Identification and Characterization of CC-AMP1-like and CC-AMP2-like Peptides in Capsicum spp.

Antimicrobial peptides (AMPs) are compounds with a variety of bioactive properties. Especially promising are their antibacterial activities, often toward drug-resistant pathogens. Across different AMP sources, AMPs expressed within plants are relatively underexplored with a limited number of plant AMP families identified. Recently, we identified the novel AMPs CC-AMP1 and CC-AMP2 in ghost pepper plants (Capsicum chinense x frutescens), exerting promising antibacterial activity and not classifying into any known plant AMP family. Herein, AMPs related to CC-AMP1 and CC-AMP2 were identified within both Capsicum annuum and Capsicum baccatum. In silico predictions throughout plants were utilized to illustrate that CC-AMP1-like and CC-AMP2-like peptides belong to two broader AMP families, with three-dimensional structural predictions indicating that CC-AMP1-like peptides comprise a novel subfamily of α-hairpinins. The antibacterial activities of several closely related CC-AMP1-like peptides were compared with a truncated version of CC-AMP1 possessing significantly more activity than the full peptide. This truncated peptide was further characterized to possess broad-spectrum antibacterial activity against clinically relevant ESKAPE pathogens. These findings illustrate the value in continued study of plant AMPs toward characterization of novel AMP families, with CC-AMP1-like peptides possessing promising bioactivity.

Lung-PNet: An Automated Deep Learning Model for the Diagnosis of Invasive Adenocarcinoma in Pure Ground-Glass Nodules on Chest CT.

BACKGROUND. Pure ground-glass nodules (pGGNs) on chest CT representing invasive adenocarcinoma (IAC) warrant lobectomy with lymph node resection. For pGGNs representing other entities, close follow-up or sublobar resection without node dissection may be appropriate. OBJECTIVE. The purpose of this study was to develop and validate an automated deep learning model for differentiation of pGGNs on chest CT representing IAC from those representing atypical adenomatous hyperplasia (AAH), adenocarcinoma in situ (AIS), and minimally invasive adenocarcinoma (MIA). METHODS. This retrospective study included 402 patients (283 women, 119 men; mean age, 53.2 years) with a total of 448 pGGNs on noncontrast chest CT that were resected from January 2019 to June 2022 and were histologically diagnosed as AAH (n = 29), AIS (n = 83), MIA (n = 235), or IAC (n = 101). Lung-PNet, a 3D deep learning model, was developed for automatic segmentation and classification (probability of IAC vs other entities) of pGGNs on CT. Nodules resected from January 2019 to December 2021 were randomly allocated to training (n = 327) and internal test (n = 82) sets. Nodules resected from January 2022 to June 2022 formed a holdout test set (n = 39). Segmentation performance was assessed with Dice coefficients with radiologists' manual segmentations as reference. Classification performance was assessed by ROC AUC and precision-recall AUC (PR AUC) and compared with that of four readers (three radiologists, one surgeon). The code used is publicly available (https://github.com/XiaodongZhang-PKUFH/Lung-PNet.git). RESULTS. In the holdout test set, Dice coefficients for segmentation of IACs and of other lesions were 0.860 and 0.838, and ROC AUC and PR AUC for classification as IAC were 0.911 and 0.842. At threshold probability of 50.0% or greater for prediction of IAC, Lung-PNet had sensitivity, specificity, accuracy, and F1 score of 50.0%, 92.0%, 76.9%, and 60.9% in the holdout test set. In the holdout test set, accuracy and F1 score (p values vs Lung-PNet) for individual readers were as follows: reader 1, 51.3% (p = .02) and 48.6% (p = .008); reader 2, 79.5% (p = .75) and 75.0% (p = .10); reader 3, 66.7% (p = .35) and 68.3% (p < .001); reader 4, 71.8% (p = .48) and 42.1% (p = .18). CONCLUSION. Lung-PNet had robust performance for segmenting and classifying (IAC vs other entities) pGGNs on chest CT. CLINICAL IMPACT. This automated deep learning tool may help guide selection of surgical strategies for pGGN management.

Apolar Extracts of St. John's Wort Alleviate the Effects of ß-Amyloid Toxicity in Early Alzheimer's Disease.

