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Magnetic resonance imaging (MRI) scanner-specific geometric distortions may contribute to scanner induced variability and decrease volumetric measurement precision for multi-site studies. The purpose of this study was to determine whether geometric distortion correction increases the precision of brain volumetric measurements in a multi-site multi-scanner study. Geometric distortion variation was quantified over a one-year period at 10 sites using the distortion fields estimated from monthly 3D T1-weighted MRI geometrical phantom scans. The variability of volume and distance measurements were quantified using synthetic volumes and a standard quantitative MRI (qMRI) phantom. The effects of geometric distortion corrections on MRI derived volumetric measurements of the human brain were assessed in two subjects scanned on each of the 10 MRI scanners and in 150 subjects with cerebrovascaular disease (CVD) acquired across imaging sites.Geometric distortions were found to vary substantially between different MRI scanners but were relatively stable on each scanner over a one-year interval. Geometric distortions varied spatially, increasing in severity with distance from the magnet isocenter. In measurements made with the qMRI phantom, the geometric distortion correction decreased the standard deviation of volumetric assessments by 35% and distance measurements by 42%. The average coefficient of variance decreased by 16% in gray matter and white matter volume estimates in the two subjects scanned on the 10 MRI scanners. Geometric distortion correction using an up-to-date correction field is recommended to increase precision in volumetric measurements made from MRI images.

Interfacial free energy is a quantitative basis for explaining and predicting interfacial behavior that is ubiquitous in nature. The contact angle (CA) method can determine the surface free energy (γ) as well as Lifshitz-van der Waals (γ

Allergic asthma which is induced by ovalbumin (OVA) is a chronic airway inflammation disease. Isoorientin (Iso) is a natural C-glucosyl flavone with many biological properties. We aimed to evaluate the effectiveness of Iso on OVA-induced allergic asthma. A total of 30 C57BL/6 mice were randomly divided into five groups: control group, OVA group, Dex (dexamethasone, 10 mg/kg) group, low-dose Iso group (Iso-L, 25 mg/kg), and high-dose Iso group (Iso-H, 50 mg/kg). The serum and bronchoalveolar lavage fluid (BALF) were collected for biochemical parameters, the lung tissue was collected for hematoxylin-eosin (H&E) staining, immunohistochemistry (IHC), and western blot. The levels of IL-4, IL-5, IL-13, malondialdehyde (MDA), NO, and reactive oxygen species (ROS) in Iso-L and Iso-H groups were significantly lower than that in model group ( p

Keshan Disease (KD) is still a serious endemic public health problem in Northeast China. Previous studies have mainly focused on soil selenium content, staple food selenium content, and human selenium level, but there are few systematic studies on soil selenium existing forms and their migration from soil to crops and human body. In order to provide visualization of the spatial distribution characteristics and migration status of soil selenium content, and to provide a reference basis for the etiological analysis, prevention, control and elimination of KD, the 121183 topsoil soil (0-20 cm) geochemical data and 30295 soil parent material data which were collected and analysed by two-layer gridding method were used to infer the barrier factors in the migration and transformation of selenium from soil to crop and human body. The total selenium average of soil, staple food and human body be counted, the soil selenium existing forms and the correlation analysis between soil aluminum trioxide, iron trioxide were analysed.The average content of topsoil selenium in Northeast China was 0.20 mg/kg, which was significantly lower than the world soil selenium content average (0.4 mg/kg) and slightly lower than the Chinese soil selenium content average (0.239 mg/kg).The average selenium content of human hair is only 0.16mg/kg in Baiquan, Heilongjiang Province. Soil-forming parent material has some influence on soil selenium content, however, epigenetic enrichment is a more significant enrichment factor on soil selenium content. Soil selenium existing in humic acid state selenium, strongly organic bound state selenium, and the contents of selenite, selenate and methyl selenocysteine which are easily used by plants are all relatively high, correlation analysis between soil selenium content and organic matter, iron and aluminium oxides shows that soil organic matter and iron and aluminium oxides were the main barrier factors for selenium migration and transformation. Lower soil selenium content may be the basic factor for the biogeochemical deficiency of selenium, the sequestration of selenium by clay chemical constituents such as iron and aluminium oxides and soil organic matter is the direct factor for the biogeochemical low selenium in the Northeastern China, which increasing the risk of KD in the population. These research findings can provide more evidence to assess the elimination of biogeochemical aetiology of diseases from a selenium nutrient perspective.

