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1.
Immunity ; 38(1): 153-65, 2013 Jan 24.
Artículo en Inglés | MEDLINE | ID: mdl-23246312

RESUMEN

Circulatory antigens transit through the small intestine via the fenestrated capillaries in the lamina propria prior to entering into the draining lymphatics. But whether or how this process controls mucosal immune responses remains unknown. Here we demonstrate that dendritic cells (DCs) of the lamina propria can sample and process both circulatory and luminal antigens. Surprisingly, antigen cross-presentation by resident CX3CR1(+) DCs induced differentiation of precursor cells into CD8(+) T cells that expressed interleukin-10 (IL-10), IL-13, and IL-9 and could migrate into adjacent compartments. We conclude that lamina propria CX3CR1(+) DCs facilitate the surveillance of circulatory antigens and act as a conduit for the processing of self- and intestinally absorbed antigens, leading to the induction of CD8(+) T cells, that partake in the control of T cell activation during mucosal immune responses.


Asunto(s)
Presentación de Antígeno/inmunología , Linfocitos T CD8-positivos/inmunología , Células Dendríticas/inmunología , Mucosa Intestinal/inmunología , Activación de Linfocitos/inmunología , Animales , Antígenos/inmunología , Linfocitos T CD4-Positivos/inmunología , Linfocitos T CD8-positivos/citología , Receptor 1 de Quimiocinas CX3C , Diferenciación Celular/inmunología , Reactividad Cruzada/inmunología , Células Dendríticas/metabolismo , Enteritis/inmunología , Enteritis/prevención & control , Epítopos de Linfocito T/inmunología , Mucosa Intestinal/citología , Intestino Delgado/inmunología , Ratones , Receptores de Quimiocina/inmunología , Receptores de Quimiocina/metabolismo
2.
Chem Rev ; 120(16): 8039-8065, 2020 08 26.
Artículo en Inglés | MEDLINE | ID: mdl-32302477

RESUMEN

Reticular chemistry has proven as a notable/distinctive discipline aimed at the deliberate assembly of periodic solids, offering great opportunities to effectively deploy the gained knowledge on net-topologies as a guide and toolbox for designed syntheses, based on the assembly of molecular building blocks into targeted and anticipated structures of crystalline extended solids. The effective practice of reticular chemistry has enriched the repertoire of crystal chemistry and afforded notable accelerating development of crystalline extended frameworks, especially metal-organic frameworks (MOFs). Here, we review a special class of trinodal MOF structures based on the reticulation of special minimal edge-transitive nets (nets with transitivity [3 2], three distinct nodes and two kind of edges) derived from edge-transitive nets (one kind of edge). The rationale for deriving these special minimal edge-transitive nets is reviewed, and their associated net-coded building (net-cBUs) for the design of trinodal MOFs is presented and discussed. The resultant inclusive list of the enumerated minimal edge-transitive nets provides a unique toolbox for the material's designer as it offers ideal blueprints for the deliberate design and rational assembly of building blocks with embedded multiple branch points into intricate trinodal MOFs.

