Enhanced Co-adsorption of Alcohols and Amines for Visible Light Driven Oxidative Condensation Using Iron-based MOF.

Imines are essential intermediates in organic transformations, and is generally produced by dehydrogenative condensation of alcohols and amines with the assist of specialized catalysts and additives. Heterogeneous photocatalysis provides a sustainable platform for such process without the using of toxic oxidants, yet a functionalized photocatalyst with optimized co-adsorption of reactants needs to be developed to promote the stoichiometric oxidative condensation under ambient conditions. Here, we show that benzyl alcohol and aniline adsorb non-interferingly on the Fe node and the linker sites of the MIL-53(Fe) metal organic frameworks (MOFs), respectively. The co-adsorption of both reactants barely influences the reduction of molecular oxygen to generate oxygen radicals, resulting in efficient formation of benzaldehyde under visible light. Additionally, the weak adsorption of water together with surface acidity of the MIL-53(Fe) promote a rapid condensation of benzaldehyde with aniline and the depletion of generated water, achieving an efficient C-N bond creation for a wide range of substrates.

Genetic Contributions to Attachment Stability Over Time: the Roles of CRHR1 Polymorphisms.

Corticotropin-releasing hormone receptor 1 (CRHR1), a hormone receptor essential to the activation of HPA axis and the subsequent release of cortisol, plays critical roles in emotional and behavioral responses relevant to attachment. However, the specific roles of CRHR1 polymorphisms in attachment remain unclear. To further clarify these genetic effects, this research conducted a three-wave study to investigate whether the CRHR1 polymorphisms (i.e., rs110402 and rs242924) are associated with the stability and variability of attachment by using a sample of freshmen (N = 604; Mage = 18.57 years, SD = 1.90; 68.8% girls). The results showed that rs110402 and rs242924 were associated with the stability of closeness-dependence. The G alleles of the both polymorphisms were found not to be related to lower attachment stability. However, these polymorphisms were not associated with the variability of attachment. Overall, these findings provide evidence for the contribution of CRHR1 to attachment stability.

Over 19 % Efficiency Organic Solar Cells Enabled by Manipulating the Intermolecular Interactions through Side Chain Fluorine Functionalization.

Fluorine side chain functionalization of non-fullerene acceptors (NFAs) represents an effective strategy for enhancing the performance of organic solar cells (OSCs). However, a knowledge gap persists regarding the relationship between structural changes induced by fluorine functionalization and the resultant impact on device performance. In this work, varying amounts of fluorine atoms were introduced into the outer side chains of Y-series NFAs to construct two acceptors named BTP-F0 and BTP-F5. Theoretical and experimental investigations reveal that side-chain fluorination significantly increase the overall average electrostatic potential (ESP) and charge balance factor, thereby effectively improving the ESP-induced intermolecular electrostatic interaction, and thus precisely tuning the molecular packing and bulk-heterojunction morphology. Therefore, the BTP-F5-based OSC exhibited enhanced crystallinity, domain purity, reduced domain spacing, and optimized phase distribution in the vertical direction. This facilitates exciton diffusion, suppresses charge recombination, and improves charge extraction. Consequently, the promising power conversion efficiency (PCE) of 17.3 % and 19.2 % were achieved in BTP-F5-based binary and ternary devices, respectively, surpassing the PCE of 16.1 % for BTP-F0-based OSCs. This work establishes a structure-performance relationship and demonstrates that fluorine functionalization of the outer side chains of Y-series NFAs is a compelling strategy for achieving ideal phase separation for highly efficient OSCs.

Amygdala signal abnormality and cognitive impairment in drug-naïve schizophrenia.

