Method development and mechanistic study on direct pulsed laser irradiation process for highly effective dechlorination of persistent organic pollutants.

Chlorine-based compounds are typical persistent organic pollutants (POPs) that are widely generated in industrial production. This paper reports an effective and rapid pulsed laser irradiation technique for the dechlorination of hexachlorobenzene (HCB), a model pollutant, without additional catalysts or supports. The effects of the laser parameters, including the laser wavelength and power, on the dechlorination efficiency, were also investigated. The optimized results showed that a lower laser wavelength of 266 nm with 10 mJ/pulse power exhibited the highest dechlorination efficiency with 95% within 15 min. In addition, the laser beam effect was examined by designing the direct-pulsed laser single and multipath irradiation system. The results showed that improving the laser beam profile resulted in more than 95% dechlorination efficiency within 5 min. Thus, the dechlorination reaction proceeded much faster as the surface area that the laser beam came in contact with increased due to the multipath system than the single pathway. Gas chromatography identified benzene as the final product of HCB with pentachlorobenzene (PCB), tetrachlorobenzene (TeCB), trichlorobenzene (TCB), dichlorobenzene (DCB), and chlorobenzene (CB) as intermediate products. The mechanism of HCB dechlorination was explained by a comparison of theoretical calculations with the experimental results. The present study reports an advanced technique for the complete dechlorination of chlorobenzenes, which holds great application potential in environmental remediation.

Improvement of Biophysical Properties and Affinity of a Human Anti-L1CAM Therapeutic Antibody through Antibody Engineering Based on Computational Methods.

The biophysical properties of therapeutic antibodies influence their manufacturability, efficacy, and safety. To develop an anti-cancer antibody, we previously generated a human monoclonal antibody (Ab417) that specifically binds to L1 cell adhesion molecule with a high affinity, and we validated its anti-tumor activity and mechanism of action in human cholangiocarcinoma xenograft models. In the present study, we aimed to improve the biophysical properties of Ab417. We designed 20 variants of Ab417 with reduced aggregation propensity, less potential post-translational modification (PTM) motifs, and the lowest predicted immunogenicity using computational methods. Next, we constructed these variants to analyze their expression levels and antigen-binding activities. One variant (Ab612)-which contains six substitutions for reduced surface hydrophobicity, removal of PTM, and change to the germline residue-exhibited an increased expression level and antigen-binding activity compared to Ab417. In further studies, compared to Ab417, Ab612 showed improved biophysical properties, including reduced aggregation propensity, increased stability, higher purification yield, lower pI, higher affinity, and greater in vivo anti-tumor efficacy. Additionally, we generated a highly productive and stable research cell bank (RCB) and scaled up the production process to 50 L, yielding 6.6 g/L of Ab612. The RCB will be used for preclinical development of Ab612.

Concurrent occurrence of electrochemical dissolution/deposition of cobalt-calcium phosphate composite.

Amorphous cobalt-calcium phosphate composite (CCPC) films are electrochemically prepared on various electrodes by utilizing the solid phase of hydroxyapatite as a phosphate source. The CCPC film formation is surface process in which the dissolution of hydroxyapatite and the deposition of CCPC film concurrently occur on the electrode surface without the mass transfer of phosphate ions into the bulk solution. Elemental, crystallographic, and morphological analyses (EDX, ICP-AES, XPS, and XRD) indicate that the CCPC is composed of amorphous cobalt oxide with calcium and phosphate. The film exhibits durable oxygen evolution reaction (OER) catalytic properties under neutral and basic aqueous condition. Compared to using solution phase of phosphate source, our preparation method utilizing solid hydroxyapatite has advantage of preventing unnecessary chemical reaction between phosphate and other chemical species in bulk solution.

Cost-Effective Synthesis of Efficient CoWO4/Ni Nanocomposite Electrode Material for Supercapacitor Applications.

In the present study, the synthesis of CoWO4 (CWO)-Ni nanocomposites was conducted using a wet chemical method. The crystalline phases and morphologies of the Ni nanoparticles, CWO, and CWO-Ni composites were analyzed using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and energy-dispersive X-ray spectroscopy (EDAX). The electrochemical properties of CWO and CWO-Ni composite electrode materials were assessed by cyclic voltammetry (CV), and galvanostatic charge-discharge (GCD) tests using KOH as a supporting electrolyte. Among the CWO-Ni composites containing different amounts of Ni1, Ni2, and Ni3, CWO-Ni3 exhibited the highest specific capacitance of 271 F g-1 at 1 A g-1, which was greater than that of bare CWO (128 F g-1). Moreover, the CWO-Ni3 composite electrode material displayed excellent reversible cyclic stability and maintained 86.4% of its initial capacitance after 1500 discharge cycles. The results obtained herein demonstrate that the prepared CWO-Ni3 nanocomposite is a promising electrode candidate for supercapacitor applications.

