Stem Cell-Derived Exosomes: A New Method for Reversing Skin Aging.

Senescence is an inevitable natural life process that involves structural and functional degeneration of tissues and organs. Recently, the process of skin aging has attracted much attention. Determining a means to delay or even reverse skin aging has become a research hotspot in medical cosmetology and anti-aging. Dysfunction in the epidermis and fibroblasts and changes in the composition and content of the extracellular matrix are common pathophysiological manifestations of skin aging. Reactive oxygen species and matrix metalloproteinases play essential roles in this process. Stem cells are pluripotent cells that possess self-replication abilities and can differentiate into multiple functional cells under certain conditions. These cells also possess a strong ability to facilitate tissue repair and regeneration. Stem cell transplantation has the potential for application in anti-aging therapy. Increasing studies have demonstrated that stem cells perform functions through paracrine processes, particularly those involving exosomes. Exosomes are nano-vesicular substances secreted by stem cells that participate in cell-to-cell communication by transporting their contents into target cells. In this chapter, the biological characteristics of exosomes were reviewed, including their effects on extracellular matrix formation, epidermal cell function, fibroblast function and antioxidation. Exosomes derived from stem cells may provide a new means to reverse skin aging.

A Semiconductive Nature of Bis(dithiolato)nickelate Radical Salt Exhibiting Broadband Photoconduction.

The fractional oxidation state [M(dmit)2] (dmit2- = 2-thioxo-1, 3-dithiole-4, 5-dithiolate) salts have long attracted attention in the molecular metal area owing to high conductivity and even superconductivity. In this study, we achieved a mixed-valence salt (1) of [Ni(dmit)2]0.5- with monovalent 1,3-N,N-dimethyl-imidazolium (DiMIm+) by a solvent evaporation approach under ambient conditions. The mixed valence of [Ni(dmit)2]0.5- has been characterized by an analysis of the IR spectrum and crystal structure. In the crystal structure of 1, two [Ni(dmit)2]0.5- anions overlap in an eclipsed mode to form a [Ni(dmit)2]21- dimer, featuring a radical bearing an S = 1/2 spin; the dimeric radicals stack into a column along the b axis, and the adjacent columns connect together via the lateral-to-lateral S···S contacts along the a axis, and through the head-to-head S···S contacts along the [101] direction. Salt 1 shows the magnetic behavior of an S = 1/2 Heisenberg antiferromagnetic uniform linear chain with J/kB = -47.5(4) K and a semiconducting feature with σ = 2.52 × 10-3 S cm-1 at 293 K, 2.32 × 10-2 S cm-1 at 373 K, and Ea = 0.22 eV, as well as broadband photoconductivity under irradiation of green and white lights. This study suggests the possibility of designing new photoconductors based on the mixed-valence [Ni(dmit)2]0.5- salt.

A 3D open-framework iron hydrogenophosphate showing high proton conductance under water and aqua-ammonia vapor.

Herein we report the first example of the proton conductivity of an open-framework metal phosphate (NH3(CH2)3NH3)2-[Fe4(OH)3(HPO4)2(PO4)3]·4H2O under aqua-ammonia vapor. Its optimized proton conductivity is 5 × 10-2 S cm-1 at 313 K and aqua-ammonium vapor from 1 M NH3·H2O solution. That is approximately two orders of magnitude greater than the maximum value under water vapor (8.0 × 10-4 S cm-1 at 317 K and 99% RH). The proton transfer mechanism has been proposed in terms of the structural analyses, activation energy calculations, and PXRD determinations.

A CsCl-type inorganic cluster-based high-symmetry crystal built from {Mo4.55V7.45PO40}10.45- with a high ratio of vanadium to molybdenum and {(H2O)0.3@K6(H2O)12}6+ clusters exhibiting proton conduction below the freezing point of water.