BACKGROUND: Recently studies had showed that the amygdala may take part in the cognitive impairment in schizophrenia (SC). However, the mechanism is still unclear, so we explored the relationship between the amygdala resting state magnetic resonance imaging (rsMRI) signal and cognitive function, to provide a reference for the follow-up study. METHODS: We collected 59 drug-naïve SCs and 46 healthy controls (HCs) from the Third People's Hospital of Foshan. The rsMRI technique and automatic segmentation tool were used to extract the volume and functional indicators of the SC's amygdala. The Positive and Negative Syndrome Scale (PANSS) was used to assess the severity of the disease, and the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) was used to assess cognitive function. Pearson correlation analysis was used to compare the relationship between the structural and functional indicators of the amygdala and PANSS and RBANS. RESULTS: (1) There was no significant difference between SC and HC in age, gender and years of education. Compared with HC, the PANSS score of SC increased and the RBANS score decreased significantly. Meanwhile, the left amygdala volume decreased (t=-3.675, p < 0.001), and the Fractional amplitude of low-frequency fluctuations (FALFF) values of bilateral amygdala increased (tL=3.916, p < 0.001; tR=3.131, p = 0.002). (2) The volumes of the left amygdala were negatively correlated with the PANSS score (rL=-0.243, p = 0.039). While the FALFF values of the bilateral amygdala were positively correlated with the PANSS score (rL=0.257, p = 0.026; rR=0.259, p = 0.026). Bilateral amygdala volumes and FALFF values were positively correlated (rL=0.445, p < 0.001; rR=0.326, p = 0.006) and negatively correlated with RBANS score (rL=-0.284, p = 0.014; rR=-0.272, p = 0.020), respectively. CONCLUSION: The abnormal volume and function of the amygdala play important roles in the disease process of SC, and are closely related to cognitive impairment.

Optimizing Photochirogenic Performance by Solvent-Driven Conformational Fixation in Enantiodifferentiating Photoisomerization of (Z)-Cyclooctene Mediated by Sensitizing ß-Cyclodextrin Hosts.

Catalytic enantiodifferentiating photoisomerization of cyclooctene (1Z) included and sensitized by regioisomeric 6-O-(o-, m-, and p-methoxybenzoyl)-ß-cyclodextrins (CDs) was performed under a variety of solvent conditions for higher enantioselectivities. The enantiomeric excess (ee) of chiral (E)-isomer (1E) produced was a critical function of all the internal and external factors examined, in particular, the sensitizer structure and the solvent conditions, to afford (R)-1E in record-high ee's of up to 67% upon sensitization with the meta-substituted ß-CD host in water and salt solutions but neither in 50% aqueous ethanol nor with the ortho- and para-substituted hosts. The mechanistic origin of the sudden ee enhancement achieved under the specific conditions is discussed on the basis of the circular dichroism spectral behaviors upon substrate inclusion and the compensatory enthalpy-entropy relationship of the activation parameters for the enantiodifferentiating photoisomerization.

A benzimidazole-based ratiometric fluorescent probe for the accurate and rapid monitoring of lysosomal pH in cell autophagy and anticounterfeiting.

The change in lysosomal pH is an important physiological indicator in the process of cell autophagy. Herein, a ratiometric fluorescent probe, 4-(2-(1H-benzo[d]imidazol-2-yl)vinyl)-N,N-dimethylaniline (BD), has been synthesized and applied for lysosomal pH detection and cell autophagy imaging. In this probe, the imidazole group and dimethylamino group possess excellent lysosomal targeting ability and the benzimidazole moiety acts as a proton reaction site. BD reveals an obvious ratiometric fluorescence emission with an ideal pKa value of 4.73 and a linear response in the range of 4.06-5.20, which is considered useful for the quantitative detection and imaging of lysosomal pH change. Meanwhile, BD exhibits a larger Stokes shift, good selectivity, strong photostability, good reversibility and good biocompatibility, which makes BD capable of being applied to complex biological environments. Ratiometric fluorescence imaging studies show that BD can selectively monitor the pH in the lysosomes of live cells, and even real-time dynamic monitoring of cell autophagy can be conducted. Moreover, BD also shows excellent application potential in the field of anticounterfeiting.

A selective electrochemical chiral interface based on a carboxymethyl-ß-cyclodextrin/Pd@Au nanoparticles/3D reduced graphene oxide nanocomposite for tyrosine enantiomer recognition.

