Widely used disposable plastic tableware is usually buried or directly discharged into the natural environment after using, which poses potential threats to the natural environment and human health. ...To solve this problem, nondegradable plastic tableware needs to be replaced by tableware composed of biodegradable structural materials with both food safety and the excellent mechanical and thermal properties. Here, a food‐safe sargassum cellulose nanofiber (SCNF) is extracted from common seaweed in an efficient and low energy consuming way under mild reaction conditions. Then, by assembling the SCNF into a dense bulk material, a strong sargassum cellulose nanofiber structural material (SCNSM) with high strength (283 MPa) and high thermal stability (>160 °C) can be prepared. The SCNSM also possesses good machinability, which can be processed into tableware with different shapes, e.g., knives and forks. The overall performance of the SCNSM‐based tableware is better than commercial plastic, wood‐based, and poly(lactic acid) tableware, which shows great application potential in the tableware field.
A food‐safe sargassum cellulose nanofiber (SCNF) is extracted through an efficient and low energy consuming way. Then, by assembling the SCNF into a dense bulk material, a strong structural material can be prepared. It possesses good machinability, which can be processed into tableware with better overall performance than that of commercial tableware, showing great application potential in the tableware field.
An All‐Natural Wood‐Inspired Aerogel Han, Zi‐Meng; Sun, Wen‐Bin; Yang, Kun‐Peng ...
Angewandte Chemie International Edition,
February 1, 2023, 2023-Feb-01, 2023-02-00, 20230201, Letnik:
62, Številka:
6
Journal Article
Recenzirano
The oriented pore structure of wood endows it with a variety of outstanding properties, among which the low thermal conductivity has attracted researchers to develop wood‐like aerogels as excellent ...thermal insulation materials. However, the increasing demands of environmental protection have put forward new and strict requirements for the sustainability of aerogels. Here, we report an all‐natural wood‐inspired aerogel consisting of all‐natural ingredients and develop a method to activate the surface‐inert wood particles to construct the aerogel. The obtained wood‐inspired aerogel has channel structure similar to that of natural wood, endowing it with superior thermal insulation properties to most existing commercial sponges. In addition, remarkable fire retardancy and complete biodegradability are integrated. With the above outstanding performances, this sustainable wood‐inspired aerogel will be an ideal substitute for the existing commercial thermal insulation materials.
An interesting surface nanocrystallization method was developed to make the surface‐inert and weakly interacting wood particles better assemble to construct the aerogel. This bottom‐up method allows the preparation of large‐size composite aerogels. The wood‐inspired oriented channel structure endows the obtained aerogel with superior thermal insulation properties to natural wood and most existing commercial sponges.
The widespread use of disposable plastic straws cause serious environmental problems and poses potential threats to human health, while paper straws, their most used alternatives, are not so ...satisfactory due to poor mechanical performance and unpleasant user experience. Here, a new kind of edible and microplastic‐free straw made from bacterial cellulose (BC) by biosynthesis is reported. Through the alginate coating, this BC‐based straw achieves better mechanical performance than paper straws and avoids additional adhesives. Owing to the 3D nanofiber network and strong interlayer connection, the comprehensive performance of this BC‐based straw surpasses that of commercially available counterparts, satisfying the requirements for practical use. Of particular note, the edible character provides a better user experience and a new end‐of‐life option for the straws, making the BC‐based straw a healthier and more eco‐friendly substitute for plastic straws.
A sustainable, microplastic‐free, ultrastrong, and edible straw is fabricated through biosynthesis. This bacterial cellulose‐based straw demonstrates great sustainability and excellent mechanical performance, representing an ideal substitute for plastic straws and a powerful competitor for paper straws. The 3D network of bacterial cellulose endows the straw with the ability to carry functional substances like flavor molecules, providing a better user experience.
The exploration of extreme environments has become necessary for understanding and changing nature. However, the development of functional materials suitable for extreme conditions is still ...insufficient. Herein, a kind of nacre‐inspired bacterial cellulose (BC)/synthetic mica (S‐Mica) nanopaper with excellent mechanical and electrical insulating properties that has excellent tolerance to extreme conditions is reported. Benefited from the nacre‐inspired structure and the 3D network of BC, the nanopaper exhibits excellent mechanical properties, including high tensile strength (375 MPa), outstanding foldability, and bending fatigue resistance. In addition, S‐Mica arranged in layers endows the nanopaper with remarkable dielectric strength (145.7 kV mm−1) and ultralong corona resistance life. Moreover, the nanopaper is highly resistant to alternating high and low temperatures, UV light, and atomic oxygen, making it an ideal candidate for extreme environment‐resistant materials.
