We found that very thin carbon nanotube films, once fed by sound frequency electric currents, could emit loud sounds. This phenomenon could be attributed to a thermoacoustic effect. The ultra small heat capacity per unit area of carbon nanotube thin films leads to a wide frequency response range and a high sound pressure level. On the basis of this finding, we made practical carbon nanotube thin film loudspeakers, which possess the merits of nanometer thickness and are transparent, flexible, stretchable, and magnet-free. Such a single-element thin film loudspeaker can be tailored into any shape and size, freestanding or on any insulating surfaces, which could open up new applications of and approaches to manufacturing loudspeakers and other acoustic devices.

Biomolecular cryptography exploiting specific biomolecular interactions for data encryption represents a unique approach for information security. However, constructing protocols based on biomolecular reactions to guarantee confidentiality, integrity and availability (CIA) of information remains a challenge. Here we develop DNA origami cryptography (DOC) that exploits folding of a M13 viral scaffold into nanometer-scale self-assembled braille-like patterns for secure communication, which can create a key with a size of over 700 bits. The intrinsic nanoscale addressability of DNA origami additionally allows for protein binding-based steganography, which further protects message confidentiality in DOC. The integrity of a transmitted message can be ensured by establishing specific linkages between several DNA origamis carrying parts of the message. The versatility of DOC is further demonstrated by transmitting various data formats including text, musical notes and images, supporting its great potential for meeting the rapidly increasing CIA demands of next-generation cryptography.

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The reproductive system of human female exhibits a much faster rate of aging than other body systems. Ovarian aging is thought to be dominated by a gradual decreasing numbers of follicles, coinciding with diminished quality of oocytes. Menopause is the final step in the process of ovarian aging. This review focuses on the mechanisms underlying the ovarian aging involving a poor complement of follicles at birth and a high rate of attrition each month, as well as the alternated endocrine factors. We also discuss the possible causative factors that contribute to ovarian aging, e.g., genetic factors, accumulation of irreparable damage of microenvironment, pathological effect and other factors. The appropriate and reliable methods to assess ovarian aging, such as quantification of follicles, endocrine measurement and genetic testing have also been discussed. Increased knowledge of the ovarian aging mechanisms may improve the prevention of premature ovarian failure. The ovary undergoes much more serious effects of age than any other tissues of the body, and the reproductive outcome has been demonstrated to be negatively correlated with age [1,2]. The ovarian aging related follicle number reduction and oocyte quality decay cause the gradual decline in fertility and ultimately natural sterility. Thus, "poor ovarian reserve (OR)" is often used synonymously with "ovarian aging". The variability of ovarian aging among individuals is evident indicated by the large variable age at menopause. This implies that some females remain fertile until the fifth decade of life, which is physiological ovarian aging, whereas others face the loss of natural fertility in their mid-thirties, which is called premature ovarian failure (POF), and is pathological ovarian aging. The mechanisms behind gradual decreasing of the follicle pool and the decaying oocyte quality are far from being totally understood, although some progress involved in the endocrine, paracrine, metabolic and genetic factors has given some light to the complex puzzle.

a b s t r a c t ⇑ Corresponding authors.

Lithium–sulfur (Li–S) batteries have attracted great attention in the past two decades, because of their high theoretical energy density of 2600 Wh kg–1 and the cost-effective sulfur cathode. However, it is still far from commercialization, unlike that of lithium-ion batteries. Although numerous research has been presented on the sulfur cathode, lithium metal anode, separator modification, intercalated layer within the cell configuration, electrolyte design, the problematic issues of the polysulfide shuttling effect cannot be solved effectively. In this Review, we summarize that most challenges in the Li–S battery have involved the electrolyte. The development of Li–S battery electrolytes was discussed from the components of salt, solvent, additives, then the current idea of electrolyte designs including the solid electrolytes was also summarized. This Review aims to give a comprehensive and depth viewpoint on the development, prospect, and challenges of Li–S battery electrolytes.

Polarimetric imaging has proved its value in medical diagnostics, bionics, remote sensing, astronomy, and in many other wide fields. Pixel-level solid monolithically integrated polarimetric imaging photo-detectors are the trend for infrared polarimetric imaging devices. For better polarimetric imaging performance the high polarization discriminating detectors are very much critical. Here we demonstrate the high infrared light polarization resolving capabilities of a quantum well (QW) detector in hybrid structure of single QW and plasmonic micro-cavity that uses QW as an active structure in the near field regime of plasmonic effect enhanced cavity, in which the photoelectric conversion in such a plasmonic micro-cavity has been realized. The detector's extinction ratio reaches 65 at the wavelength of 14.7 μm, about 6 times enhanced in such a type of pixel-level polarization long wave infrared photodetectors. The enhancement mechanism is attributed to artificial plasmonic modulation on optical propagation and distribution in the plasmonic micro-cavities.