Palladium@gold nanoparticle modified three-dimensional-reduced graphene oxide (3D-rGO/Pd@Au) was coupled with carboxymethyl-ß-cyclodextrin to form a novel nanocomposite (3D-rGO/Pd@Au/CM-ß-CD). The 3D-rGO/Pd@Au/CM-ß-CD served as a chiral sensing interface for the electrochemical enantiorecognition of tyrosine (Tyr) via a differential pulse voltammetry (DPV) approach. The 3D-rGO/Pd@Au demonstrates good electrical conductivity and efficient catalytic activity as an electrochemical indicator. Simultaneously, the CM-ß-CD displays a supramolecular chiral selectivity to reveal a higher binding affinity to the target L-tyrosine (L-Tyr) than to D-tyrosine (D-Tyr). Under the optimized determining conditions, the oxidation peak current ratio of L-Tyr to D-Tyr (IL/ID) was 2.12, meanwhile, the peak currents of the two isomers were linearly proportional to the concentration over the range of 0.8-130 µM with LODs of 52 nM and 96 nM for L- and D-Tyr (S/N = 3), respectively. This approach exhibits distinguished sensitivity, excellent selectivity and good reproducibility, as well as great stability, which can accurately determine the relative content of L- or D-Tyr enantiomers in a racemic solution.

Host-Guest Complexation-Induced Aggregation Based on Pyrene-Modified Cyclodextrins for Improved Electronic Circular Dichroism and Circularly Polarized Luminescence.

Several γ-cyclodextrin (CD) derivatives mono- or di-substituted by pyrenes at the primary rim of the CD were demonstrated to aggregate into nano-strips in aqueous solutions, with the pyrene moieties interpenetrating into γ-CD cavities. The hydrophobic complexation-induced aggregation provides a rigid chiral environment for the pyrenes and leads to significant electronic circular dichroism (ECD) and circularly polarized luminescence (CPL) activities, giving unprecedently high gabs and glum values up to 4.3×10-2 and 5.3×10-2 , respectively. The aggregates lead to excimer emission with high quantum yields and show BCPL and BiCPL up to 338. 6 M-1 cm-1 and 169.3 M-1 cm-1 , respectively.

Guest-Binding-Induced Interhetero Hosts Charge Transfer Crystallization: Selective Coloration of Commonly Used Organic Solvents.

Unprecedented interheteromacrocyclic hosts charge transfer (CT) crystals were generated by cooling organic solutions containing p-dimethoxybenzene-constituted pillar[5]arene (P5A) and p-benzoquinone-constituted pillar[5]quinone (P5Q). Despite the weak CT interaction known between p-dimethoxybenzene and p-benzoquinone and the lack of formation of CT complexes between P5A and P5Q in the solution phase, CT cocrystals between P5A and P5Q were formed with solvent molecules included into the hosts' cavities. Such a cocrystallization arises from an elegant synergy between the CT interaction and solvent-binding-promoted crystallization. The interhetero hosts CT crystals were studied by optical and electron microscopic techniques, X-ray powder diffraction, solid-state NMR, UV-vis, IR spectroscopic studies, and X-ray single-crystal studies. The solvent complexation was critical for formation of the supramolecular CT microcrystals. The CT absorption bands faded upon removing the solvent molecules under vacuum, but they could be recovered by reuptake of the solvent molecules. Intriguingly, the CT absorption bands and uptake kinetics are distinguishably different for various organic solvents, thus providing a unique way to distinguish between different commonly used chemicals.

Development of a piperazinyl-NBD-based fluorescent probe and its dual-channel detection for hydrogen sulfide.

To selectively detect H2S based on the thiolysis reaction of 7-nitro-1,2,3-benzoxadiazole (NBD), amines attracted increasing attention since NBD amine is regarded as a new H2S reaction site. Herein, a novel fluorescent probe, triphenylamine piperazine NBD (TPA-Pz-NBD), was developed. The results showed that it exhibited high selectivity towards H2S via fluorescence spectroscopy and solution color. Furthermore, TPA-Pz-NBD not only detected H2S by a dual-channel, turn-on fluorescence signal at 500 nm and turn-off fluorescence signal at 545 nm, respectively, but also displayed a wide detection range of 0-125 µM. In addition, living cell imaging results indicated that TPA-Pz-NBD holds potential for the detection of intracellular H2S.

A ratiometric and far-red fluorescence "off-on" sensor for sequential determination of copper(II) and L-histidine based on FRET system between N-acetyl-L-cysteine-capped AuNCs and N,S,P co-doped carbon dots.