Ultraviolet Patterned Calixarene-Derived Supramolecular Gels and Films with Spatially Resolved Mechanical and Fluorescent Properties.

Supramolecular assemblies have in the past been considered mechanically weak and in most cases unable to withstand their own weight. Calixarene-derived networks can, however, provide robust supramolecular gels. Incorporating a photoreactive stilbene moiety, we show that the aggregation state of the material can be tuned by heating and UV exposure in order to control the mechanical as well as the fluorescent properties. Regulating the extent of heating to control the proportion of H-aggregates and J-aggregates and further cross-linking of H-aggregates by control over UV exposure allows for adjustable photopatterning of the fluorescence as well as the material stiffness in the range from ∼100 to 450 kPa. We expect this straightforward supramolecular system will be suitable for advanced prototyping in applications where modulus and shape are important design criteria.

Highly selective fluorescence imaging of zinc distribution in HeLa cells and Arabidopsis using a naphthalene-based fluorescent probe.

2-(N,N-Dimethylamino)naphthalene-based probe 1 was found to exhibit a dramatic enhancement in fluorescence upon addition of Zn(2+), but not with any other metal ions. Probe 1 as a chemoprobe enabled high-resolution fluorescence imaging of zinc ions in HeLa cells and Arabidopsis.

Efficacy and safety of deferasirox estimated by serum ferritin and labile plasma iron levels in patients with aplastic anemia, myelodysplastic syndrome, or acute myeloid leukemia with transfusional iron overload.

BACKGROUND: Patients receiving red blood cell (RBC) transfusions are at risk of iron overload, which can cause significant organ damage and is an important cause of morbidity and mortality. STUDY DESIGN AND METHODS: This study was an open-label, single-arm, prospective clinical study to evaluate the efficacy and safety of deferasirox (DFX) in patients with aplastic anemia (AA), myelodysplastic syndrome (MDS), or acute myeloid leukemia (AML). Patients with serum ferritin levels of at least 1000 ng/mL and ongoing transfusion requirements were enrolled. DFX was administered for up to 1 year. A total of 100 patients were enrolled. RESULTS: Serum ferritin levels decreased significantly following treatment (from 2000 to 1650 ng/mL, p = 0.004). The median absolute reduction in serum ferritin levels was -65 ng/mL in AA (p = 0.037), -647 ng/mL in lower-risk MDS (MDS-LR; p = 0.007), and -552 ng/mL in higher-risk MDS (MDS-HR)/AML (p = 0.482). Mean labile plasma iron (LPI) levels decreased from 0.24 µmol/L at baseline to 0.03 µmol/L at 1 year in all patients (p = 0.036). The mean LPI reduction in each group was -0.17 µmol/L in AA, -0.21 µmol/L in MDS-LR, and -0.30 µmol/L in MDS-HR/AML. Gastrointestinal disorders were commonly observed among groups (16.0%). DFX was temporarily skipped for adverse events in seven patients (7.0%) and was permanently discontinued in 11 patients (11.0%). CONCLUSION: DFX reduced serum ferritin and LPI levels in patients with transfusional iron overload. Despite the relatively high percentage of gastrointestinal side effects, DFX was tolerable in all subgroups.

A turn-on fluorogenic Zn(II) chemoprobe based on a terpyridine derivative with aggregation-induced emission (AIE) effects through nanofiber aggregation into spherical aggregates.

The self-assembly of a terpyridine-based ligand in a DMSO/water solvent mixture (1 : 99 v/v) with a high content of water formed a nanofibrillar structure and showed a non-emissive process. On the other hand, the self-assembly of the terpyridine-based ligand exhibited strong emission in the presence of Zn(2+) due to the formation of coordination bonds between the terpyridine moieties and the Zn(2+) by the aggregation-induced emission effect. The morphology of this aggregate represented a spherical structure.

Reversibly tunable helix inversion in supramolecular gels trigged by Co(2+).

