Charge-Assisted Ionic Hydrogen-Bonded Organic Frameworks: Designable and Stabilized Multifunctional Materials.

Hydrogen-bonded organic frameworks (HOFs) are a class of crystalline framework materials assembled by hydrogen bonds. HOFs have the advantages of high crystallinity, mild reaction conditions, good solution processability, and reproducibility. Coupled with the reversibility and flexibility of hydrogen bonds, HOFs can be assembled into a wide diversity of crystalline structures. Since the bonding energy of hydrogen bonds is lower than that of ligand and covalent bonds, the framework of HOFs is prone to collapse after desolventisation and the stability is not high, which limits the development and application of HOFs. In recent years, numerous stable and functional HOFs have been developed by π-π stacking, highly interpenetrated networks, charge-assisted, ligand-bond-assisted, molecular weaving, and covalent cross-linking. Charge-assisted ionic HOFs introduce electrostatic attraction into HOFs to improve stability while enriching structural diversity and functionality. In this paper, we review the development, the principles of rational design and assembly of charge-assisted ionic HOFs, and introduces the different building block construction modes of charge-assisted ionic HOFs. Highlight the applications of charge-assisted ionic HOFs in gas adsorption and separation, proton conduction, biological applications, etc., and prospects for the diverse design of charge-assisted ionic HOFs structures and multifunctional applications.

Water-Induced Single-Crystal to Single-Crystal Transformation of Ionic Hydrogen-Bonded Organic Frameworks with Enhanced Proton Conductivity.

Two ionic hydrogen-bonded organic frameworks (iHOF-10, iHOF-11) were prepared using 1,1'-diamino-4,4'-bipyridine diiodide (Dbpy ⋅ 2I) and tetrakis(4-sulfophenyl)ethylene (H4 TPE). With increasing RH and temperature, water molecules induce single crystal to single crystal (SCSC) transformation of iHOF-10, resulting in the formation of iHOF-11. At 90 °C, 98 % RH, the proton conductivity of iHOF-11 (7.03×10-3  S cm-1 ) is 2.09 times higher than iHOF-10 (3.37×10-3  S cm-1 ). At 50 °C, 98 % RH, iHOF-11 (9.49×10-4  S cm-1 ) is 19.06 times higher than iHOF-10 (4.98×10-5  S cm-1 ). The proton conductivity shows water molecules enter the crystal and induce crystal transformation and reorganization of the hydrogen bonding structure, thus increasing the proton conductivity and stability.

Ex utero intrapartum treatment for giant congenital omphalocele.

BACKGROUND: To determine whether ex utero intrapartum treatment (EXIT) is an appropriate approach for managing fetuses antenatally diagnosed with giant congenital omphaloceles. METHODS: We retrospectively reviewed patients with omphaloceles who underwent either an EXIT procedure or a traditional repair surgery. Basic and clinical parameters including gender, gestational age, birth weight, maternal blood loss, operative times and operative complications were analyzed. During the 6-12-month follow-ups, postoperative complications including bowel obstruction, abdominal infections, postoperative abdominal distension were monitored, and survival rate was analyzed. RESULTS: A total of seven patients underwent the EXIT procedure and 11 patients underwent the traditional postnatal surgery. We found no differences in maternal age, gestational age at diagnosis, gestational age at delivery and birth weight between the two groups. In the EXIT group, the average operation time for mother was 68.3 ± 17.5 minutes and the average maternal blood loss was 233.0 ± 57.7 mL. The operation time in the EXIT group (22.0 ± 4.5 minutes) was shorter than that in the traditional group (35 ± 8.7 minutes), but the length of hospital stay in the EXIT group (20.5 ± 3.1 days) was longer than that in the traditional group (15.7 ± 2.5 days, P < 0.05). During the follow-up, one patient in the EXIT group had an intestinal obstruction, one developed abdominal compartment syndrome and one died in the traditional group. CONCLUSIONS: In our experience, EXIT is a safe and effective procedure for the treatment of giant congenital omphaloceles. However, more experience is needed before this procedure can be widely recommended.

Novel Insights into the Pathogenesis of Hirschsprung's-associated Enterocolitis.

OBJECTIVE: To systematically summary the updated results about the pathogenesis of Hirschsprung's-associated enterocolitis (HAEC). Besides, we discussed the research key and direction based on these results. DATA SOURCES: Our data cited in this review were obtained mainly from PubMed from 1975 to 2015, with keywords "Hirschsprung enterocolitis", "Hirschsprung's enterocolitis", "Hirschsprung's-associated enterocolitis", "Hirschsprung-associated enterocolitis", "HAEC", and "EC". STUDY SELECTION: Articles regarding the pathogenesis of HAEC were selected, and the articles mainly regarding the diagnosis, surgical approach, treatment, and follow-up were excluded. RESULTS: Several factors, mainly including mucus barrier, intestinal microbiota, and immune function, as well as some other factors such as genetic variations and surgical reasons, have been found to be related to the pathogenesis of HAEC. Changed quantity and barrier property of mucus, different composition of microbiota, and an abnormal immune state work together or separately trigger HAEC. CONCLUSIONS: The maintenance of intestinal homeostasis is due to a well cooperation of microbiota, mucus barrier, and immune system. If any part presents abnormal, intestinal homeostasis will be broken. Meanwhile, for patients with Hirschsprung's disease or HAEC, dysfunction of these parts has been found. Thus, the happening of HAEC may be mainly attributed to the disorders of intestinal microbiota, mucus barrier, and immune system.