A far-red fluorescence "off-on" sensing strategy is described for sequential ratiometric determination of Cu2+ and L-histidine (L-His) based on fluorescence resonance energy transfer (FRET) system. N,S,P co-doped carbon dots (N,S,P-CDs) and N-acetyl-L-cysteine functionalized gold nanoclusters (NAC-AuNCs) are used in the FRET system, which serve as energy donor and acceptor, respectively. After adding NAC-AuNCs into the solution of N,S,P-CDs, the fluorescence of N,S,P-CDs is effectively quenched, while the far-red fluorescence of NAC-AuNCs appears. Cu2+ can decrease fluorescence of NAC-AuNCs, and then L-His can effectively recover the fluorescence of NAC-AuNCs. The possible reason is that the stronger affinity between Cu2+ and L-His can pull Cu2+ away from the surface of NAC-AuNCs. Through it all, the emission intensity of N,S,P-CDs remains nearly constant, so the ratio of fluorescence intensities at 485 and 625 nm exhibits a linear correlation to the Cu2+ and L-His concentration, respectively. The sensing platform shows good selectivity towards Cu2+ and L-His with a linear range of 0.65-26.58 µM and 3.13-56.25 µM and determination limits of 0.50 µM and 0.374 µM, respectively. The proposed method has been successfully used for Cu2+ and L-His determination in real samples with satisfying results. Graphical abstract.

Redox-Triggered Chirality Switching and Guest-Capture/Release with a Pillar[6]arene-Based Molecular Universal Joint.

A chiral electrochemically responsive molecular universal joint (EMUJ) was synthesized by fusing a macrocyclic pillar[6]arene (P[6]) to a ferrocene-based side ring. A single crystal of an enantiopure EMUJ was successfully obtained, which allowed, for the first time, the definitive correlation between the absolute configuration and the circular dichroism spectrum of a P[6] derivative to be determined. The self-inclusion and self-exclusion conformational change of the EMUJ led to a chiroptical inversion of the P[6] moiety, which could be manipulated by both solvents and changes in temperature. The EMUJ also displayed a unique redox-triggered reversible in/out conformational switching, corresponding to an occupation/voidance switching of the P[6] cavity, respectively. This phenomenon is an unprecedented electrochemical manipulation of the capture and release of guest molecules by supramolecular hosts.

An Ultimate Stereocontrol in Supramolecular Photochirogenesis: Photocyclodimerization of 2-Anthracenecarboxylate Mediated by Sulfur-Linked ß-Cyclodextrin Dimers.

Stereoisomeric ß-cyclodextrin (CD) dimers linked with a sulfur atom or an arene spacer were designed to create a tethered dual CD capsule for precisely manipulating the regio- and enantioselectivities of the photocyclodimerization of 2-anthracenecarboxylate (AC) to four stereoisomeric classical 9,10:9',10'-cyclodimers and two nonclassical 5,8:9',10'-cyclodimers. Among the dimeric CD hosts prepared, exo-3-thia-ß-CD dimer formed 1:1 and 1:2 host-guest complexes with AC in aqueous solutions, the former of which hindered but the latter facilitated the AC photocyclodimerization with regio- and enantioselectivities much higher than those obtained with native ß-CD or the rest of the ß-CD dimers. The stereochemical outcomes turned out to be highly sensitive to and hence critically manipulable by the linking position and configuration of the connected saccharide units and the linker length, as well as the external variants, such as temperature, pH, and added salt. Eventually, the photocyclodimerization of AC mediated by the dimeric ß-CD host gave enantiopure syn-head-to-tail-9,10:9',10'-cyclodimer in 97-98% yield in a pH 5.1 buffer solution at 0.5 °C and also in an aqueous CsCl solution at -20 °C.

Simultaneous electrochemical sensing of serotonin, dopamine and ascorbic acid by using a nanocomposite prepared from reduced graphene oxide, Fe3O4 and hydroxypropyl-ß-cyclodextrin.