3.
Emerg Radiol ; 28(3): 549-555, 2021 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-33428044

RESUMEN

PURPOSE: Benefits of overnight attending radiologist final reports are debated, often stating low resident discrepancy rates, usually assessed retrospectively. The objective of this study was to assess the impact of overnight final reporting on the recall rates for patients in the emergency department (ED) receiving overnight imaging. METHODS: Retrospective matched cohorts of two separate years prior (prior-16 and prior-17) and 1 year after (post-18) introduction of overnight attending radiologist final reporting. Patients receiving imaging between 22:00 and 07:00 h and returned to ED within 48 h of initial visit discharge were electronically identified. String matching identified return visits possibly related to imaging completed on first visit. Identified return visit notes were scored by three observers individually. Unclear and discrepant cases were resolved by consensus meeting, using full patient charts where needed. Incidences were provided and logistic regression analysis defined if coverage model was a predictor for recall. Odds ratios were calculated. RESULTS: ED patient count with imaging completed overnight in prior-16 was 9200, in prior-17 was 9543, and in post-18 was 9992. The number of overnight imaging studies performed was respectively 13,883, 14,463, and 15,112. Imaging-related ED recalls were respectively 54, 61, and 7, a decrease with the new coverage model of 89% to true and at least 90% of expected recalls.Logistic regression demonstrated that coverage model was a significant predictor of ED recalls with chi-square of 59.86 and p < 0.001, an R2 of 0.03 (Hosmer and Lemeshow). Compared to post-18, ED patients had an odds ratio of 8.42 (prior-16) and 9.18 (prior-17) to be called back to ED. CONCLUSION: Overnight final reporting significantly decreases ED recalls for patients receiving diagnostic imaging overnight. While numbers are low even prior to rollout, the number should be minimized wherever possible to diminish patient anxiety and discomfort, reduce ED overcrowding and expedite definitive management. KEY MESSAGES/WHAT THIS PAPER ADDS: Section 1: What is already known on this subject • Radiology resident preliminary report discrepancy rates are low. • Overnight attending radiologist coverage is a model increasingly applied in academic and large non-academic centers. • Patient recalls to the ED are a burden to the patient and impact patient throughput in (over)crowded EDs. Section 2: What this study adds • First study to look at the impact of overnight attending final reports on the recall rate for ED patients with overnight imaging performed. • While absolute numbers are low, there is a significant decrease in patients returning to ED for imaging related issues after introducing overnight attending coverage. • Resident autonomy can be preserved and training enhanced while increasing patient safety and comfort.


Asunto(s)
Servicio de Urgencia en Hospital , Radiólogos , Diagnóstico por Imagen , Humanos , Estudios Retrospectivos
4.
J Am Chem Soc ; 142(20): 9258-9266, 2020 May 20.
Artículo en Inglés | MEDLINE | ID: mdl-32336085

RESUMEN

Introducing multiclusters and multiligands (mm) in a well-defined array will greatly increase the diversity of metal-organic frameworks (MOFs). Here, a series of porous mm-MOFs constructed from a pillared-layer and pore-space partition (PL-PSP) have been achieved. FJU-6 with {Co3}-cluster-based sheets and {Co6}-cluster-based pillars exhibits new (3,9,12)-connected llz topology. By using the substituted analogues of the ligands and metal ions, seven isoreticular mm-MOFs (FJU-6-X, X = PTB, TATB, Me-INA, F-INA, NDC, BrBDC, Ni) have been synthesized with the adjustable BET surface areas ranging from 731 to 1306 m2/g as well as the adsorption capacity of CO2 increasing by 77%. The C2H2/CO2 mixture can be effectively separated in the breakthrough experiments in the fixed bed filled with solid FJU-6-TATB at ambient temperature. In all, integrating pillared-layer strategy and pore-space partitioning is effective at constructing mm-MOFs with multivariate environments for the optimization of gas adsorption and separation.

5.
J Am Chem Soc ; 142(39): 16795-16804, 2020 09 30.
Artículo en Inglés | MEDLINE | ID: mdl-32894014

RESUMEN

The first bioinspired microporous metal-organic framework (MOF) synthesized using ellagic acid, a common natural antioxidant and polyphenol building unit, is presented. Bi2O(H2O)2(C14H2O8)·nH2O (SU-101) was inspired by bismuth phenolate metallodrugs, and could be synthesized entirely from nonhazardous or edible reagents under ambient aqueous conditions, enabling simple scale-up. Reagent-grade and affordable dietary supplement-grade ellagic acid was sourced from tree bark and pomegranate hulls, respectively. Biocompatibility and colloidal stability were confirmed by in vitro assays. The material exhibits remarkable chemical stability for a bioinspired MOF (pH = 2-14, hydrothermal conditions, heated organic solvents, biological media, SO2 and H2S), attributed to the strongly chelating phenolates. A total H2S uptake of 15.95 mmol g-1 was recorded, representing one of the highest H2S capacities for a MOF, where polysulfides are formed inside the pores of the material. Phenolic phytochemicals remain largely unexplored as linkers for MOF synthesis, opening new avenues to design stable, eco-friendly, scalable, and low-cost MOFs for diverse applications, including drug delivery.