Hypericum perforatum (St. John's wort) has been described to be beneficial for the treatment of Alzheimer's disease (AD). Different extractions have demonstrated efficiency in mice and humans, esp. extracts with a low hypericin and hyperforin content to reduce side effects such as phototoxicity. In order to systematically elucidate the therapeutic effects of H. perforatum extracts with different polarities, APP-transgenic mice were treated with a total ethanol extract (TE), a polar extract obtained from TE, and an apolar supercritical CO2 (scCO2) extract. The scCO2 extract was formulated with silicon dioxide (SiO2) for better oral application. APP-transgenic mice were treated with several extracts (total, polar, apolar) at different concentrations. We established an early treatment paradigm from the age of 40 days until the age of 80 days, starting before the onset of cerebral ß-amyloid (Aß) deposition at 45 days of age. Their effects on intracerebral soluble and insoluble Aß were analyzed using biochemical analyses. Our study confirms that the scCO2H. perforatum formulation shows better biological activity against Aß-related pathological effects than the TE or polar extracts. Clinically, the treatment resulted in a dose-dependent improvement in food intake with augmentation of the body weight, and, biochemically, it resulted in a significant reduction in both soluble and insoluble Aß (-27% and -25%, respectively). We therefore recommend apolar H. perforatum extracts for the early oral treatment of patients with mild cognitive impairment or early AD.

[Predictive effect of the dual-parametric MRI modified maximum diameter of the lesions with PI-RADS 4 and 5 on the clinically significant prostate cancer].

OBJECTIVE: To assess the rationality of the maximum lesion diameter of 15 mm in prostate imaging reporting and data system (PI-RADS) as a criterion for upgrading a lesion from category 4 to 5 and improve it to enhance the prediction of clinically significant prostate cancer (csPCa). METHODS: In this study, the patients who underwent prostate magnetic resonance imaging (MRI) and prostate biopsy at Peking University First Hospital from 2019 to 2022 as a development cohort, and the patients in 2023 as a validation cohort were reviewed. The localization and maximum diameter of the lesion were fully evaluated. The area under the curve (AUC) and the cut-off value of the maximum diameter of the lesion to predict the detection of csPCa were calculated from the receiver operating characteristics (ROC) curve. Confounding factors were reduced by propensity score matching (PSM). Diagnostic efficacy was compared in the validation cohort. RESULTS: Of the 589 patients in the development cohort, 358 (60.8%) lesions were located in the peripheral zone and 231 (39.2%) were located in the transition zone, and 496 (84.2%) patients detected csPCa. The median diameter of the lesions in the peripheral zone was smaller than that in the transition zone (14 mm vs. 19 mm, P < 0.001). In the ROC analysis of the maximal diameter on the csPCa prediction, there was no statistically significant difference between the peri-pheral zone (AUC=0.709) and the transition zone (AUC=0.673, P=0.585), and the cut-off values were calculated to be 11.5 mm for the peripheral zone and 16.5 mm for the migrating zone. By calcula-ting the Youden index for the cut-off values in the validation cohort, we found that the categorisation by lesion location led to better predictive results. Finally, the net reclassification index (NRI) was 0.170. CONCLUSION: 15 mm as a criterion for upgrading the PI-RADS score from 4 to 5 is reasonable but too general. The cut-off value for peripheral zone lesions is smaller than that in transitional zone. In the future consideration could be given to setting separate cut-off values for lesions in different locations.

Genome-wide identification of RNA modification-related single nucleotide polymorphisms associated with rheumatoid arthritis.

BACKGROUND: RNA modification plays important roles in many biological processes, such as gene expression control. The aim of this study was to identify single nucleotide polymorphisms related to RNA modification (RNAm-SNPs) for rheumatoid arthritis (RA) as putative functional variants. METHODS: We examined the association of RNAm-SNPs with RA in summary data from a genome-wide association study of 19,234 RA cases and 61,565 controls. We performed eQTL and pQTL analyses for the RNAm-SNPs to find associated gene expression and protein levels. Furthermore, we examined the associations of gene expression and circulating protein levels with RA using two-sample Mendelian randomization analysis methods. RESULTS: A total of 160 RNAm-SNPs related to m6A, m1A, A-to-I, m7G, m5C, m5U and m6Am modifications were identified to be significantly associated with RA. These RNAm-SNPs were located in 62 protein-coding genes, which were significantly enriched in immune-related pathways. RNAm-SNPs in important RA susceptibility genes, such as PADI2, SPRED2, PLCL2, HLA-A, HLA-B, HLA-DRB1, HLA-DPB1, TRAF1 and TXNDC11, were identified. Most of these RNAm-SNPs showed eQTL effects, and the expression levels of 26 of the modifiable genes (e.g., PADI2, TRAF1, HLA-A, HLA-DRB1, HLA-DPB1 and HLA-B) in blood cells were associated with RA. Circulating protein levels, such as CFB, GZMA, HLA-DQA2, IL21, LRPAP1 and TFF3, were affected by RNAm-SNPs and were associated with RA. CONCLUSION: The present study identified RNAm-SNPs in the reported RA susceptibility genes and suggested that RNAm-SNPs may affect RA risk by affecting the expression levels of corresponding genes and proteins.