Reduced graphene oxide containing Fe3O4 nanoparticles was decorated with hydroxypropyl-ß-cyclodextrin (HP-ß-CD) to construct a novel nanocomposite (3D-rGO/Fe3O4/HP-ß-CD). The composite was placed on a glassy carbon electrode (GCE) to design an electrochemical sensor for detecting simultaneously serotonin (5-HT), dopamine (DA), and ascorbic acid (AA). The interconnected porous reduced graphene oxide framework tightly anchored to the Fe3O4 magnetic nanoparticles warrants good electrical conductivity and efficient catalytic activity. The HP-ß-CD acts as a supramolecular host with high recognition ability for 5-HT, DA and AA. Well-separated oxidation peaks and increased peak currents were observed for 5-HT, DA, and AA individually and in mixtures by differential pulse voltammetry (DPV). The following figures of merit were found for simultaneous electrochemical determination of 5-HT, DA, and AA: (a) Well separated peaks at around 0.316, 0.16 and - 0.044 V; (b) linear responses in the 0.01 - 25 µM, 0.02 - 25 µM and 10 - 350 µM; (c) detection limits of 3.3 nM, 6.7 nM and 3.3 µM (S/N = 3), and (d) recoveries of 96.9-103%, 97.3%-102% and 96.3-105% from spiked serum samples, respectively. All relative standard deviation (RSD) are less than 4%. Graphical abstractSchematic representation of simultaneous detecting serotonin (5-HT), dopamine (DA) and ascorbic acid (AA) for three-dimensional reduced-graphene oxide/Fe3O4/hydroxypropyl-ß-cyclodextrin (3D-rGO/Fe3O4/HP-ß-CD) by differential pulse voltammetry (DPV) approach.

Supramolecular Assembly-Improved Triplet-Triplet Annihilation Upconversion in Aqueous Solution.

Water-soluble 9,10-diphenylanthracene-modified γ-cyclodextrin derivatives A1 and A2, in which the γ-cyclodextrin unit serves as a molecular host for a binding sensitizer, and the 9,10-diphenylanthracene moiety plays a role as an emitter/annihilator, were synthesized to investigate the supramolecular triplet-triplet annihilation (TTA) upconversion in aqueous solution. Both A1 and A2 readily aggregate and form nanoscale assemblies in water as a combined result of host-guest complexation and π-π stacking among the 9,10-diphenylanthracenes. The aggregation behavior of the supramolecular emitters was fully characterized by using a diversity of methods, including dynamic light scattering (DLS), SEM, NMR, fluorescence, and circular dichroism studies. Fluorescence spectroscopic analysis reveals that the emitters have high fluorescence quantum yields in water (82 and 90 % for A1 and A2, respectively), thus demonstrating that aggregation does not quench the fluorescence. By using a coordinated ruthenium sensitizer, a high TTA upconversion quantum yield of up to 6.9 % was observed for this supramolecular TTA system, which is significantly higher than the value (<0.5 %) obtained with nonassembled emitters in organic solvent and in contrast to the fact that TTA upconversion emission in aqueous solution is usually low or negligible. We ascribe the strong TTA upconversion emission in the present supramolecular assembly system to an efficient TTA process, which is facilitated along the stacked emitters by triplet energy migration and improved triplet-triplet energy transfer through host-guest complexation.

Temperature-Driven Planar Chirality Switching of a Pillar[5]arene-Based Molecular Universal Joint.

The study of an enantiopure bicyclic pillar[5]arene-based molecular universal joint (MUJ) by single-crystal X-ray diffraction allowed for the first time the unequivocal assignment of the absolute configuration of a planar chiral pillar[5]arene by circular dichroism spectroscopy. Crucially, the absolute configuration of the MUJ was switched reversibly by temperature, with an accompanying sign inversion of the anisotropy factor that varied by as much as 0.03, which is the largest value ever reported. Mechanistically, the reversible chirality switching of the MUJ is driven by the threading/dethreading motion of the fused ring and hence is dependent on both the size and nature of the ring and the solvent employed, reflecting the critical balance between the self-complexation of the ring by pillar[5]arene, the solvation to the excluded ring, and the inclusion of solvent molecules in the cavity.

Inherently Chiral Azonia[6]helicene-Modified ß-Cyclodextrin: Synthesis, Characterization, and Chirality Sensing of Underivatized Amino Acids in Water.

The (P)- and (M)-3-azonia[6]helicenyl ß-cyclodextrins exhibit L/D selectivities of up to 12.4 and P/M preferences of up to 28.2 upon complexation with underivatized proteinogenic amino acids in aqueous solution at pH 7.3.

Solvent- and phase-controlled photochirogenesis. Enantiodifferentiating photoisomerization of (Z)-cyclooctene sensitized by cyclic nigerosylnigerose-based nanosponges crosslinked by pyromellitate.

