NeuTox: A weighted ensemble model for screening potential neuronal cytotoxicity of chemicals based on various types of molecular representations.

Chemical-induced neurotoxicity has been widely brought into focus in the risk assessment of chemical safety. However, the traditional in vivo animal models to evaluate neurotoxicity are time-consuming and expensive, which cannot completely represent the pathophysiology of neurotoxicity in humans. Cytotoxicity to human neuroblastoma cell line (SH-SY5Y) is commonly used as an alternative to animal testing for the assessment of neurotoxicity, yet it is still not appropriate for high throughput screening of potential neuronal cytotoxicity of chemicals. In this study, we constructed an ensemble prediction model, termed NeuTox, by combining multiple machine learning algorithms with molecular representations based on the weighted score of Particle Swarm Optimization. For the test set, NeuTox shows excellent performance with an accuracy of 0.9064, which are superior to the top-performing individual models. The subsequent experimental verifications reveal that 5,5'-isopropylidenedi-2-biphenylol and 4,4'-cyclo-hexylidenebisphenol exhibited stronger SH-SY5Y-based cytotoxicity compared to bisphenol A, suggesting that NeuTox has good generalization ability in the first-tier assessment of neuronal cytotoxicity of BPA analogs. For ease of use, NeuTox is presented as an online web server that can be freely accessed via http://www.iehneutox-predictor.cn/NeuToxPredict/Predict.

A Case of CD5-Positive Primary Cutaneous Diffuse Large B-Cell Lymphoma, Leg Type Secondary to Chronic Lymphedema.

ABSTRACT: Primary cutaneous lymphoma occurring at the site of lymphedema is a rare complication. A total of 13 cases of primary cutaneous lymphoma associated with chronic lymphedema have been reported in international studies. We reported a case of cutaneous diffuse large B-cell lymphoma (DLBCL) (leg type) secondary to chronic lymphedema of the lower limbs. Histopathology showed hyperkeratosis of epidermis, acanthosis, and significant edema in the superficial dermis, with diffuse mononuclear infiltration in the dermis. Immunohistochemical studies revealed the expression of CD5, CD20, Pax-5, Bcl-2, Bcl-6, MUM-1, c-myc, and Ki-67. Therefore, the diagnosis of cutaneous DLBCL (leg type) was made. The study further confirmed the association between lymphoma and lymphedema. Especially, it showed CD5 expression. CD5-positive DLBCLs is a specific subgroup of DLBCLs, only approximately 10% of DLBCLs express CD5.

In silico identification of novel inhibitors targeting the DNA-binding domain of the human estrogen receptor alpha.

The human estrogen receptor alpha (ERα) is an important regulator in breast cancer development and progression. The frequent ERα mutations in the ligand-binding domain (LBD) can increase the resistance of antiestrogen drugs, highlighting the need to develop new drugs to target ERα-positive breast cancer. In this study, we combined molecular docking, molecular dynamics simulations and binding free energy calculations to develop a structure-based virtual screening workflow to identify hit compounds capable of interfering with the recognition of ERα by the specific response element of DNA. A druggable pocket on the DNA binding domain (DBD) of ERα was identified as the potential binding site. The hits binding modes were further analyzed to reveal the structural characteristics of the DBD-inhibitor complexes. The core structure of the lead molecules was synthesized and was found to inhibit the E2-induced cell proliferation in MCF-7 cell lines. These findings provide an insight into the structural basis of ligand-ERα for alternate sites beyond the LBD-based pocket. The core structure proposed in this study could potentially be used as the lead molecule for further rational optimization of the antiestrogen drug structure with stronger binding of DBD and higher activity.

Uniportal thoracoscopic pulmonary lobectomy in the treatment of Lung Cancer.