As a class of anionic oxoclusters of early transition metals in their highest oxidation states, polyoxometalates (POMs) show considerable structural versatility and unique chemical and physical properties, making them promising multifunctional materials. In this study, a Keggin-type POM has been achieved, with a formula of [(H2O)0.3@K6(H2O)12]H4.45[PV7.45Mo4.55O40]·11H2O (1), and its microcrystals and nanocrystals have been obtained, respectively. This POM was characterized by elemental analysis for C, H and N, ICP-MS, TG, PXRD, SEM, X-band EPR and XPS techniques. Single crystal X-ray diffraction analysis demonstrated that 1 shows a rare extended structure with a high-connected three-dimensional (3D) all inorganic network of a Keggin-type POM, built from {Mo4.55V7.45PO40}10.45- polyoxoanions and {(H2O)0.3@K6(H2O)12}6+ clusters with CsCl-type crystal structure. In addition, to the best of our knowledge, 1 shows the highest ratio of vanadium to molybdenum among Keggin-type POMs reported thus far. Most interestingly, 1 exhibits intrinsic proton conduction below the freezing point of water, with a proton conductivity of 6.90 × 10-7 S cm-1 at 249 K and further reaching 3.36 × 10-6 S cm-1 at 272 K and Ea = 0.44 eV at 249-272 K.

Comprehensively understanding the steric hindrance effect on the coordination sphere of Pb2+ ions and photophysical nature of two luminescent Pb(ii)-coordination polymers.

New luminescent Pb(ii)-coordination polymers (Pb(ii)-CPs), [Pb(2-anc)2]n (1) and [Pb(3-qlc)2(H2O)2]n (2) (2-anc = 2-aminonicotinate, 3-qlc = 3-quinolinecarboxylate), were synthesized by a solvothermal reaction and characterized using microanalysis, IR spectrometry and thermogravimetric analysis. Single crystal structure analysis revealed that the Pb2+ ion displays a hemi-directed coordination geometry in 1 and a holo-directed coordination geometry in 2. The difference between the coordination spheres of 1 and 2 is related to the steric hindrance effect of the ligands. A two-dimensional (2D) corrugated layer structure is formed in 1, and the neighboring layers are further extended into a three-dimensional (3D) van der Waals crystal by ππ interactions between the pyridyl rings in the neighboring layers. In contrast, a one-dimensional (1D) coordination polymeric chain is formed in 2, and the adjacent chains are connected in a 2D network by hydrogen bonds. The photophysical properties of 1 and 2 were studied at ambient conditions, disclosing that 1 emits phosphorescence at 548 nm with a millisecond-scale emission lifetime and an absolute quantum yield of 2.2%; 2 emits only blue fluorescence with an absolute quantum yield of 3.5% and nanosecond-scale emission lifetime. The reasons for the difference in the photophysical nature of 1 and 2 are discussed in regards to the electron band structure and density of states analysis.

Extra thermo- and water-stable one-dimensional organic-inorganic hybrid perovskite [N-methyldabconium]PbI3 showing switchable dielectric behaviour, conductivity and bright yellow-green emission.

Haloplumbate-based perovskites display promising functionalities for advanced photovoltaic, optoelectronic and other applications with high performances and low costs. Herein, we present a study of variable-temperature crystal structures, dielectrics and conductance at 153-513 K, and luminescence at ambient temperature for a one-dimensional organic-inorganic perovskite, [N-methyldabconium]PbI3 (1). Hybrid 1 shows extra thermo- and water-stability (thermal decomposition at ca. 653 K), switchable dielectric behaviour and conductance at around 348 K, owing to symmetry-breaking structure phase transition from the hexagonal space group P63/mmc in the high-temperature phase to the orthogonal space group Pcba in the low-temperature phase, and bright yellow-green emission at room temperature, originating from the electron transition within the semiconducting {PbI3}∞ chains. This study will broaden the scope of lead halide-based hybrid materials for practical application in optical and electrical devices.

Fluorite-type coordination compound as iodide ion conductor: crystal structure and ionic conductivity.

