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In recent years, the application of low-refractive-index materials in the optical field has attracted considerable attention due to it high transmittance and high optical sensitivity. In this study, we synthesized SiO

ImportanceEpidural anesthesia is a primary choice for cesarean delivery, but supplemental analgesics are often required to relieve pain during uterine traction.ObjectiveTo investigate the sedative and analgesic effects of intravenous esketamine administered before childbirth via cesarean delivery with the patient under epidural anesthesia.Design, Setting, and ParticipantsThis multicenter, double-blind randomized clinical trial assessed 903 women 18 years or older who had full-term single pregnancy and were scheduled for elective cesarean delivery with epidural anesthesia in 5 medical centers in China from September 18, 2021, to September 20, 2022.InterventionPatients were randomized to receive intravenous injection of 0.25 mg/kg of esketamine or placebo before incision.Main Outcomes and MeasuresThe coprimary outcomes included scores on the numeric rating scale of pain (an 11-point scale, with 0 indicating no pain and 10 indicating the worst pain; a difference of ≥1.65 points was clinically meaningful) and Ramsay Sedation Scale (a 6-point scale, with 1 indicating restlessness and 6 indicating deep sleep without response; a difference of ≥2 points was clinically meaningful) immediately after fetal delivery. Secondary outcomes included neonatal Apgar score assessed at 1 and 5 minutes after birth.ResultsA total of 600 women (mean [SD] age, 30.7 [4.3] years) were enrolled and randomized; all were included in the intention-to-treat analysis. Immediately after fetal delivery, the score on the numeric rating scale of pain was lower with esketamine (median [IQR], 0 [0-1]) than with placebo (median [IQR], 0 [0-2]; median difference, 0; 95% CI, 0-0; P = .001), but the difference was not clinically important. The Ramsay Sedation Scale scores were higher (sedation deeper) with esketamine (median [IQR], 4 [3-4]) than with placebo (median [IQR], 2 [2-2]; median difference, 2; 95% CI, 2-2; P P = .98) and at 5 minutes (median difference, 0; 95% CI, 0-0; P = .27). Transient neurologic or mental symptoms were more common in patients given esketamine (97.7% [293 of 300]) than in those given placebo (4.7% [14 of 300]; P Conclusions and RelevanceFor women undergoing cesarean delivery under epidural anesthesia, a subanesthetic dose of esketamine administered before incision produced transient analgesia and sedation but did not induce significant neonatal depression. Mental symptoms and nystagmus were common but transient. Indications and the optimal dose of esketamine in this patient population need further clarification, but study should be limited to those who require supplemental analgesia.Trial RegistrationClinicalTrials.gov Identifier: NCT04548973

Ultra-thin electromagnetic absorption materials promise great application potential in stealth technology and integrated microwave device. However, the large thickness of the current low-density carbon-based composites is still a critical issue to hinder their practical application. Herein, the carbon nanotubes (CNTs) were oxidized by using mixed acid and strong oxidant, and the lightweight resin-based CNTs coatings were fabricated via a facile method. The composite coatings after modification demonstrate an excellent microwave absorption performance at low thickness. With the low filler loading of 2.3 wt%, the maximum absorption is as strong as 20.4 dB and the effective absorption bandwidth (reflection loss ≤ − 10 dB) reaches 4.51 GHz covering 45.1% of the entire measured bandwidth at only 1.2 mm thickness. Compared with the CNTs coatings before modification, the CNTs coatings after modification possess broader effective absorption bandwidth, and the optimal filler loading of the absorbent shifts to a lower concentration. This work provides a feasible approach for the preparation of composite coatings with high-performance absorption.

Absorbents with lightweight, low filler loading and broadband absorption are highly desired in electromagnetic wave absorbing field. Herein, the carbon black/reduced graphene oxide (CB/RGO) composite materials were fabricated via a facile synthetic method. The composite absorbents demonstrate an excellent microwave absorption performance. With the low filler loading of 7 wt%, the maximum absorption is as strong as 47.5 dB and the effective absorption bandwidth (reflection loss

Silica nanospheres with a well-controlled particle size were prepared via a nucleation-to-growth synthesis process. A facile method is proposed for improving the self-assembly behavior of silica colloidal particles in droplet coatings by the simple controlling of the drying temperature. It is shown that a periodically arranged, opal-structured, photonic crystal film with a large area of approximately 4.0 cm2 can be prepared, even when the particle size is up to 840 nm. When the band gap of the silica photonic crystals falls in the visible-light region, the crystals exhibit distinct structural colors. Moreover, the wavelength of the reflected light increases with an increasing particle size of silica. When the photonic band gap overlaps the wavelength of the laser source, the overall Raman spectrum intensity is significantly enhanced. Accordingly, the proposed nucleation-to-growth process and drop-coating method provides a cheap and simple approach for the manufacture of uniform sized silica and surface-enhanced Raman scattering substrates, respectively.

Carbon nanotube (CNTs) based heterostructures, such as CNT/metal, CNT/polymer, CNT/semiconductor, are attractive for the combined properties and unique applications in cutting-edge electronics and devices. Here in this work, nanostructured beta-silicon carbide (β-SiC)/CNTs heterostructures were synthesized by carbothermal reduction of silica (SiO 2 ) and CNTs with diverse mixing ratios of n C : n Si . Different techniques were carried out for the characterization of the structures and morphologies of the achieved heterostructures, demonstrating dramatic different morphologies which were associated with the different starting ratios of the n C : n Si . The dielectric properties and microwave absorption of wax-based composites were investigated. The parameters for morphologically controllable synthesis and related mechanism for dielectric properties and electromagnetic attenuation were discussed.

