Chromatographic stationary phases based on porous graphitic carbon were invented 30 years ago, while columns have been commercially available for 20 years. This special occasion deserved a complete ...review on this material. In this paper, we describe current knowledge on graphitic carbon stationary phases, based on over 400 fundamental studies and applications.
Two recent destructive earthquakes in 1994 and 2004 near Al Hoceima highlight that the northern Moroccan margin is one of the most seismically active regions of the Western Mediterranean area. ...Despite onshore geodetic, seismological and tectonic field studies, the onshore–offshore location and extent of the main active faults remain poorly constrained. Offshore Al Hoceima, high-resolution seismic reflection and swath-bathymetry have been recently acquired during the Marlboro-2 cruise. These data at shallow water depth, close to the coast, allow us to describe the location, continuity and geometry of three active faults bounding the offshore Nekor basin. The well-expressed normal-left-lateral onshore Trougout fault can be followed offshore during several kilometers with a N171°E±3° trend. Westward, the Bousekkour–Aghbal normal-left-lateral onshore fault is expressed offshore with a N020°E±4° trending fault. The N030°E±2° Bokkoya fault corresponds to the western boundary of the Plio-Quaternary offshore Nekor basin in the Al Hoceima bay and seems to define an en échelon tectonic pattern with the Bousekkour–Aghbal fault. We propose that these three faults are part of the complex transtensional system between the Nekor fault and the Al-Idrissi fault zone. Our characterization of the offshore expression of active faulting in the Al Hoceima region is consistent with the geometry and nature of the active fault planes deduced from onshore geomorphological and morphotectonic analyses, as well as seismological, geodetic and geodynamic data.
•We report a shallow marine geophysical survey.•We use high-resolution seismic reflection and swath bathymetry offshore Al Hoceima.•Increasing our knowledge of the offshore location of active faults•Fault scarps showing evidence of recent cumulative transtensional deformation•Strike–slip related basin forming between the Al-Idrissi fault zone and Nekor fault
Since the Miocene, the thinned continental crust below the Alboran Sea and its overlying sedimentary cover have been undergoing deformation caused by both convergence of Eurasia and Africa and by ...deep processes related to the Tethyan slab retreat. Part of this deformation is recorded at the Xauen and Tofiño banks in the southern Alboran Sea. Using swath bathymetry and multichannel seismic reflection data, we identified different stages and styles of deformation. The South Alboran Basin is made up of Early Miocene to Pliocene sedimentary layers that correlate with the West Alboran Basin depocenter and are dominated by E‐W trending folds and thrusts. The Xauen and Tofiño Banks first recorded the phase of extension and strike‐slip movement during the slab retreat, followed by the phase of compressional inversion since the Tortonian and are now structured by tight folds, thrusts, and mud bodies. This study proposes that the Banks were located on the southern‐inherited Subduction Tear Edge Propagator (STEP) fault related to the westward migration of the Alboran domain during the Miocene. The STEP fault zone, acting as a boundary between the African block and the Alboran block, was located along the onshore Jebha‐Nekor fault and the offshore Alboran Ridge and the Yusuf fault zone. Thick‐skinned and thin‐skinned shortening occurred when slab retreat stopped, and inversion began. The present‐day style of the deformation seems to be linked to a decollement level made of undercompacted shale on top of the Ghomaride complex.
Key Points
The reactivation of the Subduction Tear Edge Propagator fault zone on the southern edge of the Alboran Domain forms the South Alboran Ridge
The style of the present‐day structure of the South Alboran region implies an interaction between thick‐skinned and thin‐skinned tectonics
Undercompacted shales and inherited crustal structures are involved in the structural evolution of the South Alboran Basin
► Halo C18 and Chromolith RP18 columns were evaluated to analyze methylated CDs by LC. ► Halo C18 column is suitable for rapid LC analysis of various CDs. ► LC-ELSD with this column was proposed as a ...generic system for CD analysis.
Halo C18 column (fused core particles) and Chromolith RP18 column (monolith) were evaluated in liquid chromatography in order to analyze methylated-β-cyclodextrins (Me-β-CD) with various degrees of substitution, DS such as the number of methyl groups per cyclodextrin ring. Chromolith RP18 enables a performing analysis of Me-β-CD with low DS but is not suitable for dimethyl-β-cyclodextrins (DM-β-CD). On the other hand, Halo C18 column allows an improved fingerprint of CDs having a DS from 4.9 up to a value major than 14 and avoiding the use of various chromatographic systems. Thus, liquid chromatography performed with this column and an evaporative light scattering detector can be used as a generic system for methylated CD analysis. Moreover, fused core particles of Halo C18 column enables a rapid analysis and liquid chromatography coupled with electrospray-mass spectrometry appears as a powerful tool to determine co-elution and to characterize various isomers of complex methylated-β-cyclodextrin mixtures.
