Diversified polyoxovanadate derivatives obtained by copper(i)-catalysed azide–alkyne cycloaddition reaction: their synthesis and structural characterization

Four novel 1,2,3-triazole functionalized polyoxovanadate (POV) organic–inorganic hybrids were successfully prepared through the copper-catalyzed azide–alkyne cycloaddition (CuAAC) procedure for the first time.

[Analysis of the effect of mesial implant position on surrounding bone stress of mandibular edentulous jaw under dynamic loads]

Objective: To evaluate the effect of different placement of mesial implants in edentulous jaws on the stress of the implant and the surrounding bone tissue by three-dimensional (3D)finite element analysis. Methods: Cone-beam CT data of mandibular edentulous patients was transferred into Mimics 17.0 and UG NX8.5 software, and three groups of 3D solid model were established: two mesial implants were implanted in the anterior region of the mandible (bilateral central incisor, lateral incisor, canine), and two distal oblique implant with 30° were implanted in the mandibular second premolar area(5 mm near the mental foramen). Set mandible 3D model with 4 implant by using UG NX8.5 software, produced 3 groups (mandible Ⅰ-Ⅲ). We took dynamic loading on models with help of software Abaqus 6.12, working side posterior teeth loading was set to 150 N and the simulation cycle was 0.875 s. The first stage: 0.000 s to 0.130 s, the lower jaw moves outward (moving toward the side of the work), with no contact between the upper and lower teeth; the second stage: 0.130 s to 0.150 s, mandibular upward, the same tooth tip of the working side were relative, the loading position were the posterior buccal tip, tongue tip; the third stage: 0.150 s to 0.260 s, the buccal slopes of buccal tips of mandibular posterior teeth glide along the lingual slopes of buccal tips of maxillary posterior teeth, the loading force was from the buccal side to the lingual side, the long axis of the tooth was 45°, loaded on the buccal slopes of buccal tips of posterior teeth; the fourth stage: 0.260 s to 0.300 s, the lingual slopes of buccal tips of mandibular posterior teeth glide along the buccal slopes of the tongue tips of maxillary posterior teeth, separate from the tip of the tooth at half the length, the loading force was from the lingual side to the buccal side, the long axis of the tooth was 45°, loaded on the lingual slopes of buccal tips of posterior teeth; the fifth stage: 0.300 s to 0.875 s, at the unloading stage, mandibular posterior teeth were separated from the maxillary teeth and returned to the intercuspal position. The loading position varied according to the mastication cycle. The stress distribution of implant and surrounding bone tissue at different stages of each model were observed. Results: From the early stage to chew occlusal contact to the end of the mastication cycle, three groups of models were displayed: the stress of distal implants was greater than that of mesial implants and the neck stress reached the maximum and gradually decreased to the root tip. The stress of distal implant bone was greater than that of mesial implant bone and the stress of distal bone of distal implant was greater than that of mesial bone of distal implant. All the stress peak showed a gradual increase, and the stress reach the maximum at the fourth stage. In the 3 models, the bone stress around the distal implant of model of the anterior implant located in the lateral incisor region was the lowest. The peak stress of cortical bone of the distal position of implant was 58.7 MPa. The bone stress around the distal implant of model of the anterior implant located in the canine region reached the maximum, and the peak stress of cortical bone of the distal position of implant was 135.6 MPa. Conclusions: When mesial implants of edentulous jaws located in the lateral incisor region, it is good for stress dispersion.

Tosylation of alcohols: an effective strategy for the functional group transformation of organic derivatives of polyoxometalates

Recently, the organic functionalization of polyoxometalates (POMs) has drawn increasing interest, and an easy and effective route to achieve organic derivatives is of great importance. Herein, the first reported synthesis of a tosyl ester derivative of the polyoxometalate (Bu4N)2[V6O13{(OCH2)3CCH2SO3C7H4}2]·2.5CH3CN (compound 1) was performed by using DMAP as an activating reagent and triethylamine as an HCl scavenger. The tosyl ester was transformed into an azide or halide group by using sodium azide or sodium bromide, respectively, as the nucleophilic agent. Two derivatives of POMs, (Bu4N)2[V6O13{(OCH2)3CCH2N3}2]·4CH3CN (compound 2) and (Bu4N)2[V6O13{(OCH2)3CCH2Br}2] (compound 3), were easily obtained. All the compounds were structurally and compositionally characterized by single-crystal X-ray diffraction, elemental analysis, IR spectroscopy, NMR spectroscopy, ESI-MS, UV-Vis spectroscopy and TGA. This work provides a new route for the functional group transformation of organic derivatives of polyoxometalates.