Multi-walled carbon nanotubes (MWCNTs) snipped by the acidification process were fabricated into alumina (Al2O3) matrices via hydrothermal crystallization and hot-pressing techniques for achieving MWCNT/Al2O3 composites. The electrical conductivity and complex permittivity of the as-fabricated composites were investigated in the range of 8.2–12.4 GHz, and the corresponding microwave reflection loss was evaluated. Compared to the pristine MWCNT/Al2O3 composites, the percolation threshold of electrical conductivity was observed to increase from the range of 0.094–2.5 wt% to 3.89 wt%, mainly owing to the decrease of MWCNT aggregations based on the shortened tubes. The resulting shortened MWCNTs/Al2O3 were found to demonstrate strong microwave absorption in the investigated region.

A yellow-leaf mutant (yl11) with chlorophyll-deficient in rice (Oryza sativa L.) was selected from the progeny of a japonica rice variety "Jiahua 1" treated with 60Co γ-radiation. In comparison with the wild-type parent, "Jiahua 1", the mutant had yellow-leaves at whole growth stages and displayed significantly decreased in chlorophyll content and net photosynthetic rate. Underdeveloped chloroplast and alterations of the major agronomic traits, such as plant-heights, were also observed in the mutant. Genetic analysis confirmed that the yellow-leaf mutant trait was controlled by a single recessive nuclear gene (yl11). Using SSR and In/Del molecular markers and 920 F2 and F3 plants from the cross of yl11 with the indica variety Peiai 64S, the yl11 was mapped between the molecular markers MM2199 and InDel21039 with a physical distance of 110 kb on the long arm of chromosome 11, in which no known functional genes for chlorophyll synthesis or chloroplast development in rice has been found. These findings will provide a foundation for the cloning and functional analysis of this gene in the future.

A novel biscalixarene with two kinds of calix[4]arene derivative units connected by four bridging chains, was facilely synthesized by “1 + 1” condensation mode in high yield. The element analyses, ESI-MS, 1 H NMR and 1 H– 1 H COSY spectrum showed that the calix[4]arene units of compound 4 were in cone conformations and compound 4 possessed biscalixarene-tube structure.

A yellow-leaf mutant (yl11) with chlorophyll-deficient in rice (Oryza sativa L.) was selected from the progeny of a japonica rice variety "Jiahua 1" treated with 60Co γ-radiation. In comparison with the wild-type parent, "Jiahua 1", the mutant had yellow-leaves at whole growth stages and displayed significantly decreased in chlorophyll content and net photosynthetic rate. Underdeveloped chloroplast and alterations of the major agronomic traits, such as plant-heights, were also observed in the mutant. Genetic analysis confirmed that the yellow-leaf mutant trait was controlled by a single recessive nuclear gene (yl11). Using SSR and In/Del molecular markers and 920 F2 and F3 plants from the cross of yl11 with the indica variety Peiai 64S, the yl11 was mapped between the molecular markers MM2199 and InDel21039 with a physical distance of 110 kb on the long arm of chromosome 11, in which no known functional genes for chlorophyll synthesis or chloroplast development in rice has been found. These findings will provide a foundation for the cloning and functional analysis of this gene in the future.

To study the emotional and depressive differences between severe acute respiratory syndrome (SARS) patients whose occupations were doctor/nurse and others.During the three months when SARS was explosive in 2003, 524 questionnaires were collected from Xuanwu Hospital, You'an Hospital, Xiaotangshan Hospital, Renmin Hospital and Ditan Hospital in Beijing. There were 109 questionnaires finished by patients as doctors/nurses themselves. For a background matching, 109 questionnaires were also finished by the others.From 218 questionnaires, we found that the score on emotional condition (46.6204 +/- 8.4408 vs. 41.6789 +/- 8.612 95, P0.001) of SARS patients whose jobs were doctor/nurse was higher than the other groups on while the score of SARS patients whose jobs were doctor/nurse was lower than the other groups (37.7615 +/- 9.026 61 vs. 41.2844 +/- 9.655 25, P = 0.006) regarding depressive condition. The scores of emotional and depressive condition were all correlated with the factor as "I can not master my future".Doctors/nurses having SARS had less emotional and depressive conditions than the others, which might due to the difference in medical knowledge, working condition and the route of infection, suggesting that psychological intervention in the post-SARS period called for attention.

Multi-wall carbon nanotubes (MWCNTs) were oxidized by soaking in mixed acids. Their microstructure and composition were characterized using transmission electron microscopy, atomic force microscopy, Raman spectroscopy and infrared spectroscopy. The influence of soaking time on microstructure and dispersibility of the cut MWCNTs in aqueous solution was investigated. Results show that the MWCNTs were oxidized at defect sites by the mixed acids and converted from highly tangled ropes into short, open-ended nanotubes with lengths of 200–1500 nm. The isoelectric point was reduced from 4.5 to 3.5 due to hydroxyl and carboxyl groups on the surface and the open ends of the cut MWCNTs. The aggregation experiments and UV–vis absorbance spectra revealed that the cut MWCNTs can be best dispersed in an aqueous solution containing 0.1 wt.% of sodium dodecyl-benzenesulfonate when sonicated at a pH value of 2 for 40 min. [New Carbon Materials 2014, 29(2): 109–117]