potentials as a universal oxygen‐self‐supplied platform to sensitize hypoxia‐limited tumor treatment means, including but not limited to PDT. Meanwhile, this study offers ideas to the production of artificial substitutes of packed RBCs for clinical blood transfusion.
Aggressive man‐made pseudo‐red blood cells (AmmRBCs) are prepared for self‐oxygen‐supplied photodynamic therapy (PDT) toward tumors. AmmRBCs can accumulate in tumors and exhibit high efficacy to combat hypoxia‐induced resistance of tumors to PDT, leading to complete tumor elimination.
In response to ecosystem degradation from rapid economic development, China began investing heavily in protecting and restoring natural capital starting in 2000. We report on China's first national ...ecosystem assessment (2000–2010), designed to quantify and help manage change in ecosystem services, including food production, carbon sequestration, soil retention, sandstorm prevention, water retention, flood mitigation, and provision of habitat for biodiversity. Overall, ecosystem services improved from 2000 to 2010, apart from habitat provision. China's national conservation policies contributed significantly to the increases in those ecosystem services.
While 5G is being commercialized worldwide, research institutions around the world have started to look beyond 5G and 6G is expected to evolve into green networks, which deliver high Quality of ...Service and energy efficiency. To meet the demands of future applications, significant improvements need to be made in mobile network architecture. We envision 6G undergoing unprecedented breakthrough and integrating traditional terrestrial mobile networks with emerging space, aerial and underwater networks to provide anytime anywhere network access. This paper presents a detailed survey on wireless evolution towards 6G networks. In this survey, the prime focus is on the new architectural changes associated with 6G networks, characterized by ubiquitous 3D coverage, introduction of pervasive AI and enhanced network protocol stack. Along with this, we discuss related potential technologies that are helpful in forming sustainable and socially seamless networks, encompassing terahertz and visible light communication, new communication paradigm, blockchain and symbiotic radio. Our work aims to provide enlightening guidance for subsequent research of green 6G.
Calcareous sand containing weak particles originated from the deposition of skeletal residue of marine organisms is susceptible to significant particle crushing under compression and shearing. The ...breakage of grains results in excessive deformation and foundation failure. This study focuses on the mechanical properties and particle crushing of calcareous sand retrieved from Nansha Island, South China Sea. A series of isotropically drained and undrained triaxial compression tests were performed on reconstituted calcareous sand samples at different initial densities and at a wide range of confining stresses. The amount of particle crushing for calcareous sand after shearing was measured and quantified. Experimental results demonstrate that the shear response of calcareous sand had been well interpreted within the critical state framework. The amount of particle crushing for calcareous sand increases with increasing density and confining stress. Compared with the undrained condition, a larger amount of particle crushing of calcareous sands is observed in the drained triaxial compression test. Stress-dilatancy curves exhibit similar varying tendency for calcareous sand. Multiple critical state lines for calcareous sands with different initial densities are identified in the void ratio and logarithm of the mean stress plane. Considering the variation in stress ratio at the critical state induced by particle crushing, all stress paths are normalized to determine the state bounding surface for calcareous sand at varying densities and stresses.
•Particle crushing for calcareous sand is jointly governed by density, stress level, and drainage condition.•Particle crushing-induced position shift of critical state line is observed for calcareous sand.•Bounding state surface is identified for calcareous sand at various initial densities.
The initial cases of novel coronavirus (2019-nCoV)-infected pneumonia (NCIP) occurred in Wuhan, Hubei Province, China, in December 2019 and January 2020. We analyzed data on the first 425 confirmed ...cases in Wuhan to determine the epidemiologic characteristics of NCIP.
We collected information on demographic characteristics, exposure history, and illness timelines of laboratory-confirmed cases of NCIP that had been reported by January 22, 2020. We described characteristics of the cases and estimated the key epidemiologic time-delay distributions. In the early period of exponential growth, we estimated the epidemic doubling time and the basic reproductive number.