OBJECTIVE: To investigate the clinical efficacy of uniportal thoracoscopic pulmonary lobectomy in the treatment of lung cancer. METHODS: One hundred and ten patients with lung cancer who were admitted to our hospital from February 2017 to June 2018 were enrolled and they were divided into the control group (55 patients) and observation group (55 patients) according to the random number table method. The patients in the observation group received uniportal thoracoscopic pulmonary lobectomy, and patients in the control group underwent triportal thoracoscopic pulmonary lobectomy. The surgical condition, postoperative pulmonary functions, postoperative complication incidence, and postoperative quality of life were compared between the two groups. RESULTS: The intraoperative blood loss and number of dissected lymph nodes of the observation group were (125.31±12.63) mL and (13.91±2.41) respectively, which were not significantly different with (127.54±13.60) mL and (13.96±2.69) of the control group (P>0.05). The incision length of the observation group was (4.22±0.31) cm, shorter than (6.97±0.42) cm of the control group, the postoperative pain score was (2.87±0.69) points, lower than (4.31±1.09) points of the control group, and the operation time was (195.21±19.42) minutes, longer than (162.68±18.52) min of the control group; the differences were significantly different (P<0.05). The postoperative forced vital capacity (FVC), Maximum Ventilatory Volume (MVV) and Forced Expiratory Volume in 1s (FEV1) in the observation group were (1.90±0.75) L, (54.59±16.03) L/minutes and (1.60±0.53) L respectively, larger than (1.06±0.28) L, (38.41±15.59) L/min and (1.02±0.15) L respectively (P<0.05). The scores of Short Form 36-item Health Survey (SF-36) of patients in the observation group was observed one month after surgery, significantly higher than those in the control group, and the difference was statistically significant (P<0.05). The incidence of complications of the postoperative complication of the observation group was 12.7%, which was not significantly different with 14.5% of the control group (P>0.05). CONCLUSION: Patients who receive uniportal video-assisted thoracoscopic pulmonary lobectomy have milder trauma, which is beneficial to the lung functions and postoperative recovery. Moreover, the number of dissected lymph nodes in uniportal thoracoscopic pulmonary lobectomy is equivalent with that in triportal thoracoscopic pulmonary lobectomy. Hence it is worth clinical promotion.

Fluorescence resonance energy transfer between NH2-NaYF4:Yb,Er/NaYF4@SiO2 upconversion nanoparticles and gold nanoparticles for the detection of glutathione and cadmium ions.

Dual-functional nanosensors based on small molecule regulation can be widely used due to their simplicity, high sensitivity and selectivity. Herein, glutathione (GSH) calibrated dual-functional system for GSH and cadmium ions (Cd2+) detection based on fluorescence resonance energy transfer (FRET) between NH2-NaYF4:Yb,Er/NaYF4@SiO2 upconversion nanoparticles (UCNPs) and gold nanoparticles (AuNPs) is designed. Unmodified AuNPs are easy to aggregate in high-salt solution and thereby quenching the red emission of UCNPs. The presence of GSH prevents the aggregation of AuNPs, so GSH can be detected by the changes in the color of solution and the recovery of red emission of UCNPs. However, Cd2+ can interact with GSH, which makes AuNPs easy to aggregate, resulting in a gradual decrease in red emission of UCNPs. The fluorescence response of the system is linear with the concentrations of GSH and Cd2+ in a wide range of concentrations, with low detection limits of 0.016 µM and 0.059 µM, respectively. Furthermore, the nanosensor demonstrates high selectivity for GSH and Cd2+ detection and can be applied for the detection of GSH in human plasma and Cd2+ in drinking water.

Fluorometric determination of antioxidant capacity in human plasma by using upconversion nanoparticles and an inner filter effect mechanism.

