[Photochemical induced vestibular ischemiawith icy water test in guinea pigs]

Objective:To ascertain the effects of a new method of photochemical reaction in vestibular function in guinea pigs.Method:Local photochemical reaction was initiated by systemic injection of rose bengal(20mg), photoillumination of the vestibule through medial wall of epitympanum for 30 minutes was started immediately after the injection of rose bengal, with a optic fiber connected to a xenon light (wavelength, 540nm; photointense, 500-600 mW/cm ²). There were 20 guinea pigs divided random equally into 2 groups. Group 1 was injected with rose bengal. Group 2 was control, injected with physiological saline solution. The ice caloric tests were performed on the second day.Result:The test group (7 ears) and the control group (6 ears) with test nystagmus showed mean frequencies were（2.0±0.33）times/s and（3.7±0.33）times/s,the mean amplitude were (3.1±0.39)mm and (3.5±0.54)mm,and the mean duration were (44.7±17.22)s and (62.0±7.22)s respectively.The nystagmus frequency difference was statistically significant, but the amplitude and the duration of the nystagmus were not significantly different. There was no obvious spontaneous nystagmus in the two groups, and there were negative results of ice water test (3 ears in the test group and 4 ears in the control group).Conclusion:Photochemical reaction can induce the ischemic state of the vestibule system in guinea pig, and produce an acute vestibular dysfunction, and ice water test shows that the frequency of nystagmus is reduced.

Prediction of the Multisegment Clot Sign on Dynamic CT Angiography of Cardioembolic Stroke

BACKGROUND AND PURPOSE

The multisegment clot sign has been observed at the site of large-artery occlusion in patients with acute ischemic stroke. This study aimed to assess its occurrence rate and relationship with stroke etiologies in patients with acute intracranial large-artery occlusion.

MATERIALS AND METHODS

We included consecutive patients with acute ischemic stroke who had acute intracranial large-artery occlusion and underwent perfusion CT within 8 hours after stroke onset. The multisegment clot sign was assessed on dynamic CT angiography derived from perfusion CT. The stroke etiologies were defined by the international Trial of Org 10172 in Acute Stroke Treatment criteria. Poisson regression analyses and diagnostic testing were used to investigate the relationship between the multisegment clot sign and stroke etiologies.

RESULTS

Finally, 194 patients with intracranial large-artery occlusion were enrolled. According to the Trial of Org 10172 in Acute Stroke Treatment criteria, 110 (56.7%) patients were diagnosed with cardioembolism; 43 (22.2%), with large-artery atherosclerosis; and 41 (21.1%), with undetermined etiology. The multisegment clot sign was found in 74 (38%) patients. Poisson regression analysis showed that the presence of the multisegment clot sign was significantly higher in patients with cardioembolism than in those with large-artery atherosclerosis (52.7% versus 9.3%; prevalence ratio, 1.53; 95% confidence interval, 1.03-2.90; P = .037). For determined etiologies, the sensitivity, specificity, and positive and negative predictive values of the multisegment clot sign for predicting cardioembolism were 52.7%, 90.7%, 93.5%, and 42.9%, respectively.

CONCLUSIONS

The presence of the multisegment clot sign on dynamic CTA specifically indicates intracranial large-artery occlusion caused by an embolism from a cardiac source, which may be useful for acute management and secondary prevention of stroke.

Puerarin Stimulates Osteogenic Differentiation and Bone Formation Through the ERK1/2 and p38-MAPK Signaling Pathways

BACKGROUND

Osteoporosis is a world-wide health problem, which leads to decreased bone strength and increased susceptibility to fractures. Puerarin, a phytoestrogen extracted from Pueraria lobata (Willd.) Ohwi, has been identified as a promising intervention for preventing bone loss and promoting bone regeneration. However, the underlying mechanisms for its anabolic action are still not clear. In the present study, we aimed to investigate the effect of puerarin on the osteogenic differentiation of bone marrow stromal cells (BMSCs) and the possible molecular mechanism mediating its action.

