Distinct Shoulder Research Articles

The Fe Kα Compton shoulder in accreting supermassive black holes

ABSTRACT Reprocessed X-ray radiation from active galactic nuclei (AGN) carries important information about the properties of the circumnuclear material around the black hole. The X-ray photons travel from the very centre of the system and interact with that material often producing strong emission lines. The $\rm {Fe\, K\alpha }$ Compton shoulder (CS) is formed by fluorescent $\rm {Fe\, K\alpha }$ photons that perform Compton scatterings with the intercepting material and lose energy to form the distinct shoulder shape. In this work, we use the ray-tracing code RefleX to explore how the physical properties of the medium, as well as its geometry, affect the shape of the CS. We start by running simulations using a simple toroidal reflector, to test the effect of the metal composition, metallicity, column density, dust presence and velocity on the $\rm {Fe\, K\alpha }$ line, and its CS. We confirm that the shape of the CS is sensitive to the optical depth of the intercepting medium, which can be regulated by either changing the metal composition or the line-of-sight column density of the circumnuclear material. Next, we create a series of models, which feature different geometrical configurations of dust and gas, and explore how the CS is affected by such configurations finding that components that can regulate the line-of-sight column density affect the $\rm {Fe\, K\alpha }$ and its CS. Finally, we test whether observatories such as the recently launched XRISM and future Athena will make the CS a useful spectral feature of nearby AGN, by applying specific models on simulated spectra of the Circinus galaxy. The CS has the potential to be used to help constrain properties of the circumnuclear material yet with some limitations.

High photoreactivity of chromophoric dissolved organic matter derived from Ulva prolifera and Sargassum

The epipelagic macroalgae of Ulva prolifera and Sargassum are the primary contributors to widespread seaweed tides globally. Both ocean plants release large amounts of chromophoric dissolved organic matter (CDOM) into the surrounding seawater. The photochemical reactivity of this CDOM, however, has not been adequately addressed. In this study, we extracted CDOM from Ulva prolifera and Sargassum, examined their ultraviolet (UV)-visible absorption characteristics, and quantified their broadband apparent quantum yields (AQY) of absorbance photobleaching and photomineralization (in terms of CO2, CO, and CH4 photoproduction). On a per-unit-weight basis, Sargassum leached 3.5 times more CDOM than did Ulva prolifera in terms of the absorption coefficient averaged over 254–500 nm. Both Ulva prolifera and Sargassum CDOM were characterized by quasi-exponential decay absorption spectra, with Sargassum CDOM exhibiting a distinct shoulder over 310–350 nm suggestive of mycosporine amino acids. The Sargassum CDOM had a higher photobleaching AQY but lower photomineralization AQYs compared to Ulva prolifera CDOM. The photobleaching and photomineralization AQYs of both macroalgal CDOM are, however, orders of magnitude higher than those of CDOM in various natural waters. Potential photoproduction rates of CO2 and CO from the Ulva prolifera CDOM and Sargassum CDOM during the bloom periods are several times to orders of magnitude higher than the air-sea fluxes of these gases in the absence of the macroalgae. This study demonstrates that CDOM released by Ulva prolifera and Sargassum is extremely prone to photobleaching and photomineralization, rendering floating mats of these plants in oceans as potential “hotspots” of greenhouse gas emissions to the atmosphere. This photochemical feedback should be considered when assessing ocean afforestation as a CO2 removal approach to mitigate climate warming.

In Solution Identification of the Lysine-Cysteine Redox Switch with a NOS Bridge in Transaldolase by Sulfur K-Edge X-ray Absorption Spectroscopy.

A novel covalent post-translational modification (lysine-NOS-cysteine) was discovered in proteins, initially in the enzyme transaldolase of Neisseria gonorrhoeae (NgTAL) [Nature 2021, 593, 460-464], acting as a redox switch. The identification of this novel linkage in solution was unprecedented until now. We present detection of the NOS redox switch in solution using sulfur K-edge X-ray absorption spectroscopy (XAS). The oxidized NgTAL spectrum shows a distinct shoulder on the low-energy side of the rising edge, corresponding to a dipole-allowed transition from the sulfur 1s core to the unoccupied σ* orbital of the S-O group in the NOS bridge. This feature is absent in the XAS spectrum of reduced NgTAL, where Lys-NOS-Cys is absent. Our experimental and calculated XAS data support the presence of a NOS bridge in solution, thus potentially facilitating future studies on enzyme activity regulation mediated by the NOS redox switches, drug discovery, biocatalytic applications, and protein design.

