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1.
Neurol India ; 72(2): 408-410, 2024 Mar 01.
Article in English | MEDLINE | ID: mdl-38691486

ABSTRACT

Acute glaucoma following carotid artery recanalization is a rare but severe complication of underlying ocular ischemic syndrome. We present a case of a 71-year-old woman with ocular ischemic syndrome and severe stenosis of the right internal and external carotid artery undergoing carotid artery stenting. Immediate postprocedural angiography showed pronounced reperfusion of the ophthalmic artery. Subsequently, the patient developed vision-threatening acute glaucoma despite treatment with acetazolamide. Monitoring of intraocular pressure is important in patients who are at risk of developing ocular ischemic syndrome because of internal carotid artery stenosis. Interventionalists should also assess the degree of vascular collateralization from the external carotid artery.


Subject(s)
Carotid Artery, Internal , Carotid Stenosis , Glaucoma , Stents , Humans , Female , Aged , Carotid Stenosis/surgery , Stents/adverse effects , Glaucoma/etiology , Glaucoma/surgery , Carotid Artery, Internal/diagnostic imaging , Ischemia/etiology
2.
JAMA ; 327(18): 1795-1805, 2022 05 10.
Article in English | MEDLINE | ID: mdl-35510389

ABSTRACT

Importance: The benefit of endovascular thrombectomy (EVT) for acute ischemic stroke is highly time-dependent, and it is challenging to expedite treatment for patients in remote areas. Objective: To determine whether deployment of a flying intervention team, compared with patient interhospital transfer, is associated with a shorter time to endovascular thrombectomy and improved clinical outcomes for patients with acute ischemic stroke. Design, Setting, and Participants: This was a nonrandomized controlled intervention study comparing 2 systems of care in alternating weeks. The study was conducted in a nonurban region in Germany including 13 primary telemedicine-assisted stroke centers within a telestroke network. A total of 157 patients with acute ischemic stroke for whom decision to pursue thrombectomy had been made and deployment of flying intervention team or patient interhospital transfer was initiated were enrolled between February 1, 2018, and October 24, 2019. The date of final follow-up was January 31, 2020. Exposures: Deployment of a flying intervention team for EVT in a primary stroke center vs patient interhospital transfer for EVT to a referral center. Main Outcomes and Measures: The primary outcome was time delay from decision to pursue thrombectomy to start of the procedure in minutes. Secondary outcomes included functional outcome after 3 months, determined by the distribution of the modified Rankin Scale score (a disability score ranging from 0 [no deficit] to 6 [death]). Results: Among the 157 patients included (median [IQR] age, 75 [66-80] y; 80 [51%] women), 72 received flying team care and 85 were transferred. EVT was performed in 60 patients (83%) in the flying team group vs 57 (67%) in the transfer group. Median (IQR) time from decision to pursue EVT to start of the procedure was 58 (51-71) minutes in the flying team group and 148 (124-177) minutes in the transfer group (difference, 90 minutes [95% CI, 75-103]; P < .001). There was no significant difference in modified Rankin Scale score after 3 months between patients in the flying team (n = 59) and transfer (n = 57) groups who received EVT (median [IQR] score, 3 [2-6] vs 3 [2-5]; adjusted common odds ratio for less disability, 1.91 [95% CI, 0.96-3.88]; P = .07). Conclusions and Relevance: In a nonurban stroke network in Germany, deployment of a flying intervention team to local stroke centers, compared with patient interhospital transfer to referral centers, was significantly associated with shorter time to EVT for patients with acute ischemic stroke. The findings may support consideration of a flying intervention team for some stroke systems of care, although further research is needed to confirm long-term clinical outcomes and to understand applicability to other geographic settings.


Subject(s)
Brain Ischemia , Endovascular Procedures , Ischemic Stroke , Patient Transfer , Thrombectomy , Aged , Aged, 80 and over , Brain Ischemia/surgery , Endovascular Procedures/methods , Female , Germany , Humans , Ischemic Stroke/surgery , Male , Stroke/surgery , Thrombectomy/methods , Time Factors , Treatment Outcome , Urban Population
3.
Molecules ; 25(21)2020 Oct 26.
Article in English | MEDLINE | ID: mdl-33114580

ABSTRACT

This review summarizes experimental and theoretical studies of transition metal complexes with two types of novel metal-carbon bonds. One type features complexes with carbones CL2 as ligands, where the carbon(0) atom has two electron lone pairs which engage in double (σ and π) donation to the metal atom [M]⇇CL2. The second part of this review reports complexes which have a neutral carbon atom C as ligand. Carbido complexes with naked carbon atoms may be considered as endpoint of the series [M]-CR3 → [M]-CR2 → [M]-CR → [M]-C. This review includes some work on uranium and cerium complexes, but it does not present a complete coverage of actinide and lanthanide complexes with carbone or carbide ligands.