METHODS

Bone marrow stromal cells (BMSCs) and intragastric administration on ovariectomized(OVX) rats were used to study the anti-osteoporotic function of puerarin. The involvement of mitogen-activated protein kinase (MAPK) signaling pathways was determined.

RESULTS

Our results demonstrated that at optimal concentration, puerarin could promote osteogenic differentiation of BMSCs in vitro. This induction was mediated by MAPK signaling pathway. Further detailed study revealed that ERK1/2-Runx2 signaling pathway had more prominent effect than p38 signaling pathway in puerarin-induced differentiation of BMSCs toward the osteogenic phenotype. We also found that puerarin protected against reduction in bone mineral density and improved femur trabecular bone structure in ovariectomized rats.

CONCLUSION

Our findings revealed the functional mechanism of puerarin in promoting osteogenic differentiation which involved ERK1/2 and p38-MAPK pathway and provided experimental evidence for the potential application of puerarin for estrogen replacement therapy of osteoporosis.

[Experiment to Enhance Catalytic Activity of α-FeOOH in Heterogeneous UV-Fenton System by Addition of Oxalate]

α-FeOOH was prepared by a symmetrical precipitation method and characterized by XRD, FT-IR, SEM, BET, and EDS techniques. The oxalate enhanced experiment for the catalytic activity of α-FeOOH during the degradation of Orange Ⅱ by the heterogeneous UV-Fenton process was evaluated. The results showed that the rate of Orange Ⅱ degradation in this heterogeneous UV-Fenton system could increase significantly with oxalate as an enhancing reagent, with the peak values of enhanced efficiency reaching 116.9% when the concentration of additional oxalate was 0.4 mmol·L^-1. Under this condition, more than 99% of Orange Ⅱ (0.2 mmol·L^-1) was degraded in 15 min. However, under the same condition, the inhibition ratios of malonate, acetate, EDTA and citrate were 5.2%, 8.1%, 23.2%, and 25.7%, respectively. Compared with the basic system, the enhanced efficiency of the mineralization rate constant can reach 69.9% when the concentration of additional oxalate was 0.4 mmol·L^-1. As a result, the time required for mineralization could be reduced greatly. In the heterogeneous UV-Fenton system, the additional oxalate could provide a new photo-reduction pathway for Fe³⁺ to Fe²⁺, enhancing the ratio of the homogeneous UV-Fenton process by increasing the Fe leaching of α-FeOOH and the concentration of hydroxyl radicals, leading to higher degradation efficiency of Orange Ⅱ. As a result, an enhancement effect of 101.5% could be obtained even after three cycles. The iron ions leached from catalysts could be re-adsorbed after treatment, avoiding the loss of active species from catalysts and additional pollution caused by iron ions. The results indicated that additional oxalate was a stable and reliable enhancing reagent on the catalytic activity of α-FeOOH in the heterogeneous UV-Fenton system.

RAF inhibitor LY3009120 sensitizes RAS or BRAF mutant cancer to CDK4/6 inhibition by abemaciclib via superior inhibition of phospho-RB and suppression of cyclin D1

KRAS, NRAS and BRAF mutations are among the most important oncogenic drivers in many major cancer types, such as melanoma, lung, colorectal and pancreatic cancer. There is currently no effective therapy for the treatment of RAS mutant cancers. LY3009120, a pan-RAF and RAF dimer inhibitor advanced to clinical study has been shown to inhibit both RAS and BRAF mutant cell proliferation in vitro and xenograft tumor growth in vivo. Abemaciclib, a CDK4/6-selective inhibitor, is currently in phase III studies for ER-positive breast cancer and KRAS mutant lung cancer. In this study, we found that combinatory treatment with LY3009120 and abemaciclib synergistically inhibited proliferation of tumor cells in vitro and led to tumor growth regression in xenograft models with a KRAS, NRAS or BRAF mutation at the doses of two drugs that were well tolerated in combination. Further in vitro screen in 328 tumor cell lines revealed that tumor cells with KRAS, NRAS or BRAF mutation, or cyclin D activation are more sensitive, whereas tumor cells with PTEN, PIK3CA, PIK3R1 or retinoblastoma (Rb) mutation are more resistant to this combination treatment. Molecular analysis revealed that abemaciclib alone inhibited Rb phosphorylation partially and caused an increase of cyclin D1. The combinatory treatment cooperatively demonstrated more complete inhibition of Rb phosphorylation, and LY3009120 suppressed the cyclin D1 upregulation mediated by abemaciclib. These results were further verified by CDK4/6 siRNA knockdown. Importantly, the more complete phospho-Rb inhibition and cyclin D1 suppression by LY3009120 and abemaciclib combination led to more significant cell cycle G₀/G₁ arrest of tumor cells. These preclinical findings suggest that combined inhibition of RAF and d-cyclin-dependent kinases might provide an effective approach to treat patients with tumors harboring mutations in RAS or RAF genes.

