Binding of carbon dioxide and acetylene to free carboxylic acid sites in a metal-organic framework.

The functionalisation of organic linkers in metal-organic frameworks (MOFs) to improve gas uptake is well-documented. Although the positive role of free carboxylic acid sites in MOFs for binding gas molecules has been proposed in computational studies, relatively little experimental evidence has been reported in support of this. Primarily this is because of the inherent synthetic difficulty to prepare MOF materials bearing free, accessible -COOH moieties which would normally bind to metal ions within the framework structure. Here, we describe the direct binding of CO2 and C2H2 molecules to the free -COOH sites within the pores of MFM-303(Al). MFM-303(Al) exhibits highly selective adsorption of CO2 and C2H2 with a high selectivity for C2H2 over C2H4. In situ synchrotron X-ray diffraction and inelastic neutron scattering, coupled with modelling, highlight the cooperative interactions of adsorbed CO2 and C2H2 molecules with free -COOH and -OH sites within MFM-303(Al), thus rationalising the observed high selectivity for gas separation.

Research progress of vitiligo repigmentation: from oxidative stress to autoimmunity.

Vitiligo belongs to a frequent chronic autoimmune skin disease with the features of pigmented plaques on the diseased skin along with potential damage of melanocytes. There are many factors underlying the pathogenesis of vitiligo, among which oxidative stress is extensively regarded to be the critical factor leading to the loss of melanocytes. The changed redox state resulting from oxidative stress, containing ROS overproduction along with the reduced activity of the skin's antioxidant system, makes melanocytes less resistant to exogenous or endogenous stimuli, and ultimately pushes normal defense mechanisms, resulting in the loss of melanocytes. Given the crucial potential of innate together with adaptive immunity in vitiligo, there is growing evidence of a relation between oxidative stress and autoimmunity. Our review offers estimable insights into the possible properties of oxidative stress and autoimmunity in pathogenesis of vitiligo, as well as the potential role of antioxidant-based supportive therapy in vitiligo repigmentation, providing a hopeful value for further research and development of effective treatments.

Detection of fluid motion direction based on the rotational Doppler effect of grafted perfect vortex beam.

Vortex beams have attracted much attention due to their unique rotational Doppler effect. With the in-depth study of vortex beams, many new vortex beams have been proposed gradually, while the detection of fluid motion is of great significance for the study of ocean turbulence. Based on the rotational Doppler effect of the grafted perfect vortex beam, we propose a non-embedded optical method for real-time detection of the magnitude and direction of fluid velocity and establish a two-dimensional fluid model for simulation verification. It is proved that the grafted perfect vortex beam can detect the magnitude and direction of the fluid velocity at the same time, which may provide a new way and theoretical support for the detection of fluid motion direction.

A Case of Coma Bullae Associated with Brachioradial Artery.

We present the first case of coma bullae observed in a 67-year-old woman due to pressure and ischemia associated with brachioradial artery. A skin biopsy taken from the ulcer border revealed extensive loss of the epidermis, fibrosis of dermis, mild infiltration by lymphocytes and neutrophils, and necrosis of the focal eccrine ducts. CT angiography of the right upper limb showed a high origin of the radial artery, meanwhile both high originating radial artery and the anastomoses were tortuous and were of relatively small caliber. The diagnosis of coma bullae was made. After tissue debridement, the skin lesions gradually recovered, leaving atrophic scars.

Innovative OPA-based optical chip for enhanced digital holography.

Digital holographic imaging has emerged as a transformative technology with significant implications for AR/VR devices. However, existing techniques often suffer from limitations such as restricted field of view (FOV), high power consumption, and contrast distortion. This paper introduces an innovative optical phased array (OPA)-based chip, integrating polarization, amplitude, and phase multiplexing for enhanced complex amplitude holographic imaging. A checkerboard-style staggered array is employed in the control strategy, substantially reducing power consumption and enabling the potential for large-scale array integration. To further enhance imaging quality, we introduce what we believe are two novel calibration strategies: one is to achieve super-resolution through block imaging methods, and the other is to image using sparse aperture methods. These advancements not only provide a robust foundation for high-quality holographic imaging, but also present a new paradigm for overcoming the inherent limitations of current active holographic imaging devices. Due to challenges in chip fabrication, the research is primarily simulation-based. Nevertheless, this work presents meaningful advancements in digital holographic imaging for AR/VR applications and provides a foundation for future experimental validations.