The solid state electrolytes show a wide range of practical applications in a variety of all-solid-state electrochemical devices, and it is highly in demand to explore new types of solid state electrolyte materials. In this study, we have designed and prepared a fluorite-type coordination compound, [Mn(en)3]I2, which has been characterized by microanalysis for C, H and N elements, infrared spectrum in the wavenumber range of 4000-400 cm-1, thermogravimetric analysis and differential scanning calorimetry. The single crystal X-ray diffraction revealed that the bigger size [Mn(en)3]2+ cations build three-dimensional network in the crystal of [Mn(en)3]I2 and the smaller size iodide ions occupy the tetrahedral or octahedral cavities surrounded by the [Mn(en)3]2+ cations, featuring as the fluorite-type compound. The impedance spectra were investigated to reveal the ionic conductivity σ = 3.45 × 10-11 S cm-1 at 303 K, while σ = 1.37 × 10-6 S cm-1 at 423 K, sharply increasing by five orders of magnitude regarding to that at 303 K. The electric modulus analysis further confirmed the conductance contributed from the migration of iodide ions. This study opens a way to design and achieve new coordination compound-based ion conductors.

Phase Transition, Dielectrics, Single-Ion Conductance, and Thermochromic Luminescence of a Inorganic-Organic Hybrid of [Triethylpropylammonium][PbI3].

In this study, we used the facile solvent evaporation method to achieve the inorganic-organic hybrid crystals of [triethylpropylammonium][PbI3], which have been characterized by elemental analysis, IR spectroscopy, thermogravimetric analysis, and differential scanning calorimetry as well as single-crystal X-ray structure analysis. The hybrid solid crystallizes in the monoclinic space group P21/c at room temperature and is composed of one-dimensional [PbI3]∞ chains, where the neighboring PbI6 coordination octahedra connect together via the face-sharing mode and the organic cations fall in the spaces between [PbI3]∞ chains. The hybrid exhibits a dielectric phase transition with a critical temperature of ca. 432 K, dielectric relaxation at frequencies below 107 Hz, and single-ion conducting behavior, the conductivity of which increases rapidly from 9.43 × 10-10 S cm-1 at 383 K to 4.47 × 10-5 S cm-1 at 473 K. The variable-temperature single-crystal and powder X-ray diffraction analyses revealed that the dielectric phase transition is related to the disorder-to-order transformation of cations in the lattice. The electric modulus and impedance spectral analyses further disclosed that the dielectric relaxation arises from the ionic displacement polarization and molecular dipole orientation of cations. The single-ion conductance is due to the migration of cations that fall in the spaces of rigid inorganic [PbI3]∞ chains. The phase transition gives rise to this hybrid showing switchable ion-conducting nature around the critical temperature of the phase transition. Besides the fascinating functionalities mentioned above, the hybrid also exhibits a thermochromic luminescence feature originating from the electron transition between the valence and conduction bands of the inorganic [PbI3]∞ chain.

UVA1 vs. narrowband UVB phototherapy in the treatment of palmoplantar pustulosis: a pilot randomized controlled study.

UVA1 phototherapy, a new therapeutic approach, has recently been shown good efficacy in the treatment of palmoplantar pustulosis (PPP). The purpose of this study was to compare the efficacy of UVA1 and narrowband UVB (NB-UVB) therapy in the treatment of PPP. Patients with PPP were randomly assigned to either UVA1 or NB-UVB therapy according to a left-right randomization table. Both treatments were performed three times weekly for up to 30 sessions. Clinical evaluation was based on the Palmoplantar Pustular Psoriasis Area and Severity Index (PPPASI) score. Totally 64 patients completed the study. Both UVA1 and NB-UVB therapy showed a statistically significant reduction of PPPASI score compared with the baseline value at the end of the treatment period (P < 0.05). There was a significantly greater mean reduction of PPPASI score in the UVA1 treated group when compared to the NB-UVB treated patients at 30 sessions (6.0 ± 2.4 vs. 4.4 ± 1.4, P < 0.05). No phototoxic reaction or bullous changes were observed in either group. Both NB-UVB and UVA1 phototherapy of PPP resulted in significant improvement. UVA1 phototherapy was more effective than NB-UVB irradiation in the treatment of PPP.

Water assisted high proton conductance in a highly thermally stable and superior water-stable open-framework cobalt phosphate.