A reversed phase HPLC method has been investigated in order to resolve three main pentacyclic triterpene acids (oleanolic-, betulinic- and ursolic acid) found in a lot of plants. Some of them ...(oleanolic and ursolic acids) are position isomers and their resolution is highly improved by the addition of derivatized cyclodextrins in mobile phase. The formation of 1:1 inclusion complexes was assumed. Apparent formation constants of triterpene acids with DM-β-CD and HP-γ-CD were determined by HPLC method. Experimental results confirmed the complexation model and explained the modification of elution order according to the type of cyclodextrin added to the mobile phase. The influence of mobile phase organic modifier on apparent formation constants was also investigated. Results proved the competition between cyclodextrins hydrophobic cavity and organic solvent towards triterpene acids affinity.
► Separation of triterpenes in resinous materials on PGC–MS is optimised. ► Varying weak solvents have greater effect on porous graphitic carbon retention. ► Electronic modifier in the mobile phase ...has no influence on triterpenes retention.
Natural resinous materials are mainly composed of pentacyclic triterpenes which exhibit a large number of interesting medicinal activities. However, the presence of numerous isomers within the active substances makes their screening by HPLC very challenging. Porous graphitic carbon was investigated as stationary phase to achieve triterpenes isomers separation. The influence of various parameters (temperature, formic acid concentration and mobile phase composition) on the retention was considered. A usual decrease of the retention of triterpenes was observed with the increase of the temperature. Therefore, separation in resinous materials was performed at 25°C. Acetonitrile–isopropanol mixture was chosen as mobile phase in gradient elution and leads to the best compromise between efficiency and high resolution. The lack of chromophore groups in the pentacyclic triterpenes structures required the use of mass spectrometry detection. Moreover, atmospheric pressure photo-ionisation mass spectrometry prevents compounds fragmentation which was helpful for spectra interpretation and compounds identification.
Summary Introduction Extra-articular distal tibia fractures include a tibial fracture line located partially or totally in the metaphyseal bone and a fibular fracture in variable areas or sometimes ...absent. There is no consensus in the literature on the conduct to address the fibula fracture. The main objective of this study was to assess its impact on tibial reduction and union. Hypothesis Fibular fixation plays a positive role in reducing tibial displacement and improving mechanical stability of the entire lesion. Material and methods This study was based on the multicenter observational group of the 2009 SOFCOT symposium, i.e., 142 metaphyseal fractures of the tibia. The fibula was intact in 10 cases and fractured in 132. In the three main categories of surgical treatment for the tibia (nailing, plating, external fixation) (126 fractures), the fibular lesion was not treated in 79 cases (61%) in this series, nine were treated with intramedullary pinning, and 38 with plate and screw fixation. Results There was no statistical relation between the anatomic situation of the diaphysis and the anatomic type of the fibular fracture or between the anatomic type of the fibular fracture and its situation compared to the tibial fracture line. The intertubercular and neck fractures were type A1 or B1 ( P < 0.001) and were combined to a tibia fracture with a torsional component; the medial-diaphyseal and subtubercular fractures were associated with tibial fracture lines with a simple transversal or comminution or metaphyseal-diaphyseal component ( P < 0.032). The rate of pseudarthrosis of the fibular fracture was 4.7% at 1 year; in all these cases, fibular treatment had been conservative. All treatments combined, the tibial axes were statistically better corrected when the fibula was treated with fixation. In four of the 11 cases of axial tibial malunion, the primary fibular fixation caused or worsened them. Discussion The present clinical series provides results similar to the biomechanical studies. The consequences of fibular fixation perpetuating a tibia reduction abnormality or on the contrary the absence of fibular fixation appeared as probable factors of residual reduction defects, lack of stability of the tibiofibular complex, and tibia non-union. Level of evidence Level IV (prospective cohort study).
