Unravelling the mechanism of water sensing by the Mg2+ dihydroxy-terephthalate MOF (AEMOF-1 ‘)

In this contribution we build upon our previous work on the MOF [Mg(H(2)dhtp)(H2O)(2)]center dot DMAc (AEMOF-1 center dot DMAc) and its activated dry version AEMOF-1 ‘ which has been shown to exhibit excellent luminescence sensing properties towards water in organic solvents. We demonstrate through combined structural and photophysical studies that the observed changes in the fluorescence properties of AEMOF-1 ‘ upon hydration arise from a structural transformation to the mononuclear complex [Mg(H(2)dhtp)(H2O)(5)]center dot H2O (H(4)dhtp = 2,5-dihydroxyterepthalic acid) (1). In the latter complex, excited state intramolecular proton transfer (ESIPT) is strongly favoured thereby leading to enhanced and red shifted emission in comparison to AEMOF-1 center dot DMAc. Powder X-ray diffraction measurements confirmed that complex 1 is identical to the hydrated form of AEMOF-1 center dot DMAc. As in the case of AEMOF-1 ‘, the dry form of complex 1 (1 ‘) is also an effective sensor for the determination of traces of water in tetrahydrofuran (THF). This work demonstrates that the same chromophore may exhibit very different emission properties when it exists in different chemical environments and that these transformations may be controlled and utilized in water sensing applications

Luminescent metal–organic frameworks as chemical sensors: common pitfalls and proposed best practices

The ever-increasing need to determine and monitor the chemical constituents of the constantly evolving environment has led the global scientific community to invest considerable research effort in the development of efficient and user-friendly chemical sensors. The development of improved chemical sensors largely depends on the synthesis of novel materials with the ability to transform a molecular recognition event into a readable signal. Among the various types of sensory materials, those where analyte detection is based on the change of a luminescence signal are gaining increasing attention due to the extremely high sensitivities which can be achieved in combination with new technological advances enabling the integration of optical detection systems in small, portable and easy to use devices. In this critical review we approach the emerging field of sensory materials based on luminescent metal-organic frameworks (LMOFs) by beginning with a survey of the general principles of luminescence-based sensing. In particular, after a brief overview, we first focus on the working principles and successes of well established sensory materials based on small molecules and conjugated polymers. Subsequently, we concentrate on the special features of LMOFs which make them promising sensory materials and we discuss best practices which researchers in the field should follow in order to prove the sensing ability of LMOFs and avoid common misconceptions and errors. We continue with presenting selected examples of LMOF-based sensors for nitroaromatics, humidity and heavy metal ions from the recent literature and we conclude with a summary of the state-of-the-art of LMOF sensors. Finally, we propose some directions for future research on LMOF sensors

Two new alkaline earth metal organic frameworks with the diamino derivative of biphenyl-4,4 ‘-dicarboxylate as bridging ligand: Structures, fluorescence and quenching by gas phase aldehydes

Alkaline earth metal ion organic frameworks (AEMOFs) represent a relatively underexplored subcategory of MOFs. Two new MOFs [Ca-6(bpdc-(NH2)(2))(5)(mu(3)-HCO2)(2)(H2O)(2.5)(DMF)(0.5)]center dot 0.5H(2)O center dot 2.5DMF (1) and [Sr-4(bpdc-(NH2)(4))( mu(2)-DMF)(2)(DMF)(1/3)]center dot 2/3(DMF) (2) [H(2)bpdc-(NH2)(2)= 2,2’-diamino-[1,1’-biphenyl]-4,4’dicarboxylic acid); DMF = N,N-dimethylformamide] are presented here. These MOFs display structural variety with diverse topologies and new structural features. Luminescence studies revealed that both MOFs display ligand based fluorescence with small differences in emission profiles possibly attributable to the difference in charge density of the metal ions combined with the different conformation adopted by the ligand in the crystal structures of 1 and 2. Furthermore, initial sensing studies reveal that both MOFs can potentially function as fluorescent sensors for gas phase aldehydes. (C) 2018 Elsevier Ltd. All rights reserved

Identifying novel regulatory effects for clinically relevant genes through the study of the Greek population

Abstract Background Expression quantitative trait loci (eQTL) studies provide insights into regulatory mechanisms underlying disease risk. Expanding studies of gene regulation to underexplored populations and to medically relevant tissues offers potential to reveal yet unknown regulatory variants and to better understand disease mechanisms. Here, we performed eQTL mapping in subcutaneous (S) and visceral (V) adipose tissue from 106 Greek individuals (Greek Metabolic study, GM) and compared our findings to those from the Genotype-Tissue Expression (GTEx) resource. Results We identified 1,930 and 1,515 eGenes in S and V respectively, over 13% of which are not observed in GTEx adipose tissue, and that do not arise due to different ancestry. We report additional context-specific regulatory effects in genes of clinical interest (e.g. oncogene ST7) and in genes regulating responses to environmental stimuli (e.g. MIR21, SNX33). We suggest that a fraction of the reported differences across populations is due to environmental effects on gene expression, driving context-specific eQTLs, and suggest that environmental effects can determine the penetrance of disease variants thus shaping disease risk. We report that over half of GM eQTLs colocalize with GWAS SNPs and of these colocalizations 41% are not detected in GTEx. We also highlight the clinical relevance of S adipose tissue by revealing that inflammatory processes are upregulated in individuals with obesity, not only in V, but also in S tissue. Conclusions By focusing on an understudied population, our results provide further candidate genes for investigation regarding their role in adipose tissue biology and their contribution to disease risk and pathogenesis

Pancreatic surgery outcomes: multicentre prospective snapshot study in 67 countries

Background: Pancreatic surgery remains associated with high morbidity rates. Although postoperative mortality appears to have improved with specialization, the outcomes reported in the literature reflect the activity of highly specialized centres. The aim of this study was to evaluate the outcomes following pancreatic surgery worldwide.Methods: This was an international, prospective, multicentre, cross-sectional snapshot study of consecutive patients undergoing pancreatic operations worldwide in a 3-month interval in 2021. The primary outcome was postoperative mortality within 90 days of surgery. Multivariable logistic regression was used to explore relationships with Human Development Index (HDI) and other parameters.Results: A total of 4223 patients from 67 countries were analysed. A complication of any severity was detected in 68.7 percent of patients (2901 of 4223). Major complication rates (Clavien-Dindo grade at least IIIa) were 24, 18, and 27 percent, and mortality rates were 10, 5, and 5 per cent in low-to-middle-, high-, and very high-HDI countries respectively. The 90-day postoperative mortality rate was 5.4 per cent (229 of 4223) overall, but was significantly higher in the low-to-middle-HDI group (adjusted OR 2.88, 95 per cent c.i. 1.80 to 4.48). The overall failure-to-rescue rate was 21 percent; however, it was 41 per cent in low-to-middle-compared with 19 per cent in very high-HDI countries.Conclusion: Excess mortality in low-to-middle-HDI countries could be attributable to failure to rescue of patients from severe complications. The authors call for a collaborative response from international and regional associations of pancreatic surgeons to address management related to death from postoperative complications to tackle the global disparities in the outcomes of pancreatic surgery (NCT04652271; ISRCTN95140761)