An experimental method for choosing the tool pin profile and shoulder size to join dissimilar aluminum alloys AA7075-T651 and AA6061-T6 joints

Many military and light weight aircraft designs call for joints between two different grades of aluminium alloy. This present study looked at the effect of tool shoulder diameter and tool pin profile on the tensile strength properties of dissimilar aluminium alloy AA6061-T6 and AA7075-T651 joints created by friction stir welding. The joints were fabricated utilizing three distinct tool shoulder diameters 15 mm, 20 mm and 25 mm along with two distinct tool pin profiles namely taper and square. The microstructure and microhardness of weld stir zone (WSZ) were examined and linked with the strength parameters of the joints. Adequate frictional heat generation from 20 mm shoulder diameter and pulsating stirring action of square pin revealed the formation of very fine grains in the weld nugget zone (WNZ). Due to enhanced material flow and the production of a defect-free stir zone, the joint created using a tool with a 20 mm shoulder diameter and square pin profile had the maximum hardness of 117 HV and the highest tensile strength of 284 MPa. The ductile mechanism of fracture is revealed by the presence of fine dimples accumulating in the tensile fractured surface of the joint fabricated by 20 mm tool shoulder diameter and square pin.

Characterisation of the flow around passenger vehicle wheels with varying tyre profiles

The flow around wheels contributes to a significant part of the aerodynamic drag of passenger vehicles, which is crucial for overall energy efficiency. The rotation and bluff-body geometry of the wheels result in a complex flow field that is sensitive to geometrical variations such as the tyre geometry, tread pattern, tyre deformation and rim design.In this work, wind tunnel tests were performed with a full-scale crossover SUV, using two rim configurations and three tyres. Utilising flow field measurements and time-resolved surface pressure measurements, the main features of the flow were identified for three sets of tyres with distinct shoulder profiles and sidewall geometry. The main differences were found close to the ground. With a narrower sidewall, a smaller contact patch vortex was formed, reducing the drag. Combining the narrow sidewall with a narrow tread, the more rounded shoulder created a larger contact patch vortex and pronounced the vortex from the outer downstream tyre shoulder.Comparing closed and open rims, the same overall flow mechanisms were observed but their relative importance was altered. An interaction between the tyre and rim design was found, mainly in terms of how the front wheel wakes affect the rear wheels.

Variation in Scapulohumeral Rhythm on Dynamic Radiography in Pathologic Shoulders: A Novel Diagnostic Tool.

Alterations in scapulohumeral joint kinematics occur in various shoulder pathologies. Conventional imaging provides a static assessment of soft tissue and morphologic changes. Quantifying the scapulohumeral rhythm (SHR), using Dynamic Digital Radiography (DDR) can offer clinicians a greater understanding of the pattern and extent of motion impairment as well as reliably monitor changes throughout the treatment course. The purpose of this study was to analyze the SHR of patients diagnosed with small (SRCT) and massive rotator cuff tears (MRCT), adhesive capsulitis (AC), and glenohumeral osteoarthritis (GH-OA) and compare their measurements to those of patient controls with healthy shoulders using DDR. The sequences of pulsed radiographs collated in DDR to create a moving image were prospectively analyzed during humeral abduction in normal controls and in 4 distinct shoulder pathology groups: SRCT, MRCT, AC, and GH-OA. GH and ST joint angles were measured at 0-30°, 30-60°, 60-90°, and maximal coronal plane humeral abduction. SHR was defined as the ratio of the change in humeral abduction over the change in scapula upward rotation during humeral abduction and was calculated within the above angle intervals. 121 shoulders were analyzed. 40 normal controls were compared to 13 SRCT, 29 MRCT, 16 AC, and 23 GH-OA. SHR during humeral abduction differed significantly in patients with MRCT (1.91 ± 0.72), AC (1.55 ± 0.37) and GH-OA (2.31 ± 1.01) compared to controls (3.39 ± 0.79). When analyzed across 30o intervals of abduction, there was a significantly lower SHR found at 0-30°, 30-60° and 60-90° in MRCT, AC, and GH-OA across each motion range compared to controls. Control patients had an arc of abduction of 103° ± 32° which was significantly larger than all other pathologies (MRCT: 76° ± 23°, SRCT: 81° ± 21°, AC: 65° ± 27°, GH-OA: 71° ± 35°) and an average scapular abduction of 33° ± 14°, which was significantly less than patients with a MRCT (46° ± 10°) and AC (65° ± 27°). SHR remained significantly lower throughout shoulder abduction in MRCT (43.65%), AC (-54.29%), and GH-OA (32.01%) compared to controls. When isolating for humeral and scapular motion, all 4 pathologies had decreased GH abduction, while AC and MRCT had an increased scapular compensatory motion compared to controls. Quantifying kinematic patterns like SHR using DDR can be implemented as a novel, safe, and cost-effective method to diagnose shoulder pathology and to monitor response to treatment.