Terpyridine-based ligands form octahedral complexes with Co(2+) at low cation concentrations to form helical assemblies which provide a supramolecular gel framework. Increasing the Co(2+) concentration above 0.6 equiv. reveals a second, co-existing square pyramidal complex derived assembly, having a distinct helicity. While this geometry dominates at 1 equiv. of Co(2+), we find this unique form of helical inversion to be fully reversible and controllable.

The efficacy and perioperative complications associated with lumbar spinal fusion surgery, focusing on geriatric patients in the republic of Korea.

OBJECTIVE: The purpose of this study was to examine the efficacy and perioperative complications associated with lumbar spinal fusion surgery, focusing on geriatric patients in the Republic of Korea. METHODS: We retrospectively investigated 485 patients with degenerative spinal diseases who had lumbar spinal fusion surgeries between March 2006 and December 2010 at our institution. Age, sex, comorbidity, American Society of Anesthesiologists (ASA) class, fusion segments, perioperative complications, and outcomes were analyzed in this study. Risk factors for complications and their association with age were analyzed. RESULTS: In this study, 81 patients presented complications (16.7%). The rate of perioperative complications was significantly higher in patients 70 years or older than in other age groups (univariate analysis, p=0.015; multivariate analysis, p=0.024). The perioperative complications were not significantly associated with the other factors tested (sex, comorbidity, ASA class, and fusion segments). Post-operative outcomes of lumbar spinal fusion surgeries for the patients were determined on the basis of MacNab's criteria (average follow up period : 19.7 months), and 412 patients (85.0%) were classified as having "excellent" or "good" results. CONCLUSION: Increasing age was an important risk factor for perioperative complications in patients undergoing lumbar spinal fusion surgery, whereas other factors were not significant. However, patients' satisfaction or return to daily activities when compared with younger patients did not show much difference. We recommend good clinical judgment as well as careful selection of geriatric patients for lumbar spinal fusion surgery.

Giant cystic cerebral cavernous malformation with multiple calcification - case report.

Cerebral cavernous malformation with giant cysts is rare and literature descriptions of its clinical features are few. In this case study, the authors describe the clinical symptoms, radiological findings, and pathological diagnosis of cerebral cavernous malformations with giant cysts, reviewing the relevant literature to clearly differentiate this from other disease entities. The authors present a case of a 19-year-old male with a giant cystic cavernous malformation, who was referred to the division of neurosurgery due to right sided motor weakness (grade II/II). Imaging revealed a large homogenous cystic mass, 7.2×4.6×6 cm in size, in the left fronto-parietal lobe and basal ganglia. The mass had an intra-cystic lesion, abutting the basal portion of the mass. The initial diagnosis considered this mass a glioma or infection. A left frontal craniotomy was performed, followed by a transcortical approach to resect the mass. Total removal was accomplished without post-operative complications. An open biopsy and a histopathological exam diagnosed the mass as a giant cystic cavernous malformation. Imaging appearances of giant cavernous malformations may vary. The clinical features, radiological features, and management of giant cavernous malformations are described based on pertinent literature review.

Systematic analysis of palladium-graphene nanocomposites and their catalytic applications in Sonogashira reaction.

Graphene has been modified with palladium nanoparticles (Pd NPs) to develop high performance catalysts for the Sonogashira cross coupling reaction. In this research, graphite oxide (GO) sheets exfoliated from graphite were impregnated with Pd(OAc)2 to prepare Pd(2+)/GO. Thermal treatments of the Pd(2+)/GO in H2 flow at 100°C produced Pd/graphene (Pd/G) nanocomposites. TEM images show that Pd NPs were distributed quite uniformly on the graphene sheet without obvious aggregation, and the mean size of Pd NPs was determined to be less than 2 nm in diameter. Morphological and chemical structures of the GO, Pd(2+)/GO, and Pd/G were investigated using FT-IR, XRD, XPS, and XAFS. The resulting Pd/G showed excellent catalytic efficiency in the Sonogashira reaction and offers significant advantages over inorganic supported catalysts such as simple recovery and recycling. Finally, deactivation process of the Pd/G in recycling was investigated. We believe that the remarkable reactivity of the Pd/G catalyst toward the Sonogashira reaction is attributed to the high degree of the Pd NP dispersion and thus the increased low coordination numbers of smaller Pd NPs.

Hydroxyapatite supported cobalt catalysts for hydrogen generation.

