Barium titanate-on-insulator has demonstrated excellent vertical optical confinement, low loss, and strong electro-optic properties. To fabricate a waveguide-based device, a region of higher ...refractive index must be created to confine a propagating mode, one way of which is through dry etching to form a ridge. However, despite recent progress achieved in etching barium titanate and similar materials, the sidewall and surface roughness resulting from the physical etching typically used limit the achievable ridge depth. This motivates the exploration of etch-free methods to achieve the required index contrast. Here, we introduce three etch-free methods to create a refractive index contrast in barium titanate-on-insulator, including a metal diffusion method, proton beam irradiation method, and crystallinity control method. Notably, molybdenum-diffused barium titanate leads to a large index change of up to 0.17. The methods provided in this work can be further developed to fabricate various on-chip barium titanate optical waveguide-based devices.
Here, we report a copper‐catalyzed asymmetric cascade cyclization/1,2‐Stevens‐type rearrangement via a non‐diazo approach, leading to the practical and atom‐economic assembly of various valuable ...chiral chromeno3,4‐cpyrroles bearing a quaternary carbon stereocenter in generally moderate to good yields with wide substrate scope and excellent enantioselectivities (up to 99 % ee). Importantly, this protocol not only represents the first example of catalytic asymmetric 1,2‐Stevens‐type rearrangement based on alkynes but also constitutes the first asymmetric formal carbene insertion into the Si−O bond.
A copper‐catalyzed asymmetric cascade cyclization/1,2‐Stevens‐type rearrangement is disclosed, affording valuable chiral chromeno3,4‐cpyrroles bearing a quaternary carbon stereocenter in generally moderate to good yields with excellent enantioselectivities. Importantly, this protocol represents the first catalytic asymmetric 1,2‐Stevens‐type rearrangement based on alkynes and the first asymmetric formal carbene insertion into the Si−O bond.
An efficient and selective electrosynthesis of phenols and anilines from arylboronic acids in aqueous ammonia is achieved in an undivided cell. By simply changing the concentration of aqueous ammonia ...and the anode potential, good yields of phenols and anilines can be obtained chemoselectively with high reaction rates. We propose that anodic oxidation could have played an important role in these transformations.
Background
During the COVID‐19 epidemic, palliative care has become even more indispensable for cancer patients.
Aim
To identify the changes in palliative care for cancer patients and improvements in ...palliative care quality during the COVID‐19 pandemic.
Design
A systematic review and narrative synthesis was conducted in PubMed, Embase and Web of Science. An evaluation tool using mixed methods was used to assess the quality of the study. The main relevant themes identified were used to group qualitative and quantitative findings.
Results
A total of 36 studies were identified, primarily from different countries, with a total of 14,427 patients, 238 caregivers and 354 health care providers. Cancer palliative care has been experiencing several difficulties following the COVID‐19 pandemic, including increased mortality and infection rates as well as delays in patient treatment that have resulted in poorer prognoses. Treatment providers are seeking solutions such as electronic management of patients and integration of resources to care for the mental health of patients and staff. Telemedicine plays an important role in many ways but cannot completely replace traditional treatment. Clinicians strive to meet patients' palliative care needs during special times and improve their quality of life.
Conclusions
Palliative care faces unique challenges during the COVID‐19 epidemic. With adequate support to alleviate care‐related challenges, patients in the home versus hospital setting will be able to receive better palliative care. In addition, this review highlights the importance of multiparty collaboration to achieve personal and societal benefits of palliative care.
Patient or Public Contribution
No Patient or Public Contribution.
Attempts to create metal–organic frameworks (MOFs) with zeolitic topologies, metal (zinc(II) and cobalt(II)) imidazolates have repeatedly been used as the metal–organic motifs of inorganic silicate ...analogues. By modulating the synthetic strategy based on the solvothermal and liquid diffusion method, seven further MOFs (including at least three zeolitic MOFs) of zinc(II) imidazolates, Zn(im)2⋅x G (G=guest molecule, x=0.2–1) 1 a–7 a, have been successfully synthesized. Of these, 1 a–3 a are isostructural with the previously reported cobalt analogues 1 b–3 b, respectively, while 4 a–7 a are new members of the metal imidazolate MOF family. Complex 4 a exhibits a structure related to silicate CaAl2Si2O8 of CrB4 topology, but with a higher network symmetry; complex 5 a has a structure with zeolitic DFT topology that was discovered in zeolite‐related materials of DAF‐2, UCSB‐3, and UCSB‐3GaGe; complex 6 a demonstrates an unprecedented zeolite‐like topology with one dimensional channels with 10‐rings; and 7 a displays a structure of natural zeolite GIS (gismondine) topology. All of these polymorphous MOFs were created only by using certain solvents as structure‐directing agents (SDAs). Further extensive metal–organic frameworks with zeolitic topologies can be envisaged if other solvents were to be used.
