A new label‐free sensing mechanism is demonstrated experimentally by monitoring the whispering‐gallery mode broadening in microcavities. It is immune to both noise from the probe laser and ...environmental disturbances, and is able to remove the strict requirement for ultra‐high‐Q mode cavities for sensitive nanoparticle detection. This ability to sense nanoscale objects and biological analytes is particularly crucial for wide applications.
Modulation of the electronic structure of metal catalysts is an effective approach to optimize the electrocatalytic activity. Herein, we show a surprisingly strong activation effect of black ...phosphorus (BP) on platinum (Pt) catalysts to give greatly enhanced catalytic activity in the hydrogen evolution reaction (HER). The unique and negative binding energy between BP and Pt leads to spontaneous formation of Pt‐P bonds producing strong synergistic ligand effects on the Pt nanoparticles. No Pt‐P bonds are formed with red phosphorus which is another allotrope of P. By controlling the number of Pt‐P bonds, 3.5‐fold enhancement in the HER activity can be achieved from the BP‐activated Pt catalyst and the activity is 6.1 times higher than that of the state‐of‐the‐art commercial Pt/C catalyst. The BP‐activated Pt catalyst exhibits a current density of 82.89 mA cm−2 with only 1 μg of Pt in 1 m KOH at an overpotential of 70 mV.
Back in black: Surprisingly strong activation effects of black phosphorus (BP) on Pt catalysts and subsequent modulation the surface electronic structure of Pt result in greatly enhanced catalytic activity in the hydrogen evolution reaction (HER).
Long-term efficacy of a hepatitis E vaccine Zhang, Jun; Zhang, Xue-Feng; Huang, Shou-Jie ...
The New England journal of medicine,
2015-Mar-05, Letnik:
372, Številka:
10
Journal Article
Recenzirano
Odprti dostop
Hepatitis E virus (HEV) is a leading cause of acute hepatitis. The long-term efficacy of a hepatitis E vaccine needs to be determined.
In an initial efficacy study, we randomly assigned healthy ...adults 16 to 65 years of age to receive three doses of either a hepatitis E vaccine (vaccine group; 56,302 participants) or a hepatitis B vaccine (control group; 56,302 participants). The vaccines were administered at 0, 1, and 6 months, and the participants were followed for 19 months. In this extended follow-up study, the treatment assignments of all participants remained double-blinded, and follow-up assessments of efficacy, immunogenicity, and safety were continued for up to 4.5 years.
During the 4.5-year study period, 60 cases of hepatitis E were identified; 7 cases were confirmed in the vaccine group (0.3 cases per 10,000 person-years), and 53 cases in the control group (2.1 cases per 10,000 person-years), representing a vaccine efficacy of 86.8% (95% confidence interval, 71 to 94) in the modified intention-to-treat analysis, rather than (95% confidence interval, 71 to 84) corrected. Of the participants who were assessed for immunogenicity and were seronegative at baseline, 87% of those who received three doses of the hepatitis E vaccine maintained antibodies against HEV for at least 4.5 years; HEV antibody titers developed in 9% in the control group. The rate of adverse events was similar in the two groups.
Immunization with this hepatitis E vaccine induced antibodies against HEV and provided protection against hepatitis E for up to 4.5 years. (Funded by the Chinese Ministry of Science and Technology and others; ClinicalTrials.gov number, NCT01014845.).
A 2D black phosphorus/platinum heterostructure (Pt/BP) is developed as a highly efficient photocatalyst for solar‐driven chemical reactions. The heterostructure, synthesized by depositing BP ...nanosheets with ultrasmall (≈1.1 nm) Pt nanoparticles, shows strong Pt–P interactions and excellent stability. The Pt/BP heterostructure exhibits obvious P‐type semiconducting characteristics and efficient absorption of solar energy extending into the infrared region. Furthermore, during light illumination, accelerated charge separation is observed from Pt/BP as manifested by the ultrafast electron migration (0.11 ps) detected by a femtosecond pump‐probe microscopic optical system as well as efficient electron accumulation on Pt revealed by in situ X‐ray photoelectron spectroscopy. These unique properties result in remarkable performance of Pt/BP in typical hydrogenation and oxidation reactions under simulated solar light illumination, and its efficiency is much higher than that of other common Pt catalysts and even much superior to that of conventional thermal catalysis. The 2D Pt/BP heterostructure has enormous potential in photochemical reactions involving solar light and the results of this study provide insights into the design of next‐generation high‐efficiency photocatalysts.