The controlled generation of H(2) from storage materials by using an efficient catalytic support is a highly sought after technology; however, the majority of successes utilize expensive materials considered unfeasible. In our report on the creation of a novel, durable, and inexpensive catalytic support material for hydrogen generation, we examine a critical surface modification of hydroxyapatite (HAP) with cobalt ions to provide the necessary catalytic transition metal for the fast hydrolysis of the hydrogen storage material, sodium borohydride (NaBH(4)). By altering the morphology and composition of the HAP crystal supports, we revealed novel methods for enhancing the hydrogen generation rates. Particularly, lowering the Ca composition during synthesis of the HAP crystals afforded a Ca deficient HAP capable of exhibiting a higher surface coverage of cobalt, thereby eliciting faster hydrolysis reaction rates in comparison with the amorphous HAP control having the characteristic Ca content for HAP. A more significant increase in hydrogen generation was observed when using single crystal HAP in comparison with amorphous and calcium deficient HAP supports. Despite the smaller surface area of the hydrothermally prepared single crystal HAP, it provided significantly faster hydrogen generation. Each of the HAP supports exhibit repeatability with catalytic efficiency decreasing by approximately 25% over 3 weeks upon repeated daily exposure to solutions of the hydrogen storage material NaBH(4). Through these experiments, we proved that altering the composition and morphology of cobalt ion exchanged HAP supports can offers a useful means for increasing the rate of controlled hydrogen generation.

The role of hyperthyroidism as the predisposing factor for superior sagittal sinus thrombosis.

Superior sagittal sinus thrombosis (SSST) is an uncommon cause of stroke, whose symptoms and clinical course are highly variable. It is frequently associated with a variety of hypercoagulable states. Coagulation abnormalities are commonly seen in patients with hyperthyroidism. To the best of our knowledge, there are few reports on the association between hyperthyroidism and cerebral venous thrombosis. We report on a 31-year-old male patient with a six-year history of hyperthyroidism who developed seizure and mental deterioration. Findings on brain computed tomography (CT) showed multiple hemorrhages in the subcortical area of both middle frontal gyrus and cerebral digital subtraction angiography (DSA) showed irregular intra-luminal filling defects of the superior sagittal sinus. These findings were consistent with hemorrhagic transformation of SSST. Findings on clinical laboratory tests were consistent with hyperthyroidism. In addition, our patient also showed high activity of factors IX and XI. The patient received treatment with oral anticoagulant and prophylthiouracil. His symptoms showed complete improvement. A follow-up cerebral angiography four weeks after treatment showed a recanalization of the SSS. In conclusion, findings of our case indicate that hypercoagulability may contribute to development of SSST in a patient with hyperthyroidism.

Comparison of posterior fixation alone and supplementation with posterolateral fusion in thoracolumbar burst fractures.

OBJECTIVE: We compared the radiological and clinical outcomes between patients who underwent posterior fixation alone and supplemented with fusion following the onset of thoracolumbar burst fractures. In addition, we also evaluated the necessity of posterolateral fusion for patients treated with posterior pedicle screw fixation. METHODS: From January 2007 to December 2009, 46 consecutive patients with thoracolumbar burst fracture were included in this study. On the basis of posterolateral fusion, we divided our patients into the non-fusion group and the fusion group. The radiological assessment was performed according to the Cobb's method, and results were obtained at immediately, 3, 6, 12 months after surgery. The clinical outcomes were evaluated using the modified Mcnab criteria at the final follow-up. RESULTS: The demographic data and the mean follow-up period were similar between the two groups. Patients of both groups achieved satisfactory clinical outcomes. The mean loss of kyphosis correction showed that patients of both groups experienced loss of correction with no respect to whether they underwent the posterolateral fusion. There was no significant difference in the degree of loss of correction at any time points of the follow-up between the two groups. In addition, we also compared the effect of fixed levels (i.e., short versus long segment) on loss of correction between the two groups and there was no significant difference. There were no major complications postoperatively and during follow-up period. CONCLUSION: We suggest that posterolateral fusion may be unnecessary for patients with thoracolumbar burst fractures who underwent posterior pedicle screw fixation.

Fluorescent composite hydrogels of metal-organic frameworks and functionalized graphene oxide.

GO MOFs! Azobenzoic acid functionalized graphene (A-GO) can act as a structure-directing template that influences hydrogel formation together with metal-organic frameworks (MOFs). Zn(2+) MOFs of pyridine derivatives work as framework linkers between the A-GO sheets (MOF-A-GO, see figure). MOF-A-GO exhibits a strong fluorescence enhancement upon gel formation. In addition, MOF-A-GO selectively recognizes trinitrotoluene.