Among the first 425 patients with confirmed NCIP, the median age was 59 years and 56% were male. The majority of cases (55%) with onset before January 1, 2020, were linked to the Huanan Seafood Wholesale Market, as compared with 8.6% of the subsequent cases. The mean incubation period was 5.2 days (95% confidence interval CI, 4.1 to 7.0), with the 95th percentile of the distribution at 12.5 days. In its early stages, the epidemic doubled in size every 7.4 days. With a mean serial interval of 7.5 days (95% CI, 5.3 to 19), the basic reproductive number was estimated to be 2.2 (95% CI, 1.4 to 3.9).
On the basis of this information, there is evidence that human-to-human transmission has occurred among close contacts since the middle of December 2019. Considerable efforts to reduce transmission will be required to control outbreaks if similar dynamics apply elsewhere. Measures to prevent or reduce transmission should be implemented in populations at risk. (Funded by the Ministry of Science and Technology of China and others.).
Metabolic reprogramming is a hallmark of cancer. However, systematic characterizations of metabolites in triple-negative breast cancer (TNBC) are still lacking. Our study profiled the polar ...metabolome and lipidome in 330 TNBC samples and 149 paired normal breast tissues to construct a large metabolomic atlas of TNBC. Combining with previously established transcriptomic and genomic data of the same cohort, we conducted a comprehensive analysis linking TNBC metabolome to genomics. Our study classified TNBCs into three distinct metabolomic subgroups: C1, characterized by the enrichment of ceramides and fatty acids; C2, featured with the upregulation of metabolites related to oxidation reaction and glycosyl transfer; and C3, having the lowest level of metabolic dysregulation. Based on this newly developed metabolomic dataset, we refined previous TNBC transcriptomic subtypes and identified some crucial subtype-specific metabolites as potential therapeutic targets. The transcriptomic luminal androgen receptor (LAR) subtype overlapped with metabolomic C1 subtype. Experiments on patient-derived organoid and xenograft models indicate that targeting sphingosine-1-phosphate (S1P), an intermediate of the ceramide pathway, is a promising therapy for LAR tumors. Moreover, the transcriptomic basal-like immune-suppressed (BLIS) subtype contained two prognostic metabolomic subgroups (C2 and C3), which could be distinguished through machine-learning methods. We show that N-acetyl-aspartyl-glutamate is a crucial tumor-promoting metabolite and potential therapeutic target for high-risk BLIS tumors. Together, our study reveals the clinical significance of TNBC metabolomics, which can not only optimize the transcriptomic subtyping system, but also suggest novel therapeutic targets. This metabolomic dataset can serve as a useful public resource to promote precision treatment of TNBC.
Conventional photodynamic therapy (PDT) has limited applications in clinical cancer therapy due to the insufficient O2 supply, inefficient reactive oxygen species (ROS) generation, and low ...penetration depth of light. In this work, a multifunctional nanoplatform, upconversion nanoparticles (UCNPs)@TiO2@MnO2 core/shell/sheet nanocomposites (UTMs), is designed and constructed to overcome these drawbacks by generating O2 in situ, amplifying the content of singlet oxygen (1O2) and hydroxyl radical (•OH) via water‐splitting, and utilizing 980 nm near‐infrared (NIR) light to increase penetration depth. Once UTMs are accumulated at tumor site, intracellular H2O2 is catalyzed by MnO2 nanosheets to generate O2 for improving oxygen‐dependent PDT. Simultaneously, with the decomposition of MnO2 nanosheets and 980 nm NIR irradiation, UCNPs can efficiently convert NIR to ultraviolet light to activate TiO2 and generate toxic ROS for deep tumor therapy. In addition, UCNPs and decomposed Mn2+ can be used for further upconversion luminescence and magnetic resonance imaging in tumor site. Both in vitro and in vivo experiments demonstrate that this nanoplatform can significantly improve PDT efficiency with tumor imaging capability, which will find great potential in the fight against tumor.
Enhanced and amplified photodynamic therapy: A multifunctional nanoplatform, UCNPs@TiO2@MnO2 core/shell/sheet nanocomposites, is designed to overcome the drawbacks of photodynamic therapy by generating O2 in situ, amplifying the content of singlet oxygen (1O2) and hydroxyl radical (•OH) via water‐splitting, and utilizing 980 nm near‐infrared light to increase penetration depth, which significantly improves PDT efficiency as well as reduces the side effects.
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