The balance between free oxygen radicals and antioxidant defense systems is usually assessed by an antioxidant capacity assay. A rapid and sensitive antioxidant capacity assay is described here. It is making use of NaYF4:Yb/Er@NaYF4 core-shell upconversion nanoparticles (UCNPs) and potassium permanganate (KMnO4). In this strategy, added KMnO4 reduces the green (540 nm) emission of the UCNPs (under 980 nm photoexcitation) due to an inner filter effect. The antioxidants cysteine, ascorbic acid and glutathione (GSH) reduce the intense purple color of KMnO4 because it is reduced to Mn(II) ion. Hence, the green upconversion fluorescence is restored after the addition of antioxidants. Figures of merit for this assay (for the case of GSH) include a detection limit of 3.3 µM, a detection range that extends from 10 µM to 2.5 mM, and an assay time of a few seconds. The assay was applied to the evaluation of antioxidant capacity in human plasma samples spiked with GSH and gave satisfactory repeatability and specificity. Graphical abstract Schematic presentation of a fluorometric assay based on inner filter effect (IFE) between upconversion nanoparticles (UCNPs) and potassium permanganate (KMnO4) for the determination of antioxidant capacity in human plasma.

Computational insights on agonist and antagonist mechanisms of estrogen receptor α induced by bisphenol A analogues.

Structural analogues of bisphenol A (BPA) have become widely used as alternatives in BPA-free products. Most toxicological investigations have focused on the estrogenic activities of these analogues, which have been considered as potential environmental estrogens. However, recent studies revealed that certain BPA analogues could dramatically inhibit the proliferation of breast cancer cells, and exhibited strong anti-estrogenic effects compared with the antagonist 4-hydroxytamoxifen (OHT). Thus, we adopted computational models combining molecular dynamics simulations and binding free energy calculations to explore the underlying molecular basis of BPA analogues binding to estrogen receptor α (ERα). We also evaluated ligand-induced structural rearrangements of ERα at the atomic level. Conformational analyses showed that induced-fit H-bonding recognition by Thr347 was an important factor distinguishing antagonist from agonist BPA analogues. Moreover, antagonists of BPA analogues could indirectly induce the structural reposition of key helix 12 and produce an antagonistic conformation of ERα. Compared with OHT, the binding affinity of BPA analogues is stronger for antagonists than agonists. Taken together, we therefore propose computational indicators for screening of anti-estrogenic activities of BPA analogues, which may be beneficial for predicting the estrogenic or anti-estrogenic effects of BPA alternatives.

Screening of Potential PFOS Alternatives To Decrease Liver Bioaccumulation: Experimental and Computational Approaches.

Perfluorooctanesulfonate (PFOS) is a persistent organic pollutant with significant bioaccumulation potential in liver tissues. Exposure to PFOS could cause increase of liver weight, induce adenomas of the liver, and cause hepatomegaly. Alternatives of PFOS might be designed and synthesized that have significantly lower liver bioaccumulation. In this study, we conducted animal exposure experiments to investigate tissue accumulations of 14 per- and polyfluoroalkyl substances. Correlation analysis demonstrated that accumulation of the compounds in rat liver had strong correlations with their binding affinities of liver fatty acid binding protein (LFABP). Thus, we combined a quantitative structure-activity relationship model with molecular dynamics (MD) simulations to develop computational models to predict the LFABP binding affinities of two newly synthesized alternatives, perfluorodecalin-2-sulfonic acid and N-diperfluorobutanoic acid. The binding characteristics of the PFOS alternatives for LFABP were elaborated to explore how the different structural modifications of molecules influenced the underlying binding mechanisms. Subsequent animal experiments demonstrated that the binding free energy calculations based on the MD simulations provided a good indicator to reflect the relative degree of liver accumulation of the PFOS alternatives in the same exposure doses and durations. Our findings from the combination of experimental exposure and computational model can provide helpful information to design potential alternatives of PFOS with weak LFABP binding capability and low liver accumulation.

Protonation state effects of estrogen receptor α on the recognition mechanisms by perfluorooctanoic acid and perfluorooctane sulfonate: A computational study.

Perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) have been reported to cause adverse health effects on wildlife as well as humans. Numerous studies demonstrated that PFOA and PFOS could interfere with the transcriptional activation of estrogen receptor α (ERα) by mimicking the function of endogenous ligand, whereas some reports suggested that the two compounds present non-estrogenic activities. These conflicting results bring a confusion to understand their molecular mechanism on the ERα-mediated signaling pathway. To address this issue, we performed the molecular docking and molecular dynamics simulations to elaborate the structural characteristics for the binding of PFOA and PFOS to ERα. Our results indicated that the two opposite binding orientations were modulated by the protonation states of key residue His524. In sub-acidic condition, PFOA and PFOS prefer to form the H-bonding interactions with the protonated His524, whereas Arg394 provided the H-bonding interactions for stable binding in sub-alkaline condition. Conformational analyses implied that the diverse binding modes were closely related to the conformational propensity of ERα for subsequent coactivator recruitment and transcription activation. Generally, our findings provide a flexible strategy to assess the pH impacts of microenvironment on the toxicities of perfluoroalkyl acids by their interactions with proteins.

Raman spectra of thiolated arsenicals with biological importance.

Surface enhanced Raman scattering (SERS) has great potential as an alternative tool for arsenic speciation in biological matrices. SERS measurements have advantages over other techniques due to its ability to maintain the integrity of arsenic species and its minimal requirements for sample preparation. Up to now, very few Raman spectra of arsenic compounds have been reported. This is particularly true for thiolated arsenicals, which have recently been found to be widely present in humans. The lack of data for Raman spectra in arsenic speciation hampers the development of new tools using SERS. Herein, we report the results of a study combining the analysis of experimental Raman spectra with that obtained from density functional calculations for some important arsenic metabolites. The results were obtained with a hybrid functional B3LYP approach using different basis sets to calculate Raman spectra of the selected arsenicals. By comparing experimental and calculated spectra of dimethylarsinic acid (DMAV), the basis set 6-311++G** was found to provide computational efficiency and precision in vibrational frequency prediction. The Raman frequencies for the rest of organoarsenicals were studied using this basis set, including monomethylarsonous acid (MMAIII), dimethylarsinous acid (DMAIII), dimethylmonothioarinic acid (DMMTAV), dimethyldithioarsinic acid (DMDTAV), S-(Dimethylarsenic) cysteine (DMAIII(Cys)) and dimethylarsinous glutathione (DMAIIIGS). The results were compared with fingerprint Raman frequencies from As─O, As─C, and As─S obtained under different chemical environments. These fingerprint vibrational frequencies should prove useful in future measurements of different species of arsenic using SERS.

Facile synthesis of an all-in-one graphene nanosheets@nickel electrode for high-power performance supercapacitor application.

We report a facile and novel approach for the fabrication of all-in-one supercapacitor electrodes by in situ electrochemical exfoliation of flexible graphite paper (FGP) on a nickel collector. The binder-free three dimensional (3D) graphene nanosheets@Ni (GNSs@Ni) supercapacitor electrodes exhibit a high specific capacitance of 196.4 F g-1 and 36.2 mF cm-2, respectively, at a scan rate of 50 mV s-1. Even at the high scan rate of 2500 mV s-1 the specific capacitance of the capacitor still shows a retention of 85.6% (168 F g-1, 31 mF cm-2). Meanwhile, the as-prepared electrode offers excellent cycling performance with 91.5% capacitance retention after 100 000 charging-discharging cycles even at the high current density of 11 A g-1. Such high rate capability, specific capacitance and exceptional cycling ability of the GNSs@Ni electrode are attributed to the all-in-one architecture which provides unique properties including high electrical conductivity, large specific surface area and excellent electrochemical stability. We anticipate that these results will shed light on new strategies to synthesize high-performance hybrid nanoarchitectures electrodes using the prepared graphene nanosheets as the support, which offers great potential in energy storage devices and electrochemical catalysis applications.

Thiolated arsenicals in arsenic metabolism: Occurrence, formation, and biological implications.

