CO2 Adsorption in a Robust Iron(III) Pyrazolate-Based MOF: Molecular-Level Details and Frameworks Dynamics From Powder X-ray Diffraction Adsorption Isotherms

Understanding adsorption processes at the molecular level, with multi-technique approaches, is nowadays at the frontier of porous materials research. In this work it is shown that with a proper data treatment, in situ high-resolution powder X-ray diffraction (HR-PXRD) at variable temperature and gas pressure can reveal atomic details of the accommodation sites, the framework dynamics as well as thermodynamic information (isosteric heat of adsorption) of the CO2 adsorption process in the robust iron(III) pyrazolate-based MOF Fe2(BDP)3 [H2BDP = 1,4-bis(1H-pyrazol-4-yl)benzene]. Highly reliable "HR-PXRD adsorption isotherms" can be constructed from occupancy values of CO2 molecules. The "HR-PXRD adsorption isotherms" accurately match the results of conventional static and dynamic gas sorption experiments and Monte Carlo simulations. These results are indicative of the impact of the molecular-level behavior on the bulk properties of the system under study and of the potential of the presented multi-technique approach to understand adsorption processes in metal-organic frameworks

Electron transfer and CO addition to polynitrido cobalt carbonyl clusters: Parallel pathways for conversion of the [Co10N2(CO)(19)](4-) anion to the novel [Co11N2(CO)(21)](3-) anion

The redox aptitude of the dinitrido anion [Co10N2(CO)19]4- has been tested from both chemical and electrochemical points of view, together with its reactivity toward CO that induces disproportionation. In any case, through a remarkable overlapping of intermediate steps, the new anion [Co11N2(CO)21]3- (4) is eventually obtained. A detailed study of the pathways to 4 allowed the identification of three labile intermediates by their characteristic IR spectra as well as their electrochemical and paramagnetic properties. The unprecedented structure of trianion 4 has been studied in details in two different crystalline salts

Ct-Guided Pancreatic Percutaneous Fine-needle Biopsy in Differential Diagnosis Between Pancreatic Cancer and Chronic Pancreatitis

Differential diagnosis between pancreatic cancer and chronic pancreatitis is still difficult to establish. In 63 patients with suspected pancreatic neoplasm we performed: serum CA 19-9 assessment, abdominal ultrasound, CT scan and CT-guided pancreatic percutaneous fine-needle biopsy. The conclusive diagnosis was pancreatic cancer in 40 patients and chronic pancreatitis in 23 patients. With regard to the differential diagnosis, sensitivity and specificity were respectively 80% and 78% for serum CA 19-9, 75% and 65% for abdominal US, 85% and 70% for CT scan, 00% and 87% for percutaneous fine-needle biopsy. We conclude that CT-guided percutaneous fine-needle biopsy is the most reliable method for differential diagnosis between pancreatic cancer and chronic pancreatitis

Thermally induced interconversions of metal-pyrimidine-4,6-dicarboxylate polymers: A structural, spectroscopic, and magnetic study

Continuing our work on the structural and magnetic aspects of the one-dimensional (1-D) coordination polymers of the [M(pmdc)(H2O)2]\ub7H2O kind (M Fe, Co, Ni, Cu, Zn; pmdc pyrimidine-4,6-dicarboxylate), we have combined ab initio X-ray powder diffraction methods with in situ thermodiffractometry and thermal analyses to characterize the selective and reversible transformation of the [M(pmdc)(H2O)2]\ub7H2O compounds (M Fe, Co, Ni, Cu) into the bis-hydrated [M(pmdc)(H2O)2] counterparts by moderate heating, which is followed by an irreversible transformation into two-dimensional (2-D) anhydrous species. The structural features of the transient bis-hydrated species and of the completely dehydrated one are described for M Cu. Remarkably, the \ufb01rst dehydration process does not alter the 1-D nature of the [M(pmdc)(H2O)2] chains; on the contrary, the second dehydration gives rise to the loss of the axially coordinated water molecules with a concomitant condensation of the 1-D chains into 2-D layers through ancillary carboxylate bridging groups. The magnetic properties of the anhydrous [M(pmdc)] species (M Co, Ni, Cu) have been investigated, showing that these phases behave as 1-D antiferromagnets with interchain interactions. Notably, in the case of the [Ni(pmdc)] system, a weak ferromagnetic ordering, arising from a spin canting phenomenon with a blocking temperature of 13 K, is observed

Multiparametric magnetic resonance imaging and clinical variables: Which is the best combination to predict reclassification in active surveillance patients?