Excitation-Wavelength-Dependent Luminescence of Chemically and Physically Mixed Europium and Terbium Phosphonates: Color-Tunable Luminescence, Near-White-Light Emission, and Selective Fe3+ Detection.

Molecular lanthanide phosphonates [Ln2 (H3 tpmm)2 (H2 O)6 ] ⋅ xH2 O (Ln=Eu, EuP; Ln=Tb, TbP) were synthesized. Single-crystal X-ray diffraction confirmed that EuP has a sandwich-like dinuclear structure, in which the Eu(III) center adopts a {EuO8 } distorted dodecahedral geometry. XRPD patterns prove that TbP and EuP are isomorphous and isostructural. EuP and TbP are highly thermally stable approaching 450 °C and exhibit red- and green-light emissions from the characteristic 4 f-4 f transition of the Eu3+ and Tb3+ , respectively. Interestingly, luminescence modulation is achieved for the chemically mixed Eu/Tb phosphonate analogues, c-Eux Tb2 -x P (x=1.5, 1, 0.5), and physically mixed Eu/Tb phosphonate materials, p-yEuP : zTbP (y : z=3 : 1, 1 : 1, 1 : 3), with varying the excitation wavelength. Of particular note, near-white-light emission is also achieved for c-EuTbP, p-EuP : TbP, and p-EuP : 3TbP when excited at 365 nm. Therefore, these dinuclear molecular lanthanide phosphonates emitting excitation wavelength and Eu3+ : Tb3+ ratio dependent luminescence might be potential candidates for color-tunable luminescence materials and white-light-emitting materials. On the other hand, the bright green-light emission makes TbP to be an excellent reusable luminescence sensor for selective detection of Fe3+ with Stern-Volmer quenching constant (KSV ) of 9.66×103  M-1 and detection limit (DL) of 0.42 µM through absorption competition caused luminescence quenching effect.

RNA modification-related variants in genomic loci associated with body mass index.

BACKGROUND: Genome-wide association studies (GWASs) have identified hundreds of loci for body mass index (BMI), but functional variants in these loci are less known. The purpose of this study was to identify RNA modification-related SNPs (RNAm-SNPs) for BMI in GWAS loci. BMI-associated RNAm-SNPs were identified in a GWAS of approximately 700,000 individuals. Gene expression and circulating protein levels affected by the RNAm-SNPs were identified by QTL analyses. Mendelian randomization (MR) methods were applied to test whether the gene expression and protein levels were associated with BMI. RESULTS: A total of 78 RNAm-SNPs associated with BMI (P < 5.0 × 10-8) were identified, including 65 m6A-, 10 m1A-, 3 m7G- and 1 A-to-I-related SNPs. Two functional loss, high confidence level m6A-SNPs, rs6713978 (P = 6.4 × 10-60) and rs13410999 (P = 8.2 × 10-59), in the intron of ADCY3 were the top significant SNPs. These two RNAm-SNPs were associated with ADCY3 gene expression in adipose tissues, whole blood cells, the tibial nerve, the tibial artery and lymphocytes, and the expression levels in these tissues were associated with BMI. Proteins enriched in specific KEGG pathways, such as natural killer cell-mediated cytotoxicity, the Rap1 signaling pathway and the Ras signaling pathway, were affected by the RNAm-SNPs, and circulating levels of some of these proteins (ADH1B, DOCK9, MICB, PRDM1, STOM, TMPRSS11D and TXNDC12) were associated with BMI in MR analyses. CONCLUSIONS: Our study identified RNAm-SNPs in BMI-related genomic loci and suggested that RNA modification may affect BMI by affecting the expression levels of corresponding genes and proteins.

Organocatalytic Asymmetric [4 + 2] Cyclization of Azadienes with Azlactones: Access to Chiral 3-Amino-δ-Lactams Derivatives.

Herein, a series of chiral δ-lactam frameworks have been synthesized and catalyzed by chiral phosphoric acid (CPA) utilizing two kinds of open-chain aza-dienes and azlactones derived from amino acids. This powerful [4 + 2] annulation produces a broad substrate scope with functional group tolerance in yield up to 97% with up to 98:2 er. Moreover, a facile scale-up and straightforward conversion to diversely substituted products verify the synthetic utility of this method featuring good compatibility and high efficiency.