Arsenic (As) is a notoriously toxic pollutant of health concern worldwide with potential risk of cancer induction, but meanwhile it is used as medicines for the treatment of different conditions including hematological cancers. Arsenic can undergo extensive metabolism in biological systems, and both toxicological and therapeutic effects of arsenic compounds are closely related to their metabolism. Recent studies have identified methylated thioarsenicals as a new class of arsenic metabolites in biological systems after exposure of inorganic and organic arsenicals, including arsenite, dimethylarsinic acid (DMAV), dimethylarsinous glutathione (DMAIIIGS), and arsenosugars. The increasing detection of thiolated arsenicals, including monomethylmonothioarsonic acid (MMMTAV), dimethylmonothioarsinic acid (DMMTAV) and its glutathione conjugate (DMMTAVGS), and dimethyldithioarsinic acid (DMDTAV) suggests that thioarsenicals may be important metabolites and play important roles in arsenic toxicity and therapeutic effects. Here we summarized the reported occurrence of thioarsenicals in biological systems, the possible formation pathways of thioarsenicals, and their toxicity, and discussed the biological implications of thioarsenicals on arsenic metabolism, toxicity, and therapeutic effects.

Minimally Invasive Pedicle Screw Fixation Using Intraoperative 3-dimensional Fluoroscopy-based Navigation (CAMISS Technique) for Hangman Fracture.

STUDY DESIGN: Retrospective comparative cohort series. OBJECTIVE: To evaluate the accuracy and feasibility of minimally invasive surgical (MIS) techniques incorporating with intraoperative 3-dimensional fluoroscopy-based navigation (ITFN) for treating Hangman fracture. SUMMARY OF BACKGROUND DATA: MIS screw fixation for Hangman fracture can decrease iatrogenic soft-tissue injury, but increase the risk of instrumentation-related complications due to lack of anatomical landmarks. With the advantages of obtaining intraoperative real-time images, automatic registration, and 3-dimensional views, the ITFN system seems to be an inherent partner for MIS. METHODS: 20 patients with Hangman fracture underwent C2-C3 pedicle screw fixation using ITFN. 6 patients used MIS technique, with the other 14 patients using conventional open technique. Operative time and blood loss were recorded. The accuracy of screw positions was studied by postoperative CT scan. Neck pain visual analogue score (VAS) was evaluated and the fusion status was ascertained in 6-month follow-up. RESULTS: The average operative time was 134.2 ±â€Š8.0 minutes in computer-assisted orthopaedics surgery (CAOS)-MIS group and 139.3 ±â€Š25.8 minutes in CAOS-open group (P > 0.01). The blood loss was 66.7 ±â€Š25.8 mL in CAOS-MIS group and 250.0 ±â€Š141.4 mL in CAOS-open group (P < 0.01). A total of 80 screws were inserted. No screw-related neurovascular injury was observed. 83.3% (20/24) screws in CAOS-MIS group and 89.3% (50/56) screws in CAOS-open group were grade 1 screw (P > 0.01). No grade 3 screw was detected in both groups. Compared with the CAOS-open group (1.7 ±â€Š0.6), neck pain VAS in 6-month follow-up in CAOS-MIS group (0.3 ±â€Š0.5) was significantly lower (P < 0.01). Solid fusion was demonstrated in all the cases. CONCLUSION: The integration of these 2 techniques MIS and ITFN, we call "computer assisted minimally invasive spinal surgery," is proved to be feasible and safe for treating Hangman fracture with the advantage of significantly reduced iatrogenic soft tissue injury. So we think CAMISS technique represents the most recent modification of spine surgery.

[Percutaneous minimally invasive pedicle screw fixation for cervical fracture using intraoperative three-dimensional fluoroscopy-based navigation].

