Current understanding of the brittleness of glass is limited by our poor understanding and control over the microscopic structure. In this study, we used a pressure quenching route to tune the ...structure of silica glass in a controllable manner, and observed a systematic increase in ductility in samples quenched under increasingly higher pressure. The brittle to ductile transition in densified silica glass can be attributed to the critical role of 5-fold Si coordination defects (bonded to 5 O neighbors) in facilitating shear deformation and in dissipating energy by converting back to the 4-fold coordination state during deformation. As an archetypal glass former and one of the most abundant minerals in the Earth's crest, a fundamental understanding of the microscopic structure underpinning the ductility of silica glass will not only pave the way toward rational design of strong glasses, but also advance our knowledge of the geological processes in the Earth's interior.
Codecs using spectral-spatial transforms efficiently compress raw camera images captured with a color filter array (CFA-sampled raw images) by changing their RGB color space into a decorrelated color ...space. This study describes two types of spectral-spatial transform, called extended Star-Tetrix transforms (XSTTs), and their edge-aware versions, called edge-aware XSTTs (EXSTTs), with no extra bits (side information) and little extra complexity. They are obtained by (i) extending the Star-Tetrix transform (STT), which is one of the latest spectral-spatial transforms, to a new version of our previously proposed wavelet-based spectral-spatial transform and a simpler version, (ii) considering that each 2-D predict step of the wavelet transform is a combination of two 1-D diagonal or horizontal-vertical transforms, and (iii) weighting the transforms along the edge directions in the images. Compared with XSTTs, the EXSTTs can decorrelate CFA-sampled raw images well: they reduce the difference in energy between the two green components by about 3.38-30.08 % for high-quality camera images and 8.97-14.47 % for mobile phone images. The experiments on JPEG 2000-based lossless and lossy compression of CFA-sampled raw images show better performance than conventional methods. For high-quality camera images, the XSTTs/EXSTTs produce results equal to or better than the conventional methods: especially for images with many edges, the type-I EXSTT improves them by about 0.03-0.19 bpp in average lossless bitrate and the XSTTs improve them by about 0.16-0.96 dB in average Bjøntegaard delta peak signal-to-noise ratio. For mobile phone images, our previous work perform the best, whereas the XSTTs/EXSTTs show similar trends to the case of high-quality camera images.
One of the main challenges for immune checkpoint blockade antibodies lies in malignancies with limited T-cell responses or immunologically "cold" tumors. Inspired by the capability of fever-like heat ...in inducing an immune-favorable tumor microenvironment, mild photothermal therapy (PTT) is proposed to sensitize tumors to immune checkpoint inhibition and turn "cold" tumors "hot." Here we present a combined all-in-one and all-in-control strategy to realize a local symbiotic mild photothermal-assisted immunotherapy (SMPAI). We load both a near-infrared (NIR) photothermal agent IR820 and a programmed death-ligand 1 antibody (aPD-L1) into a lipid gel depot with a favorable property of thermally reversible gel-to-sol phase transition. Manually controlled NIR irradiation regulates the release of aPD-L1 and, more importantly, increases the recruitment of tumor-infiltrating lymphocytes and boosts T-cell activity against tumors. In vivo antitumor studies on 4T1 and B16F10 models demonstrate that SMPAI is an effective and promising strategy for treating "cold" tumors.
To realize graphene-based electronics, various types of graphene are required; thus, modulation of its electrical properties is of great importance. Theoretic studies show that intentional doping is ...a promising route for this goal, and the doped graphene might promise fascinating properties and widespread applications. However, there is no experimental example and electrical testing of the substitutionally doped graphene up to date. Here, we synthesize the N-doped graphene by a chemical vapor deposition (CVD) method. We find that most of them are few-layer graphene, although single-layer graphene can be occasionally detected. As doping accompanies with the recombination of carbon atoms into graphene in the CVD process, N atoms can be substitutionally doped into the graphene lattice, which is hard to realize by other synthetic methods. Electrical measurements show that the N-doped graphene exhibits an n-type behavior, indicating substitutional doping can effectively modulate the electrical properties of graphene. Our finding provides a new experimental instance of graphene and would promote the research and applications of graphene.
The land-based oil extraction activity has led to serious pollution of the soil. While microbes may play an important role in the remediation of contaminated soils, ecological effects of oil ...pollution on soil microbial relationships remain poorly understood. Here, typical contaminated soils and undisturbed soils from seven oilfields of China were investigated in terms of their physicochemical characteristics, indigenous microbial assemblages, bacterial co-occurrence patterns, and metabolic enzymes. Network visualization based on k-core decomposition illustrated that oil pollution reduced correlations between co-existing bacteria. The core genera were altered to those related with oil metabolism (Pseudarthrobacter, Alcanivorax, Sphingomonas, Chromohalobacter and Nocardioides). Under oil pollution pressure, the indigenous bacteria Gammaproteobacteria was domesticated as biomarker and the enzyme expression associated with the metabolism of toxic benzene, toluene, ethylbenzene, xylene and polycyclic aromatic hydrocarbons was enhanced. Functional pathways of xenobiotics biodegradation were also stimulated under oil contamination. Finally, twelve culturable hydrocarbon-degrading microbes were isolated from these polluted soils and classified into Stenotrophomonas, Delftia, Pseudomonas and Bacillus. These results show that the soil microbial communities are transformed under oil pollution stress, and also provide useful information for future bioremediation processes.