Two new species of the diatom genus Meridion (Bacillariophyta, Tabellariaceae) from Aleutian Islands

Two new species of Meridion (Bacillariophyta, Tabellariaceae) are described from Unalaska Island (Aleutian Islands, USA) based on light and scanning electron microscope investigations. Meridion tenuipes sp. nov. is characterized by very slender valves with capitate headpole, lack of costae at the footpole and rimoportula positioned close to valve apex. Meridion humerosum sp. nov. possesses more robust valves with capitate poles, separated by distinct shoulders, costae distributed through the whole valve length and rimoportula displaced some distance from the apex. Comparison of these new species with other heteropolar representatives of the genus is provided. Our data indicate that the degree of Meridion endemism in North America is even higher than it was previously supposed.

Individual heme a and heme a3 contributions to the Soret absorption spectrum of the reduced bovine cytochrome c oxidase

Bovine cytochrome c oxidase (CcO) contains two hemes, a and a3, chemically identical but differing in coordination and spin state. The Soret absorption band of reduced aa3-type cytochrome c oxidase consists of overlapping bands of the hemes a2+ and a32+. It shows a peak at ∼444 nm and a distinct shoulder at ∼425 nm. However, attribution of individual spectral lineshapes to hemes a2+ and a32+ in the Soret is controversial. In the present work, we characterized spectral contributions of hemes a2+ and a32+ using two approaches. First, we reconstructed bovine CcO heme a2+ spectrum using a selective Ca2+-induced spectral shift of the heme a2+. Second, we investigated photobleaching of the reduced Thermus thermophilus ba3- and bovine aa3-oxidases in the Soret induced by femtosecond laser pulses in the Q-band. The resolved spectra show splitting of the electronic B0x-, B0y-transitions of both reduced hemes. The heme a2+ spectrum is shifted to the red relative to heme a32+ spectrum. The ∼425 nm shoulder is mostly attributed to heme a32+.

Novel Imido‐Cr/Silica Ethylene Polymerization Catalysts Modified from the Phillips Catalyst

AbstractIn this work, novel imido‐Cr/silica catalysts are synthesized by modifying the Phillips catalyst CrOx/silica with isocyanates. The imido‐Cr/silica, which has moderate activities of 200–300 kgPE molCr−1 bar−1, shows lower efficiency than CrOx/silica for C2H4 polymerization. On the other hand, regarding to the modified catalysts, the productivity can be improved almost linearly with increasing C2H4 pressure, and very stable activities are observed during the 1 h run of C2H4 polymerization. When compared with CrOx/silica, the modified catalysts can produce polyethylene (PE) with much higher molecular weight (MW) and broader molecular weight distribution (MWD), which is featured by a distinct ultrahigh MW shoulder. Meanwhile, the MW and MWD of the PE products can be reduced obviously by adding a small amount of H2 before C2H4 polymerization. In addition, it is found that more 1‐hexene can be copolymerized by CrOx/silica, and it is preferentially incorporated into a portion of the PE chains. While such a preference is much less significant for the modified catalysts.