Cyclic nigerosylnigerose (CNN), a saucer-shaped cyclic tetrasaccharide with a shallow concave surface, was reacted with pyromellitic dianhydride in 1:2 and 1:4 ratios to give two CNN-based polymers of different degrees of crosslinking, both of which swelled upon soaking in water, acting as a 'nanosponge' (NS). These NSs evolved several phases from isotropic solution to flowing and rigid gels via suspension by gradually increasing the concentration in water. The CNN-NSs thus prepared effectively mediated the enantiodifferentiating photoisomerization of (Z)-cyclooctene (1Z) to chiral (E)-isomer (1E). The enantiomeric excess (ee) of 1E obtained was a critical function of the solvent composition and the phase evolved at different CNN-NS concentrations in water. In isotropic solution, the enantioselectivity was generally low (−4% to +6% ee) but the chiral sense of 1E was inverted by increasing the methanol content. Interestingly, the product's ee was controlled more dramatically by the phase evolved, as was the case with the cyclodextrin-based nanosponge (CD-NS) reported previously. Thus, the ee of 1E was low in solution and suspension, but suddenly leaped at the phase border of flowing gel and rigid gel to give the highest ee of 22­24%, which are much higher than those obtained with CD-NSs (6­12% ee), revealing the positive roles of the chiral void space formed upon gelation of the crosslinked saccharide polymer.

Application of Platysma Myocutaneous Flap in Surgical Repair after T2-3 Glottic Carcinoma Resection.

OBJECTIVE: Numerous methods and materials are available for vertical partial laryngectomy. In this study, the reparative effects of the platysma myocutaneous flap (PMF) and ribbon myocutaneous flap (RMF) on the postoperative voice quality of patients were compared to provide a reference for selecting a method conducive to improving postoperative voice quality. METHODS: A retrospective analysis was performed on patients with unilateral T2-3 glottic carcinoma. Following vertical partial laryngectomy, the defect was repaired with a PMF or simple RMF. Twelve months after surgery, voice quality was assessed according to voice acoustics, aerodynamics, and subjective perceptual evaluation, and glottic morphology was recorded using a laryngeal stroboscopy. RESULTS: A total of 70 patients were identified, including 54 in the PMF group and 16 in the RMF group. The PMF group was superior to the RMF group in terms of voice quality assessed by voice acoustics, aerodynamics, and subjective perceptual evaluation. In the PMF group, 72.2% of patients performed phonation with their vocal cords, and approximately 27.8% of patients were affected by supraglottic compression. In the RMF group, 81.3% of patients were affected by supraglottic compression. No significant difference was found in the 5-year survival rate between the two groups. CONCLUSION: For defect repair following vertical partial laryngectomy, a PMF can allow better postoperative voice quality to be achieved than an RMF because a PMF can provide more tissue (including strap muscle under the flap) for padding, which enables the glottic portion corresponding to the vocal cord to close well. LEVEL OF EVIDENCE: 3 Laryngoscope, 134:3181-3186, 2024.

Intermittent fasting alleviates IMQ-induced psoriasis-like dermatitis via reduced γδT17 and monocytes in mice.

Psoriasis is a chronic immune mediated inflammatory skin disease with systemic manifestations. It has been reported that caloric restriction could improve severity of psoriasis patients. However, the mechanism of intermittent fasting effects on psoriasis has not been investigated. Caloric restriction is known to reduce the number of circulating inflammatory monocytes in a CCL2-dependent manner. However, it is still unknown whether caloric restriction can improve psoriasis by regulating monocytes through CCL2. In this study, we used imiquimod (IMQ)-induced psoriasis-like mouse model to explore the effects and the mechanisms of intermittent fasting on psoriasis-like dermatitis. We found that intermittent fasting could significantly improve IMQ-induced psoriasis-like dermatitis, and reduce the number of γδT17 cells and IL-17 production in draining lymph nodes and psoriatic lesion via inhibiting proliferation and increasing death of γδT17 cells. Furthermore, intermittent fasting could significantly decrease monocytes in blood, and this was associated with decreased monocytes, macrophages and DC in psoriasis-like skin inflammation. Reduced monocytes in circulation and increased monocytes in BM of fasting IMQ-induced psoriasis-like mice is through reducing the production of CCL2 from BM to inhibit monocyte egress to the periphery. Our above data shads light on the mechanisms of intermittent fasting on psoriasis.