Zinc(II)-Based Ring-and-Rod Coordination Layer as an Excitation-Wavelength-dependent Dual-Emissive Chemosensor for Discriminating Fe3+, Cr3+, and Al3+ in Water.

The reactions of Zn(NO3)2, 3,6-bis(pyridin-3-yl)-9H-carbazole (bpycz), and 2,5-dihydroxyterephthalic acid (H4dhbdc) or 2-bromoterephthalic acid (Br-1,4-H2bdc) under hydro(solvo)thermal conditions yielded corresponding coordination polymers (CPs) {[Zn(H2dhbdc)(bpycz)]•0.5H2O}n (1) and [Zn(Br-1,4-bdc)(bpycz)]•2DMAc•H2O (2), respectively, with high thermal stability approaching 350 °C. CP 1 adopts a ring-and-rod layer structure, which is topologically described as a 4-connected net with the point symbol of 2•65. Two layers are interpenetrated in parallel interlocking mode to form a double 2D → 2D polyrotaxane entanglement with extra-framework void space of 19.6%. CP 2 has a non-interpenetrating ring-and-rod layer structure of 4-connected 2•65 net topology, with extra-framework void space of 16.6%. Thermally activated 1 and 2 revealed CO2 uptakes of 101.1 and 98.6 cm3 g-1, respectively, at P/P0 = 1 and 195 K. X-ray powder diffraction (XRPD) patterns confirmed that 1 and 2 both possessed high chemical stability in H2O, CH3OH, acetone, and DMF, and framework stability during gas adsorption-desorption. The H2O suspension of 1 displayed excitation-dependent dual-emissive properties, appearing at 432 nm upon excitation at 300 nm and at 528 nm upon excitation at 365 nm. Of note, 1 was capable of detection of Fe3+, Cr3+, and Al3+ ions in H2O, showing good anti-interference ability, excellent selectivity, and high sensitivity. More interesting, the dual-emissive properties make 1 to be an excellent luminescence chemosensor to screen Fe3+, Cr3+, and Al3+ from a pool of metal ions in H2O upon excitation at 300 nm via luminescence quenching effect and then discriminate Fe3+, Cr3+, and Al3+ upon excitation at 365 nm via luminescence quenching, unaltered, and enhancement responses, respectively. On the other hand, the H2O suspension of 2 demonstrated an excitation-independent emission appearing at around 430 nm, which could be utilized to sensitively detect Fe3+ and Cr3+ ions with good anti-interference ability and excellent selectivity via luminescence quenching effect. Further, 1 and 2 were recyclability and possessed cycling stability. The plausible sensing mechanisms for 1 and 2 toward Fe3+, Cr3+, and Al3+ were also explored in detail.

The experiences of adolescent solid organ transplantation recipients, parents, and healthcare professionals in healthcare transition: A qualitative systematic review.

PROBLEM: The transition from paediatric-centred to adult healthcare services in adolescent solid organ transplantation recipients is a period of increased risk and vulnerability, the issues related to healthcare transition have become key concerns to the healthcare community. ELIGIBILITY CRITERIA: Qualitative studies of any design and qualitative components of mixed method studies that explored the experiences of healthcare transition among adolescent solid organ transplant recipients, parents, and healthcare professionals were included. SAMPLE: Nine articles were finalised and included in the review. METHODS: A systematic review of qualitative studies was conducted. Databases searched were Scopus, PsycINFO, EMBASE, Web of Science, PubMed, CINAHL and ProQuest Dissertations and Theses. Studies published between the inception of respective database and December 2022 inclusive were considered. A three-step inductive thematic synthesis method outlined by Thomas and Harden was used to form descriptive themes and the 10-item Joanna Briggs Institute Critical Appraisal Checklist was utilised to appraise the quality of included articles. RESULTS: Two hundred and twenty studies were screened, and 9 studies published between 2013 and 2022 were included. Five analytical themes were generated: 'the struggle of being an adolescent with a transplant'; 'perceptions of transition'; 'the role of parents'; 'lack of transition readiness' and 'the need for better support'. CONCLUSIONS: Adolescent solid organ transplant recipients, parents, and healthcare professionals faced multiple challenges in the healthcare transition. IMPLICATIONS: Future interventions and health policies should provide targeted intervention strategies that address the barriers present in the healthcare transition to facilitate the optimization of the youth healthcare transition.