Ethylene Polymerization over Supported Vanadium-Magnesium Catalysts with Different Vanadium Content: The Effect of Hydrogen on Molecular Weight Characteristics of the Produced Bimodal Polyethylene

Data are presented on the activity of supported vanadium-magnesium catalysts (VMCs) with different vanadium content in ethylene polymerization and the molecular weight characteristics of the produced polyethylene. The VC1 catalyst, with a very low vanadium content (0.12 wt.%), showed a sixfold higher activity per unit weight of vanadium than the VC2 catalyst with a high-vanadium content (4.0 wt.%). Additionally, the total activity of VC2 (kg PE/g cat·h) was fivefold higher when compared to VC1. The introduction of hydrogen in polymerization leads to a considerable decrease in the activity of both catalysts. The polyethylene obtained in the presence of hydrogen over both catalysts has a broad bimodal molecular weight distribution (MWD) with a distinct shoulder in the high-molecular region (Mw ≥ 106 g/mol). Decomposition of the MWD curves of bimodal polyethylene into two fractions (high- and low-molecular fractions) made it possible to determine for the first time the ratio of the reaction rate constants of chain transfer with hydrogen (KtrH) and polymer chain propagation (Kp) for two groups of the VMC active sites producing low- and high-molecular fractions of bimodal polyethylene.

High-Energy Resolution Fluorescence Detected X-ray Absorption Spectroscopy for the Speciation of Fe in Aerosol Samples

In this study, we compared the high-energy resolution X-ray fluorescence X-ray absorption near-edge structure (HERFD-XANES) and normal XANES spectra of various iron (Fe) species and Fe in atmospheric aerosol samples to explore the advantages of Fe K-edge HERFD-XANES for Fe speciation in aerosols using the linear combination fitting (LCF) of XANES spectra. We also conducted Fe extraction experiments to validate the LCF-XANES. In the HERFD-XANES spectra, the pre-edge region showed specific structures absent in normal XANES. HERFD-XANES also produced more distinctive shoulders within each spectrum than normal XANES. HERFD-XANES was applied to an aerosol sample (MT21-S2) collected in Tokyo, Japan. Normal XANES identified ferrihydrite, biotite, and montmorillonite, whereas HERFD-XANES clearly detected goethite as a fourth component. Normal XANES did not distinguish between ferrihydrite and goethite in LCF because of their similar structures. A similar trend was observed in the pre-edge region, and the Fe extraction experiment result was consistent with the LCF result in the pre-edge region. Thus, LCF of HERFD-XANES, in particular for the pre-edge region, can be a powerful tool for Fe speciation in aerosols.

Arthroscopic repair of inferior glenoid labrum tears (Down Under lesions) produces similar outcomes to other glenoid tears.

Inferior glenoid labral tears are an uncommon but distinct shoulder injury. Only a small number of studies have reported outcomes following arthroscopic repair. The aim of the current study was to report minimum 2-year outcomes following inferior labral repair and to compare outcomes and risk factors associated with the injury to non-inferior labral tears. Whether preoperative MRI or MRA identified inferior labral tears was also assessed. A prospective study of 162 consecutive patients undergoing arthroscopic glenoid labral repair, excluding isolated superior labral tears, was conducted. Of the 130 patients available for follow-up, 18 (13.7%) had an inferior labral tear ("Down Under lesion"), the remainder had anterior, posterior or mixed anterior/posterior lesions that did not include the inferior pole. Mean follow-up time for theDown Under group was 44months (SD 10, range 27-57), and 30months (SD 14, range 4-60) for the non-Down Under group. Postoperative outcomes included the Oxford Shoulder Instability Score and recurrent instability. Associations between Down Under lesions and injury mechanism, instability at presentation, recurrent instability and family history were assessed with multivariable logistic regression. Preoperative MRI or MRA reports by radiologists were examined to determine if Down Under lesions were identified. Oxford Shoulder Instability Scores indicated that most patients in both groups had little pain or shoulder problems postoperatively (average Oxford Score 41; 48 = no symptoms). Oxford Scores were not significantly different between the Down Under and non-Down Under groups. Four patients (22.2%) in the Down Under group had recurring symptoms (pain and instability) compared to 12 (10.6%) in the non-Down Under group; this difference was not statistically significant (adjusted OR 1.09, 95% CI 0.19,4.77). Family history of shoulder instability was positively associated with a Down Under lesion (adjusted OR 5.0, 95%CI 1.51,16.7). MRI or MRA identified 52.9% of Down Under lesions. Down Under lesions were an infrequent type of glenoid labral injury, yet postoperative outcomes were similar to other labral tears. Patients with Down Under lesions had a significant risk factor due to family history of shoulder instability. MRI and MRA could not reliably identify Down Under lesions. Level III.