[A combination use of endoscope and microscope in cerebral pontine angle surgery]

Objective: To evaluate the application of combination use of microscope and endoscope in cerebral pontine angle (CPA) surgery. Methods: A total of 72 patients undergone lateral skull base surgeries via endoscope under microscopic control from January 2006 to January 2015 was reviewed respectively. The patients including 35 males and 37 females were composed of 22 cases of vestibular swannnomas, 45 cases of cranial neuropathy and 5 cases of CPA chelesteatoma. Twenty cases of vestibular swannnomas, 15 cases of cranial neuropathy and 2 cases of CPA chelesteatoma undergone the surgery via retrosigmoid approach, while other cases undergone the surgery via retrolabyrinthine approach. Surgical procedures were accomplished under the control of microscope and different angular endoscope with imaging fusion. The surgical results were evaluated according to subjective and objective criteria, and all patients were followed up for 15 years. Results: The symptoms was disappeared in the cranial neuropathy patients, without facial paralysis, complication of other nerves or hearing loss. Twenty-two patients with vestibular schwannomas got total tumor removal without facial palsy or neurological deficits; useful hearing was preserved in 16 of 22 patients (72.7%), and no tumor recurrence was found during 1-5 years follow-up. There was also no facial palsy or other complications in 5 cases of CPA chelesteatoma, which gained completely surgical removal; useful hearing was preserved in 3 of 5 cases of these patients and no recurrence was occurred during 1-1.5 years follow-up. Conclusions: A combination use of endoscope and microscope could combine advantages and avoid disadvantages of two techniques. It can provide better exposure with minimal invasion in CPA surgery, and is especially applicable in surgery for cranial neuropathy, vestibular schwannoma and CPA cholesteatoma, which should be performed through retrosigmoid approach and retrolabyrinthine approach.

[Relationship and influencing factors between the amplitude change of supramaximal facial nerve stimulation during acoustic neuroma removal and facial function outcome]

OBJECTIVE

To investigate the relationship between the amplitude change of supramaximal facial nerve stimulation during acoustic neuroma removal and facial function outcome, and discuss its influencing factors.

METHODS

Retrospective study of 34 acoustic neuroma patients. Intraoperative amplitude by supramaximal stimulation, facial function outcome, tumor size, surgical approach, facial nerve course pattern, and tumor cystic status, as well as tumor adhesion degree were collected and analyzed by SPSS 17.0.

RESULTS

Acoustic neurnomas were removed in all 34 patients without intra- and postoperative complications, the facial nerve were all anatomically preserved. Two weeks later, 5 cases showed facial function HB Grade Ⅰ, 13 HB Ⅱ, 11 HB Ⅲ and 5 HB Ⅳ. The amplitude changes under supramaximal stimulation after tumor removal were 12.9%-100%, average (63.9±25.7)%. The facial function outcomes were poor (HB Ⅳ) in the cases whose intraoperative amplitude decreases were more than 70%. Different postoperative facial function group showed significantly different intraoperative amplitude changes (F=7.585, P=0.001), except HB Ⅰ group and HB Ⅱ group. The existence of cystic degeneration showed strong correlation (r=-0.635) to the amplitude changes, the level of tumor adhesion showed moderately negative correlation (r=-0.455), and tumor size showed weak negative correlation (r=-0.292), surgical approach and the facial nerve course pattern were not statistically relevant.

CONCLUSIONS

The amplitude change of facial nerve supramaxial stimulation can predict the postoperative facial function. The amplitude change is valuable for early treatment of facial nerve damage.

Plasmonic reflection color filters with metallic random nanostructures

We develop reflective color filters with randomly distributed nanodisks and nanoholes fabricated with hydrogen silsesquioxane and Ag films on silicon substrate. They exhibit high resolution, angle-independence and easily up-scalable fabrication, which are the most important factors for color filters for industrial applications. We uncover the underlying mechanism after systematically analyzing the localized surface plasmon polariton coupling in the electric-field distribution. The agreement of the experimental results with those from the simulation indicates that tunable colors across the visible spectrum can be obtained by simply varying the diameter of the nanodisks, promoting their applications.

