Cooperative CO2 adsorption mechanism in a perfluorinated CeIV-based metal organic framework.

Adsorbents able to uptake large amounts of gases within a narrow range of pressure, i.e., phase-change adsorbents, are emerging as highly interesting systems to achieve excellent gas separation performances with little energy input for regeneration. A recently discovered phase-change metal-organic framework (MOF) adsorbent is F4_MIL-140A(Ce), based on CeIV and tetrafluoroterephthalate. This MOF displays a non-hysteretic step-shaped CO2 adsorption isotherm, reaching saturation in conditions of temperature and pressure compatible with real life application in post-combustion carbon capture, biogas upgrading and acetylene purification. Such peculiar behaviour is responsible for the exceptional CO2/N2 selectivity and reverse CO2/C2H2 selectivity of F4_MIL-140A(Ce). Here, we combine data obtained from a wide pool of characterisation techniques - namely gas sorption analysis, in situ infrared spectroscopy, in situ powder X-ray diffraction, in situ X-ray absorption spectroscopy, multinuclear solid state nuclear magnetic resonance spectroscopy and adsorption microcalorimetry - with periodic density functional theory simulations to provide evidence for the existence of a unique cooperative CO2 adsorption mechanism in F4_MIL-140A(Ce). Such mechanism involves the concerted rotation of perfluorinated aromatic rings when a threshold partial pressure of CO2 is reached, opening the gate towards an adsorption site where CO2 interacts with both open metal sites and the fluorine atoms of the linker.

The Long-term Efficacy and Safety of Fecal Microbiota Transplant for Recurrent, Severe, and Complicated Clostridium difficile Infection in 146 Elderly Individuals.

OBJECTIVES: Clostridium difficile infection (CDI) in the elderly has a higher prevalence, greater morbidity and mortality, and lower response to conventional treatment than the general population. Fecal microbiota transplant (FMT) is highly effective therapy for CDI but has not been studied specifically in the elderly. This study aims to determine the long-term efficacy and safety of FMT for recurrent (RCDI), severe (SCDI), and complicated (CCDI) CDI in elderly patients. METHODS: A multicenter, long-term follow-up study was performed with demographic, pre-FMT, and post-FMT data collected from elderly patients with RCDI, SCDI, and CCDI, through a 47-item questionnaire. Outcome measures included primary and secondary cure rates, early (<12 wk) and late (≥12 wk) recurrence rates, and adverse events (AEs), including post-FMT diagnoses. RESULTS: Of 168 eligible patients, 146 patients met the inclusion criteria. Of these, 68.5% were women. The mean (range) age was 78.6 (65 to 97) years and the follow-up period was 12.3 (1 to 48) months. FMT was performed for RCDI in 89 (61%), SCDI in 45 (30.8%), and CCDI in 12 (8.2%) patients. The primary and secondary cure rates were 82.9% and 95.9%, respectively. Early and late recurrences occurred in 25 and 6 patients, respectively. AEs included CDI-negative diarrhea in 7 (4.8%) and constipation in 4 (2.7%) patients. Serious AEs, recorded in 6 patients, were hospital admissions for CDI-related diarrhea, one of which culminated in death. New diagnoses post-FMT included microscopic colitis (2), Sjogren syndrome (1), follicular lymphoma (1), contact dermatitis and idiopathic Bence-Jones proteinuria (1), and laryngeal carcinoma (1)-all, however, were associated with predisposing factors. CONCLUSIONS: FMT is a safe and effective treatment option for RCDI, SCDI, and CCDI in elderly patients.

Long-term Follow-up Study of Fecal Microbiota Transplantation for Severe and/or Complicated Clostridium difficile Infection: A Multicenter Experience.