Asunto(s)
Materiales Biocompatibles/síntesis química , Bismuto/química , Ácido Elágico/química , Estructuras Metalorgánicas/síntesis química , Materiales Biocompatibles/química , Teoría Funcional de la Densidad , Estructuras Metalorgánicas/química , Estructura Molecular
6.
Can Assoc Radiol J ; 71(3): 388-395, 2020 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-32174156

RESUMEN

A mass casualty incident (MCI) is an event that generates more patients at one time than locally available resources can manage using routine procedures. By their nature, many of these incidents have no prior notice but result in large numbers of casualties with injuries that range in severity. They can happen anywhere and at any time and regional hospitals and health-care providers have to mount a response quickly and effectively to save as many lives as possible. Radiologists must go from passenger to pilot when it comes to MCI planning. When involved at the hospital-wide planning stage, they can offer valuable expertise on how radiology can improve triage accuracy and at what cost in terms of time and resources and thereby contribute a pragmatic understanding of radiology's role and value during MCIs. By taking ownership of MCI planning in their own departments, radiologists can ensure that the radiology department can respond quickly and effectively to unforeseen emergencies. Well-designed radiology protocols will save lives in an MCI setting.


Asunto(s)
Planificación en Desastres , Servicio de Urgencia en Hospital/organización & administración , Incidentes con Víctimas en Masa , Política Organizacional , Servicio de Radiología en Hospital/organización & administración , Heridas y Lesiones/diagnóstico por imagen , Humanos , Triaje/métodos
7.
Can Assoc Radiol J ; 71(3): 362-370, 2020 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-32189521

RESUMEN

Since the advent of multidetecter computed tomography (CT), radiologist sensitivity in detection of traumatic bowel and mesenteric abnormalities has significantly improved. Although several CT signs have been described to identify intestinal injury, accurate interpretation of these findings can remain challenging. Early detection of bowel and mesenteric injury is important as it alters patient management, disposition, and follow-up. This article reviews the common imaging findings of traumatic small bowel and mesenteric injury.


Asunto(s)
Traumatismos Abdominales/diagnóstico por imagen , Intestinos/lesiones , Mesenterio/lesiones , Tomografía Computarizada Multidetector/métodos , Accidentes de Tránsito , Medios de Contraste , Diagnóstico Precoz , Humanos , Sensibilidad y Especificidad
8.
J Am Chem Soc ; 141(1): 488-496, 2019 01 09.
Artículo en Inglés | MEDLINE | ID: mdl-30449084

RESUMEN

We report the design and synthesis of two metal-organic frameworks (MOFs) with permanent porosity, MOF-818 and MOF-919, using a small ditopic organic linker, 1H-pyrazole-4-carboxylic acid (H2PyC), 0.4 nm in length. Three mesoporous cages of unprecedented polyhedra are identified in these MOFs, a wuh cage in MOF-818 and yys and liu cages in MOF-919, with diameters of 3.8, 4.9, and 6.0 nm, respectively. The ditopic H2PyC linker functions as the edge in the structure, while two types of metal-containing second building units (SBUs) function as the vertices. 28 vertices are present in the wuh cage; 50 in the yys cage; and 70 in the liu cage. Systematic analysis of these cages along with other mesoporous cages in supramolecules and MOFs constructed by ditopic linkers reveals that the extension of cage size is dictated by both the number and connectivity of the vertices. The increase in cage size is proportional to the number of vertices, while the growth rate is determined by their connectivity. The reduction in connectivity is found to be an effective way to create large cages. All three cages in this report are constructed by three-connecting (3-c) vertices and two-connecting (2-c) vertices. This [2-c, 3-c] connectivity represents the least connectivity required for the construction of cages and the most effective one for cage size expansion. The largest cage, liu, exhibits a cage size to linker size ratio of 15, outstanding in supramolecules and MOFs. MOF-818 is stable in water with a wide pH range (pH = 2-12), and the wuh cage is big enough for the inclusion of biomolecules such as vitamin B12 and insulin.