Abdominal obesity and risk of hip fracture: a meta-analysis of prospective studies

We conducted a meta-analysis to qualitatively summarize the evidence of the association between abdominal obesity and hip fracture risk. The results indicated that abdominal obesity as measured by waist circumference and waist-hip ratio might be associated with an increased risk of hip fracture.

INTRODUCTION

Epidemiological investigations evaluating the association of abdominal obesity with hip fracture risk have yielded conflicting results. Therefore, a meta-analysis was conducted to qualitatively summarize the evidence of the associations between waist circumference, waist-hip ratio, and hip circumference and the risk of hip fracture, respectively.

METHODS

PubMed, Embase, and Web of Science were searched for relevant articles published up to March 2017. Pooled relative risks (RRs) with 95% confidence intervals (CIs) were calculated with a random-effects model. Dose-response relationship was assessed by restricted cubic spline.

RESULTS

Seven studies involving 180,600 participants for hip circumference, six studies involving 199,828 participants for waist-hip ratio, and five studies involving 170,796 participants for waist circumference were finally included in this meta-analysis. The combined RRs with 95% CIs of hip fracture for the highest versus lowest category of waist circumference, waist-hip ratio, and hip circumference were 1.58 (95% CI 1.20-2.08), 1.32 (95% CI 1.15-1.52), and 0.87 (95% CI 0.74-1.02), respectively. For dose-response analysis, a nonlinear relationship was found (P _nonlinearity < 0.001) between waist circumference and the risk of hip fracture, and a linear relationship (P _nonlinearity = 0.911) suggested that the risk of hip fracture increased about 3.0% (1.03 (1.01-1.04)) for each 0.1 unit increment of waist-hip ratio.

CONCLUSIONS

This meta-analysis suggested that abdominal obesity as measured by waist circumference and waist-hip ratio might be associated with an increased risk of hip fracture. From a public health perspective, indicators of abdominal obesity may be usable predictors of hip fracture risk.

Real-Time Motor Cortex Mapping for the Safe Resection of Glioma: An Intraoperative Resting-State fMRI Study

BACKGROUND AND PURPOSE

Resting-state functional MR imaging has been used for motor mapping in presurgical planning but never used intraoperatively. This study aimed to investigate the feasibility of applying intraoperative resting-state functional MR imaging for the safe resection of gliomas using real-time motor cortex mapping during an operation.

MATERIALS AND METHODS

Using interventional MR imaging, we conducted preoperative and intraoperative resting-state intrinsic functional connectivity analyses of the motor cortex in 30 patients with brain tumors. Factors that may influence intraoperative imaging quality, including anesthesia type (general or awake anesthesia) and tumor cavity (filled with normal saline or not), were studied to investigate image quality. Additionally, direct cortical stimulation was used to validate the accuracy of intraoperative resting-state fMRI in mapping the motor cortex.

RESULTS

Preoperative and intraoperative resting-state fMRI scans were acquired for all patients. Fourteen patients who successfully completed both sufficient intraoperative resting-state fMRI and direct cortical stimulation were used for further analysis of sensitivity and specificity. Compared with those subjected to direct cortical stimulation, the sensitivity and specificity of intraoperative resting-state fMRI in localizing the motor area were 61.7% and 93.7%, respectively. The image quality of intraoperative resting-state fMRI was better when the tumor cavity was filled with normal saline (P = .049). However, no significant difference between the anesthesia types was observed (P = .102).