Proton-conducting materials show important technological applications as key components in energy conversion, electrochemical sensing and electrochromic devices; the exploration for new types of proton-conducting materials is crucial for the development of efficient electrochemical devices. In this study, we investigated the proton transport nature of an inorganic-organic hybrid crystal of open-framework cobalt phosphate, (C2N2H10)0.5CoPO4. The structure of the hybrid crystal consists of the [CoPO4]-∞ anionic framework, and the proton carriers, H2en2+ cations (en = ethylenediamine), are located in the pores to compensate the negative charges of the inorganic framework. The open-framework is thermally stable up to 653 K (380 °C) at least, and also shows superior water stability. The open-framework exhibits negligible conductance in an anhydrous environment even at 473 K; however, there is evident water-assisted proton conduction. The conductivity reaches 2.05 × 10-3 S cm-1 at 329 K and 98% RH. Such high proton conductivity can compete with numerous state-of-the-art MOFs/PCPs-based proton conductors, and this material has promising applications in diverse electrochemical devices.

Insight into Understanding Dielectric Behavior of a Zn-MOF Using Variable-Temperature Crystal Structures, Electrical Conductance, and Solid-State 13C NMR Spectra.

A Zn-based metal-organic framework (MOF)/porous coordination polymer (PCP), (EMIM)[Zn(SIP)] (1) (SIP3- = 5-sulfoisophthalate, EMIM+ = 1-ethyl-3-methylimidazolium), was synthesized using the ionothermal reaction. The Zn2+ ion adopts distorted square pyramid coordination geometry with five oxygen atoms from three carboxylates and one sulfo group. One of two carboxylates in SIP3- serves as a µ2-bridge ligand to link two Zn2+ ions and form the dinuclear SBU, and such SBUs are connected by SIP3- ligands to build the three-dimensional framework with rutile (rtl) topology. The cations from the ion-liquid fill the channels. This MOF/PCP shows two-step dielectric anomalies together with two-step dielectric relaxations; the variable-temperature single-crystal structure analyses disclosed the dielectric anomaly occurring at ca. 280 K is caused by an isostructural phase transition. Another dielectric anomaly is related to the dynamic disorder of the cations in the channels. Electric modulus, conductance, and variable-temperature solid-state 13C CP/MAS NMR spectra analyses revealed that two-step dielectric relaxations result from the dynamic motion of the cations as well as the direct-current conduction and electrode effect, respectively.

Robust Crystalline Hybrid Solid with Multiple Channels Showing High Anhydrous Proton Conductivity and a Wide Performance Temperature Range.

A proton conductor displaying high anhydrous proton conductivity (≈10(-2) S cm(-1)) and good performance over a broad temperature range is presented. This hybrid material is produced via doping HCl into open-framework chalcogenide(C2N2H10)(C2N2H9)2 Cu8 Sn3S12, and has cubopolyhedral cavities and multiple channels.

An amphidynamic inorganic-organic hybrid crystal of bromoplumbate with 1,5-bis(1-methylimidazolium)pentane exhibiting multi-functionality of a dielectric anomaly and temperature-dependent dual band emissions.

Organic-inorganic hybrid crystals, [1,5-bis(1-methylimidazolium)pentane][PbBr3]2 (1), were achieved through the mutual diffusion of a bi-imidazolium based ionic liquid and PbBr2 solution of DMF in a glass tube. The hybrid solid crystallizes in the orthorhombic space group Fdd2 at room temperature; and is composed of one-dimensional [PbBr3]∞ chains where the neighbouring PbBr6 coordination octahedra are linked together via the face-sharing mode and the inorganic chains are surrounded by organic cations. The hybrid solid exhibits a dielectric anomaly around 443 K and dielectric relaxation above 400 K, the dielectric response mechanism was investigated using variable-temperature X-ray single crystal and powder diffraction as well as DSC techniques. Fascinatingly, this hybrid solid shows dual band emissions, moreover, the fluorescence nature of the two emission bands exhibits a distinct response to temperature, leading to a temperature-dependent fluorescence color, this feature has promising application in the emission temperature-sensing field.

Investigation of the structure and ionic conductivity of intercalated kaolinites with potassium acetate in hydrous and anhydrous phases.