Utility of diffusion weighted imaging-based radiomics nomogram to predict pelvic lymph nodes metastasis in prostate cancer.

BACKGROUND: Preoperative pelvic lymph node metastasis (PLNM) prediction can help clinicians determine whether to perform pelvic lymph node dissection (PLND). The purpose of this research is to explore the feasibility of diffusion-weighted imaging (DWI)-based radiomics for preoperative PLNM prediction in PCa patients at the nodal level. METHODS: The preoperative MR images of 1116 pathologically confirmed lymph nodes (LNs) from 84 PCa patients were enrolled. The subjects were divided into a primary cohort (67 patients with 192 positive and 716 negative LNs) and a held-out cohort (17 patients with 43 positive and 165 negative LNs) at a 4:1 ratio. Two preoperative pelvic lymph node metastasis (PLNM) prediction models were constructed based on automatic LN segmentation with quantitative radiological LN features alone (Model 1) and combining radiological and radiomics features (Model 2) via multiple logistic regression. The visual assessments of junior (Model 3) and senior (Model 4) radiologists were compared. RESULTS: No significant difference was found between the area under the curve (AUCs) of Models 1 and 2 (0.89 vs. 0.90; P = 0.573) in the held-out cohort. Model 2 showed the highest AUC (0.83, 95% CI 0.76, 0.89) for PLNM prediction in the LN subgroup with a short diameter ≤ 10 mm compared with Model 1 (0.78, 95% CI 0.70, 0.84), Model 3 (0.66, 95% CI 0.52, 0.77), and Model 4 (0.74, 95% CI 0.66, 0.88). The nomograms of Models 1 and 2 yielded C-index values of 0.804 and 0.910, respectively, in the held-out cohort. The C-index of the nomogram analysis (0.91) and decision curve analysis (DCA) curves confirmed the clinical usefulness and benefit of Model 2. CONCLUSIONS: A DWI-based radiomics nomogram incorporating the LN radiomics signature with quantitative radiological features is promising for PLNM prediction in PCa patients, particularly for normal-sized LNM.

Fluorescence-Responsive Detection of Ag(I), Al(III), and Cr(III) Ions Using Cd(II) Based Pillared-Layer Frameworks.

Two Cd(II) based coordination polymers, {Cd3(btc)2(BTD-bpy)2]∙1.5MeOH∙4H2O}n (1) and [Cd2(1,4-ndc)2(BTD-bpy)2]n (2), where BTD-bpy = bis(pyridin-4-yl)benzothiadiazole, btc = benzene-1,3,5-tricarboxylate, and 1,4-ndc = naphthalene-1,4-dicarboxylate, were hydro(solvo)thermally synthesized. Compound 1 has a three-dimensional non-interpenetrating pillared-bilayer open framework with sufficient free voids of 25.1%, which is simplified to show a topological (4,6,8)-connected net with the point symbol of (324256)(344454628)(3442619728). Compound 2 has a three-dimensional two-fold interpenetrating bipillared-layer condense framework regarded as a 6-connected primitive cubic (pcu) net topology. Compounds 1 and 2 both exhibited good water stability and high thermal stability approaching 350 °C. Upon excitation, compounds 1 and 2 both emitted blue light fluorescence at 471 and 479 nm, respectively, in solid state and at 457 and 446 nm, respectively, in the suspension phase of H2O. Moreover, compounds 1 and 2 in the suspension phase of H2O both exhibited a fluorescence quenching effect in sensing Ag+, attributed to framework collapse, and a fluorescence enhancement response in sensing Al3+ and Cr3+, ascribed to weak ion-framework interactions, with high selectivity and sensitivity and low detection limit.

A Novel Huntington's Disease Assessment Platform to Support Future Drug Discovery and Development.

Huntington's disease (HD) is a lethal neurodegenerative disorder without efficient therapeutic options. The inefficient translation from preclinical and clinical research into clinical use is mainly attributed to the lack of (i) understanding of disease initiation, progression, and involved molecular mechanisms; (ii) knowledge of the possible HD target space and general data awareness; (iii) detailed characterizations of available disease models; (iv) better suitable models; and (v) reliable and sensitive biomarkers. To generate robust HD-like symptoms in a mouse model, the neomycin resistance cassette was excised from zQ175 mice, generating a new line: zQ175Δneo. We entirely describe the dynamics of behavioral, neuropathological, and immunohistological changes from 15-57 weeks of age. Specifically, zQ175Δneo mice showed early astrogliosis from 15 weeks; growth retardation, body weight loss, and anxiety-like behaviors from 29 weeks; motor deficits and reduced muscular strength from 36 weeks; and finally slight microgliosis at 57 weeks of age. Additionally, we collected the entire bioactivity network of small-molecule HD modulators in a multitarget dataset (HD_MDS). Hereby, we uncovered 358 unique compounds addressing over 80 different pharmacological targets and pathways. Our data will support future drug discovery approaches and may serve as useful assessment platform for drug discovery and development against HD.