GOAL: Our aim was to investigate fecal microbiota transplantation (FMT) efficacy in patients with severe and/or complicated Clostridium difficile infection (CDI). BACKGROUND: FMT is successful for recurrent CDI, although its benefit in severe or complicated CDI has not specifically been evaluated. STUDY METHODS: A multicenter long-term follow-up study was performed in patients who received FMT for severe and/or complicated CDI (diagnosed using standard criteria). Pre-FMT and post-FMT questionnaires were completed. Study outcomes included cure rates and time to resolution of symptoms. RESULTS: A total of 17 patients (82% inpatients, 18% outpatients) were included (76.4% women; mean age, 66.4 y; mean follow-up, 11.4 mo). Patients had severe and complicated (76.4%) or either severe or complicated (23.6%) CDI. Sixteen patients (94.1%) had diarrhea, which resolved in 12 (75%; mean time to resolution, 5.7 d) and improved in 4 (25%) after FMT. Eleven patients (64.7%) had abdominal pain, which resolved in 8 (72.7%; mean time to resolution, 9.6 d) and improved in 3 (27.3%) after FMT. Two of 17 patients experienced early CDI recurrence (≤90 d) after FMT (primary cure rate, 88.2%); and in 1 patient, a second FMT resulted in cure (secondary cure rate, 94.1%). Late CDI recurrence (≥90 d) was seen in 1 of 17 patients (5.9%) in association with antibiotics and was successfully treated with a repeat FMT. No adverse effects directly related to FMT occurred. CONCLUSIONS: FMT was successful and safe in this cohort of patients with severe or complicated CDI. Primary and secondary cure rates were 88.2% and 94.1%, respectively.

Fecal microbiota transplant for treatment of Clostridium difficile infection in immunocompromised patients.

OBJECTIVES: Patients who are immunocompromised (IC) are at increased risk of Clostridium difficile infection (CDI), which has increased to epidemic proportions over the past decade. Fecal microbiota transplantation (FMT) appears effective for the treatment of CDI, although there is concern that IC patients may be at increased risk of having adverse events (AEs) related to FMT. This study describes the multicenter experience of FMT in IC patients. METHODS: A multicenter retrospective series was performed on the use of FMT in IC patients with CDI that was recurrent, refractory, or severe. We aimed to describe rates of CDI cure after FMT as well as AEs experienced by IC patients after FMT. A 32-item questionnaire soliciting demographic and pre- and post-FMT data was completed for 99 patients at 16 centers, of whom 80 were eligible for inclusion. Outcomes included (i) rates of CDI cure after FMT, (ii) serious adverse events (SAEs) such as death or hospitalization within 12 weeks of FMT, (iii) infection within 12 weeks of FMT, and (iv) AEs (related and unrelated) to FMT. RESULTS: Cases included adult (75) and pediatric (5) patients treated with FMT for recurrent (55%), refractory (11%), and severe and/or overlap of recurrent/refractory and severe CDI (34%). In all, 79% were outpatients at the time of FMT. The mean follow-up period between FMT and data collection was 11 months (range 3-46 months). Reasons for IC included: HIV/AIDS (3), solid organ transplant (19), oncologic condition (7), immunosuppressive therapy for inflammatory bowel disease (IBD; 36), and other medical conditions/medications (15). The CDI cure rate after a single FMT was 78%, with 62 patients suffering no recurrence at least 12 weeks post FMT. Twelve patients underwent repeat FMT, of whom eight had no further CDI. Thus, the overall cure rate was 89%. Twelve (15%) had any SAE within 12 weeks post FMT, of which 10 were hospitalizations. Two deaths occurred within 12 weeks of FMT, one of which was the result of aspiration during sedation for FMT administered via colonoscopy; the other was unrelated to FMT. None suffered infections definitely related to FMT, but two patients developed unrelated infections and five had self-limited diarrheal illness in which no causal organism was identified. One patient had a superficial mucosal tear caused by the colonoscopy performed for the FMT, and three patients reported mild, self-limited abdominal discomfort post FMT. Five (14% of IBD patients) experienced disease flare post FMT. Three ulcerative colitis (UC) patients underwent colectomy related to course of UC >100 days after FMT. CONCLUSIONS: This series demonstrates the effective use of FMT for CDI in IC patients with few SAEs or related AEs. Importantly, there were no related infectious complications in these high-risk patients.