9.
J Am Chem Soc ; 141(51): 20480-20489, 2019 Dec 26.
Artículo en Inglés | MEDLINE | ID: mdl-31794212

RESUMEN

Minimal edge-transitive nets are regarded as suitable blueprints for the successful practice of reticular chemistry, and par excellence ideal for the deliberate design and rational construction of highly coordinated metal-organic frameworks (MOFs). We report the systematic generation of the highly connected minimal edge-transitive related nets (transitivity [32]) from parent edge-transitive nets (transitivity [21] or [11]), and their use as a guide for the deliberate design and directional assembly of highly coordinated MOFs from their associated net-coded building units (net-cBUs), 12-connected (12-c) double six-membered ring (d6R) building units. Notably, the generated related nets enclose the distinctive highly coordinated d6R (12-c) due to the subsequent coordination number increase in one node of the resultant new related net; that is, the (3,4,12)-c kce net is the (4,6)-c soc-related net, and the (3,6,12)-c kex and urx nets are the (6,6)-c nia-related nets. Intuitively, the combination of 12-connected hexagonal prismatic rare-earth (RE) nonanuclear [RE9(µ3-O)2(µ3-OH)12(O2C-)12] carboxylate-based clusters with purposely chosen organic or organic-inorganic hybrid building units led to the formation of the targeted highly coordinated MOFs based on selected minimal edge-transitive related nets. Interestingly, the kex-MOFs can alternatively be regarded as a zeolite-like MOF (ZMOF) based on the zeolite underlying topology afx, by considering the dodecacarboxylate ligand as a d6R building unit, delineating a new avenue toward the construction of ZMOFs through the composite building units as net-cBUs. This represents a significant step toward the effective discovery and design of novel minimal edge-transitive and highly coordinated materials using the d6Rs as net-cBUs.

10.
Chem Soc Rev ; 47(12): 4642-4664, 2018 Jun 18.
Artículo en Inglés | MEDLINE | ID: mdl-29726872

RESUMEN

The geometry of simple knots and catenanes is described using the concept of linear line segments (sticks) joined at corners. This is extended to include woven linear threads as members of the extended family of knots. The concept of transitivity that can be used as a measure of regularity is explained. Then a review is given of the simplest, most 'regular' 2- and 3-periodic patterns of polycatenanes and weavings. Occurrences in crystal structures are noted but most structures are believed to be new and ripe targets for designed synthesis.

11.
J Am Chem Soc ; 140(28): 8858-8867, 2018 07 18.
Artículo en Inglés | MEDLINE | ID: mdl-29923711

RESUMEN

Rational design and construction of metal-organic frameworks (MOFs) with intricate structural complexity are of prime importance in reticular chemistry. We report our latest addition to the design toolbox in reticular chemistry, namely the concept of merged nets based on merging two edge-transitive nets into a minimal edge-transitive net for the rational construction of intricate mixed-linker MOFs. In essence, a valuable net for design enclosing two edges (not related by symmetry) is rationally generated by merging two edge-transitive nets, namely (3,6)-coordinated spn and 6-coordinated hxg. The resultant merged-net, a (3,6,12)-coordinated sph net with net transitivity [32] enclosing three nodes and two distinct edges, offers potential for deliberate design of intricate mixed-linker MOFs. We report implementation of the merged-net approach for the construction of isoreticular rare-earth mixed-linker MOFs, sph-MOF-1 to -4, based on the assembly of 12-c hexanuclear carboxylate-based molecular building blocks (MBBs), displaying cuboctahedral building units, 3-c tritopic ligands, and 6-c hexatopic ligands. The resultant sph-MOFs represent the first examples of MOFs where the underlying net is merged from two 3-periodic edge-transitive nets, spn and hxg. Distinctively, the sph-MOF-3 represents the first example of a mixed-linker MOF to enclose both trigonal and hexagonal linkers. The merged-nets approach allows the logical practice of isoreticular chemistry by taking into account the mathematically correlated dimensions of the two ligands to afford the deliberate construction of a mixed-linker mesoporous MOF, sph-MOF-4. The merged-net equation and two key parameters, ratio constant and MBB constant, are disclosed. A merged-net strategy for the design of mixed-linker MOFs by strictly controlling the size ratio between edges is introduced.