Subject(s)
Carbon/chemistry , Coordination Complexes/chemistry , Transition Elements/chemistry , Ligands
4.
Chemistry ; 22(25): 8536-46, 2016 06 13.
Article in English | MEDLINE | ID: mdl-27166027

ABSTRACT

This work reports the syntheses and the first crystal structures of the cationic carbone adducts [FC(PPh3 )2 ](+) and [BrC(PPh3 )2 ](+) and the protonated dication [FC(H)(PPh3 )2 ](2+) , which are derived from the carbone C(PPh3 )2 . Quantum chemical calculations and bonding analyses were carried out for the series of cations [AC(PPh3 )2 ](+) and dications [AC(H)(PPh3 )2 ](2+) , where A=H, Me, F, Cl, Br, I. The bonding analysis suggests that the cations are best described as phosphane complexes L→(CA)(+) ←L (L=PPh3 ), which are related to the neutral borylene adducts L→(BA)←L (L=cyclic carbene; A=H, aryl) that were recently isolated. The carbone adducts [AC(PPh3 )2 ](+) possess a π electron lone pair at carbon and they can easily be protonated to the dications [AC(H)(PPh3 )2 ](2+) . The calculations of the dications indicate that the molecules are best represented as complexes L→(CHA)(2+) ←L (L=PPh3 ) where a carbene dication is stabilized by the ligands. The central carbon atom in the cations and even in the dications carries a negative partial charge, which is larger than the negative charge at fluorine. There is also the peculiar situation in which the carbon-fluorine bonds in [FC(PPh3 )2 ](+) and [FC(H)(PPh3 )2 ](2+) exhibit the expected polarity with the negative end at fluorine, but the carbon atom has a larger negative charge than fluorine. Given the similarity of carbodiphosphorane C(PPh3 )2 and carbodicarbene C(NHC)2 , we expect that analogous compounds [AC(NHC)2 ](+) and [AC(H)(NHC)2 ](2+) with similar features as [AC(PPh3 )2 ](+) and [AC(H)(PPh3 )2 ](2+) can be isolated.

5.
Chempluschem ; 78(9): 1024-1032, 2013 Sep.
Article in English | MEDLINE | ID: mdl-31986749

ABSTRACT

Quantum chemical calculations at the BP86/TZVPP//BP86/SVP level of theory have been performed for the isoelectronic series of compounds [(PPh3 )2 C→EH2 ]q (Eq =Be, B+ , C2+ , N3+ , O4+ ). The equilibrium geometries and bond dissociation energies were calculated and the nature of the C→E bond was investigated with charge and energy decomposition methods. The dication [(PPh3 )2 C→CH2 ]2+ could become isolated as a salt compound with two counter ions [AlBr4 ]- . The X-ray structure analysis of [(PPh3 )2 C→CH2 ]2+ gave bond lengths and angles that are in good agreement with the calculated data. The geometry optimization of [(PPh3 )2 C→OH2 ]4+ gave [(PPh3 )2 C→OH]3+ as the equilibrium structure. Bonding analysis of [(PPh3 )2 C→EH2 ]q shows that [(PPh3 )2 C→BeH2 ] and [(PPh3 )2 C→BH2 ]+ possess donor-acceptor bonds in which the σ and π lone-pair electrons of (PPh3 )2 C donate into the vacant orbitals of the acceptor fragment. The multiply charged compounds are better described as substituted olefins [(PPh3 )2 CCH2 ]2+ , [(PPh3 )2 CNH2 ]3+ , and [(PPh3 )2 COH]3+ , which possess electron-sharing σ and π bonds that arise from the interaction between the triplet states of [(PPh3 )2 C]2+ and the respective fragment CH2 , (NH2 )+ , and (OH)+ . The multiply charged cations [(PPh3 )2 CCH2 ]2+ , [(PPh3 )2 CNH2 ]3+ , and [(PPh3 )2 COH]3+ are calculated to be stable toward dissociation.

6.
FEMS Microbiol Ecol ; 59(2): 396-408, 2007 Feb.
Article in English | MEDLINE | ID: mdl-17313584

ABSTRACT

Ciliate diversity was investigated in situ in freshwater ecosystems of the maritime (South Shetland Islands, mainly Livingston Island, 63 degrees S) and continental Antarctic (Victoria Land, 75 degrees S), and the High Arctic (Svalbard, 79 degrees N). In total, 334 species from 117 genera were identified in both polar regions, i.e. 210 spp. (98 genera) in the Arctic, 120 spp. (73 genera) in the maritime and 59 spp. (41 genera) in the continental Antarctic. Forty-four species (13% of all species) were common to both Arctic and Antarctic freshwater bodies and 19 spp. to both Antarctic areas (12% of all species). Many taxa are cosmopolitans but some, e.g. Stentor and Metopus spp., are not, and over 20% of the taxa found in any one of the three areas are new to science. Cluster analysis revealed that species similarity between different biotopes (soil, moss) within a study area was higher than between similar biotopes in different regions. Distinct differences in the species composition of freshwater and terrestrial communities indicate that most limnetic ciliates are not ubiquitously distributed. These observations and the low congruence in species composition between both polar areas, within Antarctica and between high- and temperate-latitude water bodies, respectively, suggest that long-distance dispersal of limnetic ciliates is restricted and that some species have a limited geographical distribution.