OBJECTIVE: To retrospectively assess the feasibility and safety of percutaneous minimally invasive pedicle screw fixation for cervical fracture using intraoperative three-dimensional fluoroscopy-based navigation. METHODS: Thirty patients admitted from April 2012 to May 2014 in Beijing Jishuitan Hospital with cervical fracture underwent pedicle screw fixation using intraoperative three-dimensional fluoroscopy-based navigation, with 8 patients using minimally invasive technique (CAOS-MIS group), and the other 22 patients using conventional open approach (CAOS-open group). Operative time, blood loss and postoperative neurovascular complications were recorded. Screw positions were studied by postoperative CT scan. All patients were followed up for at least 6 months. Neck visual analogue score (VAS) and American Spinal Injury Association (ASIA) classification were evaluated preoperatively and at 6-month follow-up. Independent-sample t test and Chi-Square test were used for statistical analysis. RESULTS: Operation time was (139 ± 18) minutes and blood loss was (73 ± 40) ml in CAOS-MIS group and correspondingly (154 ± 42) minutes and (296 ± 171) ml in CAOS-open group. The blood loss in CAOS-MIS group was significantly lower than that in CAOS-open group (t = 5.695, P < 0.01). No screw-related injury to nerve or vertebral artery was observed. Thirty-four screws were placed in CAOS-MIS group with 28 screws (82.4%) classified as Grade I, meanwhile in CAOS-open group 108 screws were placed with 96 screws (88.9%) classified as Grade I. There was no statistical difference between the two groups (χ² = 0.998, P > 0.01). VAS score showed no statistical difference preoperatively (t = 0.334, P > 0.01), however statistical difference existed at 6 months follow-up (t = 4.111, P < 0.01) with (0.4 ± 0.5) in CAOS-MIS group and (1.5 ± 0.7) in CAOS-open group. There were 1 patient from class B to improve to D, 1 case from D to E in CAOS-MIS group, and 1 patient from class A to improve to B, 1 case from B to D, 2 cases from C to D, 3 cases from D to E in CAOS-open group 6 months after surgery. Cervical X-ray demonstrated fractures healed well in all cases at 6 months follow-up. CONCLUSION: It is feasible and safe for percutaneous minimally invasive pedicle screw fixation for cervical fracture using intraoperative three-dimensional fluoroscopy-based navigation, which can also decreases the incidence of postoperative neck pain.

[Ethyl acetate-soluble chemical constituents from branch of Hypericum petiolulatum].

The stems and branches of Hypericum petiolulatum were extracted by alcohol and liquid-liquid extraction. Seven furofuran lignans were isolated from the ethyl acetate fraction of ethanol extract of H. petiolulatum by using silica gelchromatography, Sephadex LH-20 chromatography, medium-pressure liquid chromatography and preparative HPLC. Their structures were identified by the spectroscopic methods as pinoresinol (1), medioresinol (2), 8-acetoxypinoresinol (3), epipinoresinol (4), (+)-syringaresinol (5), (+)-1-hydroxysyringaresinol (6) and erythro-buddlenolE (7). All the isolates were firstly found in H. petiolulatum. In the bioassay, compound 7 showed remarkable antioxidative activity inhibiting Fe(+2)-cystine induced rat liver microsomal lipid peroxidation with inhibitory rate 38% at a concentration of 1 x 10(-6) mol · L(-1) (positive control Vit E with the inhibitory rate of 35% at the same concentration).

[Posterior C1-C2 transarticular screw fixation for atlantoaxial instability assisted by intraoperative 3-dimensional fluoroscopy-based navigation].

