Arrestins recognize different receptor phosphorylation patterns and convert this information to selective arrestin functions to expand the functional diversity of the G protein-coupled receptor ...(GPCR) superfamilies. However, the principles governing arrestin-phospho-receptor interactions, as well as the contribution of each single phospho-interaction to selective arrestin structural and functional states, are undefined. Here, we determined the crystal structures of arrestin2 in complex with four different phosphopeptides derived from the vasopressin receptor-2 (V2R) C-tail. A comparison of these four crystal structures with previously solved Arrestin2 structures demonstrated that a single phospho-interaction change results in measurable conformational changes at remote sites in the complex. This conformational bias introduced by specific phosphorylation patterns was further inspected by FRET and
H NMR spectrum analysis facilitated via genetic code expansion. Moreover, an interdependent phospho-binding mechanism of phospho-receptor-arrestin interactions between different phospho-interaction sites was unexpectedly revealed. Taken together, our results provide evidence showing that phospho-interaction changes at different arrestin sites can elicit changes in affinity and structural states at remote sites, which correlate with selective arrestin functions.
Two-dimensional (2D) metal-organic framework (MOF) nanosheets have emerged as a new member of 2D nanomaterials for molecular sieving, energy conversion and storage, catalysis and biomedicine. In this ...paper, a highly dense assembly of porphyrin achievable in porphyrin-integrated MOF nanosheets induced by an ionic liquid is obtained by sonication exfoliation of its bulk crystals. The 2D layered structure MOF, BMI
2
Ca
3
(H
2
TCPP)
2
(μ
2
-OH
2
)
2
(H
2
O)
2
(
1
), was firstly prepared by using the ionic liquid assisted synthetic method (H
6
TCPP =
meso
-tetra(carboxyphenyl) porphyrin, BMI = 1-butyl-3-methylimidazolium). The laminated layers in
1
clearly indicate a weak interlayer non-covalent interaction but a strong metal-carboxylate bonding within the layers, which facilitates the exfoliation of
1
to form 2D MOF nanosheets (
1 NSs
). Powder X-ray diffraction (PXRD), high-resolution transmission electron microscopy (HR-TEM) and fast Fourier transform (FFT) patterns revealed that
1 NSs
could maintain their crystalline structure after exfoliation. These MOF nanosheets exhibited excellent aqueous dispersibility, biodegradability and high cytotoxicity under light irradiation against MCF-7 cells.
A facile fabrication of porphyrin-integrated MOF nanosheets as efficient photosensitizers for photodynamic therapy (PDT) is presented.
Biomass charcoal is dominantly made from lignin. It is necessary to study lignin carbonization process to improve the quality of biomass charcoal. A Thermo-Gravimetric Analyzer coupled with a Fourier ...Transform Infrared Spectrometry (TG-FTIR) was applied to investigate the kinetics of lignin carbonization. Three mass loss stages (drying, pyrolysis and carbonization) were observed below 900°C and another stage (structural rearrangement stage) with a slight mass loss was noticed between 900 and 1200°C. Charcoal obtained at different temperatures was analyzed by FTIR to track the variation of functional groups. The pyrolysis of lignin started at 200°C and charcoal was initially formed till 500°C together with the intensive evolution of volatiles including various phenyl compounds. Amorphous carbon was formed between 500 and 900°C, while most benzene rings structures were transformed into aromatic structures with emission of CO. When the temperature increased from 900°C to 1400°C, most CC bonds were cleaved and a new charcoal structure, between amorphous carbon and graphite structures, was probably formed. The activation energies of the above three stages were estimated to be 54kJ/mol, 70kJ/mol and 178kJ/mol.