Engineered Bifunctional Luminescent Pillared-Layer Frameworks for Adsorption of CO2 and Sensitive Detection of Nitrobenzene in Aqueous Media.

Through a dual-ligand synthetic approach, five isoreticular primitive cubic (pcu)-type pillared-layer metal-organic frameworks (MOFs), [Zn2 (dicarboxylate)2 (NI-bpy-44)]⋅x DMF⋅y H2 O, in which dicarboxylate=1,4-bdc (1), Br-1,4-bdc (2), NH2 -1,4-bdc (3), 2,6-ndc (4), and bpdc (5), have been engineered. MOFs 1-5 feature twofold degrees of interpenetration and have open pores of 27.0, 33.6, 36.8, 52.5, and 62.1 %, respectively. Nitrogen adsorption isotherms of activated MOFs 1'-5' at 77 K all displayed type I adsorption behavior, suggesting their microporous nature. Although 1' and 3'-5' exhibited type I adsorption isotherms of CO2 at 195 K, MOF 2' showed a two-step gate-opening sorption isotherm of CO2 . Furthermore, MOF 3' also had a significant influence of amine functions on CO2 uptake at high temperature due to the CO2 -framework interactions. MOFs 1-5 revealed solvent-dependent fluorescence properties; their strong blue-light emissions in aqueous suspensions were efficiently quenched by trace amounts of nitrobenzene (NB), with limits of detection of 4.54, 5.73, 1.88, 2.30, and 2.26 µm, respectively, and Stern-Volmer quenching constants (Ksv ) of 2.93×103 , 1.79×103 , 3.78×103 , 4.04×103 , and 3.21×103 m-1 , respectively. Of particular note, the NB-included framework, NB@3, provided direct evidence of the binding sites, which showed strong host-guest π-π and hydrogen-bonding interactions beneficial for donor-acceptor electron transfer and resulting in fluorescence quenching.

A Cd(II) Luminescent Coordination Grid as a Multiresponsive Fluorescence Sensor for Cr(VI) Oxyanions and Cr(III), Fe(III), and Al(III) in Aqueous Medium.

Hydro(solvo)thermal reactions of Cd(NO3)2, N-(pyridin-3-ylmethyl)-4-(pyridin-4-yl)-1,8-naphthalimide (NI-mbpy-34), and 5-bromobenzene-1,3-dicarboxylic acid (Br-1,3-H2bdc) afforded a luminescent coordination polymer, {[Cd(Br-1,3-bdc)(NI-mbpy-34)(H2O)]∙2H2O}n (1). Single-crystal X-ray diffraction analysis showed that 1 features a two-dimensional (2-D) gridlike sql layer with the point symbol of (44·62), where the Cd(II) center adopts a {CdO5N2} pentagonal bipyramidal geometry. Thermogravimetric (TG) analysis confirmed the thermal stability of 1 up to about 340 °C, whereas XRPD patterns proved the maintenance of crystallinity and framework integrity of 1 in CH2Cl2, H2O, CH3OH, and toluene. Photoluminescence studies indicated that 1 displayed intense blue fluorescence emissions in both solid-state and H2O suspension-phase. Owing to the good fluorescent properties, 1 could serve as an excellent turn-off fluorescence sensor for selective and sensitive Cr(VI) detection in water, with LOD = 15.15 µM for CrO42- and 14.91 µM for Cr2O72-, through energy competition absorption mechanism. In addition, 1 could also sensitively detect Cr3+, Fe3+, and Al3+ ions in aqueous medium via fluorescence-enhancement responses, with LOD = 2.81 µM for Cr3+, 3.82 µM for Fe3+, and 3.37 µM for Al3+, mainly through an absorbance-caused enhancement (ACE) mechanism.

Solvent-Induced Controllable Supramolecular Isomerism: Phase Transformation, CO2 Adsorption, and Fluorescence Sensing toward CrO42-, Cr2O72-, MnO4-, and Fe3.