Summary Elbow dislocations are the most frequently encountered dislocations after shoulder dislocations. In their vast majority these injuries involve only the joint and carry a good prognosis. Close ...anatomic proximity to the joint of neurovascular structures put them at risk of concomitant injury but this occurrence remains, actually very rare. The objective of this study is to retrospectively analyze the results of nine cases of elbow dislocations with brachial artery complications and to propose coherent therapeutic guidelines derived from this experience. Materials and methods From 1999 to 2004, 357 elbow dislocations were treated by the traumatology team at the Purpan University Hospital and 340 at the Rangueil University Hospital in Toulouse, France. These two teaching institutions combined their series, contributing to seven dislocations associated with a brachial artery partial rupture, resulting in ischemia. Between 2001 and 2006 at the Le Mans Regional Hospital Center, 138 dislocations of the elbow were treated, and included two cases involving rupture of the brachial artery. In all these institutions’ emergency departments, elbow dislocations were mainly treated on an outpatient basis: closed reduction under ultra short-acting products general anesthesia, with stability evaluation followed by cast immobilization. In the rare instances of ischemia, the artery was repaired in concert with the vascular surgery team. All the nine cases had a similar treatment protocol and were submitted to an identical outcome evaluation method. The patients were all males with a mean age of 37.3 years (range, 18–58 years). The combined injury occurred at sports in two cases, because of a fall in three cases and as a result of a traffic accident in four cases. Ischemia was complete in three cases (no radial or ulnar pulse and devascularized hand). In the six other cases, the clinical presentation was subacute. An arteriogram was obtained in five cases after reduction of the dislocation, confirming the brachial axis disruption. Median and/or ulnar nerve injury was suspected in six patients. Only five elbows remained stable after reduction allowing plaster cast immobilization. In the other cases, dislocation recurrence or consequential residual varus/valgus laxity required external fixation or a cross-pinning fixation. An autologous vein, brachial artery bypass was performed in eight cases and an end-to-end anastomosis was carried out in one case. Revascularization was reestablished between 4 and 19 h after injury (mean 10.5 h). Results All the patients were seen at a minimum of 2 years’ follow-up (mean of 4.3 years). On the basis of Mayo Clinic score, the results were considered excellent in three cases, good in four cases, and poor in two cases. No patients complained of elbow instability. The X-rays showed a reduced elbow in all cases and heterotopic ossifications in three cases. No degenerative lesion was observed at the longest follow-up. Discussion The incidence of a combined vascular injury with dislocation remains difficult to establish because the literature reports sporadic short series of clinical cases. The prevalence of this association is estimated to be between 0.3 and 1.7% in hospitals. The vascular lesion risk is probably related to the displacement extent and this later as a consequence of the injury intensity. This context calls for a diagnostic warning signal of possibly associated vascular involvement. Assessment of arterial vascularization should be systematic and mandatory with any osteoarticular injury. The slightest vascular status clinical doubt after reducing any dislocation presses for vascular patency work-up: echo-Doppler, angio-scan, arteriography. The multi-parametric nature of these combined injuries explain why their sometimes disappointing outcome remains dependent on the ability to deal with contradictory healing concerns: skin condition, capsular, and ligaments damages, type of revascularization procedure used, joint stability after closed reduction. This last parameter, being a substantial determinant for the period of immobilization, appears crucial to the final functional outcome, particularly in terms of range of motion loss or residual flexion contracture. Level of evidence Level IV. Therapeutic retrospective study.
► Twenty-six natural resins are classified with 3D bubble charts and hierarchical cluster analysis. ► GC–MS and LC–APPI-MS fingerprints are easily compared using bubble charts. ► Hierarchical cluster ...analysis provides a complete description of the class of the resins. ► GC–MS and LC–MS tools are complementary and appropriate to authenticate unknown samples.
Twenty-six resins from six botanical sources belonging to the class Magnoliopsida were compared based on gas chromatography–mass spectrometry and liquid chromatography–mass spectrometry data. The extracts were analysed by GC after silylation and by reversed phase LC combined with atmospheric pressure photoionisation (APPI) mass spectrometry. The chromatograms were re-organized in data matrices, where each sample was represented by a single column comprising 2755 observations (intensity, time, m/z) in GC–MS and 360 observations in LC–MS. A simple comparison of resin fingerprints was attempted by organizing data according to a three dimensional bubble chart (retention time against m/z where each point was a bubble which size represented the ion intensity) where it is possible to easily superimpose the fingerprints. Thus the common and different species can be easily observed enabling to classify the resins. Hierarchical cluster analysis based on characteristics of GC–MS and LC–MS profiles affords a complete description of the classes of the resins and shows that 26 resins are divided into five main clusters Commiphora mukul, Daniella oliveri, Gardenia gummifera, Canarium madagascariensis, Boswellia dalzielii and Boswellia serrata, respectively. In conclusion, the proposed method has been applied to three other resinous samples from the Burseraceae family to evaluate their alteration state.
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