Achieving controllable fine-tuning of defects in catalysts at the atomic level has become a zealous pursuit in catalysis-related fields. However, the generation of defects is quite random, and their flexible manipulation lacks theoretical basis. Herein, we present a facile and highly controllable thermal tuning strategy that enables fine control of nanodefects via subtle manipulation of atomic/lattice arrangements in electrocatalysts. Such thermal tuning endows common carbon materials with record high efficiency in electrocatalytic degradation of pollutants. Systematic characterization and calculations demonstrate that an optimal thermal tuning can bring about enhanced electrocatalytic efficiency by manipulating the N-centered annulation–volatilization reactions and C-based sp3/sp2 configuration alteration. Benefiting from this tuning strategy, the optimized electrocatalytic anodic membrane successfully achieves >99% pollutant (propranolol) degradation during a flow-through (~2.5 s for contact time), high-flux (424.5 L m−2 h−1), and long-term (>720 min) electrocatalytic filtration test at a very low energy consumption (0.029 ± 0.010 kWh m−3 order−1). Our findings highlight a controllable preparation approach of catalysts while also elucidating the molecular level mechanisms involved.

The facile exfoliation of a two-dimensional metal-organic nanosheet of {[Co(HL)(H

Based on pH-responsive fluorescence associated with alkaline hydrolysis, a fluorometric method is proposed for characterizing the stability of MOFs. It can be used to monitor the whole process from nondestructive local hydrolysis to complete destructive hydrolysis.

There are three traditional surgical approaches to hemiarthroplasty (HA) for femoral neck fractures, respectively, the anterior approach (AA), the lateral approach (LA) and the posterior approach (PA). However, the optimum approach is still controversial, the purpose of this meta-analysis is to identify the merits and demerits of all three approaches. All clinical published studies in PubMed, Web of Science, Embase, and the Cochrane Library from January 2000 to April 2022 were searched which compared different surgical approaches and covered surgery-related outcomes and frequent complications. Five randomized controlled trials and 26 cohort studies for a total of 31 clinical trials were included in the meta-analysis. The dislocation of PA was significantly higher than LA (OR: 3.00 95% CI: 2.25–4.01 I2 = 27% P I2 = 0% P = 0.0005); PA was substantially more than LA in terms of risk of postoperative reoperation (P

White spot syndrome virus (WSSV) is a fatal pathogen threatening global crustacean industry with no commercially available drugs to control. Herbal medicines have been widely used to treat a number of viral infections, which could offer a rich reserve for antiviral drug discovery. Here, we evaluated the inhibition activities of 30 herbal medicines against WSSV in Chinese mitten crab Eriocheir sinensis. A WSSV infection model in E. sinensis was firstly established in order to determine the antiviral effects of the plant extracts and to explore the potential action mechanisms. Results showed that the highest anti-WSSV activity was obtained by the treatment of Ophiopogon japonicus extract (93.03%, 100 mg/kg). O. japonicus treatment decreased viral loads in a dose-dependent manner and significantly improved the survival of WSSV-challenged crabs. O. japonicus reduced the expression of vital genes in viral life cycle in vivo, particularly for the immediate-early stage gene ie1. Further results indicated that O. japonicus could repress the JAK-STAT signaling pathway to block ie1 transcription. Moreover, O. japonicus could modulate certain immune genes such as the myosin, toll-like receptor, crustin, and prophenoloxidase in the interactions between WSSV and crabs. The up-regulated expression of pro-autophagic factors (Gabarap and Atg7) and elevated levels of antioxidant enzymes (SOD, CAT and GSH) suggested that O. japonicus may induce autophagy and attenuate WSSV-induced oxidative stress. Taken together, O. japonicus could inhibit WSSV proliferation and improve the survival of WSSV-challenged crabs. Thus, O. japonicus may have the potential to be developed as a preventive or therapeutic agent against WSSV, and its effective compounds merit further isolation and identification.