CONCLUSIONS

This study demonstrates the feasibility of using intraoperative resting-state fMRI for real-time localization of functional areas during a neurologic operation. The findings suggest that using intraoperative resting-state fMRI can avoid the risk of intraoperative seizures due to direct cortical stimulation and may provide neurosurgeons with valuable information to facilitate the safe resection of gliomas.

[Effect of sandblasting on bending strength and subcritical crack growth of the dental zirconia ceramics]

Objective: To evaluate the effect of sandblasting on bending strength and subcritical crack growth (SCG) under cyclic loading of yttria-stabilized tetragonal zirconia polycrystal (Y-TZP) ceramics. Methods: After being polished, sixty bar-shaped specimens of Y-TZP (Wieland zirconia ceramics) were assigned to two groups (n=30) according to the random number table, the sandblasting group (SG) which was treated with sandblasting and the control group (CG) which remained untouched. In each group, half of the specimens (n=15) were subjected to bending strength test, and the results were examined by Weibull statistics and analyzed with ANOVA. The other 15 specimens in each group were subjected to fatigue tests. The results were examined by Weibull statistics and subcritical crack propagation rates were calculated. Results: The bending strengths of SG and CG were (1 291±133) and (1 140±124) MPa (F=10.117, P=0.004), and the Weibull modules of the two groups were 11.06 and 10.64 respectively. The crack growth rate of SCG of SG was lower than that of CG under the same cyclic loading. Conclusions: Proper sandblasting on Y-TZP ceramic can increase its bending strength and resistance to SCG.

Direct-Liquid-Evaporation Chemical Vapor Deposition of Nanocrystalline Cobalt Metal for Nanoscale Copper Interconnect Encapsulation

In advanced microelectronics, precise design of liner and capping layers become critical, especially when it comes to the fabrication of Cu interconnects with dimensions lower than its mean free path. Herein, we demonstrate that direct-liquid-evaporation chemical vapor deposition (DLE-CVD) of Co is a promising method to make liner and capping layers for nanoscale Cu interconnects. DLE-CVD makes pure, smooth, nanocrystalline, and highly conformal Co films with highly controllable growth characteristics. This process allows full Co encapsulation of nanoscale Cu interconnects, thus stabilizing Cu against diffusion and electromigration. Electrical measurements and high-resolution elemental imaging studies show that the DLE-CVD Co encapsulation layer can improve the reliability and thermal stability of Cu interconnects. Also, with the high conductivity of Co, the DLE-CVD Co encapsulation layer have the potential to further decrease the power consumption of nanoscale Cu interconnects, paving the way for Cu interconnects with higher efficiency in future high-end microelectronics.

A comparative analysis of genetic diversity of candidate genes associated with type 2 diabetes in worldwide populations

Over the last decade, a larger number of type 2 diabetes mellitus (T2DM) susceptible candidate genes have been reported by numerous genome-wide association studies (GWAS). Understanding the genetic diversity of these candidate genes among worldwide populations not only facilitates to elucidating the genetic mechanism of T2DM, but also provides guidance to further studies of pathogenesis of T2DM in any certain population. In this study, we identified 170 genes or genomic regions associated with T2DM by searching the GWAS databases and related literatures. We next analyzed the genetic diversity of these genes (or genomic regions) among present-day human populations by curetting the 1000 Genomes Projects phase1 dataset covering 14 worldwide populations. We further compared the characteristics of T2DM genes in different populations. No significant differences of genetic diversity were observed among the 14 worldwide populations between the T2DM candidate genes and the non-T2DM genes in terms of overall pattern. However, we observed some genes, such as IL20RA, RNMTL1-NXN, NOTCH2, ADRA2A-BTBD7P2, TBC1D4, RBM38-HMGB1P1, UBE2E2, and PPARD, show considerable differentiation between populations. In particular, IL20RA (FST=0.1521) displays the greatest population difference which is mainly contributed by that between Africans and non-Africans. Moreover, we revealed genetic differences between East Asians and Europeans on some candidate genes such as DGKB-AGMO (FST=0.173) and JAZF1 (FST=0.182). Our results indicate that some T2DM susceptible candidate genes harbor highly-differentiated variants between populations. These analyses, despite preliminary, should advance our understanding of the population difference of susceptibility to T2DM and provide insightful reference that future studies can relay on.