OBJECTIVE: To assess the feasibility, efficacy and indication of posterior C1-C2 transarticular screw fixation for atlantoaxial instability assisted by intraoperative 3-dimensional fluoroscopy-based navigation. METHODS: From November 2005 to October 2012, 58 patients with atlantoaxial instability underwent posterior C1-C2 transarticular screw fixation assisted by intraoperative 3-dimensional fluoroscopy-based navigation. Those with excellent atlantoaxial reduction and no need for decompression underwent percutaneously minimally invasive procedures. Operative duration, blood loss volume, reduction of atlantoaxial joints and postoperative neurovascular complications were recorded. Screw positions were studied by postoperative computed tomography (CT) and divided into 3 categories. The follow-up period was at least 3 months. Local symptoms (assessed by visual analogue scale (VAS) score), neurological conditions (Nurick classification) and bone graft fusion were evaluated. RESULTS: Among them, the procedure was either open surgery (n = 51) or percutaneously minimally invasive surgery (n = 7). A total of 111 screws were placed satisfactorily. Five patients underwent only unilateral C1-C2 transarticular screw fixation. No severe complications were encountered. The mean operative duration was 202.2 ± 54.2 minutes and the average volume of blood loss 412.6 ± 281.2 ml. And the values were comparable to those for the traditional fluoroscopy-guided free-hand procedures. No statistical significance existed between open and percutaneously minimally invasive procedures in operative duration, blood loss volume and precision of screw placement. The patients with incompletely reduced C1-C2 dislocation had comparable clinical outcomes with those with complete reduction. After a 3-month follow-up, all of them showed significant improvements of local symptoms. VAS score decreased from 4.5 ± 1.3 preoperatively to 0.7 ± 0.8 postoperatively while the Nurick classification improved from 2.4 ± 1.1 to 0.6 ± 1.0. And bone graft fusion was satisfactory. CONCLUSIONS: Posterior C1-C2 transarticular screw fixation for atlantoaxial instability assisted by intraoperative 3-dimensional fluoroscopy-based navigation is both feasible and safe. Combined with minimally invasive techniques, this procedure may achieve greater precision and minimal invasion.

In vivo metabolism of 2,2',4,4'-tetrabromodiphenyl ether (BDE-47) in young whole pumpkin plant.

Polybrominated diphenyl ethers (PBDEs) are widely distributed persistent organic pollutants. In vitro and in vivo research using various animal models have shown that PBDEs might be transformed to hydroxylated PBDEs, but there are few studies on in vivo metabolism of PBDEs by intact whole plants. In this research, pumpkin plants (Cucurbita maxima × C. moschata) were hydroponically exposed to 2,2',4,4'-tetrabromodiphenyl ether (BDE-47). A debromination product (BDE-28) and four hydroxylated metabolites (5-OH-BDE-47, 6-OH-BDE-47, 4'-OH-BDE-49, and 4-OH-BDE-42) were detected in different parts of the whole plant. In addition, 4-methoxylated-2,2',3,4'-tetraBDE (4-MeO-BDE-42) was observed as a methoxylation product. Root exudates in solution were found to play an important role in metabolizing BDE-47 to a specific OH-PBDE: 4'-OH-BDE-49. BDE-28 was found to translocate more easily and accumulate in shoots than BDE-47 due to the lower hydrophobicity and molecular weight. The concentration ratio between metabolites and parent compound BDE-47 was lower for OH-PBDEs than that for both BDE-28 and 4-MeO-BDE-42. The metabolism pathway of BDE-47 in young whole plants was proposed in this study.

Surgical management of symptomatic os odontoideum with posterior screw fixation performed using the magerl and harms techniques with intraoperative 3-dimensional fluoroscopy-based navigation.