Topping topologies: Extended zeolitic metal–organic frameworks (ZMOFs) of zinc(II) imidazolates have been synthesized by using a nonsolvothermal synthetic strategy, involving buffering and structure‐directing agents (BA and SDA; see scheme). As genuine metal–organic analogues of inorganic silica, the metal imidazolates and metal imidazole derivates can be expected to generate further extensive ZMOFs.
Objective
Although excess mortality, especially suicide, is a critical trait in people living with HIV, consensus about gender differences in these areas is lacking. We conducted meta‐analyses to ...examine gender differences in suicidal ideation, suicide attempts, and suicide death among people living with HIV.
Methods
We systematically searched PubMed and Web of Science for studies written in English. In this review, suicide among people living with HIV includes suicide death, suicidal ideation, and suicide attempts. Studies reporting the suicide prevalence among males and females living with HIV were eligible for inclusion in our review. Odds ratios (ORs) and 95% confidence intervals (CIs) served as the effect size index. Fixed‐effects or random‐effects meta‐analyses were chosen based on the size of the heterogeneity.
Results
A total of 27 studies comprising 801 017 participants from 11 countries were included in the meta‐analysis. The overall prevalence of suicidal ideation was 18.0% (95% CI 13.3%–22.8%) in males and 20.8% (95% CI 16.4%–25.1%) in females, and there was a statistically significant higher risk of suicidal ideation in females living with HIV (OR 1.30; 95% CI 1.09–1.56; p < 0.05). The overall prevalence of suicide attempts was 16.8% (95% CI 9.0%–24.5%) in males and 24.7% (95% CI 12.4%–37.1%) in females, and there was a statistically significant higher risk of suicide attempts in females living with HIV (OR 1.34; 95% CI 1.02–1.75; p < 0.05). The pooled prevalence of suicide death was 1.2% (95% CI 0.5%–1.9%) among males and 0.2% (95% CI 0.1%–0.3%) among females, and the risk of suicide death between genders was not statistically significant (OR 0.78; 95% CI 0.50–1.24; p = 0.298).
Conclusions
There were gender differences in suicidal ideation and suicide attempts among people living with HIV. Females living with HIV were more likely to experience suicidal ideation and make suicide attempts, but there were no statistically significant gender differences in suicide death. Appropriate initiatives to optimize the recognition, treatment, and management suicide behaviours of males and females living with HIV may narrow this gender gap.
Understanding the role of gold nanoparticles (AuNPs) in electrochemiluminescence (ECL) processes of the Ru(bpy)32+ (bpy= 2, 2′-bipyridine)/tripropylamine (TPA) system would be beneficial to develop ...novel ECL sensors for a variety of applications. In this work, we found that the AuNPs on the surface of indium tin oxide (ITO) electrode could catalyze the electrochemical oxidation of TPA, greatly enhancing the ECL signal of Ru(bpy)32+/TPA, present in the solution. If physical separation of AuNPs away from electrode surface after hybridization with target ssDNA, ECL signal decreased dramatically due to the loss of electrochemical activity of AuNPs, based on which a sensitive and specific DNA sensor in a “switch-off” mode was constructed with a detection limit of 0.2 pM. In addition, a suppressing effect of the AuNPs on the ECL of Ru(bpy)32+ was experimentally confirmed by decreasing the electrocatalytic effect to overall ECL emission, including selection of oxalate as a coreactant instead of TPA, or introduction of gold electrode as substrate. Furthermore, when Ru(bpy)32+ and AuNPs were both immobilized on the ITO electrode at close proximity, the ECL quenching induced by energy/electron transfer was predominant. ECL emission of the Ru(bpy)32+/TPA system resulted from a competition between electrocatalytic enhancement and quenching effect. However, the quenched ECL signal would return in case of the AuNPs moving far away from ECL emitters after a hybridization reaction as before, and a separation distance dependent surface enhancement was observed as well. Based on the role change for AuNPs from quenching to enhancing ECL intensity of Ru(bpy)32+/TPA system, a novel ECL DNA sensing strategy in a “turn-on” mode was developed, enabling quantitative analysis of target ssDNA over the range of 0.05 pM to 0.5 nM with a detection limit of 12 fM. Overall, we demonstrated the existence of three effects of AuNPs on the ECL of Ru(bpy)32+/TPA system, and which played the leading role was dependent on the placement of AuNPs, Ru(bpy)32+, and their separation distance. The ECL sensors based on the role change for AuNPs showed both high sensitivity and excellent selectivity.