12.
J Am Chem Soc ; 140(20): 6194-6198, 2018 05 23.
Artículo en Inglés | MEDLINE | ID: mdl-29719954

RESUMEN

Using diverse building blocks, such as different heterometallic clusters, in metal-organic framework (MOF) syntheses greatly increases MOF complexity and leads to emergent synergistic properties. However, applying reticular chemistry to syntheses involving more than two molecular building blocks is challenging and there is limited progress in this area. We are therefore motivated to develop a strategy for achieving systematic and differential control over the coordination of multiple metals in MOFs. Herein, we report the design and synthesis of a diverse series of heterobimetallic MOFs with different metal ions and clusters severally distributed throughout two or three inorganic secondary building units (SBUs). By taking advantage of the bifunctional isonicotinate linker and its derivatives, which can coordinatively distinguish between early and late transition metals, we control the assembly and topology of up to three different inorganic SBUs in one-pot solvothermal reactions. Specifically, M6(µ3-O) n(µ3-OH)8- n(CO2)12 (M = Zr4+, Hf4+, Dy3+) SBUs are formed along with metal-pyridyl complexes. By controlling the geometry of the metal-pyridyl complexes, we direct the overall topology to produce eight new MOFs with fcu, ftw, and previously unreported trinodal pfm crystallographic nets.

13.
Chem Rev ; 116(19): 12466-12535, 2016 Oct 12.
Artículo en Inglés | MEDLINE | ID: mdl-27627623

RESUMEN

Rod MOFs are metal-organic frameworks in which the metal-containing secondary building units consist of infinite rods of linked metal-centered polyhedra. For such materials, we identify the points of extension, often atoms, which define the interface between the organic and inorganic components of the structure. The pattern of points of extension defines a shape such as a helix, ladder, helical ribbon, or cylinder tiling. The linkage of these shapes into a three-dimensional framework in turn defines a net characteristic of the original structure. Some scores of rod MOF structures are illustrated and deconstructed into their underlying nets in this way. Crystallographic data for all nets in their maximum symmetry embeddings are provided.

14.
J Am Chem Soc ; 139(10): 3619-3622, 2017 03 15.
Artículo en Inglés | MEDLINE | ID: mdl-28240898

RESUMEN

The structure-directing role of the inorganic secondary building unit (SBU) is key for determining the topology of metal-organic frameworks (MOFs). Here we show that organic building units relying on strong π interactions that are energetically competitive with the formation of common inorganic SBUs can also play a role in defining the topology. We demonstrate the importance of the organic SBU in the formation of Mg2H6(H3O)(TTFTB)3 (MIT-25), a mesoporous MOF with the new ssp topology. A delocalized electronic hole is critical in the stabilization of the TTF triad organic SBUs and exemplifies a design principle for future MOF synthesis.