Complexes {[Zn(bpdc)(Cz-3,6-bpy)]·DMF·H2O}n (1α-DMF, H2bpdc = biphenyl-4,4'-dicarboxylic acid, Cz-3,6-bpy = 3,6-bis(pyridine-4-yl)-9H-carbazole, DMF = N,N'-dimethylformamide) and {[Zn(bpdc)(Cz-3,6-bpy)]·2DMAc·H2O}n (1ß-DMAc, DMAc = N,N'-dimethylacetamide) as a couple of solvent-induced supramolecular isomers were hydro(solvo)thermally synthesized using DMF/H2O and DMAc-only as reaction media, respectively. Complexes 1α-DMF and 1ß-DMAc adopt very similar wavy sql sheet structures but present great differences in the 3-fold interweaving 2D → 2D nets, which result in free voids of 17.6 and 33.4%, respectively. Desolvated 1ß has about 2 times the free voids compared to that of desolvated 1α; however, the former displays a CO2 uptake of 87.9 cm3 g-1 STP at 195 K and P/P0 = 1 which is only slight larger than that (73.7 cm3 g-1 STP) of the latter under the same conditions. This is mainly interpreted by activation- and adsorption-induced framework distortion that caused partial transformation of crystal phase from 1ß to 1α and thus reduced free voids. The isosteric heat of CO2 adsorption (Qst) at zero loading is 29.8 kJ mol-1 for desolvated 1α and 30.6 kJ mol-1 for desolvated 1ß. On the other hand, results from XRPD, IR, and TGA measurements imply that 1α-DMF and 1ß-DMAc are highly stable in several different solvents, with the exception of 1α-DMF in DMAc, which experienced complete transformation to convert to 1ß-DMAc and 1ß-DMAc in acetone and methanol, which would respectively completely and partially transform to the crystal phase of 1α-DMF. Remarkably, 1α-DMF and 1ß-DMAc display intense blue and cyan fluorescence emissions, respectively, promising them to be multifunctional sensing platforms in sensitive detection of CrO42-, Cr2O72-, MnO4-, and Fe3+ with high selectivity and a fairly low limit of detection through perceptible fluorescence quenching effect. The possible sensing mechanisms were also investigated.

Fluorescent Cadmium Bipillared-Layer Open Frameworks: Synthesis, Structures, Sensing of Nitro Compounds, and Capture of Volatile Iodine.

Fluorescent Cd metal-organic frameworks (MOFs), [Cd2 (dicarboxylate)2 (NI-bpy-44)2 ] (dicarboxylate=benzene-1,4-dicarboxylate (1,4-bdc, 1), 2-bromobenzene-1,4-dicarboxylate (Br-1,4-bdc, 2), 2-nitrobenzene-1,4-dicarboxylate (NO2 -1,4-bdc, 3), biphenyl-4,4'-dicarboxylate (bpdc, 4); NI-bpy-44=N-(pyridin-4-yl)-4-(pyridin-4-yl)-1,8-naphthalimide)), featuring non- and twofold interpenetrating pcu-type bipillared-layer open structures with sufficient free voids of 58.4, 51.4, 51.5, and 41.4 %, respectively, have been hydro(solvo)thermally synthesized. MOFs 1-4 emitted solid-state blue or cyan fluorescence emissions at 447±7 nm, which mainly arose from NI-bpy-44 and are dependent on the incorporated solvents. After immersing the crystalline samples in different solvents, that is, H2 O and DMSO (1 and 2) as well as nitrobenzene and phenol (1-4), they exhibited a remarkable fluorescence quenching effect, whereas o-xylene and p-xylene (4) caused significant fluorescence enhancement. The sensing ability of MOFs 1-4 toward nitro compounds carried out in the vapor phase showed that nitrobenzene and 2-nitrophenol displayed detectable fluorescence quenching with 1, 2, and 4 whereas 4-nitrotoluene was an effective fluorescence quencher for 1 and 2; this is most likely attributed to their electron-deficient properties and higher vapor pressures. Moreover, MOFs 1-4 are highly reusable for quick capture of volatile iodine, as supported by clear crystal color change and also by immense fluorescence quenching responses owing to the donor-acceptor interaction. Low-pressure CO2 adsorption isotherms indicate that activated materials 1'-4' are inefficient at taking up CO2 .

An Unprecedented Interpenetrating Structure Built from Two Differently Bonded Frameworks: Synthesis, Characteristics, and Efficient Removal of Anionic Dyes from Aqueous Solutions.