Subject(s)
Ciliophora/classification , Ciliophora/growth & development , Ecosystem , Fresh Water/microbiology , Animals , Antarctic Regions , Arctic Regions , Ciliophora/physiology , Cluster Analysis , Geography , Species Specificity
8.
Inorg Chem ; 45(22): 9053-63, 2006 Oct 30.
Article in English | MEDLINE | ID: mdl-17054366

ABSTRACT

The difluorcarbene complex [Fe2(CO)8(mu-CF2)] (2) reacts with AsMe3 under CO substitution to give the mu-CF2 containing complexes [Fe2(CO)6(AsMe3)2(mu-CF2)] (4) and [Fe2(CO)5(AsMe3)3(mu-CF2)] (5) which have an [Fe2(CO)9]-like structure as shown by X-ray analyses. In the solid state, 4 forms two isomers, 4a and 4b, in a 3 to 1 ratio, which differ in the position of the mu-CF(2) ligand; 4a has a local C(2) axis and 4b has C1 symmetry. The Fe-Fe distances in 4 and 5 are 2.47 A and are the shortest ones found in [Fe2(CO)9]-like compounds. Efforts were also undertaken to replace one or more CO groups in 2 by other ligands, such as N (bpy, phen, pzy, etc.) or P donors (dppe, dppm). With dppm, only the CF(2) free complex, [Fe2(CO)4(mu-Ph2PCH2PPh2)2(mu-CO)] (6), could be detected and characterized by X-ray analysis. Most of the reactions resulted in the formation of red-brown materials which were insoluble in the usual solvents and which could not be characterized. The use of CH2Cl2 during the attempts to crystallize a product from the reaction of 2 and phen gave [Fe(phen)3]Cl2 (7) in low yields. For 4 and 5, the electronic structures were analyzed using the atoms in molecules (AIM) theory. No electron density was found between the two iron atoms, and the short contacts can be interpreted in terms of a pi-interaction.

9.
Inorg Chem ; 44(5): 1263-74, 2005 Mar 07.
Article in English | MEDLINE | ID: mdl-15732966

ABSTRACT

We report about the first X-ray structure analyses of the CS2 and CO2 adducts with carbodiphosphorane C(PPh3)2 and the synthesis and X-ray structure analysis of group 6 carbonyl complexes with compound S2CC(PPh3)2 as a ligand [(CO)4MS2CC(PPh3)2] (M = Cr, Mo, W). The nature of the carbon-carbon bonding in X2CC(PPh3)2 and in the model compounds X2CC(PH3)2 and the metal-ligand bonding in [(CO)4MoS2CC(PH3)2] have been analyzed with charge and energy decomposition methods using DFT calculations. Carbodiphosphoranes C(PR3)2 are double electron pair donors having sigma- and pi-carbon lone-pair orbitals as the two highest occupied MOs.

10.
J Eukaryot Microbiol ; 52(1): 1-10, 2005.
Article in English | MEDLINE | ID: mdl-15702973

ABSTRACT

Two new urostylid ciliates, Metaurostylopsis songi n. sp. and Metaurostylopsis salina n. sp. and Metaurostylopsis marina (Kahl 1932) are investigated using live observation and protargol impregnation. These species were isolated in Korea from intertidal sediments, saline ponds, and coastal waters. Metaurostylopsis songi is in vivo about 120 microm x 25 microm, has a slenderly ellipsoidal body, colorless cortical granules in rows on ventral and dorsal body sides, about 54 macronuclear nodules, 28-47 adoral membranelles, five frontal, two or three frontoterminal and six or seven transverse cirri, and 9-12 midventral cirral pairs followed posteriorly by 1-3 single cirri. In vivo M. salina is about 60 microm x 25 microm, has a pyriform body, colorless cortical granules irregularly arranged, about 45 macronuclear nodules, 18-23 adoral membranelles, three frontal, three to five frontoterminal and two to five transverse cirri, and four or five midventral cirral pairs followed posteriorly by five to seven single cirri. Both species have three marginal cirral rows on each body side and 3 long dorsal kineties. The Korean specimens of M. marina match the Chinese population in all main features. Metaurostylopsis songi differs from M. marina by the more slender body, the number of frontal cirri (invariably five vs. four), and the arrangement of cortical granules (in rows on dorsal and ventral cortex vs. only along dorsal kineties and anterior body margin). Metaurostylopsis salina differs from its congeners by the distinctly smaller size, the pyriform body shape, the scattered cortical granules (vs. in rows), and number of frontal cirri. It differs from M. marina also by the number of midventral cirral pairs (four or five vs. seven to 11).


Subject(s)
Ciliophora/isolation & purification , Ciliophora/ultrastructure , Animals , Geologic Sediments/parasitology , Korea , Microscopy, Interference , Seawater/parasitology
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