Aluminum Oxide Nanoparticles Impair Working Memory and Neuronal Activity through the GSK3ß/BDNF Signaling Pathway of Prefrontal Cortex in Rats.

Studies demonstrated that alumina nanoparticles (alumina NPs) impair spatial cognition and hippocampus-dependent synaptic plasticity. Although alumina NPs accumulate in the prefrontal cortex (PFC), their effects on PFC-mediated neuronal and cognitive function have been not yet documented. Here, alumina NPs (10 or 20 µg/kg of body weight) were bilaterally injected into the medial PFC (mPFC) of adult rats, and the levels of glycogen synthase kinase 3ß (GSK3ß) and the brain-derived neurotrophic factor (BDNF) were detected. The PFC-dependent working memory task with one-minute or three-minute delay time was conducted. Meanwhile, the neuronal correlates of working memory performance were recorded. The specific expression of neuronal BDNF was assessed by colabeled BDNF expression with the neuronal nuclear antigen (NeuN). Whole-cell patch-clamp recordings were employed to detect neuronal excitability. Intra-mPFC alumina NP infusions significantly enhanced the expression of GSK3ß but reduced the phosphorylation of GSK3ß (pGSK3ß) and BDNF levels more severely at a dose of 20 µg/kg. Alumina NPs acted in a dose-dependent manner to impair working memory. The neuronal expression of BDNF in the 20 µg/kg group was markedly declined compared with the 10 µg/kg group. During the delay time, the neuronal frequency of pyramidal cells but not interneurons was significantly weakened. Furthermore, both the frequency and amplitude of the excitatory postsynaptic currents (EPSCs) were descended in the mPFC slices. Additionally, the infusion of GSK3ß inhibitor SB216763 or BDNF could effectively attenuate the impairments in neuronal correlate, neuronal activity, and working memory. From the perspective of the identified GSK3ß/BDNF pathway, these findings demonstrated for the first time that alumina NPs exposure can be a risk factor for prefrontal neuronal and cognitive functions.

Tracking objects outside the line of sight using laser Doppler coherent detection.

Based on the laser Doppler coherent detection method, a laser Doppler Non-Line-of Sight imaging technique (LD-NLOS) is proposed to obtain a series of effective information about the detected objects outside the line of sight. According to the analysis of the frequency and light intensity characteristics of the scattered signal, the information of the detected object hidden in the intermediate scattering surface is decoded. Without relying on complicated back-end algorithm processing and expensive experimental detection cost, the proposed LD-NLOS technique can detect the target vibration velocity and stably reconstruct its 2D shape.

Facial Erythema Due to Lupus Vulgaris and Candida albicans Infections: A Case Report.

Co-infection of Mycobacterium tuberculosis (MTB) and Candida albicans with erythema on the face is rare. A familiar red spot on the face can easily lead to missed diagnosis and misdiagnosis. Untreated lupus vulgaris (LV) can form scar tissue. And the fungal infection that cannot be diagnosed and treated timely can also lead to failure of LV treatment, resulting in facial scarring, disfigurement, and psychological stress. In this study, we reported a case of a 58-year-old immunocompetent female co-infected with MTB and Candida albicans on her face. After anti-tuberculous and anti-fungal therapy, she recovered with no scar on her face.

Ultrapure Blue Phosphorescent Organic Light-Emitting Diodes Employing a Twisted Pt(II) Complex.

Described herein is a stable complex, Pt(mpzpyOczpy-mesi), embodying efficient, narrow blue emission. The highly twisted structure of the complex improves the stability and efficiency of photo- and electroluminescence by reducing the intermolecular interactions. The complex in solution shows high photoluminescence efficiency (>95%) and radiative decay rate (Kr = 2.9 × 105 s-1) with a narrow emission spectrum. The bottom-emitting phosphorescent device, BE1, exhibits durable deep blue emission with CIE coordinates of (0.145, 0.166) and 5.2 h of LT50 at an initial luminance of 685 cd/m2. Top-emitting devices, TE1 and TE2, achieve ultrapure blue color with CIEx,y values of (0.141, 0.068) and (0.140, 0.071), respectively. TE4 shows high brightness of 3405 cd m-2 at 50 mA m-2, EQE of 10.2% at 1000 cd/m2, and almost negligible color deviation around (0.135, 0.096) at viewing angles of 0°-60°.

Mixed matrix membranes containing fluorescent coordination polymers for detecting Cr2O72- with high sensitivity, stability and recyclability.