BACKGROUND Nonoperative management (NOM) is a promising therapeutic modality for patients with perforated peptic ulcer (PPU). However, the risk factors for poor efficacy and adverse events of NOM are a concern. AIM To investigate the factors predictive of poor efficacy and adverse events in patients with PPU treated by NOM. METHODS This retrospective case-control study enrolled 272 patients who were diagnosed with PPU and initially managed nonoperatively from January 2014 to December 2018. Of these 272 patients, 50 converted to emergency surgery due to a lack of improvement (surgical group) and 222 patients were included in the NOM group. The clinical data of these patients were collected. Baseline patient characteristics and adverse outcomes were compared between the two groups. Logistic regression analysis and receiver operating characteristic curve analyses were conducted to investigate the factors predictive of poor efficacy of NOM and adverse outcomes in patients with PPU. RESULTS Adverse outcomes were observed in 71 patients (32.0%). Multivariate analyses revealed that low serum albumin level was an independent predictor for poor efficacy of NOM and adverse outcomes in patients with PPU. CONCLUSION Low serum albumin level may be used as an indicator to help predict the poor efficacy of NOM and adverse outcomes, and can be used for risk stratification in patients with PPU.

Sulfones play a pivotal role in modern organic chemistry. They are highly versatile building blocks and find various applications as drugs, agrochemicals, or functional materials. Therefore, sustainable access to this class of molecules is of great interest. Herein, the goal was to provide a summary on recent developments in the field of sustainable sulfone synthesis. Advances and existing limitations in traditional approaches towards sulfones were reviewed on selected examples. Furthermore, novel emerging technologies for a more sustainable sulfone synthesis and future directions were discussed.

This article presents a fuzzy adaptive tracking control algorithm for hypersonic flight vehicles with input quantization and faults. Different from the usual stabilization results, we present a method to achieve asymptotic tracking with predefined-time performance. An error transformation is established and a modified Lyapunov function (MLF) is constructed. The predefined-time asymptotic tracking control goal can be achieved by simply guaranteeing the boundness of the proposed MLF which is related to the transformed tracking errors. The proposed control strategy has three advantages. First, the predefined-time tracking performance can be ensured even when the initial tracking conditions are completely unknown. Second, no compensation is required for the fuzzy reconstruction errors to achieve accurate tracking control such that the control design is significantly simplified. Third, the derived controller is fault-tolerant, and since the system is controlled by quantized signals, the communication burden can be considerably reduced. Theoretical proof and numerical simulation are presented to demonstrate the effectiveness of the proposed control algorithm.

A sensitivity-enhanced optical pressure sensor based on molybdenum disulfide (MoS

Postoperative delirium (POD) is a frequent complication in geriatric patients with hip fractures, which is linked to poorer functional recovery, longer hospital stays, and higher short-and long-term mortality. Patients with increased age, preoperative cognitive impairment, comorbidities, perioperative polypharmacy, and delayed surgery are more prone to develop POD after hip fracture surgery. In this narrative review, we outlined the latest findings on postoperative delirium in geriatric patients with hip fractures, focusing on its pathophysiology, diagnosis, prevention, and treatment. Perioperative risk prediction, avoidance of certain medications, and orthogeriatric comprehensive care are all examples of effective interventions. Choices of anesthesia technique may not be associated with a significant difference in the incidence of postoperative delirium in geriatric patients with hip fractures. There are few pharmaceutical measures available for POD treatment. Dexmedetomidine and multimodal analgesia may be effective for managing postoperative delirium, and adverse complications should be considered when using antipsychotics. In conclusion, perioperative risk intervention based on orthogeriatric comprehensive care is the most effective strategy for preventing postoperative delirium in geriatric patients with hip fractures.