A 2D black phosphorus/platinum heterostructure (Pt/BP) is developed as a highly efficient photocatalyst. The Pt/BP exhibits a broad adsorption range (>1800 nm), ultrafast electron migration (0.11 ps), and efficient electron accumulation on Pt. These unique properties result in remarkable performance of Pt/BP in solar‐driven chemical reactions and the efficiency is superior to that of conventional thermal catalysis.
As new 2D layered nanomaterials, Bi2O2Se nanoplates have unique semiconducting properties that can benefit biomedical applications. Herein, a facile top‐down approach for the synthesis of Bi2O2Se ...quantum dots (QDs) in a solution is described. The Bi2O2Se QDs with a size of 3.8 nm and thickness of 1.9 nm exhibit a high photothermal conversion coefficient of 35.7% and good photothermal stability. In vitro and in vivo assessments demonstrate that the Bi2O2Se QDs possess excellent photoacoustic (PA) performance and photothermal therapy (PTT) efficiency. After systemic administration, the Bi2O2Se QDs accumulate passively in tumors enabling efficient PA imaging of the entire tumors to facilitate imaging‐guided PTT without obvious toxicity. Furthermore, the Bi2O2Se QDs which exhibit degradability in aqueous media not only have sufficient stability during in vivo circulation to perform the designed therapeutic functions, but also can be discharged harmlessly from the body afterward. The results reveal the great potential of Bi2O2Se QDs as a biodegradable multifunctional agent in medical applications.
2D Bi2O2Se quantum dots (QDs) are synthesized by a facile top‐down approach. Boasting large photothermal conversion efficiency and excellent photoacoustic performance as well as suitable biodegradability, the Bi2O2Se QDs facilitate photoacoustic imaging of the entire tumors in photothermal cancer therapy. The semiconducting QDs are promising as a near‐infrared‐triggered theranostic agent in cancer therapy.
Ultrahigh‐Q optical whispering gallery microcavities are promising platforms for fundamental studies and applied photonics. A new type of on‐chip microcavity is experimentally realized, which ...supports both highly unidirectional emission and ultra‐high‐Q factors exceeding 100 million in near infrared. By doping erbium, the unidirectional‐emission lasing is observed in 1550 nm band with the threshold as low as 2 μW.
The novel coronavirus disease (COVID-19) pandemic is emerging as a global health threat and shows a higher risk for men than women. Thus far, the studies on andrological consequences of COVID-19 are ...limited. To ascertain the consequences of COVID-19 on sperm parameters after recovery, we recruited 41 reproductive-aged male patients who had recovered from COVID-19, and analyzed their semen parameters and serum sex hormones at a median time of 56 days after hospital discharge. For longitudinal analysis, a second sampling was obtained from 22 of the 41 patients after a median time interval of 29 days from first sampling. Compared with controls who had not suffered from COVID-19, the total sperm count, sperm concentration, and percentages of motile and progressively motile spermatozoa in the patients were significantly lower at first sampling, while sperm vitality and morphology were not affected. The total sperm count, sperm concentration, and number of motile spermatozoa per ejaculate were significantly increased and the percentage of morphologically abnormal sperm was reduced at the second sampling compared with those at first in the 22 patients examined. Though there were higher prolactin and lower progesterone levels in patients at first sampling than those in controls, no significant alterations were detected for any sex hormones examined over time following COVID-19 recovery in the 22 patients. Although it should be interpreted carefully, these findings indicate an adverse but potentially reversible consequence of COVID-19 on sperm quality.
Lanthanide‐Coordinated Black Phosphorus Wu, Lie; Wang, Jiahong; Lu, Jiang ...
Small (Weinheim an der Bergstrasse, Germany),
July 19, 2018, Letnik:
14, Številka:
29
Journal Article
Recenzirano
Black phosphorus (BP) possesses unique physical properties and, owing to its intrinsic instability, the proper surface and chemical coordination is the key point in many applications. Herein, a ...facile and efficient surface lanthanide‐coordination strategy based on lanthanide (Ln) sulfonate complexes is designed to passivate and functionalize different BP‐based nanostructures including quantum dots, nanosheets, and microflakes. By means of Ln–P coordination, the lone‐pair electrons of phosphorus are occupied, thus preventing oxidation of BP, and the LnL3@BP exhibits excellent stability in both air and water. Furthermore, accompanied by the original photothermal performance of BP nanostructures, the Gd‐coordinated BP has high R1 relativities in magnetic resonance (MR) imaging, and other Ln (Tb, Eu, and Nd) coordinated BP structures exhibit fluorescence spanning the visible to near‐infrared regions. Not only is LnL3 surface passivation an efficient method to enhance the stability of BP, but also the MR or fluorescence derived from lanthanide ions extends the application of BP to optoelectronics and biomedical engineering.
