Plasmonic nanomaterials have been widely used for photothermal therapy (PTT) of cancer, but their recognition specificity remains challenging. We prepared monosaccharide-imprinted gold nanorods ...(AuNRs) for targeted cancer PTT, using sialic acid (SA) as a representative monosaccharide. The SA-imprinted AuNRs exhibited good specificity, enabling the killing of cancer cells without damaging healthy cells.
SARS-CoV-2 is the underlying cause for the COVID-19 pandemic. Like most enveloped RNA viruses, SARS-CoV-2 uses a homotrimeric surface antigen to gain entry into host cells. Here we describe S-Trimer, ...a native-like trimeric subunit vaccine candidate for COVID-19 based on Trimer-Tag technology. Immunization of S-Trimer with either AS03 (oil-in-water emulsion) or CpG 1018 (TLR9 agonist) plus alum adjuvants induced high-level of neutralizing antibodies and Th1-biased cellular immune responses in animal models. Moreover, rhesus macaques immunized with adjuvanted S-Trimer were protected from SARS-CoV-2 challenge compared to vehicle controls, based on clinical observations and reduction of viral loads in lungs. Trimer-Tag may be an important platform technology for scalable production and rapid development of safe and effective subunit vaccines against current and future emerging RNA viruses.
The COVID-19 pandemic has caused an unprecedented global public health and economic crisis. The origin and emergence of its causal agent, SARS-CoV-2, in the human population remains mysterious, ...although bat and pangolin were proposed to be the natural reservoirs. Strikingly, unlike the SARS-CoV-2-like coronaviruses (CoVs) identified in bats and pangolins, SARS-CoV-2 harbors a polybasic furin cleavage site in its spike (S) glycoprotein. SARS-CoV-2 uses human angiotensin-converting enzyme 2 (ACE2) as its receptor to infect cells. Receptor recognition by the S protein is the major determinant of host range, tissue tropism, and pathogenesis of coronaviruses. In an effort to search for the potential intermediate or amplifying animal hosts of SARS-CoV-2, we examined receptor activity of ACE2 from 14 mammal species and found that ACE2s from multiple species can support the infectious entry of lentiviral particles pseudotyped with the wild-type or furin cleavage site-deficient S protein of SARS-CoV-2. ACE2 of human/rhesus monkey and rat/mouse exhibited the highest and lowest receptor activities, respectively. Among the remaining species, ACE2s from rabbit and pangolin strongly bound to the S1 subunit of SARS-CoV-2 S protein and efficiently supported the pseudotyped virus infection. These findings have important implications for understanding potential natural reservoirs, zoonotic transmission, human-to-animal transmission, and use of animal models.
SARS-CoV-2 uses human ACE2 as a primary receptor for host cell entry. Viral entry mediated by the interaction of ACE2 with spike protein largely determines host range and is the major constraint to interspecies transmission. We examined the receptor activity of 14 ACE2 orthologs and found that wild-type and mutant SARS-CoV-2 lacking the furin cleavage site in S protein could utilize ACE2 from a broad range of animal species to enter host cells. These results have important implications in the natural hosts, interspecies transmission, animal models, and molecular basis of receptor binding for SARS-CoV-2.
•A morphology-maintaining DMP-Cu decorated by DMTZ was prepared and characterized.•The CHP facilely served as the source of metal and in situ converted to MOF shell.•A SPE method with AFS was ...developed for the determination of trace mercury in rice.•The Hg2+adsorption were fitted by pseudo second-order kinetics and Langmuir model.•XPS and Raman spectra verified the interaction between Hg2+ and S/N groups on DMP-Cu.
A novel copper hydroxy phosphate@MOF composite DMP-Cu decorated by 2, 5-dimercapto-1, 3, 4-thiadiazol was facilely prepared and characterized. A dispersive SPE strategy using DMP-Cu as adsorbent combined with atomic fluorescence spectroscopy was developed for the selective capture of trace total mercury in rice sample. The adsorption mechanism showed that the Hg2+ removal process was fitted with pseudo second-order kinetics and the Langmuir adsorption model. The adsorbent was easy to be regenerated and the maximum adsorption capacity for the removal of Hg2+ was 249.5 mg g−1 at the optimal pH of 4. X-ray photoelectron spectroscopy and Raman spectra verified the selective and strong interaction between Hg2+ and thiol/nitrogen-containing functional groups of DMTZ on DMP-Cu. The trace total mercury in rice samples was determined with detection limit of 0.0125 ng mL−1 and relative standard deviation below 6%. The high recoveries were obtained in range of 98.8–109% for the spiked rice samples.