A nacre‐inspired nanopaper is fabricated through an aerosol‐assisted biosynthesis (AABS) strategy. Based on the AABS strategy and biomimetic structure design, the nanopaper has excellent mechanical properties, high dielectric strength, and ultralong corona resistance time. The dielectric‐mechanical comprehensive performance of the nanopaper is far beyond that of various commercial mica papers.
All‐natural materials derived from cellulose nanofibers (CNFs) are expected to be used to replace engineering plastics and have attracted much attention. However, the lack of crack extension ...resistance and 3D formability of nanofiber‐based structural materials hinders their practical applications. Here, a multiscale interface engineering strategy is reported to construct high‐performance cellulose‐based materials. The sisal microfibers are surface treated to expose abundant active CNFs with positive charges, thereby enhancing their interfacial combination with the negatively charged CNFs. The robust multiscale dual network enables easy molding of multiscale cellulose‐based structural materials into complex 3D special‐shaped structures, resulting in nearly twofold and fivefold improvements in toughness and impact resistance compared with those of CNFs‐based materials. Moreover, this multiscale interface engineering strategy endows cellulose‐based structural materials with better comprehensive performance than petrochemical‐based plastics and broadens cellulose's potential for lightweight applications as structural materials with lower environmental effects.
A high‐performance multiscale cellulose‐based structural material is constructed through a multiscale interface engineering strategy. The positive and negative charges treatment of microfibers and nanofibers effectively solves the interface bonding problem in multiscale design, and allows them to be easily shaped into complex three‐dimensional special‐shaped structures. This sustainable material offers superior mechanical and thermal properties compared to petrochemical‐based plastics.
46,XY disorders of sex development (DSD) is characterized by incomplete masculinization genitalia, with gonadal dysplasia and with/without the presence of Müllerian structures. At least 30 genes ...related to 46,XY DSD have been found. However, the clinical phenotypes of patients with different gene mutations overlap, and accurate diagnosis relies on gene sequencing technology. Therefore, this study aims to determine the prevalence of pathogenic mutations in a Chinese cohort with 46,XY DSD by the targeted next-generation sequencing (NGS) technology. Eighty-seven 46,XY DSD patients were enrolled from the Peking Union Medical College Hospital (Beijing, China). A total of fifty-four rare variants were identified in 60 patients with 46,XY DSD. The incidence of these rare variants was approximately 69.0% (60/87). Twenty-five novel variants and 29 reported variants were identified. Based on the American College of Medical Genetics and Genomics (ACMG) guidelines, thirty-three variants were classified as pathogenic or likely pathogenic variants and 21 variants were assessed as variants of uncertain significance. The overall diagnostic rate was about 42.5% based on the pathogenic and likely pathogenic variants. Androgen receptor (AR), steroid 5-alpha-reductase 2 (SRD5A2) and nuclear receptor subfamily 5 Group A member 1 (NR5A1) gene variants were identified in 21, 13 and 13 patients, respectively. The incidence of these three gene variants was about 78.3% (47/60) in patients with rare variants. It is concluded that targeted NGS is an effective method to detect pathogenic mutations in 46,XY DSD patients and AR, SRD5A2, and NR5A1 genes were the most common pathogenic genes in our cohort.