The intercalated kaolinite with potassium acetate (K-KAc), with ca. 91.9% intercalation ratio, was prepared. Thermogravimetric and variable-temperature X-ray powder diffraction analyses disclosed that a small amount of water is easily absorbed into the interlayer space of the K-KAc. The previously reported phase with the 14.2 Å interlayer distance is actually the hydrous K-KAc, which has an approximate formula of Al2Si2O5(OH)4·0.5KAc·0.25H2O. The crystal structures of hydrous and anhydrous phases of K-KAc were simulated in the density functional theory framework, demonstrating that the interactions between the K(+) and acetate ions and the inner surface of kaolinite are significantly strengthened in the anhydrous phase with regard to the hydrous phase. The ionic conductivity of K-KAc indicated that the mobility of the interlayer ions is strongly improved by thermal activation and the conductivity increased by four orders of magnitude from 363 to 423 K.

Precisely tunable magnetic phase transition temperature, TC, through the formation of a molecular alloy in [NixPt1-x(mnt)2](-)-based spin systems (mnt(2-) = maleonitriledithiolate, x = 0.09-0.91).

Nine molecular substitutional alloys with formula [Cl-BzPy][NixPt1-x(mnt)2] (x = 0.09-0.91) were prepared by mixing the isostructural [Cl-BzPy][Ni(mnt)2] and [Cl-BzPy][Pt(mnt)2] in acetonitrile according to the molar ratio of x/(1 - x), where mnt(2-) = maleonitriledithiolate, Cl-BzPy(+) = 1-(4'-chloro-benzyl)pyridinium. Each alloy compound is isostructural with the parent compounds and shows a magnetic transition; the TC decreases linearly with the molar fraction x, indicating that TC is precisely tunable in this alloy system.

Observation of hysteretic magnetic phase transitions coupled with orientation motion of ions and dielectric relaxation in a one-dimensional nickel-bis-dithiolene molecule solid.

The second polymorph, the ß-crystal, of the nickel-bis-dithiolene compound [4'-CF3bzPy][Ni(mnt)2], where 4'-CF3bzPy = 1-(4'-trifluoromethylbenzyl)pyridinium and mnt(2-) = maleonitriledithiolate, was obtained. The variable-temperature single crystal structures, magnetic behavior in 1.8-300 K and dielectric nature in 123-373 K have been investigated for the ß-crystal. This polymorph experiences two hysteretic magnetic phase transitions in a narrow temperature region (190-217 K) with the thermal hysteresis loops ca. 6 K and ca. 11 K. The two hysteretic magnetic phase transitions are coupled with two isostructural phase transitions (IPTs), respectively, which are driven by the novel step-wise dynamic orientation motion of the anion and cation in the ß-crystal. There is an absence of a dielectric anomaly in the structural transformation temperature interval. However, a dielectric relaxation, related to the dipole motion of polar CF3 groups in the cations under an ac electrical field, emerges in the high-temperature phase.

Intercalated supramolecular compounds of kaolinite with ethanolamine and ethylene glycol: structures and dielectric properties.

Kaolinite (K), a polar and layered aluminosilicate mineral, was used as the host; ethanolamine (EOA) and ethylene glycol (EG) were inserted into the kaolinite interlayer to give the intercalated supramolecular compounds kaolinite-ethanolamine (K-EOA) and kaolinite-ethylene glycol (K-EG), respectively. The intercalation of EOA and EG resulted in an increase in the d(001)-value by 3.4 and 3.68 Å, which corresponds to expansion of the interlayer space by 156.7 Å(3) in K-EOA and 169.6 Å(3) in K-EG, respectively. The characteristic infrared-active ν(O-H) modes ν1, ν2 and ν3 besides ν5, which were quite sensitive to the host-guest interaction, were not significantly affected by intercalation in K-EOA and K-EG, and two intercalated compounds showed lower deintercalation temperature (115 and 109 °C for K-EOA and K-EG, respectively). These are due to weakly intermolecular interactions between the intercalant molecules and the kaolinite framework, which is in agreement with the theoretical analysis of crystal structures of the intercalated compounds. K-EOA and K-EG showed novel dielectric relaxation behavior, which originates from the dynamic orientation motion of intercalant molecules.

Two segregated columnar stack platinum-bis-dithiolene molecule solids showing spin-Peierls-type transition above room temperature.