Drought stress causes heavy damages to crop growth and productivity under global climatic changes. Transcription factors have been extensively studied in many crops to play important roles in plant ...growth and defense. However, there is a scarcity of studies regarding WRKY transcription factors regulating drought responses in maize crops. Previously, ZmWRKY79 was identified as the regulator of maize phytoalexin biosynthesis with inducible expression under different elicitation. Here, we elucidated the function of ZmWRKY79 in drought stress through regulating ABA biosynthesis. The overexpression of ZmWRKY79 in Arabidopsis improved the survival rate under drought stress, which was accompanied by more lateral roots, lower stomatal aperture, and water loss. ROS scavenging was also boosted by ZmWRKY79 to result in less H2O2 and MDA accumulation and increased antioxidant enzyme activities. Further analysis detected more ABA production in ZmWRKY79 overexpression lines under drought stress, which was consistent with up-regulated ABA biosynthetic gene expression by RNA-seq analysis. ZmWRKY79 was observed to target ZmAAO3 genes in maize protoplast through acting on the specific W-boxes of the corresponding gene promoters. Virus-induced gene silencing of ZmWRKY79 in maize resulted in compromised drought tolerance with more H2O2 accumulation and weaker root system architecture. Together, this study substantiates the role of ZmWRKY79 in the drought-tolerance mechanism through regulating ABA biosynthesis, suggesting its broad functions not only as the regulator in phytoalexin biosynthesis against pathogen infection but also playing the positive role in abiotic stress response, which provides a WRKY candidate gene to improve drought tolerance for maize and other crop plants.
We present a new strategy, called dual-template docking oriented molecular imprinting (DTD-OMI), for facile and highly efficient imprinting within mesoporous materials. As compared with bulk ...imprinting, which is a widely used strategy, DTD-OMI did not require additional steps, but provided significantly improved imprinting efficiency and binding properties.
Though cervical cancer is one of the leading causes of cancer-related death globally, its incidence is nearly entirely preventable. Young people have been an international priority for screening as ...this population has historically been under-screened. However, in both high-income and low-income countries, young people have not been screened appropriately according to country-specific guidelines. The aim of this systematic review was to systematically characterize the existing literature on barriers and facilitators for cervical cancer screening (CCS) among adolescents and young people globally.
We conducted a systematic review following PRISMA guidelines of three key databases: Medline-OVID, EMBASE, and CINAHL. Supplementary searches were done through ClinicialTrials.Gov and Scopus. Databases were examined from 1946 until the date of our literature searches on March 12th 2020. We only examined original, peer-reviewed literature. Articles were excluded if they did not specifically discuss CCS, were not specific to individuals under the age of 35, or did not report outcomes or evaluation. All screening, extraction, and synthesis was completed in duplicate with two independent reviewers. Outcomes were summarized descriptively. Risk of bias for individual studies was graded using an adapted rating scale based on the Risk of Bias Instrument for Cross-Sectional Surveys of Attitudes and Practices.
Of the 2177 original database citations, we included 36 studies that met inclusion criteria. The 36 studies included a total of 14,362 participants, and around half (17/36, 47.2%) of studies specifically targeted students. The majority of studies (31/36, 86.1%) discussed barriers and facilitators to Pap testing specifically, while one study analyzed self-sampling (1/36, 2.8%), one study targeted HPV DNA testing (1/36, 2.8%), and the remainder (4/36, 11.1%) were not specified. Our systematic review found that there are three large categories of barriers for young people: lack of knowledge/awareness, negative perceptions of the test, and systemic barriers to testing. Facilitators included stronger relationships with healthcare providers, social norms, support from family, and self-efficacy.
There are unique barriers and facilitators that affect CCS rates in adolescents and young people. Health systems and healthcare providers worldwide should address the challenges for this unique population.