Unilateral and bilateral training competitive archers differ in some potentially unhealthy neck-shoulder region movement behaviour characteristics

BackgroundExcessive unilateral joint loads may lead to overuse disorders. Bilateral training in archery is only performed as a supportive coordination training and as a variation of typical exercise. However, a series of studies demonstrated a crossover transfer of training-induced motor skills to the contralateral side, especially in case of mainly unilateral skills. We compared the cervical spine and shoulder kinematics of unilateral and bilateral training archers.MethodsIn this cross-sectional study, 25 (5 females, 48 ± 14 years) bilaterally training and 50 age-, sex- and level-matched (1:2; 47.3 ± 13.9 years) unilaterally training competitive archers were included. Cervical range of motion (RoM, all planes) and glenohumeral rotation were assessed with an ultrasound-based 3D motion analysis system. Upward rotation of the scapula during abduction and elevation of the arm were measured by means of a digital inclinometer and active shoulder mobility by means of an electronic caliper. All outcomes were compared between groups (unilaterally vs. bilaterally) and sides (pull-hand- vs. bow-hand-side).ResultsUnilateral and bilateral archers showed no between group and no side-to-side-differences in either of the movement direction of the cervical spine. The unilateral archers had higher pull-arm-side total glenohumeral rotation than the bilateral archers (mean, 95% CI), (148°, 144–152° vs. 140°, 135°-145°). In particular, internal rotation (61°, 58–65° vs. 56°, 51–61°) and more upward rotation of the scapula at 45 degrees (12°, 11–14° vs. 8°, 6–10°), 90 degrees (34°, 31–36° vs. 28°, 24–32°), 135 degrees (56°, 53–59° vs. 49°, 46–53°), and maximal (68°, 65–70° vs. 62°, 59–65°) arm abduction differed. The bow- and pull-arm of the unilateral, but not of the bilateral archers, differed in the active mobility of the shoulder (22 cm, 20–24 cm vs. 18 cm, 16–20 cm).ConclusionsUnilaterally training archers display no unphysiologic movement behaviour of the cervical spine, but show distinct shoulder asymmetris in the bow- and pull-arm-side when compared to bilateral archers in glenohumeral rotation, scapula rotation during arm abduction, and active mobility of the shoulder. These asymmetries in may exceed physiological performance-enhancing degrees. Bilateral training may seems appropriate in archery to prevent asymmetries.

Phenotyping the shoulder patient based on ultrasound-detected pathologies: a cross-sectional study in general practice.

Shoulder complaints arise from a single pathology or a combination of different underlying pathologies that are hard to differentiate in general practice. Subgroups of pathologies have been identified on the basis of ultrasound imaging that might affect treatment outcomes. Our aim was to validate the existence of different subgroups of patients with shoulder complaints, based on ultrasound-detected pathology, and compare clinical features among them. Profiling shoulder patients into distinct shoulder pathology phenotypes could help designing tailored treatment trials. This was a cross-sectional study in general practice. Data were extracted from 840 first visit patient records at a single diagnostic centre in the Netherlands. Exclusion criteria were age <18 years and previous shoulder surgery. Latent class analysis was used to uncover cross-combinations of ultrasound detected pathologies, yielding subgroups of shoulder patients. The uncovered subgroups were compared for demographic and clinical characteristics. We uncovered four distinct subgroups of patients with shoulder complaints: (i) Frozen shoulder group (11%), (ii) Limited pathology group (44%), (iii) Degenerative pathology group (31%) and (iv) Calcifying tendinopathy group (15%). Group comparisons showed significant differences in demographic and clinical characteristics among subgroups, consistent with the literature. In a general practice population, we uncovered four different phenotypes of shoulder patients on the basis of ultrasound detected pathology. These phenotypes can be used designing tailored treatment trials in patients with shoulder complaints.

Influences of welding parameters on friction stir welding of AA 6063 Al-alloy and copper plates – An experimental study

Friction stir welding is a solid state welding technique for the welding of metallic compounds. The Aluminium alloy 6063 and commercially available copper of 6 mm thickness are welded in circular butt joint geometry by friction stir welding (FSW) process, using vertical milling machine. The Friction stir welding was carried out at each rotational speed of 800 rpm and 1000 rpm for different travel speed 20 and 40 mm/min at constant probe depth of 2.9 mm, towards the trailing edge and a dwell time of 3 sec. One of the critical elements for the achievement of this method is the friction stir welding tool. It comprises of a distinct geometry cylindrical shoulder and a pin. The said instrument was intended for friction stir welding of the dissimilar metal plates in the experimental job with cylindrical pin profile. The results have been correlated with the micro structural characteristics at the bond interface using scanning electron microscopy. The results show the characteristics of different types of intermetallic compound formed at the interface derived from energy input.