► Pyrolysis, amorphous carbon forming and structure reforming are important stages. ► Amorphous carbon formed at 500~900°C as benzene rings became aromatic structure. ► A structure between amorphous carbon and graphite appeared at 900~1400°C. ► Most CC bonds broke when the temperature increased from 900 to 1400°C.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
CdSe/CdS core/shell quantum dots (QDs) can be used as stable and highly active photoredox catalysts for efficient transfer hydrogenation of imines to amines with thiophenol as a hydrogen atom donor. ...This reaction proceeds via a proton-coupled electron transfer (PCET) from the QDs conduction band to the protonated imine followed by hydrogen atom transfer from the thiophenol to the α-aminoalkyl radical. This precious metal free transformation is easy to scale up and can be carried out by a one-pot protocol directly from aldehyde, amine, and thiophenol. Additional advantageous features of this protocol include a wide substrate scope, high yield of the amine products, extremely low catalyst loading (0.001 mol %), high turnover number (105), and the mild reaction conditions of using visible light or sun light at room temperature in neutral media.
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IJS, KILJ, NUK, PNG, UL, UM
We present the instance of two aromatic double bonds and an imine double bond involved thermal 6π‐azaelectrocyclization and, on this basis, a one‐step synthesis of triazacoronenes (TACs) from ...triphenylene‐1,5,9‐triamines and aldehydes under nonacidic conditions. This method has several advantages such as simplicity, high yields, and extensive substrate scope. A plausible reaction mechanism has been proposed with several experimental supports. A typical derivative shows a unique dimer holding together via a π‐π interaction and six H‐bonds and a zigzag superstructure stabilized by three centered H‐bonds and Br ⋅⋅⋅ π interaction between the adjacent dimers.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
To evaluate safety and efficacy of one- vs. two-session radiofrequency ablation (RFA) of parathyroid hyperplasia for patients with secondary hyperparathyroidism (SHPT) and to compare the outcome of ...both methods on hypocalcemia. Patients with secondary hyperparathyroidism underwent ultrasound guided RFA of parathyroid hyperplasia. Patients were alternately assigned to either group 1 (n = 28) with RFA of all 4 glands in one session or group 2 (n = 28) with RFA of 2 glands in a first session and other 2 glands in a second session. Serum parathyroid hormone (PTH), calcium, phosphorus and alkaline phosphatase (ALP) values were measured at a series of time points after RFA. RFA parameters, including operation duration and ablation time and hospitalization length and cost, were compared between the two groups. Mean PTH decreased in group 1 from 1865.18 ± 828.93 pg/ml to 145.72 ± 119.27 pg/ml at 1 day after RFA and in group 2 from 2256.64 ± 1021.72 pg/ml to 1388.13 ± 890.15 pg/ml at 1 day after first RFA and to 137.26 ± 107.12 pg/ml at 1 day after second RFA. Group 1's calcium level decreased to 1.79 ± 0.31 mmol/L at day 1 after RFA and group 2 decreased to 1.89 ± 0.26 mmol/L at day 1 after second session RFA (P < 0.05). Multivariate analysis showed that hypocalcemia was related to serum ALP. Patients with ALP ≥ 566 U/L had lower calcium compared to patients with ALP < 566 U/L up to a month after RFA (P < 0.05). Group 1's RFA time and hospitalization were shorter and had lower cost compared with Group 2. US-guided RFA of parathyroid hyperplasia is a safe and effective method for treating secondary hyperparathyroidism. Single-session RFA was more cost-effective and resulted in a shorter hospital stay compared to two sessions. However, patients with two-session RFA had less hypocalcemia, especially those with high ALP.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Evidence for the effects of dietary diversity changes and cognitive frailty (CF) in the older adults is not clear. This study aimed to investigate the relationship between dietary diversity changes ...and CF in older adults Chinese. A total of 14,382 participants (mean age: 82.3 years) were enrolled. Dietary diversity scores (DDSs) were collected and calculated using a food frequency questionnaire. DDS changes between baseline and first follow-up were categorized into nine patterns. The associations between DDS changes and the incidence of CF were estimated using Cox proportional hazards models. During an 80,860 person-year follow-up, 3023 CF cases were identified. Groups with a decrease in DDS had increased CF risk compared with the high-to-high DDS group, with adjusted hazard ratios (HRs; 95% confidence intervals (Cis)) of 1.30 (1.06, 1.59), 2.04 (1.51, 2.74), and 1.81 (1.47, 2.22) for high-to-medium, high-to-low, and medium-to-low groups, respectively. Lower overall DDS groups were associated with greater CF risks, with HRs (95% CIs) of 1.49 (1.19, 1.86) for the low-to-medium group and 1.96 (1.53, 2.52) for the low-to-low group. Compared with the high-to-high group, significant associations with CF were found in other DDS change groups; HRs ranged from 1.38 to 3.12 for the plant-based DDS group and from 1.24 to 1.32 for the animal-based DDS group. Additionally, extreme and moderate declines in overall DDS increased CF risk compared with stable DDS, with HRs (95% CIs) of 1.67 (1.50, 1.86) and 1.13 (1.03, 1.24), respectively. In conclusion, among older adults, a declining or persistently low DDS and a moderately or extremely declining DDS were linked to higher incident CF. Plant-based DDS changes correlated more strongly with CF than animal-based DDS changes.