To study the evolution of stress on the ring and segment interfaces during the construction process of the concrete encapsulation of the main arch ring in a rigid-frame arch bridge, alongside its ...impact on the ultimate load-bearing capacity of the main arch ring, a 1:10 scale model experiment was conducted by taking the 600 m Tian'e Longtan Bridge as the prototype. The key cross-section concrete strain data were collected during the entire construction process of the main arch ring via fiber-optic strain sensors, which were used to investigate the stress evolution at ring and segment interfaces. ANSYS APDL was employed to simulate the ultimate bearing capacity under various loading conditions of two different finite element models, which were, respectively, formed segmentally and by single pouring. The results revealed that (1) after the closure of the concrete encapsulation of the main arch ring, the concrete stress in the cross-section exhibits significant stress disparities. At the same cross-section, the level of the web concrete stress can reach 76% of the floor concrete stress, while the roof concrete stress level is less than 20% of the floor concrete stress. (2) At the junction of two adjacent work planes, there are considerable differences in the stress levels of the concrete on both sides. After the closure of the main arch ring, the intersegment stress ratios of the floor, web, and roof concrete are 60~70%, 40~60%, and 0~5%, respectively. (3) Loading conditions remarkably affected the ultimate bearing capacity of the main arch ring. Under mid-span loading and 1/4 span symmetrical loading conditions, compared to single-pour concrete encapsulation, the ultimate bearing capacity of the main arch ring with concrete encapsulated by segmented and ring-divided pouring decreased by 19.16% and 5.23%, respectively, compared to single-pour concrete encapsulation. This suggests that the non-uniformity of stress distribution in the concrete sheath can lead to reductions in the ultimate bearing capacity of the arch ring.
All kinds of mutagenic factors may cause physiological, biochemical and genetic changes of all organisms. To characterize their characteristic biology effects, the concept of Relaxation Time (RT) was ...introduced for the first time, and the specific process was as follows. After mutation of organisms, the offsprings will be continuingly cultured (or cultivated) to the next generation (Rx). Once a biological effect began to show no significant difference compared to the untreated controls, the Rx was defined as the RT of the effect. In this paper, three kinds of mutagenic factors were selected to treat the seeds or seedlings of Astragalus sinicus L., subsequently, the corresponding RT was calibrated. The results showed that the RT was diverse not only among different biological effects but also among different mutagenic factors. For the RT of chemical mutagens and gamma rays, most of which are concentrated on R
, whereas the heavy ion beams have significant differences among different tracks. Among biological effects, the SOD activity and superoxide anion free radical content in the Peak region are more prominent, and their RT reaches R
and R
, respectively. Thus, the RT may characterize the characteristic biological effects from differently mutagenic factors.
▶ The grafting of zwitterionic polymer on polypropylene non-woven fabric (NWF) membrane surface. ▶ Surface grafting on NWF membrane via O
2 plasma pretreatment combining with UV-irradiated technique. ...▶ Modification of NWF membrane improves resistance to static/dynamic protein fouling and platelet adhesion.
This work described the graft polymerization of a zwitterionic polymer, 3-(methacryloylamino)propyl-dimethyl(3-sulfopropyl) ammonium hydroxide (MPDSAH), onto polypropylene non-woven fabric (NWF) membrane via O
2 plasma pretreatment and UV-irradiated technique. The surfaces of the modified NWF membranes were principally characterized using attenuated total reflectance Fourier transform infrared spectroscopy (FTIR-ATR), X-ray photoelectron spectroscopy (XPS), and static water contact-angle measurement. The wettability was measured by water contact angle and equilibrium water adsorption. It was found that the water contact angles for the membranes decreased from 123° to 17° with increasing grafting density of poly(MPDSAH) from 0 to 349.2
μg/cm
2, while the equilibrium water adsorption reached a maximum at the grafting density of 120.5
μg/cm
2. The decreases of protein adsorption and platelet adhesion on the modified membrane revealed the enhancement protein resistance and excellent resistance to platelet adhesion due to the incorporation of zwitterionic poly(MPDSAH). Besides, microfiltration experiments were carried out to test the antifouling properties. Water flux recovery ratio was achieved as high as 90% for the modified membrane with respect to only about 30% for the neat NWF membrane.
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