The first example of one single crystal (NTOU-5) containing two different organic-inorganic hybrid open-framework structures was obtained using a hydro(solvo)thermal method and structurally characterized by single-crystal X-ray diffraction. Remarkably, under the same synthetic conditions, the zinc ions are respectively coordinated by oxalic acid (OX) and 1,2,4,5-tetrakis(imidazol-1-ylmethyl)benzene (TIMB) linkers to form two significantly different frameworks: anionic [Zn2 (OX)3 ]2- and cationic [Zn(TIMB)]2+ networks that interweave with each other to give an unprecedented interpenetrating structure with two differently-bonded open-frameworks. From the inorganic chemistry perspective, it is extremely difficult to control to which metal center the oxygen-donor linkers or/and nitrogen-donor ligands bind. A mixed Co/Zn analogue was also obtained by a similar method. The single-crystal XRD and EDS analyses indicate that the octahedral Zn ions of the anionic framework are replaced by cobalt cations, whereas the Zn ions in the tetrahedral positions of the cationic networks remain intact. This leads to the formation of the interpenetrating analogue with a mixed metal composition. Furthermore, NTOU-5 shows structural stability and efficiently removes organic dyes from aqueous solutions at concentrations of 10 ppm.

Anion-Directed Metallocages: A Study on the Tendency of Anion Templation.

Self-assembly of Cu(NO3 )2 ⋅3 H2 O and di(3-pyridylmethyl)amine (dpma) with addition of different acids (HNO3 , HOAc, HCl, HClO4 , HOTf, HPF6 , HBF4 , and H2 SO4 ) afforded a family of anion-templated tetragonal metallocages with a cationic prismatic structure of [(Gn- )⊂{Cu2 (Hdpma)4 }](8-n)+ (Gn- =NO3- , PF6- , SiF62- ) with different ligating anions/solvents (NO3- , Cl- , ClO4- , OTf- , H2 O) outside the cage. Systematic competitive experiments have rationalized the tendency of anion templation towards the formation of metallocages [(Gn- )⊂{Cu2 (Hdpma)4 }](8-n)+ as occurring in the order SiF62- ≈PF6- >NO3- >SO42- ≈ClO4- ≈BF4- . This sequence is mostly elucidated by shape control over size selectivity and electrostatic attraction between the cationic {Cu2 (Hdpma)4 }8+ host and the anionic guests. In addition, these results have also roughly ranked the anion coordination ability in the order Cl- , ClO4- , OTf- >NO3- >BF4- , CH3 SO4- . Magnetic studies of metallocages 1 t and 2-4 suggest that the fitted magnetic interaction, being weakly magnetically coupled overall, is interpreted as a result of the combination of intracage ferromagnetic coupling integrals and intercage antiferromagnetic exchange; both contributions are very weak and comparable in strength.

Anion-Directed Copper(II) Metallocages, Coordination Chain, and Complex Double Salt: Structures, Magnetic Properties, EPR Spectra, and Density Functional Study.

A series of Cu(II) metallo-assemblies showing anion-directed structural variations, including five metallocages [(G(n-) )⊂{Cu2 (Hdpma)4 }]((8-n)+) (A(-) )8-n (G(n-) =NO3 (-) , ClO4 (-) , SiF6 (2-) , BF4 (-) , SO4 (2-) ; A(-) =NO3 (-) , ClO4 (-) , BF4 (-) , CH3 SO4 (-) ; Hdpma=bis(3-pyridylmethyl)ammonium cation), a complex double salt, namely, (H3 dpma)4 (CuCl4 )5 Cl2 , and a coordination chain, namely, [Cu2 (dpma)(OAc)4 ], are reported. The influence of the anion can be explained by its coordinating ability, the affinity of which for the Cu(II) center interferes significantly with metallocage formation, and its shape, which offers host-guest recognition ability to engage in weak metal-anion coordination and hydrogen bonding to the organic ligand, which are responsible for metallocage templation. EPR studies of these metallocages in the powder phase at room temperature and 77 K showed a trend of the g values (g|| >2.10>g⊥ >2.00) indicating a dx2-y2 -based ground state with square-pyramidal geometry for the Cu(II) centers. The magnetism of these metallocages can be interpreted as the result of a combination of relatively small magnetic coupling integrals and a substantial contribution of temperature-independent paramagnetism (TIP). The weak magnetic interaction is corroborated by the results of DFT calculations and the EPR spectra. Availability of the low-lying state for spin population was confirmed by a magnetization study, which revealed a magnetic moment approaching 2Nß, which would explain the presence of the larger TIP term.