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•UV–vis and colorimetric detection of Ni2+ in low concentrations was realized using paper-based sensor.•Indicator displacement assays were achieved at paper-based substrate for the ...first time.•A new strategy for fabricating paper-based sensor strips has been describe to enable sensitive detection of metal ions.
A facile and reliable colorimetric sensor in both solution and paper-based membrane was presented for the determination of nickel ions. Commercial organometallic reagent zincon had been incorporated within hollow ZnSiO3 nanospheres to serve as hybrid ionophore, the blue color of which faded after successive addition of Ni2+ due to competition and displacement of Zn2+ in the ionophore. The selectivity was very good and can be further improved using Na2-EDTA as a masking agents which eventually becomes a co-ionophore. The detection solutions were further used to coat cellulose membrane modified with TiO2 and silylating reagent to fabricate paper-based sensors for naked-eye detection of Ni2+. With optimum conditions selected, the assays in solution obtained a detection limit of 35.6nM with linear range from 32nM to 9.2mM, while for the paper-based assays, the detection limit goes to 83nM with linear range between 78nM and 76μΜ. Besides, the assay enable naked-eye differentiation of nickel ions down to 0.1μΜ. Testing the present paper sensor on real river turbulent water shows a maximum 5% relative error, demonstrating the feasibility of present assays for real applications.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
Higher serum periostin concentrations are associated with mortality after head trauma. We further determined the relationship between periostin concentrations, severity, and clinical outcome in ...patients with intracerebral hemorrhage (ICH).
We prospectively included 128 controls and 128 consecutive patients with acute ICH within the first 24h after onset. At admission, we measured serum periostin concentrations.
Serum periostin concentrations were significantly higher in the patients than in the controls. Serum periostin concentrations were positively related to National Institutes of Health Stroke Scale (NIHSS) score (r=0.526) and hematoma volume (r=0.586). An unfavorable outcome (defined as modified Rankin scale >2) was observed in 65 (50.8%) patients. Serum periostin odds ratio (OR), 1.008; 95% confidence interval (CI), 1.002–1.013, NIHSS score (OR, 1.462; 95% CI, 1.209–1.767), hematoma volume (OR, 1.134; 95% CI, 1.047–1.227) and age (OR, 1.060; 95% CI, 1.015–1.108) emerged as independent predictors for 6-month unfavorable outcome. In terms of ROC AUC, serum periostin concentrations had significantly higher predictive value compared with age and showed similar predictive value compared with NIHSS score and hematoma volume.
High concentrations of serum periostin in acute ICH patients are associated with increasing severity and a poor functional prognosis.
•Serum periostin levels are increased after intracerebral hemorrhage.•Serum periostin levels are correlated with hemorrhagic severity.•Serum periostin is an independent predictor for 6-month poor prognosis.•Serum periostin levels possess high prognostic predictive ability.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
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