Herein we reported a Mn(OAc)

Cellulose nanocrystals (CNCs), as the promising reinforcing fillers in the rubber industry, their surface chemical groups have vital effects on the vulcanization kinetics, cross-linking densities, and mechanical properties of rubber composites. Herein, CNCs with acidic carboxyl (CCA) and alkaline amino groups (CCP) were produced by modifying the sulfonic CNCs (CCS) in environment-friendly ways. Studies found the CCS and CCA with acid groups have obvious inhibiting effects on the vulcanization of natural rubber (NR), while CCP with alkaline amino groups accelerates the vulcanization of NR. Differential scanning calorimeter, Fourier transform infrared spectroscopy, and Electron paramagnetic resonance, etc. were performed to clarify the effecting mechanisms of CNCs surface groups on NR vulcanization. It was found that NR/CCS and NR/CCA nanocomposites vulcanize through radical reactions, and the surface acidic groups of CCS and CCA, i.e., hydroxyl, sulfonate, and carboxyl groups inactivate the sulfur radicals generated during vulcanization and depress the vulcanization activity. The amino groups of the polyethyleneimine of CCP promote the ring opening of sulfur (S

In this paper, a graphene composite structure based optical absorption pressure sensor is proposed. First, a composite structure which is composed of PDMS micro-pyramid structure, graphene film, and waveguide is introduced. The sensitive mechanism and dynamic working state of the pressure sensor are analyzed continuously. Second, the mapping between the pressure on PDMS and its contact area with the graphene film is deeply analyzed, as well as the optical transmission properties of graphene combined with waveguides, followed by a series of simulations about the optical power output performance facing different pressure conditions. Finally, the designed sensor samples are prepared and a series of performance verification experiments were carried out. The experimental results show that the range of the pressure sensor is 0-870kPa. The sensitivity in the pressure range of 0-100kPa is 2.83×10−1µW/kPa. The experimental results effectively prove that the designed graphene composite structure based optical absorption pressure sensor has high sensitivity and good repeatability, which further verifies the feasibility of the design and analysis method.

The reliability of the integrated circuits (ICs) has become one of the greatest challenges with the increasing complexity of the electromagnetic environment. On this basis, an explicit difference in the damage location is observed in the high-power microwave (HPM) radiated CMOS inverters. The detailed damage mechanism analysis is performed. The analysis shows that the overcurrent-dominant failure and the latch-up-dominant failure are induced in positive and negative half radiation cycle respectively, resulting in the damage location discrepancy. The depletion region current $I_{\textrm {SS}}$ and the body current $I_{\textrm {body}}$ are derived from the established theoretical charge transport model. TCAD simulations demonstrate the junctional-overcurrent and latch-up process, empirical formula is obtained to explain the damage mechanism and predict the thermal damage location. The damage dependency on interference characteristics is discussed for further understanding. Corresponding experiments are performed using the six-integrated-inverters chip. The results support the theoretical charge transport model well.