Effect of shallow angles on compressive strength of biaxial and triaxial laminates

Background

Biaxial (BX) and triaxial (TX) composite laminates with ±45° angled plies have been widely used in wind turbine blades. As the scale of blades increases, BX and TX laminates with shallow-angled plies (i.e. off-axis ply angle <45°) might be utilized for reducing mass and/or improving performance. The compressive properties of shallow-angled BX and TX laminates are critical considering their locations in a wind turbine blade, and therefore in this study, the uniaxial static compression tests were conducted using BX and TX laminates with angled-plies of ±45°, ±35°, and ±25°, for the purpose of evaluation. On the other hand, Mori–Tanaka mean field homogenization method was employed to predict elastic constants of plies in BX and TX laminates involved in tests; linear regression analyses of experimentally measured ply strengths collected from various sources were then performed to estimate strengths of plies in BX and TX laminates; finally, Tsai–Wu, Hashin, and Puck failure criteria were chosen to predict compressive strengths of BX and TX laminates. Comparison between theoretical predictions and test results were carried out to illustrate the effectiveness of each criterion.

Results

The compressive strength of BX laminate decreases as ply angle increases, and the trend was successfully predicted by all three failure criteria. For TX laminates, ±35° angled plies rather than ±45° angled plies led to the lowest laminate compressive strength. Hashin and Puck criteria gave good predictions at certain ply angles for TX laminates, but Tsai–Wu criterion was able to capture the unexpected strength variation of TX laminates with ply angle.

Conclusion

It was concluded that the transverse tensile stress in 0° plies of TX laminates, which attains its maximum when the off-axis ply angle is 35°, is the dominant factor in failure determination if using Tsai–Wu criterion. This explains the unexpected strength variation of TX laminates with ply angle, and also indicates that proper selection of ply angle is the key to fully utilizing the advantages of shallow-angled laminates.

[Application of gadolinium enhanced magnetic resonance imaging of inner ear to observe bilateral inner ears hydrops in patients with unilateral Meniere's disease]

Objective:Department of Otolaryngology Head and Neck Surgery,Xinhua Hospital,Shanghai Jiaotong University School of Medicine,Shanghai Jiaotong University Ear Institute,Shanghai,200092,China This study was designed to study the correlation between endolympahatic hydrops image results and auxiliary examinations by magnetic resonance imaging after intratympanic administration of gadolinium in both ears in unilateral Meniere's disease patients.Meanwhile,the contralateral endolympahatic hydrops of the "asym ptomatic " ear in patients with unilateral Meniere's was also observed.Method:Thirty-one patients with unilateral Meniere's disease were enrolled in this study.All the patients underwent pure tone audiometry,electrocochleography(ECochG),cervical-vestibular evoked myogenic potentials(cVEMP) before intratympanic gadolinium contrast agents injected.All the patients underwent three-dimensional fast fluid attenuated inversion recovery sequence magnetic resonance imaging(3D-FLAIR MRI) after intratympanic gadolinium contrast agents injected 24 hours.The images were graded in accordance with the severity of endolympatic hydrops.Spearman correlation analysis was performed between the scores of the images and results of auxiliary examination results.Meanwhile,Student's t test was performed for the significance test of the age,duration of the disease and the hearing level of the affected ears between the group with contralateral endolympatic hydrops and the group without contralateral endolympatic hydrops.Result:Pure tone average and the degree of the cochlear hydrops(r=0.383,P <0.05),the SP/AP ratio and the degree of the cochlear hydrops(r=0.496,P<0.01),and interaural amplitude difference and the degree of the vestibular hydrops(r=0.635,P<0.01) showed a significant correlation.The duration of the disease[(6.7±6.3) years vs(2.9±3.1) years,P <0.05] and the hearing level of the affected ear[(70.3±7.4)dB vs(52.5±3.8)dB,P <0.05)] showed a significant difference between the group with contralateral endolympatic hydrops and the group without contralateral endolympatic hydrops.Conclusion:Pure tone average and the degree of the cochlear hydrops,-SP/AP ratio and the degree of the cochlear hydrops,and interaural amplitude difference and the degree of the vestibular hydrops also showed a significant correlation,which suggesting that MRI image can reflect the auditory-vestibular function in patients with Meniere's disease.Endolympatic hydrops and hearing loss are closely related,but not necessarily result in Meniere's disease symptoms.Patients with longer duration of the disease and worse hearing in the affected ears are more likely to develop bilateral endolympatic hydrops.

Contrast-enhanced ultrasound for differential diagnosis of malignant and benign ovarian tumors: systematic review and meta-analysis

OBJECTIVE

To assess the performance of contrast-enhanced ultrasound (CE-US) in the differential diagnosis of malignant and benign ovarian tumors.

