The clinic applications of bioabsorbable magnesium (Mg) and its alloys have been significantly restricted owing to their poor corrosion resistance. Besides elemental alloying, surface modification ...and functionality is a major approach to increasing corrosion resistance for magnesium alloys. This article reviews the cutting-edge advances and progress of biodegradable surface coatings upon Mg alloys over the last decades, aims to build up a knowledge framework of surface modification on biodegradable Mg alloys. A considerable number of conversion, deposition, mechanical and functional coatings and their preparation methods are discussed. The emphasis has been placed on the composition of chemical conversion and deposited coatings to overcome the disadvantages of adhesion, corrosion resistance and biocompatibility of a single coating for biomedical materials. The issues have been addressed on the integration of the structural and functional factors of the composite coatings.
The development of electrocatalysts capable of efficient reduction of nitrate (NO
) to ammonia (NH
) is drawing increasing interest for the sake of low carbon emission and environmental protection. ...Herein, we present a CuCo bimetallic catalyst able to imitate the bifunctional nature of copper-type nitrite reductase, which could easily remove NO
via the collaboration of two active centers. Indeed, Co acts as an electron/proton donating center, while Cu facilitates NO
adsorption/association. The bio-inspired CuCo nanosheet electrocatalyst delivers a 100 ± 1% Faradaic efficiency at an ampere-level current density of 1035 mA cm
at -0.2 V vs. Reversible Hydrogen Electrode. The NH
production rate reaches a high activity of 4.8 mmol cm
h
(960 mmol g
h
). A mechanistic study, using electrochemical in situ Fourier transform infrared spectroscopy and shell-isolated nanoparticle enhanced Raman spectroscopy, reveals a strong synergy between Cu and Co, with Co sites promoting the hydrogenation of NO
to NH
via adsorbed *H species. The well-modulated coverage of adsorbed *H and *NO
led simultaneously to high NH
selectivity and yield.
The antioxidant defense system in malignant cells, which involves antioxidant enzymes and antioxidant molecules, is an innate barrier to photodynamic therapy (PDT). Because of the complexity of the ...endogenous antioxidant mechanisms of these cells, simply inhibiting individual antioxidant pathways has a limited effect on improving the lethality of ROS. To enhance the efficacy of PDT for tumor treatment, a versatile nanoparticle (NP)‐based drug is developed, which the authors call PZB NP, containing the glutathione inhibitor l‐buthionine sulfoximine (BSO) and the heme oxygenase 1 (HO‐1) inhibitor protoporphyrin zinc(II) (ZnPP) to suppress the innate antioxidant defense system of cancer cells in a two‐pronged manner. BSO reduces intracellular glutathione levels to minimize ROS elimination and protein protection during PDT, and ZnPP inhibits the ROS‐stimulated upregulation of the antioxidant HO‐1, thus preventing ROS removal by cells after PDT. Thus, BSO and ZnPP synergistically suppress the antioxidant defense systems of cancer cells both during and after protoporphyrin‐IX‐mediated PDT in a two‐pronged manner, resulting in tumor cell death through excess oxidative pressure. The results demonstrate that the construction of nanodrugs having dual antioxidation defense suppression properties is a promising route for the development of highly efficient ROS‐based therapies.
A simple and versatile nanodrug, PZB nanoparticle, is developed to enhance PDT efficacy using a two‐pronged antioxidant suppression strategy. In short, the nanoparticle‐loaded BSO reduces the existing intracellular antioxidant (glutathione) concentration before PDT. Subsequently, the loaded protoporphyrin zinc(II) (ZnPP) inhibits ROS‐stimulated antioxidant enzymes (heme oxygenase 1) after PDT. These significantly enhance intracellular oxidative stress, leading to increased cancer cell death.
Dysbiosis, departure of the gut microbiome from a healthy state, has been suggested to be a powerful biomarker of disease incidence and progression
. Diagnostic applications have been proposed for ...inflammatory bowel disease diagnosis and prognosis
, colorectal cancer prescreening
and therapeutic choices in melanoma
. Noninvasive sampling could facilitate large-scale public health applications, including early diagnosis and risk assessment in metabolic
and cardiovascular diseases
. To understand the generalizability of microbiota-based diagnostic models of metabolic disease, we characterized the gut microbiota of 7,009 individuals from 14 districts within 1 province in China. Among phenotypes, host location showed the strongest associations with microbiota variations. Microbiota-based metabolic disease models developed in one location failed when used elsewhere, suggesting that such models cannot be extrapolated. Interpolated models performed much better, especially in diseases with obvious microbiota-related characteristics. Interpolation efficiency decreased as geographic scale increased, indicating a need to build localized baseline and disease models to predict metabolic risks.
A wide area quantum key distribution (QKD) network deployed on communication infrastructures provided by China Mobile Ltd. is demonstrated. Three cities and two metropolitan area QKD networks were ...linked up to form the Hefei-Chaohu-Wuhu wide area QKD network with over 150 kilometers coverage area, in which Hefei metropolitan area QKD network was a typical full-mesh core network to offer all-to-all interconnections, and Wuhu metropolitan area QKD network was a representative quantum access network with point-to-multipoint configuration. The whole wide area QKD network ran for more than 5000 hours, from 21 December 2011 to 19 July 2012, and part of the network stopped until last December. To adapt to the complex and volatile field environment, the Faraday-Michelson QKD system with several stability measures was adopted when we designed QKD devices. Through standardized design of QKD devices, resolution of symmetry problem of QKD devices, and seamless switching in dynamic QKD network, we realized the effective integration between point-to-point QKD techniques and networking schemes.