[Efficacy of oral appliance therapy of obstructive sleep apnea and hypopnea syndrome in different periods of treatment]

OBJECTIVE

To investigate the long-term efficacy of oral appliance treating of obstructive sleep apnea and hypopnea syndrome (OSAHS) in different periods of treatment.

METHODS

A total of 55 patients were included in the study. Patients were all diagnosed with OSAHS by overnight polysomnography and all received oral appliance (OA) as the therapy. The OA positioned the mandible at 60%-70% of the maximal mandible advancement position and created a 4-5 mm incisor separation. The patients were instructed to wear the appliance during sleep, 6-8 hours per day, for 5-7 days per week. They were divided into four groups by the period of treatment, including less than 1 year group; 1-2 years group; 2-6 years group and 6-9 years group. The polysomnographic study was used to investigate the efficacy of the four groups. The outcome measures included the score on the apnea-hypopnea index (AHI), the longest apnea time and the lowest oxygen saturation (LSaO₂) levels during an overnight sleep.

RESULTS

The AHI decreased significantly in all the four groups. The less than 1 year group decreased from 24.50 (14.65, 54.05) to 7.40 (2.12,10.00) events/h (P<0.001); The 1-2 years group decreased from 19.50 (12.15, 39.23) to 1.80 (0.70, 6.58) events/h (P=0.001); The 2-6 years group decreased from 25.00 (11.41, 42.60) to 4.50 (1.35, 7.90) events/h (P=0.001); The 6-9 years group decreased from 26.2 (16.95, 47.45) to 4.00 (1.90, 26.70) events/h (P=0.043). The longest apnea decreased significantly in less than 1 year group, 1-2 years group and 2-6 years group. The longest apnea decreased from 57.00 (37.70, 61.50) to 25.00 (15.90, 33.50) seconds (P<0.001) in the less than 1 year group, from 41.00 (25.50, 62.26) to 13.10 (0.00, 22.10) seconds (P=0.001) in the 1-2 year group and from 42.50 (30.35, 58.15) to 15.60 (0.00, 28.10) seconds (P=0.003) in the 2-6 year group. The LSaO₂ levels increased significantly in the less than 1 year group and 2-6 years group. The LSaO(2) levels rose significantly in the less than 1 year group, from 74.18%±7.96% to 84.06%±7.67% (P=0.001), and in the 2-6 years group, from 76.71%±10.98% to 84.06%±4.64% (P=0.006), The LSaO₂ levels did not increase significantly in the 1-2 years and 6-9 years groups. Kruskal-Wallis test showed that there were no statistically significant differences in the AHI, longest apnea time and LSaO(2) in 4 the groups.

CONCLUSION

The oral appliance is an effective therapy for patients with OSAHS in the long-term treatment. However, it's recommended to make appointments with patients as a follow-up supervision whether there is any efficacy decrease. And the oral appliance should be replaced if necessary.

Cinepazide Maleate Improves Cognitive Function and Protects Hippocampal Neurons in Diabetic Rats with Chronic Cerebral Hypoperfusion

To determine the combined effect of type 2 diabetes (T2D) and chronic cerebral hypoperfusion (CCH) on learning and spatial memory, we developed a rat model of CCH by permanent occlusion of bilateral common carotid arteries (2-vessel occlusion (2VO)) in high-fat diet (HFD)-fed rats injected with low-dose streptozotocin (STZ). Furthermore, we examined the effect of cinepazide maleate (CM) on cognitive deficits and brain damage in this rat model. Rats were maintained on HFD for 6 weeks and then injected with 35 mg/kg STZ to induce T2D. Sham or 2VO surgery was performed in non-diabetic or diabetic (DM) rats to obtain four groups: blank, DM, CCH, and DM-CCH groups. Cognitive function was tested by the Morris water maze (MWM) test. To determine the effects of the vasodilator cinepazide maleate (CM) on cognitive deficits and brain damage, DM-CCH rats were administered with 10 mg/kg CM or saline daily for 14 d. Neuronal damage in DM-CCH rats was associated with increased expression of glial fibrillary acidic protein (GFAP) and β-secretase 1 (BACE1), but decreased expression of choline acetyltransferase (ChAT). Moreover, the levels of all these proteins were significantly alleviated by CM treatment. These results suggest that T2D exacerbated CCH-induced brain damage and cognitive impairment, and CM ameliorated these effects.