●Enhancing ECL intensity of Ru(bpy)32+/TPA system by electrocatalysis or SPR-field.●Quenching the Ru(bpy)32+* in excited state though energy/electron transfer.●Distance-dependent competition of enhancement and quenching have been observed.●ECL sensors in “turn-off” and “turn-on” modes based on the role change for AuNPs.
This study compared the influences of differential protein levels of feed on growth, copper‐induced digestive enzyme activity, immune response, oxidative stress and Nrf2 signalling molecules genes ...expression of Rhynchocypris lagowski in a biofloc‐based system and traditional autotrophic system. Four hundred and fifty R. lagowski were fed four experimental dietary containing graded levels of protein from 25% to 37% (referred as biofloc technology BFT25, BFT29, BFT33 and BFT37, respectively) in a biofloc‐based system, and 37% crude protein level (control group) were cultured in an autotrophic system in 8 weeks. At the end of the trial, there was an improvement of 50.35%–61.64% in terms of growth performance (weight gain rate); 0.25–0.53 (U/mg prot) amylase; 6.9–8.02 (U/ml) lysozyme (LZM); and 7.98–8.12 (U/ml) total superoxide dismutase (T‐SOD) in R. lagowski cultured in BFT37 groups as compared to control. Obviously, the growth performance, digestive enzymes activity, immune response, antioxidant statue and antioxidant‐related genes expression of R. lagowski fed with the same protein level in BFT system were significantly higher than those in the control group (p < .05). Furthermore, the level of T‐SOD in liver and kidney and interferon‐γ in liver of BFT33 group were also significantly higher than that of control group (p < .05). Moreover, there was no notable difference of LZM, alkaline phosphatase, complement C3, C4, heat shock proteins 70, heat shock proteins 90, insulin‐like growth factor I, glutathione peroxidase, catalase, total antioxidant capacity, malondialdehyde, Ascorbic acid in gill, liver, kidney, gut and serum among the BFT29 groups and those in the control (p > .05). Besides, bioflocs assists in regulating the expression of Nrf2 signalling molecules including Nrf2, Keap1, Maf, HO‐1, CAT, CuZn‐SOD, GPX and GCLC. We summarized that despite the low protein content in feed, BFT system has the potential to promote growth performance, alleviate copper‐induced immunosuppression and oxidative stress of juvenile R. lagowski.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Abstract
Two-dimensional covalent organic frameworks (2D COFs) are promising for gas sensing owing to the large surface area, abundant active sites, and their semiconducting nature. However, 2D COFs ...are usually produced in the form of insoluble micro-crystallites. Their poor contacts between grain boundaries severely suppress the conductivity, which are too low for chemresistive gas sensing. Here, we demonstrate that halide perovskites can be employed as electric glues to bond 2D COF crystallites to improve their conductivity by two orders of magnitude, activating them to detect NO
2
with high selectivity and sensitivity. Resonant microcantilever, grand canonical Monte Carlo, density functional theory and sum-frequency generation analyses prove that 2D COFs can enrich and transfer electrons to NO
2
molecules, leading to increased device conductivity. This work provides a facile approach for improving the conductivity of polycrystalline 2D COF films and may expand their applications in semiconductor devices, such as sensors, resistors, memristors and field-emission transistors.
Global warming threatens many aspects of human life, for example, by reducing crop yields. Breeding heat-tolerant crops using genes conferring thermotolerance is a fundamental way to help deal with ...this challenge. Here we identify a major quantitative trait locus (QTL) for thermotolerance in African rice (Oryza glaberrima), Thermo-tolerance 1 (TT1), which encodes an α2 subunit of the 26S proteasome involved in the degradation of ubiquitinated proteins. Ubiquitylome analysis indicated that OgTT1 protects cells from heat stress through more efficient elimination of cytotoxic denatured proteins and more effective maintenance of heat-response processes than achieved with OsTT1. Variation in TT1 has been selected for on the basis of climatic temperature and has had an important role in local adaptation during rice evolution. In addition, we found that overexpression of OgTT1 was associated with markedly enhanced thermotolerance in rice, Arabidopsis and Festuca elata. This discovery may lead to an increase in crop security in the face of the ongoing threat of global warming.
Celotno besedilo
Dostopno za:
DOBA, IJS, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SBMB, UILJ, UKNU, UL, UM, UPUK
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