15.
J Am Chem Soc ; 139(8): 3265-3274, 2017 03 01.
Artículo en Inglés | MEDLINE | ID: mdl-28161947

RESUMEN

Highly connected and edge-transitive nets are of prime importance in crystal chemistry and are regarded as ideal blueprints for the rational design and construction of metal-organic frameworks (MOFs). We report the design and synthesis of highly connected MOFs based on reticulation of the sole two edge-transitive nets with a vertex figure as double six-membered-ring (d6R) building unit, namely the (4,12)-coordinated shp net (square and hexagonal-prism) and the (6,12)-coordinated alb net (aluminum diboride, hexagonal-prism and trigonal-prism). Decidedly, the combination of our recently isolated 12-connected (12-c) rare-earth (RE) nonanuclear [RE9(µ3-OH)12(µ3-O)2(O2C-)12] carboxylate-based cluster, points of extension matching the 12 vertices of hexagonal-prism d6R, with 4-connected (4-c) square porphyrinic tetracarboxylate ligand led to the formation of the targeted RE-shp-MOF. This is the first time that RE-MOFs based on 12-c molecular building blocks (MBBs), d6R building units, have been deliberately targeted and successfully isolated, paving the way for the long-awaited (6,12)-c MOF with alb topology. Indeed, combination of a custom-designed hexacarboxylate ligand with RE salts led to the formation of the first related alb-MOF, RE-alb-MOF. Intuitively, we successfully transplanted the alb topology to another chemical system and constructed the first indium-based alb-MOF, In-alb-MOF, by employing trinuclear [In3(µ3-O)(O2C-)6] as the requisite 6-connected trigonal-prism and purposely made a dodecacarboxylate ligand as a compatible 12-c MBB. Prominently, the dodecacarboxylate ligand was employed to transplant shp topology into copper-based MOFs by employing the copper paddlewheel [Cu2(O2C-)4] as the complementary square building unit, affording the first Cu-shp-MOF. We revealed that highly connected edge-transitive nets such shp and alb are ideal for topological transplantation and deliberate construction of related MOFs based on minimal edge-transitive nets.

16.
Faraday Discuss ; 201: 127-143, 2017 09 08.
Artículo en Inglés | MEDLINE | ID: mdl-28660983

RESUMEN

Highly-connected and minimal edge-transitive nets (with one or two kinds of edge) can be regarded as ideal blueprints for the rational design and construction of metal-organic frameworks (MOFs). Here we report and affirm the prominence of highly-connected nets as suitable targets in reticular chemistry for the design and synthesis of MOFs. Of special interest are augmented highly-connected binodal edge-transitive nets embedding a unique and precise positioning and connectivity of the net vertex figures, regarded as net-coded building units (net-cBUs). Explicitly, a definite net-cBU encompasses precise geometrical information that codes a selected net uniquely and matchlessly, a compelling perquisite for the rational design of MOFs. Interestingly, the double six-membered ring (d6R) building unit offers great potential to be used as a net-cBU for the deliberate reticulation of the sole two edge-transitive nets with a vertex figure as a d6R, namely the (4,12)-coordinated shp net (square and hexagonal prism) and the (6,12)-coordinated alb net (aluminium diboride, hexagonal prism and trigonal prism). We envisioned and proposed various MOF structures based on the derived shp and alb nets. Gaining access to the requisite net-cBUs is essential for the successful practice of reticular chemistry; correspondingly organic and inorganic chemistries were deployed to afford concomitant molecular building blocks (MBBs) with the looked-for shape and connectivity. Practically, the combination of the 12-connected (12-c) rare-earth (RE) polynuclear, points of extension matching the 12 vertices of the hexagonal prism (d6R) with a 4-connected tetracarboxylate ligand or a 6-connected hexacarboxylate ligand afforded the targeted shp-MOF or alb-MOF, respectively. A dodecacarboxylate ligand can be conceived as, and is shown to be, a compatible 12-c MBB, plausibly affording the positioning of the carbon centers of the twelve carboxylate groups on the vertices of the desired hexagonal prism building unit, and combined with the complementary 4-c copper paddlewheel [Cu2(O2C-)4] cluster or 6-c metal trinuclear [M3O(O2C-)6] clusters/zinc tetranulcear [Zn4O(O2C-)6] clusters to credibly afford the construction of new MOF structures with underlying topologies based on derived shp and alb nets.

17.
Pol J Radiol ; 82: 731-741, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-29657639

RESUMEN

Vascular malformations pose a diagnostic and therapeutic challenge due to the broad differential diagnosis as well as common utilization of inadequate or inaccurate classification systems among healthcare providers. Therapeutic approaches to these lesions vary based on the type, size, and extent of the vascular anomaly, necessitating accurate diagnosis and classification. Magnetic resonance (MR) imaging (MRI) is an effective modality for classifying vascular anomalies due to its ability to delineate the extent and anatomic relationship of the malformation to adjacent structures. In addition to anatomical mapping, the complete evaluation of vascular anomalies includes hemodynamic characterization. Dynamic time-resolved contrast-enhanced MR angiography provides information regarding hemodynamics of vascular anomalies, differentiating high- and low-flow vascular malformations. Radiologists must identify the MRI features of vascular malformations for better diagnosis and classification.