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•Ecological effects of soil oil contamination were revealed.•Oil-affected microbial communities were enriched with Gammaproteobacteria.•Petroleum contamination altered the soil bacterial co-occurrence pattern.•Oil stress stimulated the expression of BTEX and PAH-related metabolic enzymes.•Twelve hydrocarbon-degrading strains were isolated from oil-polluted soils.
The spread of SARS-CoV-2 virus in the ongoing global pandemic has led to infections of millions of people and losses of many lives. The rapid, accurate and convenient SARS-CoV-2 virus detection is ...crucial for controlling and stopping the pandemic. Diagnosis of patients in the early stage infection are so far limited to viral nucleic acid or antigen detection in human nasopharyngeal swab or saliva samples. Here we developed a method for rapid and direct optical measurement of SARS-CoV-2 virus particles in one step nearly without any sample preparation using a spike protein specific nanoplasmonic resonance sensor. As low as 370 vp/mL were detected in one step within 15 min and the virus concentration can be quantified linearly in the range of 0 to 107 vp/mL. Measurements shown on both generic microplate reader and a handheld smartphone connected device suggest that our low-cost and rapid detection method may be adopted quickly under both regular clinical environment and resource-limited settings.
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•15min one step SARS-CoV-2 viral particles detection.•No sample processing and low-cost equipment and biosensor chip.•Sensitive for asymptomatic carriers diagnosis potentially.
•The estimated self-reported rates of anxiety symptoms and depression symptoms among medical staff were 13.3% and 18.4% respectively under COVID-19 epidemic.•Up to 23.9% investigated medical staff ...reported having anxiety or depression symptoms.•Psychological interventions for medical staff should be integrated into the strategies for fighting COVID-19.
It is well known that unexpected pandemic has led to an increase in mental health problems among a variety of populations.
In this study, an online non-probability sample survey was used to anonymously investigate the anxiety and depression symptoms among medical staff under the COVID-19 outbreak. The questionnaire included Perceived Stress Scale-10 (PSS-10), Generalized Anxiety Disorder 7-Item Scale (GAD-7) and Patient Health Questionnaire-9 (PHQ-9). Factors associated with anxiety and depression symptoms were estimated by logistic regression analysis.
A total of 1090 medical staff were investigated in this study. The estimated self-reported rates of anxiety symptoms, depression symptoms and both of the two were 13.3%, 18.4% and 23.9% respectively. Factors associated with self-reported anxiety symptoms include married status (OR=2.3, 95%CI: 1.2, 4.4), not living alone (OR=0.4, 95%CI: 0.2, 0.7), never confiding their troubles to others (OR=2.2, 95%CI: 1.4, 3.5) and higher stress (OR=14.4, 95%CI: 7.8, 26.4). Factors associated with self-reported depression symptoms include not living alone (OR=0.4, 95%CI: 0.3, 0.7), sometimes/often getting care from neighbours (OR=0.6, 95%CI: 0.4, 0.9), never confiding their troubles to others (OR=2.0, 95%CI: 1.3, 3.0) and higher stress (OR=9.7, 95%CI: 6.2, 15.2).
The study was a non-probability sample survey. Besides, scales used in this study can only identify mental health states.
Under outbreak of COVID-19, self-reported rates of anxiety symptoms and depression symptoms were high in investigated medical staff. Psychological interventions for those at high risk with common mental problems should be integrated into the work plan to fight against the epidemic.
Since the outbreak of SARS-CoV-2, mRNA vaccine development has undergone a tremendous drive within the pharmaceutical field. In recent years, great progress has been made into mRNA vaccine ...development, especially in individualized tumor vaccines. mRNA vaccines are a promising approach as the production process is simple, safety profiles are better than those of DNA vaccines, and mRNA-encoded antigens are readily expressed in cells. However, mRNA vaccines also possess some inherent limitations. While side effects such as allergy, renal failure, heart failure, and infarction remain a risk, the vaccine mRNA may also be degraded quickly after administration or cause cytokine storms. This is a substantial challenge for mRNA delivery. However, appropriate carriers can avoid degradation and enhance immune responses, effector presentation, biocompatibility and biosafety. To understand the development and research status of mRNA vaccines, this review focuses on analysis of molecular design, delivery systems and clinical trials of mRNA vaccines, thus highlighting the route for wider development and further clinical trials of mRNA vaccines.
Molecular dynamics (MD) simulations were carried out to study bulk silica glass and amorphous silica nanowire under uniaxial tension. Periodic boundary conditions were employed to mimic infinite bulk ...samples. Cutting and casting methods were used to prepare nanowires. Our study shows that simulation parameters, such as system size, cooling rate, working temperature and strain rate, need to be carefully chosen in order to correctly reproduce the brittle fracture behavior of amorphous silica. The stiffness of silica glass is less sensitive to these parameters than the tensile strength and the failure strain. However, the sample density and the anomalous nonlinear elasticity of silica glass should be correctly taken into account to get an accurate estimate of its stiffness from MD simulations. Our study also shows that, with proper simulation parameters, amorphous silica nanowires down to 1nm in radius still exhibits a brittle fracture behavior. Nanowires prepared by the cutting method have a lower stiffness and tensile strength but a higher failure strain than the cast ones, due to more surface defects generated during the cutting process at low temperatures. Defects-induced ductility could be an effective way to make less brittle nanostructures of amorphous silica.
► Proper MD parameters are needed to reproduce the brittle fracture of silica glass. ► Nonlinear elasticity of silica glass should be taken into account for stiffness. ► Silica nanowires down to 1nm in radius still exhibits a brittle fracture behavior.
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