Three coordination polymers (CPs) were synthesized by using CdII, fluorescent 9,10-di(4-pyridyl)anthracene (dpa), and cyclohexane-1,4-dicarboxylic acid (H2cda), and they are [Cd2(dpa)2(cda)Cl2]n (1), [Cd(dpa)2(cda)]n (2) and [Cd(dpa)(cda)(H2O)]n (3). Both 1 and 2 are fluorescent and contain nonporous layers. 3 is an isomer of 2 and contains a porous diamondoid network. Fluorescent mixed matrix membranes were prepared by dispersing the particles of 1 or 2 within the matrix of polymethyl methacrylate, and showed high sensitivity and selectivity for detecting Cr2O72- in water. Both stability and recyclability of the MMMs were remarkably higher than those of the CP powders.

Exceptional Packing Density of Ammonia in a Dual-Functionalized Metal-Organic Framework.

We report the reversible adsorption of ammonia (NH3) up to 9.9 mmol g-1 in a robust Al-based metal-organic framework, MFM-303(Al), which is functionalized with free carboxylic acid and hydroxyl groups. The unique pore environment decorated with these acidic sites results in an exceptional packing density of NH3 at 293 K (0.801 g cm-3) comparable to that of solid NH3 at 193 K (0.817 g cm-3). In situ synchrotron X-ray diffraction and inelastic neutron scattering reveal the critical role of free -COOH and -OH groups in immobilizing NH3 molecules. Breakthrough experiments confirm the excellent performance of MFM-303(Al) for the capture of NH3 at low concentrations under both dry and wet conditions.

High Ammonia Adsorption in MFM-300 Materials: Dynamics and Charge Transfer in Host-Guest Binding.

Ammonia (NH3) is a promising energy resource owing to its high hydrogen density. However, its widespread application is restricted by the lack of efficient and corrosion-resistant storage materials. Here, we report high NH3 adsorption in a series of robust metal-organic framework (MOF) materials, MFM-300(M) (M = Fe, V, Cr, In). MFM-300(M) (M = Fe, VIII, Cr) show fully reversible capacity for >20 cycles, reaching capacities of 16.1, 15.6, and 14.0 mmol g-1, respectively, at 273 K and 1 bar. Under the same conditions, MFM-300(VIV) exhibits the highest uptake among this series of MOFs of 17.3 mmol g-1. In situ neutron powder diffraction, single-crystal X-ray diffraction, and electron paramagnetic resonance spectroscopy confirm that the redox-active V center enables host-guest charge transfer, with VIV being reduced to VIII and NH3 being oxidized to hydrazine (N2H4). A combination of in situ inelastic neutron scattering and DFT modeling has revealed the binding dynamics of adsorbed NH3 within these MOFs to afford a comprehensive insight into the application of MOF materials to the adsorption and conversion of NH3.

A porous organic polymer nanosphere-based fluorescent biosensing platform for simultaneous detection of multiplexed DNA via electrostatic attraction and π-π stacking interactions.

One key challenge in oligonucleotide sequence sensing is to achieve multiplexed DNA detection in one sensor. Herein, a simple and efficient fluorescent biosensing platform is constructed to simultaneously detect multiplexed DNA depending on porous organic polymer (POP) nanospheres. The developed sensor is based on the concept that the POP nanospheres can efficiently quench the fluorescence emission of dye-labeled single-stranded DNA (ssDNA). Fluorescence quenching is achieved by the non-covalent assembly of multiple probes on the surface of POP nanospheres through electrostatic attraction and π-π stacking interactions, in which the electrostatic attraction plays a more critical role than π-π stacking. The formed dsDNA could be released off the surface of POP via hybridizing with the target DNA. Consequently, the target DNA can be quickly detected by fluorescence recovery. The biosensor could sensitively and specifically identify three target DNAs in the range of 0.1 to 36 nM, and the lowest detection limits are 50 pM, 100 pM, and 50 pM, respectively. It is noteworthy that the proposed platform is successfully applied to detect DNA in human serum. We perceive that the proposed sensing system represents a simple and sensitive strategy towards simultaneous and multiplexed assays for DNA monitoring and early clinical diagnosis.

Blue-Phosphorescent Pt(II) Complexes of Tetradentate Pyridyl-Carbolinyl Ligands: Synthesis, Structure, Photophysics, and Electroluminescence.