18.
Pol J Radiol ; 82: 748-759, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-29657641

RESUMEN

This study aims to identify the 50 most highly cited articles on dual energy computed tomography (DECT) in abdominal radiology Thomson Reuters Web of Science All Databases was queried without year or language restriction. Only original research articles with a primary focus on abdominal radiology using DECT were selected. Review articles, meta-analyses, and studies without human subjects were excluded. Fifty articles with the highest average yearly citation were identified. These articles were published between 2007 and 2017 in 12 journals, with the most in Radiology (12 articles). Articles had a median of 7 authors, with all first authors but one primarily affiliated to radiology departments. The United States of America produced the most articles (16), followed by Germany (13 articles), and China (7 articles). Most studies used Dual Source DECT technology (35 articles), followed by Rapid Kilovoltage Switching (14 articles), and Sequential Scanning (1 article). The top three scanned organs were the liver (24%), kidney (16%), and urinary tract (15%). The most commonly studied pathology was urinary calculi (28%), renal lesion/tumor (23%), and hepatic lesion/tumor (20%). Our study identifies intellectual milestones in the applications of DECT in abdominal radiology. The diversity of the articles reflects on the characteristics and quality of the most influential publications related to DECT.

19.
J Am Chem Soc ; 138(6): 1970-6, 2016 Feb 17.
Artículo en Inglés | MEDLINE | ID: mdl-26790573

RESUMEN

A bismuth-based metal-organic framework (MOF), [Bi(BTC)(H2O)]·2H2O·MeOH denoted CAU-17, was synthesized and found to have an exceptionally complicated structure with helical Bi-O rods cross-linked by 1,3,5-benzenetricarboxylate (BTC(3-)) ligands. Five crystallographically independent 1D channels including two hexagonal channels, two rectangular channels, and one triangular channel have accessible diameters of 9.6, 9.6, 3.6, 3.6, and 3.4 Å, respectively. The structure is further complicated by twinning. Rod-incorporated MOF structures typically have underlying nets with only one unique node and three or four unique edges. In contrast, topological analysis of CAU-17 revealed unprecedented complexity for a MOF structure with 54 unique nodes and 135 edges. The complexity originates from the rod packing and the rods themselves, which are related to aperiodic helices.

20.
J Am Chem Soc ; 138(17): 5678-84, 2016 05 04.
Artículo en Inglés | MEDLINE | ID: mdl-27113684

RESUMEN

A new metal-organic framework Zn2(H2O)(dobdc)·0.5(H2O) (UTSA-74, H4dobdc = 2,5-dioxido-1,4-benzenedicarboxylic acid), Zn-MOF-74/CPO-27-Zn isomer, has been synthesized and structurally characterized. It has a novel four coordinated fgl topology with one-dimensional channels of about 8.0 Å. Unlike metal sites in the well-established MOF-74 with a rod-packing structure in which each of them is in a five coordinate square pyramidal coordination geometry, there are two different Zn(2+) sites within the binuclear secondary building units in UTSA-74 in which one of them (Zn1) is in a tetrahedral while another (Zn2) in an octahedral coordination geometry. After activation, the two axial water molecules on Zn2 sites can be removed, generating UTSA-74a with two accessible gas binding sites per Zn2 ion. Accordingly, UTSA-74a takes up a moderately high and comparable amount of acetylene (145 cm(3)/cm(3)) to Zn-MOF-74. Interestingly, the accessible Zn(2+) sites in UTSA-74a are bridged by carbon dioxide molecules instead of being terminally bound in Zn-MOF-74, so UTSA-74a adsorbs a much smaller amount of carbon dioxide (90 cm(3)/cm(3)) than Zn-MOF-74 (146 cm(3)/cm(3)) at room temperature and 1 bar, leading to a superior MOF material for highly selective C2H2/CO2 separation. X-ray crystal structures, gas sorption isotherms, molecular modeling, and simulated and experimental breakthroughs comprehensively support this result.

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