Two new one-dimensional (1-D) compounds, [CH3-BzPy][Pt(mnt)2] (1) and [CH3-BzPy-d5][Pt(mnt)2] (2) (CH3-BzPy(+) = 1-N-(4-CH3-benzyl)pyridinium and the pyridine in CH3-BzPy(+) was replaced by pyridine-d5 to give the CH3-BzPy-d5(+); mnt(2-) = maleonitriledithiolate), were synthesized and characterized. 1 and 2 show similar magnetic behavior in 1.8-400 K; they experience a spin-Peierls-type transition around 320 K and show a uniform antiferromagnetic S = 1/2 chain behavior in high temperature (HT) phase, a spin gap feature in low temperature (LT) phase. A symmetry breaking structural phase transition is associated with the spin-Peierls-type transition. Two isostructural compounds crystallize in space group P2(1)/c in HT phase, with a = 12.3066(8) Å, b = 27.0522(18) Å, c = 7.4248(4) Å, ß = 104.204(6)° and V = 2396.3(3) Å(3) for 1 versus a = 12.3331(9) Å, b = 27.087(4) Å, c = 7.4501(9) Å, ß = 104.149(13)° and V = 2413.3(6) Å(3) for 2 at 353 K, while space group P1[combining macron] in LT phase, with a = 7.3203(10) Å, b = 12.2816(16) Å, c = 26.904(4) Å, α = 88.500(4)°, ß = 86.731(4)°, γ = 75.421(4)° and V = 2337.0(5) Å(3) for 1 versus a = 7.3308(8) Å, b = 12.2848(13) Å, c = 26.930(3) Å, α = 88.479(3)°, ß = 86.652(4)°, γ = 75.563(3)° and V = 2344.5(4) Å(3) for 2 at 296 K. DSC measurements revealed 1 and 2 showing almost the same T(C). This observation is distinction from the [Ni(mnt)2](-)-based spin-Peierls-type analogues [CH3-BzPy][Ni(mnt)2] and [CH3-BzPy-d5][Ni(mnt)2] where the deuteration leads to T(C) up shifting 2.3 K.

Bis(1-ethyl-4,4'-bipyridin-1-ium) bis-(1,2-di-cyano-ethene-1,2-di-thiol-ato-κ(2) S,S')nickelate(II).

In the anion of the title compound, (C12H13N2)[Ni(C4N2S2)2], the Ni(II) atom is coordinated by four S atoms from two 1,2-di-cyano-ethene-1,2-di-thiol-ate (mnt) ligands in a suqare-planar geometry. Weak C-H⋯N and C-H⋯S hydrogen bonds between the 1-ethyl-4,4'-bipyridin-1-ium cations and mnt anions and weak π-π inter-actions between the pyridine rings of the cations [centroid-centroid distances = 3.808 (3) and 3.972 (3) Å] lead to a two-dimensional network parallel to (010).

The association between a single nucleotide polymorphism rs11966200 in MHC region and clinical features of generalized vitiligo in Chinese Han population.

Vitiligo is an acquired pigmentary disorder characterized by loss of epidermal melanocytes. A strong association at a single nucleotide polymorphism (SNP) rs11966200 within MHC region had been identified in a recent genome-wide association study of generalized vitiligo in Chinese Han population. This study aims to investigate the relationships between SNP rs11966200 and the clinical features of generalized vitiligo in Chinese Han population. We compared the allele and genotype frequency among different vitiligo subphenotypes including age onset, extent of disease, clinical subtypes, family history of vitiligo and history of autoimmune disease. Our data showed SNP rs11966200 was associated with early-onset vitiligo (onset age ≤ 20 years) (odds ratio [OR], 1.54; p = 2.01 × 10(-13)), moderate-severe vitiligo (involved body surface ≥ 5 %) (OR, 1.17; p = 0.025), vitiligo vulgaris (OR, 1.13; p = 0.043), and focal vitiligo (OR, 0.86; p = 0.018). The study suggested that the underlying risk causal allele tagged by SNP rs11966200 might not only play important roles in the development of vitiligo, but also contribute to the diverse clinical characteristics of generalized vitiligo at least in Chinese Han population.