Blue phosphorescent tetradentate pyridyl-carbolinyl Pt(II) complexes, Pt(ppzOclpy-Me), Pt(ppzOclpy-iPr), and Pt(ppzOclpy-mesi), were purposefully synthesized and investigated with their photophysical and luminescent properties. The complexes, incorporating with carbolinyl moieties, have twisted planar structure. X-ray crystallography revealed that the intraligand N···H-C hydrogen bond reversely turned the twisty pyridyl moiety back into the chelating plane. Computational analyses confirmed that the metal-to-ligand charge-transfer transition character appears in the singlet manifolds. However, the ligand-centered transitions rule in their triplet states, which accounts for the phosphorescent emission. The Pt(II) complexes emit blue light with peak wavelengths (λmax) of 461-481 nm and moderate photoluminescent quantum yields (Φ = 34-46% in dichloromethane and Φ = 44-52% in films). The electroluminescent devices were fabricated by solution processes, giving blue emissions peaking at around 470 nm.

Three metal-organic framework isomers of different pore sizes for selective CO2 adsorption and isomerization studies.

Metal-organic frameworks (MOFs) or porous coordination polymers (PCPs) with tunable pore sizes, shapes and functionalities have excellent prospects in many applications, such as carbon capture. Molecular sieving can usually enable very high CO2 adsorption selectivity but has rarely been achieved, because it is difficult to precisely control the pore size in the range of 3-4 Å. We report here three MOF isomers built from CdII, terephthalic acid and 3,6-di(pyridin-4-yl)-1,2,4,5-tetrazine with the same stoichiometric ratio, among which 1 and 2 are framework-catenation isomers and 2 and 3 are framework-topological isomers. 1 contains 2-fold interpenetrated networks (topology of pcu) and 1D ultra-micropores and shows highly selective adsorption of CO2 over N2 and CH4, which is mainly ascribed to the molecular sieving effect of the framework. 2 contains a pcu network with 3D interconnected micropores, and 3 contains a kag network with much larger pores of 15 Å. Framework isomerization, in this case, was shown to be a feasible way of tuning the pore size of a MOF for selective CO2 adsorption. The effects of hydrothermal reaction conditions and additives on the structures and the formation of the MOF isomers were also studied.

Tetrazole-based porous metal-organic frameworks for selective CO2 adsorption and isomerization studies.

Tetrazole-based molecules have numerous bridging coordination modes which afford great synthetic possibilities for the preparation of porous metal-tetrazolate architectures for many applications, such as carbon capture. We reported here three tetrazole-based MOFs: 1, {[Cu12(ttz)8/3Cl5(H2O)16]11+·11Cl-}n (H3ttz = N2,N4,N6-tris(4-(1H-tetrazol-5-yl)phenyl)-1,3,5-triazine-2,4,6-triamine), contains highly positively charged Cu12 clusters and the largest mesopores (32 Å) among the reported MOFs based on a tri-topic tetrazole ligand. 2 and 3 are two MOF isomers built by using CuII and 2-(1H-tetrazol-5-yl)pyrimidine. 3 contains nonporous layers, while 2 contains 1D channels and showed high selectivity for adsorbing CO2, which should be attributed to the high density of free nucleophilic tetrazole N atoms on the pore surfaces. We found that the isomerization between 2 and 3 was caused by the diverse coordination modes of tetrazole-based ligands and can be controlled in synthesis processes.

Direct observation of supramolecular binding of light hydrocarbons in vanadium(iii) and (iv) metal-organic framework materials.

Fine tuning of host-guest supramolecular interactions in porous systems enables direct control over the properties of functional materials. We report here a modification of hydrogen bonding and its effect on guest binding in a pair of redox-active metal-organic frameworks (MOFs). Oxidation of MFM-300(VIII) {[VIII2(OH)2(L)], LH4 = biphenyl-3,3',5,5'-tetracarboxylic acid} is accompanied by deprotonation of the bridging hydroxyl groups to afford isostructural MFM-300(VIV), [VIV2O2(L)]. The precise role of the hydroxyl groups, O-carboxylate centres and π-π interactions in the supramolecular binding of C2 hydrocarbons in these materials has been determined using neutron diffraction and inelastic neutron scattering, coupled with DFT modelling. The hydroxyl protons are observed to bind to adsorbed unsaturated hydrocarbons preferentially in MFM-300(VIII), particularly to C2H2, which is in a sharp contrast to MFM-300(VIV) where interactions with O-carboxylate centres and π-π interactions predominate. This variation in structure and redox leads to notably higher separation selectivity for C2H2/CH4 and C2H4/CH4 in MFM-300(VIII) than in MFM-300(VIV). Significantly, owing to the specific host-guest interactions, MFM-300(VIII) shows a record packing density for adsorbed C2H2 at 303 K and 1 bar, demonstrating its potential for use in portable acetylene stores.