STUDY DESIGN: Retrospective case series. OBJECTIVE: To evaluate the accuracy of screw fixation using intraoperative three-dimensional fluoroscopy-based navigation (ITFN) and to assess the clinical outcomes of this treatment regimen. SUMMARY OF BACKGROUND DATA: The surgical management of symptomatic os odontoideum poses considerable difficulties due to the highly variable anatomy of the upper cervical spine and surrounding neurovascular structures. Various methods have been described for the treatment of symptomatic os odontoideum, all of which have limitations. METHODS: Nineteen patients with symptomatic os odontoideum were investigated. Pain scores were assessed using the visual analogue scale. Myelopathy was assessed using the Nurick scale and Odom's criteria. Radiological imaging was carried out in all patients for diagnosis and to assess the atlantodens interval, space available for cord, and presence of intramedullary hyperintensity signals on T2-weighted images at the C1-C2 level. Posterior stabilization was performed for all patients by using ITFN. RESULTS: The mean Nurick score improved from 2.3 before surgery to 0.7 at the time of follow-up. The mean follow-up period was 34.7 months (range, 12-65 mo). According to Odom's criteria, outcomes were as follows: excellent, 47%; good, 37%; fair, 11%; and poor, 5%. All patients with preoperative neck pain had symptom relief or improvement, with all of these patients having more than 83.7% improvement in visual analogue scale scores. The mean preoperative space available for cord value of 9.3 mm improved to 17.7 mm. Solid fusion and reduction of atlantoaxial dislocation were achieved in every patient without screw failure. Sixty screws were placed in 19 patients. Two C2 polyaxial screws in 2 patients and 1 transarticular screw in 1 patient slightly penetrated the transverse foramen with no vascular injury and clinical sequelae. CONCLUSION: ITFN is a safe, accurate, and effective tool for screw placement in patients with symptomatic os odontoideum.

Posterior fixation and fusion of unstable Hangman's fracture by using intraoperative three-dimensional fluoroscopy-based navigation.

PURPOSE: The purpose of this study was to assess the efficacy and accuracy of posterior screw fixation for unstable Hangman's fracture using intraoperative 3D fluoroscopy-based navigation. METHODS: 14 patients with unstable Hangman's fractures (11 males and 3 females), ranging in age from 21 to 59 years, received posterior fixation assisted by an intraoperative 3D fluoroscopy-based navigation system: 11 Levine-Edwards type II and three type IIA cases. The American Spine Injury Association grade was D in 2 and E in 12 cases. RESULTS: Operation time was 110 min (range 90-140 min). Hospital stay was 7.6 days (range 5-12 days). All the patients were observed for an average of 28.8 months (range 15-50 months). No screw-related injury to nerve, or vertebral artery was observed intraoperatively. An average of four screws/patient were inserted. Pedicle screws were placed into C2 and C3, and 5 screws were into the lateral mass of C3. Screw placement accuracy was evaluated using postoperative CT, according to the modified classification of Gertzbein and Robbins; one screw was grade 2 in C2, and three screws were grade 2 in the pedicle of C3. No grade 3 misplacement or clinical deficits were noted. C3 lateral mass screws were successfully inserted. Neck pain was relieved in each case. Neurologic status improved from D to E in 2 cases. Solid fusion was demonstrated in all the cases by static and dynamic films during the final follow-up. CONCLUSIONS: This case series demonstrates that intraoperative 3D fluoroscopy-based navigation is a safe, accurate, and effective tool for screw placement in patients with unstable Hangman's fracture.

Inducing growth of FeNi-Pt match-like magnetic nanoheterostructures on Pt nanotips and dechlorination of hydrochloric ether.

Newly designed magnetic FeNi-Pt match-like heterostructured nanorods were synthesized by means of induced growth of FeNi nanorods on Pt nanotips. The proposed synthesis mechanism is corroborated by SEM, TEM, XRD and XPS. The magnetic behavior shows that the magnetic saturation and coercivity are strongly dependent on both the shape and the alloy composition. The saturation magnetizations (Ms) and the coercivity (Hc) of nanorods synthesized are larger than those of nanoparticles because of the relatively large anisotropy of nanorods. Maximum saturation magnetization is obtained for Fe(82) Ni(15) -Pt(3) at 226.6 emu g(-1), whereas maximum coercivity is obtained for Fe(20)Ni(77)-Pt(3) at 136.8 Oe. Shape-dependent reactivity toward the reduction of chlorinated solvents was observed for the FeNi-Pt heterostructured nanomaterials. In particular, the Fe(82)Ni(15)-Pt(3) nanorods are highly reactive in the dechlorination process of 1,1,2,2-tetrachloroethane.