Epitaxial Growth of MgxCa1-xO on GaN by Atomic Layer Deposition

We demonstrate for the first time that a single-crystalline epitaxial Mg_xCa_1-xO film can be deposited on gallium nitride (GaN) by atomic layer deposition (ALD). By adjusting the ratio between the amounts of Mg and Ca in the film, a lattice matched Mg_xCa_1-xO/GaN(0001) interface can be achieved with low interfacial defect density. High-resolution X-ray diffraction (XRD) shows that the lattice parameter of this ternary oxide nearly obeys Vegard's law. An atomically sharp interface from cross-sectional transmission electron microscopy (TEM) confirmed the high quality of the epitaxy. High-temperature capacitance-voltage characterization showed that the film with composition Mg_0.25Ca_0.75O has the lowest interfacial defect density. With this optimal oxide composition, a Mg_0.25Ca_0.75O/AlGaN/GaN metal-oxide-semiconductor high-electron-mobility (MOS-HEMT) device was fabricated. An ultrahigh on/off ratio of 10¹² and a near ideal SS of 62 mV/dec were achieved with this device.

μSR investigation of a new diluted magnetic semiconductor Li(Zn,Mn,Cu)As with Mn and Cu codoping at the same Zn sites

We report the successful synthesis and characterization of a new type I-II-V bulk form diluted magnetic semiconductor (DMS) Li(Zn,Mn,Cu)As, in which charge and spin doping are decoupled via (Cu,Zn) and (Mn,Zn) substitution at the same Zn sites. Ferromagnetic transition temperature up to  ∼33 K has been observed with a coercive field  ∼40 Oe for the 12.5% doping level. μSR measurements confirmed that the magnetic volume fraction reaches nearly 100% at 2 K, and the mechanism responsible for the ferromagnetic interaction in this system is the same as other bulk form DMSs.

Nonlinear Transition from Mitigation to Suppression of the Edge Localized Mode with Resonant Magnetic Perturbations in the EAST Tokamak

Evidence of a nonlinear transition from mitigation to suppression of the edge localized mode (ELM) by using resonant magnetic perturbations (RMPs) in the EAST tokamak is presented. This is the first demonstration of ELM suppression with RMPs in slowly rotating plasmas with dominant radio-frequency wave heating. Changes of edge magnetic topology after the transition are indicated by a gradual phase shift in the plasma response field from a linear magneto hydro dynamics modeling result to a vacuum one and a sudden increase of three-dimensional particle flux to the divertor. The transition threshold depends on the spectrum of RMPs and plasma rotation as well as perturbation amplitude. This means that edge topological changes resulting from nonlinear plasma response plays a key role in the suppression of ELM with RMPs.

[Abnormality in bone metabolism after burn]

Burn causes bone metabolic abnormality in most cases, including the changes in osteoblasts and osteoclasts, bone mass loss, and bone absorption, which results in decreased bone mineral density. These changes are sustainable for many years after burn and even cause growth retardation in burned children. The mechanisms of bone metabolic abnormality after burn include the increasing glucocorticoids due to stress response, a variety of cytokines and inflammatory medium due to inflammatory response, vitamin D deficiency, hypoparathyroidism, and bone loss due to long-term lying in bed. This article reviews the pathogenesis and regularity of bone metabolic abnormality after burn, the relationship between bone metabolic abnormality and burn area/depth, and the treatment of bone metabolic abnormality, etc. and discusses the research directions in the future.