Stepwise observation and quantification and mixed matrix membrane separation of CO2 within a hydroxy-decorated porous host.

The identification of preferred binding domains within a host structure provides important insights into the function of materials. State-of-the-art reports mostly focus on crystallographic studies of empty and single component guest-loaded host structures to determine the location of guests. However, measurements of material properties (e.g., adsorption and breakthrough of substrates) are usually performed for a wide range of pressure (guest coverage) and/or using multi-component gas mixtures. Here we report the development of a multifunctional gas dosing system for use in X-ray powder diffraction studies on Beamline I11 at Diamond Light Source. This facility is fully automated and enables in situ crystallographic studies of host structures under (i) unlimited target gas loadings and (ii) loading of multi-component gas mixtures. A proof-of-concept study was conducted on a hydroxyl-decorated porous material MFM-300(VIII) under (i) five different CO2 pressures covering the isotherm range and (ii) the loading of equimolar mixtures of CO2/N2. The study has successfully captured the structural dynamics underpinning CO2 uptake as a function of surface coverage. Moreover, MFM-300(VIII) was incorporated in a mixed matrix membrane (MMM) with PIM-1 in order to evaluate the CO2/N2 separation potential of this material. Gas permeation measurements on the MMM show a great improvement over the bare PIM-1 polymer for CO2/N2 separation based on the ideal selectivity.

Modulating supramolecular binding of carbon dioxide in a redox-active porous metal-organic framework.

Hydrogen bonds dominate many chemical and biological processes, and chemical modification enables control and modulation of host-guest systems. Here we report a targeted modification of hydrogen bonding and its effect on guest binding in redox-active materials. MFM-300(VIII) {[VIII2(OH)2(L)], LH4=biphenyl-3,3',5,5'-tetracarboxylic acid} can be oxidized to isostructural MFM-300(VIV), [VIV2O2(L)], in which deprotonation of the bridging hydroxyl groups occurs. MFM-300(VIII) shows the second highest CO2 uptake capacity in metal-organic framework materials at 298 K and 1 bar (6.0 mmol g-1) and involves hydrogen bonding between the OH group of the host and the O-donor of CO2, which binds in an end-on manner, =1.863(1) Å. In contrast, CO2-loaded MFM-300(VIV) shows CO2 bound side-on to the oxy group and sandwiched between two phenyl groups involving a unique ···c.g.phenyl interaction [3.069(2), 3.146(3) Å]. The macroscopic packing of CO2 in the pores is directly influenced by these primary binding sites.

[Effect of drug-spreading moxibustion for primary dysmenorrheal with cold-damp stagnation and its uterine artery blood flow].

OBJECTIVE: To observe the effect difference between drug-spreading moxibustion and the oral administration of meloxicam for primary dysmenorrheal with cold stagnation and to explore its mechanism. METHODS: A total of 101 patients with primary dysmenorrheal were randomly assigned into a drug-moxibustion group(52 cases) and a western medication group(49 cases). Drug-spreading moxibustion was used on the lumbosacral acupoints area and then around lower abdominal five days before menstruation until the 3rd day of menstruation,once three days,while western medicine meloxicam was prescribed one day before menstruation,7.5 mg at a time,once a day and continuously for three days. The clinical effects after one course,namely three menstrual cycles,were compared between the two groups. Meanwhile,the resistance index(RI) and the pulsatility index (PI) of uterine artery and arcus arteriarum were examined through color Doppler ultrasound before and after treatment. RESULTS: After one-course treatment,the effective rate was 92.3%(48/52) in the drug-spreading moxibustion group,which was better than 67.3%(33/49) in the western medication group(P<0.05). Also,all the RI and PI in the drug-spreading moxibustion group were obviously decreased than those before treatment(all P<0.05),and the ones were superior to those of the western medication group(all P<0.05),which showed no apparent decrease after treatment(all P>0.05). CONCLUSIONS: Drug-spreading moxibustion can improve the symptoms of primary dysmenorrheal with cold-damp stagnation,and the effect is better than that of meloxicam. The mechanism may be related to improve the blood supply to the uterus.