Positive cooperative binding, a phenomenon prevalent in biological processes, holds great appeal for the design of highly sensitive responsive molecules and materials. It has been demonstrated that metal-organic frameworks (MOFs) can show positive cooperative adsorption to the benefit of gas separation, but potential binding cooperativity is largely ignored in the study of sensory MOFs. Here, we report the first demonstration of positive cooperative protonation of a MOF and the relevant pH response in fluorescence and proton conduction. The MOF is built of Zr-O clusters and bipyridyl-based tetracarboxylate linkers and has excellent hydrolytic stability. It shows a unique pH response that features two synchronous abrupt turn-off and turn-on fluorescent transitions. The abrupt transitions, which afford high sensitivity to small pH fluctuations, are due to cooperative protonation of the pyridyl sites with a Hill coefficient of 1.6. The synchronous dual-emission response, which leads to visual color change, is ascribable to proton-triggered switching between (n, π*) and (π, π*) emissions. The latter emission can be quenched by electron donating anion-dependent through photoinduced electron transfer and ground-state charge transfer. Associated with cooperative protonation, the proton conductivity of the MOF is abruptly enhanced at low pH by two orders, but overhigh acid concentration is adverse because excessive anions can interrupt the conducting networks. Our work shows new perspectives of binding cooperativity in MOFs and should shed new light on the development of responsive fluorescent MOFs and proton conductive materials.

Membrane bioreactors (MBRs) have been and will continue playing an important role in industrial wastewater treatment and reuse in China. The sustainable development of MBR technology in its mature-application stage requires reciprocal interactions between engineering and research participants. Thus, in this study, a total of 182 large-scale MBR projects treating industrial wastewater (with individual treatment capacities ≥ 5000 m3·d-1) commissioned and under construction from 2003 to 2019 were analyzed comprehensively. Fast growth of the cumulative treatment capacity was observed, with extension to diverse industries, and the super large-scale was enhanced recently. The treatment processes, pollutant removal efficiencies, and actual operational parameters were summarized regarding the particularity of industrial wastewater compared to municipal wastewater. Economic features including the total investment costs of the projects, their total footprint, and their operational energy consumption were analyzed as well. A vigorous MBR market has formed in China with the fast development of membrane elements and engineering suppliers, continuously increasing official oriented projects, and responsive and innovative business modes. MBR technology has been mostly applied in specific economic zones and water-deficient areas, but its widespread use all over China is foreseeable considering the vast future market for industrial wastewater treatment and recycling. The policy-economy and market-technology driving forces revealed that MBR is consistent with the national development demand. According to the survey and analysis, prospective development in both engineering and research aspects of MBR is proposed to maintain its competitive edge.

Sensory materials that show color and/or fluorescence changes in response to specific gases or vapors have important applications in many fields. Here, we report the postsynthetic preparation of novel sensory metal-organic frameworks (MOFs) and their multiple responsive properties. Through postsynthetic N-amination, the 2,2'-bipyridyl spacers in a Zr(IV) MOF are partially transformed into N-aminobipyridinium. The new MOF (Zr-bpy-A) shows chromic behavior toward ammonia and amines because the electron-deficient pyridinium groups form charge-transfer complexes with amino moieties. It also shows a unique chromic response to formaldehyde owing to the Schiff-base condensation with the N-amino groups. Furthermore, the N-amino group can be used to graft different polycyclic aromatic hydrocarbons, which endow the MOF with strong fluorescence of variable colors and afford a high-contrast fluorescence response to ammonia/amines and formaldehyde associated with the chromic response. The presence of the unquaternized bipyridyl group also leads to a fluorescence response to HCl. The multiple responsive behaviors hold appeal for applications in sensing, switching, and antifake marking, which are illustrated with a test paper and writing ink.

Inverse synthetic aperture radar (ISAR) imaging is an important technique for moving target identification and classification. For the space spinning targets, a long-time observation is required to estimate the spinning parameter in the conventional ISAR imaging methods. However, for the advanced multifunctional radar, which is used for multi-target surveillance, a long-time observation for only one target is the loss outweighs the gain. To decrease the observation time, we propose a novel imaging method for spinning space targets with short time observation in this paper. Firstly, we build the imaging model by using the azimuth rotation angle caused by the spinning motion rather than the translation motion to obtain the azimuth resolution. Secondly, we utilize the orthogonal coding signals with different delays to obtain enough equivalent pulses in the short observation time. Moreover, since the equivalent pulses are block-missing to avoid overlapping of the transmitting duration and the receiving duration, we transform the imaging problem to the compressed sensing (CS) problem and solve it by modifying the Smoothed L0-norm (SL0) algorithm. Finally, both the simulations and the experiments on real data are shown to demonstrate the validity of the proposed method. Since the observing time of the proposed method only needs to cover a small percentage of one spinning period, the proposed method can be used in multi-target surveillance such as satellites and space debris.