Dissolved organic matter in hand-dug well water as groundwater quality indicator: assessment using laser-induced fluorescence spectroscopy and multivariate statistical techniques

In groundwater, dissolved organic matter (DOM), a complex material, is a contaminant of concern owing to its ability to influence water quality and stimulate microbial metabolism. Using a 445-nm diode laser-induced fluorescence (LIF) spectroscopy, DOM contamination levels have been investigated of well water samples fetched from ten privately owned hand-dug wells during dry and wet seasons of 2016, 2017 and 2018, in Ghana. The results showed spatio-temporal heterogeneities in the LIF spectra, and the fluorescence intensity peaks were generally higher and broader during the wet season than the dry season. In this study, DOM fluorescence spectra at an emission wavelength band of 460–650 nm showed two distinct broad peak shoulders within 480–500 nm and 550–570 nm, engulfing the water Raman peak at 527 ± 2 nm for all the water samples studied. Furthermore, principal component analysis and cluster analysis were used to differentiate the 2016 water samples based on their DOM contamination levels. In each case, three groups or clusters were identified based on their similarities and dissimilarities. The study revealed humic DOM substances as the most typical well water fluorophores. Applying the K-nearest neighbour algorithm as a classifier method for the classification of 30 water samples studied in 2016, 16.7% (5/30) were classified as very good drinking water, 46.7% (14/30) as good, 26.7% (8/30) as fairly good, and 10% (3/30) as bad drinking water samples. In general, levels of dissolved organic matter contamination increased over the study period during the rainy seasons for wells situated in close proximity to septic tanks, refuse dumps, public toilets and in wetlands. Thus, in the study the fluorescence intensity depends on the sampling site and the season, and indicates the DOM contamination level.

Generalizing movement patterns following shoulder fixation.

Generalizing newly learned movement patterns beyond the training context is challenging for most motor learning situations. Here we tested whether learning of a new physical property of the arm during self-initiated reaching generalizes to new arm configurations. Human participants performed a single-joint elbow reaching task and/or countered mechanical perturbations that created pure elbow motion with the shoulder joint free to rotate or locked by the manipulandum. With the shoulder free, we found activation of shoulder extensor muscles for pure elbow extension trials, appropriate for countering torques that arise at the shoulder due to forearm rotation. After locking the shoulder joint, we found a partial reduction in shoulder muscle activity, appropriate because locking the shoulder joint cancels the torques that arise at the shoulder due to forearm rotation. In our first three experiments, we tested whether and to what extent this partial reduction in shoulder muscle activity generalizes when reaching in different situations: 1) different initial shoulder orientation, 2) different initial elbow orientation, and 3) different reach distance/speed. We found generalization for the different shoulder orientation and reach distance/speed as measured by a reliable reduction in shoulder activity in these situations but no generalization for the different elbow orientation. In our fourth experiment, we found that generalization is also transferred to feedback control by applying mechanical perturbations and observing reflex responses in a distinct shoulder orientation. These results indicate that partial learning of new intersegmental dynamics is not sufficient for modifying a general internal model of arm dynamics.NEW & NOTEWORTHY Here we show that partially learning to reduce shoulder muscle activity following shoulder fixation generalizes to other movement conditions, but it does not generalize globally. These findings suggest that the partial learning of new intersegmental dynamics is not sufficient for modifying a general internal model of the arm's dynamics.

Postoperative neck tilt in Lenke 1 and 2 AIS patients after correction surgery: a novel predictive index