Antibiotics and antibiotic resistance genes (ARGs) are prevalent in estuarine and coastal environments due to substantial terrestrial input, aquaculture effluent, and sewage discharge. In this ...article, based on peer-reviewed papers, the sources, spatial patterns, driving factors, and environmental implications of antibiotics and ARGs in global estuarine and coastal environments are discussed. Riverine runoff, WWTPs, sewage discharge, and aquaculture, are responsible for the prevalence of antibiotics and ARGs. Geographically, pollution due to antibiotics in low- and middle-income countries is higher than that in high-income countries, and ARGs show remarkable latitudinal variations. The distribution of antibiotics is driven by antibiotic usage and environmental variables (heavy metals, nutrients, organic pollutants, etc.), while ARGs are affected by antibiotics residues, environmental variables, microbial communities, and mobile genetic elements (MGEs). Antibiotics and ARGs alter microbial communities and biogeochemical cycles, as well as pose threats to marine organisms and human health. Our results provide comprehensive insights into the transport and environmental behaviors of antibiotics and ARGs in global estuarine and coastal environments.
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•Antibiotics distribution is driven by antibiotic usage and environmental variables.•Latitudinal variations of ARGs link with environmental variables and MGEs.•ARGs distribution exhibits distance decay law at continental and global scale.•Antibiotics and ARGs interfere element cycling via inhibiting functional bacteria.•Antibiotics and ARGs pose potential health threats to marine organisms and humans.
Aggravated behaviors of hepatocellular carcinoma (HCC) will occur after inadequate thermal ablation. However, its underlying mechanisms are not fully understood. Here, we assessed whether the ...increased matrix stiffness after thermal ablation could promote the progression of residual HCC. Heat‐treated residual HCC cells were cultured on tailorable 3D gel with different matrix stiffness, simulating the changed physical environment after thermal ablation, and then the mechanical alterations of matrix stiffness on cell phenotypes were explored. Increased stiffness was found to significantly promote the proliferation of the heat‐treated residual HCC cells when the cells were cultured on stiffer versus soft supports, which was associated with stiffness‐dependent regulation of ERK phosphorylation. Heat‐exposed HCC cells cultured on stiffer supports showed enhanced motility. More importantly, vitamin K1 reduced stiffness‐dependent residual HCC cell proliferation by inhibiting ERK phosphorylation and suppressed the in vivo tumor growth, which was further enhanced by combining with sorafenib. Increased matrix stiffness promotes the progression of heat‐treated residual HCC cells, proposing a new mechanism of an altered biomechanical environment after thermal ablation accelerates HCC development. Vitamin K1 plus sorafenib can reverse this protumor effect.
Increased matrix stiffness after thermal ablation accelerates the progression of heat‐exposed residual HCC cells. Vitamin K1 and sorafenib disrupt the stiffness‐induced ERK activation to reverse the pro‐tumor effect as the potential therapeutic drugs. This new finding will help design strategy to treat the local tumor progression and prevent its rapid progression after RFA in the treatment of medium or large HCC.
With the help of quantum key distribution (QKD), two distant peers are able to share information-theoretical secure key bits. Increasing the key rate is ultimately significant for the applications of ...QKD in the lossy channel. However, it has been proven that there is a fundamental rate-distance limit, called the linear bound, which restricts the performance of all existing repeaterless protocols and realizations. Surprisingly, a recently proposed protocol, called twin-field (TF) QKD, can beat the linear bound with no need for quantum repeaters. Here, we present one of the first implementations of the TF-QKD protocol and demonstrate its advantage of beating the linear bound at a channel distance of 300 km. In our experiment, a modified TF-QKD protocol that does not assume phase postselection is considered, and thus a higher key rate than the original one is expected. After controlling the phase evolution of the twin fields traveling through hundreds of kilometers of optical fibers, the implemented system achieves high-visibility single-photon interference and allows stable and high-rate measurement-device-independent QKD. Our experimental demonstration and results confirm the feasibility of the TF-QKD protocol and its prominent superiority in long-distance key distribution services.
Gonorrhea remains one of the most common sexually transmitted diseases worldwide. Successful treatment has been hampered by emerging resistance to each of the antibiotics recommended as first-line ...therapies. We retrospectively analyzed the susceptibility of gonorrhea to azithromycin and ceftriaxone using data from the China Gonococcal Resistance Surveillance Programme (China-GRSP) in order to provide evidence for updating the treatment recommendations in China.
In this study, we included 3,849 isolates collected from patients with a confirmed positive Neisseria gonorrhoeae (N. gonorrhoeae) culture at clinic visits during the period of 1 January 2013 through 31 December 2016 in 7 provinces. Antimicrobial susceptibility testing of gonorrhea isolates using agar dilution was conducted to determine minimum inhibitory concentration (MIC). Resistance to azithromycin (RTA) was defined as MIC ≥ 1.0 mg/l, and decreased susceptibility to ceftriaxone (DSC) was defined as MIC ≥ 0.125 mg/l. The prevalence of isolates with RTA was 18.6% (710/3,827; 95% CI 17.4%-19.8%). The percentage of patients with DSC fluctuated between 9.7% and 12.2% over this period. The overall prevalence of isolates with both RTA and DSC was 2.3% (87/3,827; 95% CI 1.9%-2.8%) and it increased from 1.9% in 2013 to 3.3% in 2016 (chi-squared test for trend, P = 0.03). Study limitations include the retrospective study design and potential biases in the sample, which may overrepresent men with symptomatic infection, coastal residents, and people reporting as heterosexual.
To our knowledge, this is the first national study on susceptibility of N. gonorrhoeae to azithromycin and ceftriaxone in China. Our findings indicate high rates of RTA and DSC from 2013 to 2016. Although dual therapy with azithromycin and ceftriaxone has been recommended by WHO and many countries to treat gonorrhea, reevaluation of this therapy is needed prior to its introduction in China.
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