The Atomic Force Microscope (AFM) is a reliable tool for 3D imaging and manipulation at the micrometer and nanometer scales. When used inside a Scanning Electron Microscope (SEM), AFM probes can be localized and controlled with a nanometer resolution by visual feedback. However, achieving trajectory control and obstacles avoidance is still a major concern for manipulation tasks. We propose a Model Predictive Control (MPC) to address these two issues while AFM probes are actuated by Piezoelectric Inertia type Actuators (PIA). The novelty of this letter is that the model of our MPC-based approach relies on a velocity map of PIAs. It enables path following and obstacle avoidance while preserving safety margins. Control inputs are optimized by Quadratic Programming, referring to their increment and distance constraints. A cost function is defined to navigate the AFM probe with a specified velocity. Simulations and experiments are carried out to demonstrate that the proposed algorithm is suitable to perform path following with obstacle avoidance using map-based velocity references. This is the first time that MPC is implemented in micro/nano-robotic systems for autonomous control inside SEM.

To evaluate the efficacy and safety of Jianpi Jieyu Decoction (JJD) for treating patients with mild-to-moderate depression of Xin (Heart)-Pi (Spleen) deficiency (XPD) syndrome.In this multi-center, randomized, controlled study, 140 patients with mild-to-moderate depression of XPD syndrome were included from Xiyuan Hospital of China Academy of Chinese Medical Sciences and Botou Hospital of Traditional Chinese Medicine from December 2017 to December 2019. They were randomly divided into JJD group and paroxetine group by using a random number table, with 70 cases in each group. The patients in the JJD group were given JJD one dose per day (twice daily at morning and evening, 100 mL each time), and the patients in the paroxetine group were given paroxetine (10 mg/d in week 1; 20 mg/d in weeks 2-6), both orally administration for a total of 6 weeks. The primary outcome was the change of 17-item Hamilton Depression Rating Scale (HAMD-17) score at week 6 from baseline. The secondary outcomes included the Hamilton Anxiety Scale (HAMA) score, Traditional Chinese Medicine Symptom Scale (TCMSS), and Clinlcal Global Impression (CGI) scores at the 2nd, 4th, and 6th weekends of treatment, HAMD-17 response (defined as a reduction in score of50%) and HAMD-17 remission (defined as a score of ⩽7) at the end of the 6th week of treatment. Adverse events (AEs) were also recorded.From baseline to week 6, the HAMD-17 scores decreased 10.2 ± 4.0 and 9.1 ± 4.9 points in the JJD and paroxetine groups, respectively (P=0.689). The HAMD-17 response occurred in 60% of patients in the JJD group and in 50% of those in the paroxetine group (P=0.292); HAMD-17 remission occurred in 45.7% and 30% of patients, respectively (P=0.128). The differences of CGI scores at the 6th week were not statistically significant (P0.05). There were significant differences in HAMD-17 scores between the two groups at 2nd and 4th week (P=0.001 and P=0.014). The HAMA scores declined 8.1 ± 3.0 and 6.9 ± 4.3 points from baseline to week 6 in the JJD and paroxetine groups, respectively (P=0.905 between groups). At 4th week of treatment, there was a significant difference in HAMA between the two groups (P=0.037). TCMSS decreased 11.4 ± 5.1, and 10.1 ± 6.8 points in the JJD and paroxetine groups, respectively (P=0.080 between groups). At the 6th week, the incidence of AEs in the JJD group was significantly lower than that in the paroxetine group (7.14% vs. 22.86%, P0.05).Compared with paroxetine, JJD was associated with a significantly lower incidence of AEs in patients with mild-to-moderate depression of XPD syndrome, with no difference in efficacy at 6 weeks. (Trial registration No. ChiCTR2000040922).