A facile lanthanide‐coordination strategy based on lanthanide sulfonate complexes is established for surface modification of black phosphorus (BP)‐based nanostructures, including quantum dots, nanosheets, and microflakes. It presents an efficient method to protect BP, and the magnetic resonance or fluorescence derived from the lanthanide enables the functionalization of BP for extending its application range.
As a novel member of the two-dimensional nanomaterial family, mono- or few-layer black phosphorus (BP) with direct bandgap and high charge carrier mobility is promising in many applications such as ...microelectronic devices, photoelectronic devices, energy technologies, and catalysis agents. Due to its benign elemental composition (phosphorus), large surface area, electronic/photonic performances, and chemical/biological activities, BP has also demonstrated a great potential in biomedical applications including biosensing, photothermal/photodynamic therapies, controlled drug releases, and antibacterial uses. The nature of the BP–bio interface is comprised of dynamic contacts between nanomaterials (NMs) and biological systems, where BP and the biological system interact. The physicochemical interactions at the nano–bio interface play a critical role in the biological effects of NMs. In this review, we discuss the interface in the context of BP as a nanomaterial and its unique physicochemical properties that may affect its biological effects. Herein, we comprehensively reviewed the recent studies on the interactions between BP and biomolecules, cells, and animals and summarized various cellular responses, inflammatory/immunological effects, as well as other biological outcomes of BP depending on its own physical properties, exposure routes, and biodistribution. In addition, we also discussed the environmental behaviors and potential risks on environmental organisms of BP. Based on accumulating knowledge on the BP–bio interfaces, this review also summarizes various safer-by-design strategies to change the physicochemical properties including chemical stability and nano–bio interactions, which are critical in tuning the biological behaviors of BP. The better understanding of the biological activity of BP at BP–bio interfaces and corresponding methods to overcome the challenges would promote its future exploration in terms of bringing this new nanomaterial to practical applications.
Supramolecular architectures and materials have attracted immense attention during the last decades because they not only open the possibility of obtaining a large variety of aesthetically ...interesting structures but also have applications in gas storage, sensors, separation, catalysis, and so on. On the other hand, cucurbitnurils (Qns), a relatively new class of macrocyclic hosts with a rigid hydrophobic cavity and two identical carbonyl fringed portals, have attracted much attention in supramolecular chemistry. Because of the strong charge–dipole and hydrogen bonding interactions, as well as hydrophobic and hydrophilic effect derived from the negative portals and rigid cavities of Qns, nearly all research in Qns has been focused on utilizing the portals and cavities to construct supramolecular assemblies similar to other macrocyclic receptors such as cyclodextrin and calixarenes. Interestingly, a recent study revealed that other weak noncovalent interactions such as hydrogen bonding and π···π stacking, as well as C–H···π and ion–dipole interactions, could also be defined as “outer-surface interactions”, which are derived from the electrostatically positive outer surface of Qns. These interactions could be the driving forces in the formation of various novel Qn-based supramolecular architectures and functional materials. In this Account, we provide a comprehensive overview of supramolecular self-assemblies based on the outer-surface interactions of Qns. These outer-surface interactions include those between Qns, Qns and aromatic molecules, Qns and calixarenes, Qns and inorganic complex ions, and Qns and polyoxometalates. Pioneering work has shown that such weak noncovalent interactions play very important roles in the formation of various Qn-based functional materials and supramolecular architectures. For example, hydrogen bonds in outer-surface interactions between Qn molecules not only function as the sole driving force in the formation of one-dimensional Qn porous channels but also assist the bonding forces of the channels in capturing and accommodating acetylene molecules and carbon dioxide in the channel cavities. Moreover, upon introduction of a third species such as an aromatic molecule or inorganic anion into the Qn/metal system, “outer-surface interactions” could lead to Qn/metal-based self-assemblies from simple finite supramolecular coordination complexes to infinite polydimensional supramolecular architectures and other structures. Overall, this Account focuses on the novel self-assembly driving force derived from Qns including (i) concepts of the outer-surface interactions of Qns, (ii) providing plausible explanations of the mechanisms of the outer-surface interactions of Qns, and (iii) introduction of an overview of the developments and practical applications of outer-surface interactions of Qns in supramolecular chemistry. It is hoped that this study based on the outer-surface interactions of Qns can enrich the field of molecular engineering of functional supramolecular systems and provide new opportunities for the construction of functional materials and architectures.
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