Comparative Study of Posterior Lumbar Interbody Fusion via Unilateral and Bilateral Approaches in Patients with Unilateral Leg Symptoms.

OBJECTIVE: We investigated the clinical and radiological advantages of unilateral laminectomy in posterior lumbar interbody fusion (PLIF) procedure comparing with bilateral laminectomy, under the same procedural condition including bilateral instrumentation and insertion of two cages, in patients with degenerative lumbar disease with unilateral leg symptoms. METHODS: We retrospectively reviewed 124 consecutive cases of PLIF via unilateral or bilateral approach between January 2006 and April 2010. In 80 cases (bilateral group), two cages were inserted via bilateral laminectomy, and in 44 cases (unilateral group), via unilateral laminectomy. The average follow-up duration was 29.5 months. The clinical outcomes were evaluated with the Visual Analogue Scale (VAS) and the Oswestry disability index (ODI). The fusion rates and disc space heights were determined by dynamic standing radiographs and/or computed tomography. Operative times, intra-operative and post-operative blood losses and hospitalization periods were also evaluated. RESULTS: In clinical evaluation, the VAS and ODI scores showed excellent outcomes in both groups. There were no significant differences in term of fusion rate, but the perioperative blood loss and the operative time of the unilateral group were lower than that of the bilateral group. CONCLUSION: Unilateral laminectomy can minimize the operative time and perioperative blood loss in PLIF procedure. However, the different preoperative disc height between two groups is a limitation of this study. Despite this limitation, solid fusion and satisfactory symptomatic improvement could be achieved uniquely by our surgical method. This surgical method can be an alternative surgical technique in patients with unilateral leg pain.

Steric blocking as a tool to control molecular film geometry at a metal surface.

The application of steric blocking in surface science is exemplified by the control of surface patterns through the selective methylation of pentacenetetrone. Pentacenetetrones interact (with one another) on Cu(111) via intermolecular hydrogen bonding involving the carbonyl oxygen and the adjacent hydrogen atoms. Steric blocking of the intermolecular interaction by the successive insertion of inert methyl groups at terminal locations transforms a dense molecular pattern first into isolated double rows and eventually into single rows in a highly predictable fashion. Density functional theory modeling reveals the underlying energetics.

Surface modification of hydroxyapatite for hydrogen generation.

Hydrogen provides a safe and clean alternative to carbon-based fuels. Having the proper catalytic support for production of hydrogen is a valuable technology. We report on the surface modification of hydroxyapatite as a novel catalytic support material for hydrogen generation. Aside from being inexpensive and durable, we reveal that Ru ion exchange on the HAP surface provides a highly active support for sodium borohydride hydrolysis, exemplifying a high total turnover number on the order of 24,000 mol H(2)/mol Ru. Moreover, we observe that the RuHAP support exhibits a long catalytic lifetime of approximately 1month upon repeated exposure to NaBH(4) solutions. We identified the ability of complex surface morphology to enhance hydrolysis by the catalytic transition metal covered surface. Particularly, we found that the complex morphology of polycrystalline RuHAP catalytic supports exhibits shorter induction times for hydrogen generation as well as improved reaction rates as compared with single crystal supports possessing the same Ru content. By decreasing induction time and enhancing catalytic activity, we find it feasible to further explore this catalyst support in the construction of a practical hydrogen generation system.

Microscopic study of hydroxyapatite dissolution as affected by fluoride ions.

Fluoride ions play a critical role in preventing tooth decay. We investigated the microscopic effects of fluoride ions on hydroxyapatite (100) surface dissolution using in situ atomic force microscopy. In the presence of 10 mM NaF, individual surface step retraction velocities decreased by about a factor of 5 as compared to NaF-free conditions. Importantly, elongated hexagonal etch pits, which are characteristic of (100) surface dissolution, were no longer observed when NaF was present. The alteration of pit shape is more distinct at a higher NaF concentration (50 mM) where triangular etch pits evolved during dissolution. Furthermore, in a fluoride concentration typical for tap water (10 µM), we observed roughening of individual step lines, resulting in the formation of scalloped morphologies. Morphological changes to individual steps across a wide range of fluoride concentrations suggest that the cariostatic capabilities of fluoride ions originate from their strong interactions with molecular steps.