BackgroundPostoperative neck tilt (PNT) is a phenomenon in adolescent idiopathic scoliosis (AIS) patients which is distinct form shoulder imbalance. There were scarce studies performed to explore the risk factors for PNT in Lenke 1 and 2 AIS patients, and whether it can be predicted after surgery remains unknown. The objective of this study is to explore the prevalence and risk factors for PNT, and introduce an index for prediction of PNT in Lenke 1 and 2 AIS patients after correction surgery.MethodsMedical records of Lenke 1 and 2 AIS patients who received correction surgery were reviewed from February 2013 to February 2015. Posteroanterior films were evaluated before surgery and at 2 years’ follow-up. Patients were divided into two groups according to whether PNT occurred at the 2 years’ follow-up. Risk factors of PNT were analyzed, and PNT Index was proposed and verified.ResultsOne hundred two Lenke 1 and 2 AIS patients were recruited in this study. The prevalence of PNT after correction was 40.2%. According to the postoperative CAT (Cervical Axis Tilt), patients were divided into two group: PNT group (CAT≧5°, n = 41) and non-PNT group (CAT< 5°, n = 61). Postoperative T1 tilt, preoperative proximal thoracic curve (PTC), postoperative PTC and postoperative coronal balance (CB) were significantly different between two groups. Logistic regression showed that postoperative PTC and postoperative CB were the primary risk factors for PNT, which could be predicted by the regression equation: PNT Index = 1.1 x postoperative PTC (degrees) - 0.9 x postoperative CB (millimeters). On the basis of ROC curve, if PNT Index was more than 10, the occurrence rate of PNT was 86%. On the contrary, the rate of no PNT phenomenon was 80%.ConclusionPostoperative PTC and postoperative CB were the important factors for PNT in Lenke 1 and 2 AIS patients. Sufficient correction of PTC and moderate correction of CB should be recommended when operating on Lenke1 and 2 AIS patients.

Optical properties of 3d transition metal ion-doped aluminophosphate glasses

P2O5–Al2O3–SiO2-GeO2-Li2O glasses doped with 3 d-transition metal (TM) ions from Sc to Zn were prepared by the conventional melting-quenching method. Their optical properties were investigated. The oxidation states, which were revealed from the UV–vis–NIR transmittance spectra, excitation and emission spectra of the studied glasses, are Sc(III), Ti(III), V(III), Cr(III), Mn(II), Fe(II,III), Co(II), Ni(II), Cu(I, II) and Zn(II). Scandium exhibits weak, broad emission at 321 nm in aluminophosphate glass probably ascribed to the formation of the ScAl center. Cr3+ emission at 890 nm due to the 4T2(4F)→4A2(4F) transition of Cr3+ ions at the weak crystal field octahedral sites was observed under excitation at 296, 457, 658, and 684 nm. Mn2+ emission at 603 nm with a distinct shoulder at ∼513 nm due to the 4T1(4G) → 6A1(6S) transition of Mn2+ ions in an octahedral coordination and tetrahedral coordination environment, respectively, were observed under excitation at 346 nm and 408 nm. Cu+ emission at 468 nm with excitation at around 290 nm was ascribed to transition from excited s state to ground d state (d9s→d10) of Cu+. No other 3dN TM ions are found to give strong visible emission in aluminophosphate glass at room temperature. Temperature dependent emission spectra for V, Cr, Mn, Fe, Cu doped aluminophosphate glass with laser excitation have also been investigated.

Synthesis and Structural Analysis of Powder Complex of Tris(bipyridine)cobalt(II) Trifluoromethanesulfonate Octahydrate

The powder complex of tris(bipyridine)cobalt(II) trifluoromethanesulfonate octahydrate has been synthesized by direct interaction of the corresponding aqueous solutions (and drops of ethanol) of cobalt(II) nitrate, bipyridine, and potassium triflate. The yellow-orange powder produced was filtered off and allowed to dry on an aeration for characterization. AAS measurement showed the content of metal to be 6.06%, corresponding to the theoretical value of 6.06% in [Co(bipy)3](CF3SO3)2.8H2O. The analysis of conductance producing the charge ratio of cation to anion to be 2:1, confirms the formula. The magnetic moment, µeff, of this complex which was to be 4.5-4.9 BM, indicates that the complex is paramagnetic corresponding to the three unpaired electrons with a significantly orbital contribution. UV-Vis spectrum of the complex reveals the first band observed at about 11100 cm–1, which is associated with the spin-allowed transition, 4T1g → 4T2g. A distinct shoulder at only about 16100 cm–1 should be associated with the spin-forbidden transition of 4T1g → 2T2g,2T2g (G). The expected second and third bands which are associated with spin-allowed transitions of 4T1g → 4T1g(P) and 4T1g → 4A2g at higher energy were not well resolved. The infrared spectrum shows absorptions of the functional group of ligand which is influenced by the metal-ligand interaction in this complex. The powder XRD of this complex was refined using Le Bail method of Rietica program and found to be fit as monoclinic symmetry with a space group of C2/c.