METHODS

We conducted a comprehensive literature search of PubMed and EMBASE to identify published articles evaluating the diagnostic potential of CE-US for the differentiation of benign and malignant ovarian tumors. Inclusion criteria were: (1) the study assessed the accuracy (or sensitivity and specificity) of CE-US for diagnosis of benign and malignant ovarian tumors; (2) it used surgery and histopathology as the reference standard for distinguishing between benign and malignant tumors; (3) it included data allowing construction of a 2×2 contingency table for true- and false-positives and negatives. We present summary sensitivity, specificity, diagnostic odds ratio (OR) and areas under the summary receiver-operating characteristics curves (AUCs).

RESULTS

Preliminary screening identified 103 papers, of which 11 fulfilled our predefined inclusion criteria and underwent final analysis. The pooled sensitivity and specificity of CE-US for diagnosis of benign and malignant ovarian tumors were 93% (95% CI, 89-96%) and 95% (95% CI, 92-96%), respectively. The pooled diagnostic OR was 171.2 (95% CI, 65.9-444.6) and the AUC was 0.98. I(2) values of sensitivity, specificity and diagnostic OR were 38.3%, 31.7% and 48.4%, respectively, all indicating moderate heterogeneity.

CONCLUSIONS

The evidence from available studies suggests CE-US is useful for discriminating between benign and malignant ovarian tumors; however, further studies are needed to examine whether CE-US has improved diagnostic test accuracy compared with that of standard two-dimensional Doppler sonography.

Is intramedullary nailing better than the use of volar locking plates for fractures of the distal radius? A meta-analysis of randomized controlled trials

We conducted a meta-analysis of randomized controlled trials that compared the use of intramedullary nails and volar locking plates in distal radial fractures. PubMed, EMBASE and the Cochrane Collaboration Central database were used to find randomized controlled trials that met the eligibility criteria. Two reviewers screened the studies, extracted the data, evaluated the methodological quality and analysed the data with RevMan 5.1 software. No statistically significant differences were detected in the disability of the arm, shoulder and hand and the Gartland and Werley scores, radiographic parameters, wrist range of motion, grip strength, total complication rate and incidence of tendon rupture between the two groups. However, carpal tunnel syndrome occurred less often after intramedullary nailing. The two fixation methods achieved equal clinical, functional and radiological outcomes for primary fixation of the indicated types of distal radial fractures.

LEVEL OF EVIDENCE

Therapeutic/LevelI.

Diagnosis of latent tuberculosis by ELISPOT assay and tuberculin skin test

OBJECTIVE

To determine the prevalence of latent tuberculosis infection (LTBI) in college students.

PATIENTS AND METHODS

Four hundred and twenty newly admitted college students were enrolled. The Enzyme-Linked ImmunoSpot assay (ELISPOT) was used. Overall, 171 students with ELISPOT assay+/TST+ were monitored for three years to detect active TB disease.

RESULTS

The overall positive rate of ELISPOT assay was 40.7% among TST+ students. The ELISPOT positive rates were 36.9%, 45.4%, and 64.3% in groups of TST induration of 10-14mm, 15-20mm, and ≥20mm, respectively, with a significant difference (χ(2)=10.136, P<0.01) but no significant difference between BCG scar and no scar (41.2% vs. 38.8%; P>0.05). None of the 171 untreated students contracted active TB within the three-year monitoring period.

CONCLUSION

The LTBI rate might be overestimated by TST compared with interferon-γ release assays. On the basis of a close monitoring, few students developed active TB despite a positive result to the TST and ELISPOT assay.

Evidence for Octupole Correlations in Multiple Chiral Doublet Bands

Two pairs of positive-and negative-parity doublet bands together with eight strong electric dipole transitions linking their yrast positive- and negative-parity bands have been identified in ^{78}Br. They are interpreted as multiple chiral doublet bands with octupole correlations, which is supported by the microscopic multidimensionally-constrained covariant density functional theory and triaxial particle rotor model calculations. This observation reports the first example of chiral geometry in octupole soft nuclei.

Magnetic field enhanced upconversion luminescence and magnetic–optical hysteresis behaviors in NaYF4: Yb, Ho nanoparticles

A magnetic field induces the enhancement of upconversion luminescence and magnetic–optical hysteresis behaviors in NaYF₄: 20% Yb, 1% Ho nanoparticles.