The outbreak of white spot syndrome (WSS) is a looming challenge, due to dramatic losses to the crustacean aquaculture industry. However, at present, there are no prophylactic or therapeutic means to control this infectious viral disease. Here, we screened fifteen medicinal plants for their inhibitory activity on the white spot syndrome virus (WSSV), using red swamp crayfish (Procambarus clarkii) as a model species. The results showed that the crude extracts of Pinellia ternata (Thunb.) Breit. had the highest inhibitory effect (91.59%, 100 mg/kg) on WSSV proliferation, and its main component, beta-sitosterol, showed a much higher activity (95.79%, 50 mg/kg). Further, beta-sitosterol potently reduced (p < 0.01) viral loads and viral gene transcription levels in a concentration-dependent fashion, and significantly promoted the survival rate of WSSV-challenged crayfish (57.14%, 50 mg/kg). The co-incubation assay indicated that beta-sitosterol did not influence the infectivity of WSSV particles. Both pre- and post-treatment of beta-sitosterol exerted a significant inhibitory effect (p < 0.01) on the viral load in vivo. Mechanistically, beta-sitosterol not only interfered with the expression of viral genes (immediate early gene 1, ie1; DNA polymerase, DNApol) that are important in initiating WSSV transcription, but it also attenuated the hijacking of innate immune signaling pathways (Toll, IMD, and JAK/STAT pathways) by viral genes to block WSSV replication. Moreover, the expression of several antiviral immune, antioxidant, pro-inflammatory, and apoptosis-related genes changed significantly in beta-sitosterol-treated crayfish. Beta-sitosterol is a potent WSSV inhibitor and has the potential to be developed as an effective anti-WSSV agent against a WSS outbreak in crustacean aquaculture.

Solid catalysts for CO2 cycloaddition to epoxides often require homogeneous halide anions in large amounts, which sacrifice the heterogeneity and ecofriendliness. Here, we demonstrate a novel appro...

The chiral phosphoric acid catalyzed regio-, diastereo- and enantioselective reaction of isoxazol-5(4H)-ones with β,γ-alkynyl-α-imino esters has been developed. With the established methodology, γ-addition of β,γ-alkynyl-α-imino esters and C-allenylation of isoxazol-5(4H)-ones were achieved with high regio- and stereoselectivities, affording diverse α-imino allenoates featuring an adjacent quaternary carbon stereocenter and an axially chiral tetrasubstituted allene motif in high yields.

A novel Eu(III) metal–organic framework (MOF) featuring 3-fold interpenetration shows multi-responsive behaviors owing to the combination of charge transfer, electron transfer, and energy transfer between different ingredients (the electron-deficient tris(pyridinium)triazine (tpt) chromophore, the electron-rich naphthalene chromophore, the Eu(III) luminophore, and the guest anion). The interframework naphthalene-to-tpt charge transfer dictated by framework interpenetration serves to sensitize the Eu(III) emission through energy transfer. The photoinduced host–guest electron transfer from the intrinsic chloride guest to tpt leads to photochromism and photoquenching of photoluminescence. The spontaneous host–guest electron transfer from extrinsic amine/ammonia to tpt allow chromic and luminescent response to ammonia and amines with size selectivity. Furthermore, the photogenerated phase shows sensitive color change and luminescence turn-on upon exposure to O2. The multi-responsive properties offer the appeal for optical switching and sensing use. The qualitative and quantitative gaseous sensing of ammonia and O2 has been demonstrated with portable and reusable MOF–polymer membranes.