Both pulsatile gonadotropin-releasing hormone （GnRH） infusion and combined gonadotropin therapy （human chorionic gonadotropin and human menopausal gonadotropin HCG/HMG） are effective to induce ...spermatogenesis in male patients with congenital hypogonadotropic hypogonadism （CH H）. However, evidence is lacking as to which treatment strategy is better. This retrospective cohort study included 202 patients with CHH： twenty had received pulsatile GnRH and 182 had received HCG/HMG. Patients had received therapy for at least 12 months. The total follow-up time was 15.6 ± 5.0 months （range： 12-27 months） for the GnRH group and 28.7 ± 13.0 months （range： 12-66 months） for the HCG/HMG group. The median time to first sperm appearance was 6 months （95% confidence interval CI： 1.6-10.4） in the GnRH group versus 18 months （95% Ch 16.4-20.0） in the HCG/HMG group （P〈 0.001）. The median time to achieve sperm concentrations 〉5 x 106 m1-1 was 14 months （95% Ch 5.8-22.2） in the GnRH group versus 27 months （95% Ch 18.9-35.1） in the HCG/HMG group （P 〈 0.001）, and the median time to concentrations 〉10 x 106 m1-1 was 18 months （95% Ch 10.0-26.0） in the GnRH group versus 39 months （95% CI unknown） in the HCG/HMG group. Compared to the GnRH group, the HCG/HMG group required longer treatment periods to achieve testicular sizes of 〉4 ml, 〉8 ml, 〉12 ml, and 〉16 ml. Sperm motility （a ＋ b ＋ c percentage） evaluated in semen samples with concentrations 〉1 × 106 ml-1 was 43.7% ± 20.4% （16 samples） in the GnRH group versus 43.2% ± 18.1% （153 samples） in the HCG/HMG group （P= 0.921）. Notably, during follow-up, the GnRH group had lower serum testosterone levels than the HCG/HMG group （8.3 ±4.6 vs 16.2 ± 8.2 nmol 1-1, P 〈 0.001）. Our study found that pulsatile GnRH therapy was associated with earlier spermatogenesis and larger testicular size compared to combined gonadotropin therapy. Additional prospective randomized studies would be required to confirm these findings.
Pulsatile gonadotropin-releasing hormone (GnRH) may induce spermatogenesis in most patients with congenital hypogonadotropic hypogonadism (CHH) by stimulating gonadotropin production, while the ...predictors for a pituitary response to pulsatile GnRH therapy were rarely investigated. Therefore, the aim of our study is to investigate predictors of the pituitary response to pulsatile GnRH therapy. This retrospective cohort study included 82 CHH patients who received subcutaneous pulsatile GnRH therapy for at least 1 month. Patients were categorized into poor or normal luteinizing hormone (LH) response subgroups according to their LH level (LH <2 IU l−1 or LH ≥2 IU l−1) 1 month into pulsatile GnRH therapy. Gonadotropin and testosterone levels, testicular size, and sperm count were compared between the two subgroups before and after GnRH therapy. Among all patients, LH increased from 0.4 ± 0.5 IU l−1 to 7.5 ± 4.4 IU l−1 and follicle-stimulating hormone (FSH) increased from 1.1 ± 0.9 IU l−1 to 8.8 ± 5.3 IU l−1. A Cox regression analysis showed that basal testosterone level (β = 0.252, P = 0.029) and triptorelin-stimulated FSH60min(β = 0.518, P = 0.01) were two favorable predictors for pituitary response to GnRH therapy. Nine patients (9/82, 11.0%) with low LH response to GnRH therapy were classified into the poor LH response subgroup. After pulsatile GnRH therapy, total serum testosterone level was 39 ± 28 ng dl−1 versus 248 ± 158 ng dl−1 (P = 0.001), and testicular size was 4.0 ± 3.1 ml versus 7.9 ± 4.5 ml (P = 0.005) in the poor and normal LH response subgroups, respectively. It is concluded that higher levels of triptorelin-stimulated FSH60minand basal total serum testosterone are favorable predictors of pituitary LH response to GnRH therapy.
Abstract Constructing structural materials from sustainable raw materials is considered an efficient way to reduce the potential threat posed by plastics. Nevertheless, challenges remain regarding ...combining excellent mechanical and thermal properties, especially the balance of strength and toughness. Here, we report a 3D nanofiber network interfacial design strategy to strengthen and toughen all‐natural structural materials simultaneously. The introduced protonated chitosan at the interface between the surface oxidized 3D nanonetwork of bacterial cellulose forms the interfacial interlocking structure of nanonetworks, achieving a robust physical connection and providing enough physical contact sites for chemical crosslinking. The obtained sustainable structural material successfully integrates excellent mechanical and thermal properties on the nanoscale of cellulose nanofibers, such as light weight, high strength, and superior thermal expansion coefficient. The relationship between structural design and comprehensive mechanical property improvement is analyzed in detail, providing a universal perspective to design sustainable high‐performance structural materials from nanoscale building blocks.
Aerogels. In their Research Article (e202211099), Qing‐Fang Guan, Shu‐Hong Yu et al. present a surface nanocrystallization method to construct wood‐inspired, large‐size composite aerogels.
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