Prevention of trauma-induced cochlear fibrosis using intracochlear application of anti-inflammatory and antiproliferative drugs

Cochlear fibrosis is a common finding following cochlear implantation. Evidence suggests that cochlear fibrosis could be triggered by inflammation and epithelial-to-mesenchymal cell transition (EMT). In this study, we investigate the mechanisms of cochlear fibrosis and the risk/benefit ratio of local administration of the anti-inflammatory drug dexamethasone (DEX) and antimitotic drug aracytine (Ara-C). Cochlear fibrosis was evaluated in cochlear fibrosis models of rat cochlear slices in vitro and in KLH-induced immune labyrinthitis and platinum wire cochlear implantation-induced fibrosis in vivo. Cochleae were invaded with tissue containing fibroblastic cells expressing α-SMA (alpha smooth muscle actin), which along with collagen I, fibronectin, and laminin in the extracellular matrix, suggests the involvement of a fibrotic process triggered by EMT in vitro and in vivo. After perilymphatic injection of an adenoviral vector expressing GFP in vivo, we demonstrated that the fibroblastic cells derived from the mesothelial cells of the scalae tympani and vestibuli. Activation of inflammatory and EMT pathways was further assessed by ELISA analysis of the expression of IL-1β and TGF-β1. Both markers were elevated in vitro and in vivo, and DEX and Ara-C were able to reduce IL-1β and TGF-β1 production. After 5days of culture in vitro, quantification of calcein-positive cells revealed that Ara-C was 30-fold more efficient in preventing fibrosis, and provoked less sensory hair cell loss, than DEX. In KLH-induced immune labyrinthitis and platinum wire-implanted models, Ara-C was more efficient in preventing proliferation of fibrosis with less side effects on hair cells and neurons than DEX. In conclusion, DEX and Ara-C both prevent fibrosis in the cochlea. Analysis of the risk/benefit ratio favors the use of Ara-C for preventing cochlear fibrosis.

Vascular endothelial growth factor +405G/C and -2578C/A polymorphisms and breast cancer risk: a meta-analysis

This study aimed to analyze the association between the 405G/C and -2578C/A polymorphisms of the vascular endothelial growth factor (VEGF) gene and breast cancer risk by meta-analysis. A systematic computerized search of PubMed, Google Scholar, and Web of Science databases was performed to identify relevant publications. After rigorous searching and screening, 9 eligible case-control studies were included in this meta-analysis. The associations between the VEGF gene 405G/C and -2578C/A polymorphisms and breast cancer risk were estimated by pooled ORs and 95%CIs using fixed- or random-effect models. Meta-analysis results showed no significant association between the 405G/C polymorphism and breast cancer risk (CC vs GG: OR = 1.04, 95%CI = 0.92-1.17; CC vs GC: OR = 1.04, 95%CI = 0.93-1.17; dominant model: OR = 0.95, 95%CI = 0.85-1.06; recessive model: OR = 0.92, 95%CI = 0.70-1.20). The results also did not show significant association for the -2578C/A polymorphism: (AA vs CC: OR = 1.03, 95%CI = 0.91-1.15; AA vs GA: OR = 0.99, 95%CI = 0.89-1.10; dominant model: OR = 1.00, 95%CI = 0.90-1.10; recessive model: OR = 1.03, 95%CI = 0.94-1.13). Similar results were observed in the subgroup analyses on ethnicity, sample size, and Hardy-Weinberg equilibrium. These findings suggested a lack of association between the VEGF gene 405G/C and -2578C/A polymorphisms and breast cancer susceptibility.

The mitochondrial thioredoxin is required for liver development in zebrafish

Thioredoxins (Trxs) are a class of small molecular redox proteins that play an important role in scavenging abnormally accumulated reactive oxygen species (ROS). Thioredoxin 2 (Trx2) is one member of this family located in mitochondria. Trx2 protects cells from increased oxidative stress and has anti-apoptosis function. Knockout of Trx2 in mice led to early embryonic lethality. However, the essential role of Trx2 during embryogenesis remains unclear. To further investigate the role of Trx2 during embryonic development, we performed Trx2 knockdown in zebrafish and investigated the regulation role of Trx2 during embryonic development. Our results indicate that Trx2 had a high expression in early zebrafish embryos and its knockdown in zebrafish led to defective liver development mainly due to increased hepatic cell death. The increased ROS and the imbalance of members of the Bcl-2 family were involved in cell death induced by Trx2 suppression in zebrafish. The dysregulation of Bax, puma and Bcl-xl promoted the reduction of mitochondrial trans-membrane potential and the mitochondria membrane permeabilization (MMP), which initiated the mitochondrial apoptosis pathway. Additionally, we found that the increase of relocated GAPDH in mitochondria may be another factor responsible for the mitochondrial catastrophe.