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kokusui shugisha no kokusai ninshiki to kokka koso :fukumoto nichinan o chushin to shite

制度:新 ; 文部省報告番号:乙1736号 ; 学位の種類:博士(文学) ; 授与年月日:2002/11/19 ; 早大学位記番号:新343

Colorectal Cancer Stage at Diagnosis Before vs During the COVID-19 Pandemic in Italy

IMPORTANCE Delays in screening programs and the reluctance of patients to seek medical attention because of the outbreak of SARS-CoV-2 could be associated with the risk of more advanced colorectal cancers at diagnosis. OBJECTIVE To evaluate whether the SARS-CoV-2 pandemic was associated with more advanced oncologic stage and change in clinical presentation for patients with colorectal cancer. DESIGN, SETTING, AND PARTICIPANTS This retrospective, multicenter cohort study included all 17 938 adult patients who underwent surgery for colorectal cancer from March 1, 2020, to December 31, 2021 (pandemic period), and from January 1, 2018, to February 29, 2020 (prepandemic period), in 81 participating centers in Italy, including tertiary centers and community hospitals. Follow-up was 30 days from surgery. EXPOSURES Any type of surgical procedure for colorectal cancer, including explorative surgery, palliative procedures, and atypical or segmental resections. MAIN OUTCOMES AND MEASURES The primary outcome was advanced stage of colorectal cancer at diagnosis. Secondary outcomes were distant metastasis, T4 stage, aggressive biology (defined as cancer with at least 1 of the following characteristics: signet ring cells, mucinous tumor, budding, lymphovascular invasion, perineural invasion, and lymphangitis), stenotic lesion, emergency surgery, and palliative surgery. The independent association between the pandemic period and the outcomes was assessed using multivariate random-effects logistic regression, with hospital as the cluster variable. RESULTS A total of 17 938 patients (10 007 men [55.8%]; mean [SD] age, 70.6 [12.2] years) underwent surgery for colorectal cancer: 7796 (43.5%) during the pandemic period and 10 142 (56.5%) during the prepandemic period. Logistic regression indicated that the pandemic period was significantly associated with an increased rate of advanced-stage colorectal cancer (odds ratio [OR], 1.07; 95%CI, 1.01-1.13; P = .03), aggressive biology (OR, 1.32; 95%CI, 1.15-1.53; P < .001), and stenotic lesions (OR, 1.15; 95%CI, 1.01-1.31; P = .03). CONCLUSIONS AND RELEVANCE This cohort study suggests a significant association between the SARS-CoV-2 pandemic and the risk of a more advanced oncologic stage at diagnosis among patients undergoing surgery for colorectal cancer and might indicate a potential reduction of survival for these patients

Chemical bonding in transition metal carbonyl clusters: Complementary analysis of theoretical and experimental electron densities

In the last few years, the quantum theory of atoms in molecules has become the paradigm for interpreting theoretical and experimental electron density distributions. Within this framework, the link between bonding modes and topological properties has been fully achieved for 'light atom' molecules. However, the derived correspondence rules cannot be extended straightforwardly to organometallic compounds since bonds to a transition metal display a different and much narrower spectrum of topological indexes. The complementary usage of theoretical computations on a set of prototype transition metal molecules and experimental determinations of the electron density in transition metal carbonyl clusters are discussed. Since these compounds are characterised by weakly bound metal cages and fluxional carbonyl ligands, the focus is on the nature of metal-metal and metal-carbonyl interactions as well as on the evolution of three-centre-four-electron M(μ-CO)M bonds along the (CO)M-M↔M(μ-CO)M↔M-M(CO) conversion path. The interpretation of the electron density distribution here proposed could be extended reasonably to a wider class of organometallic compounds. © 2002 Elsevier Science B.V. All rights reserved