Search

Inspired by the active-site structure of the [NiFe] hydrogenase, we have computationally designed the iron complex [P tBu2N tBu2)Fe(CN)2CO] by using an experimentally ready-made diphosphine ligand with pendant amines for the hydrogenation of CO2 to methanol. Density functional theory calculations indicate that the rate-determining step in the whole catalytic reaction is the direct hydride transfer from the Fe center to the carbon atom in the formic acid with a total free energy barrier of 28.4 kcal mol−1 in aqueous solution. Such a barrier indicates that the designed iron complex is a promising low-cost catalyst for the formation of methanol from CO2 and H2 under mild conditions. The key role of the diphosphine ligand with pendent amine groups in the reaction is the assistance of the cleavage of H2 by forming a Fe−Hδ−⋅⋅⋅Hδ+−N dihydrogen bond in a fashion of frustrated Lewis pairs. [ABSTRACT FROM AUTHOR]

Inspired by the recent observation of correlated excitation energy fluctuations of neighboring chromophores (Lee et al. Science2007,316, 1462), quantum chemistry calculations and molecular dynamics simulations were employed to calculate the electronic–vibrational coupling in the excited states of the photosynthetic reaction center of purple bacteria Rhodobacter (Rb.)sphaeroides. The ground states and lowest excited (Qy) states of isolated bacteriochlorophyll a (BChl a) and bacteriopheophytin (BPhe) molecules were first optimized using density functional theory (DFT) and time-dependent density functional theory (TDDFT). Normal mode analyses were then performed to calculate the Huang–Rhys factors of the intramolecular vibrational modes. To account for intermolecular electronic–vibrational coupling, molecular dynamics simulations were first performed. The ZINDO/S method and partial charge coupling method were then used to calculate the excitation energy fluctuations caused by the protein environment and obtain the spectral density. No obvious correlations in transition energy fluctuations between BChl aand BPhe pigments were observed in the time scale of our MD simulation. Finally, by comparing the calculated absorption spectra with experimental ones, magnitudes of inhomogeneous broadening due to the static disorder were estimated. The large amplitude of the static disorder indicates that a large portion of the spectral density and their correlations may still be hidden in the inhomogeneous broadening due to the finite MD simulation time. [ABSTRACT FROM AUTHOR]

Comparative analysis of butadiene yield in the pyrolysis products of four kinds of light hydrocarbons and refinery resources, proposed that the raw feedstock with high cycloalkanes (especially C6 ~ C8 cycloalkanes) content, low pyrolysis temperature, and high water-oil ratio are favorable for high butadiene yield. To maximize the economic benefits, the effects of the yield of butadiene, olefin market price and the coking problem must be taken into consideration in he selection of pyrolysis feedstock. [ABSTRACT FROM AUTHOR]

Biomarkers concerning antioxidant reactions and detoxification metabolics were evaluated in Meretrix meretrix exposed to cadmium (Cd, 10 μg/L) and phenanthrene (PHE, 100 μg/L) individually and in combination (10 μg/L Cd + 100 μg/L PHE) for 7 days. The accumulation of Cd and PHE measured in the digestive gland, gill, mantle, and axe foot of the clam showed significant increase in combination treatment and it was higher than the single Cd or single PHE treatment. The activities of oxidative stress-related enzymes, the expression of Cu/Zn SOD, and the content of MDA increased after Cd and PHE exposure in the digestive gland and gill at most cases. In the digestive gland, CAT gene expression was significantly induced in Cd-single group and significantly inhibited in PHE-single group and Cd-PHE mixed group at both day 3 and day 7; in the gill, CAT gene expression was significantly inhibited in all groups at day 3 and except for Cd-single group at day 7. MT expression was significantly induced in Cd-single and Cd-PHE mixed groups at day 7, while hsp70 expression was significantly inhibited in PHE-single and Cd-PHE mixed groups at day 7. The results indicated that SOD, CAT, GST, MDA, Cu/Zn SOD, CAT, MT and hsp70 were sensitive to cadmium and PHE in a water environment, and can be used as indicators of marine heavy metal pollution., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Inc.)

Background: The novel coronavirus pneumonia (COVID-19) outbreak in late 2019 killed millions worldwide. Coronaviruses cause diseases such as severe acute respiratory syndrome (SARS-Cov) and SARS-COV-2. Many peptides in the host defense system have antiviral activity. How to establish a set of efficient models to identify anti-coronavirus peptides is a meaningful study., Methods: Given this, a new prediction model EACVP is proposed. This model uses the evolutionary scale language model (ESM-2 LM) to characterize peptide sequence information. The ESM model is a natural language processing model trained by machine learning technology. It is trained on a highly diverse and dense dataset (UR50/D 2021_04) and uses the pre-trained language model to obtain peptide sequence features with 320 dimensions. Compared with traditional feature extraction methods, the information represented by ESM-2 LM is more comprehensive and stable. Then, the features are input into the convolutional neural network (CNN), and the convolutional block attention module (CBAM) lightweight attention module is used to perform attention operations on CNN in space dimension and channel dimension. To verify the rationality of the model structure, we performed ablation experiments on the benchmark and independent test datasets. We compared the EACVP with existing methods on the independent test dataset., Results: Experimental results show that ACC, F1-score, and MCC are 3.95%, 35.65% and 0.0725 higher than the most advanced methods, respectively. At the same time, we tested EACVP on ENNAVIA-C and ENNAVIA-D data sets, and the results showed that EACVP has good migration and is a powerful tool for predicting anti-coronavirus peptides., Conclusion: The results prove that this model EACVP could fully characterize the peptide information and achieve high prediction accuracy. It can be generalized to different data sets. The data and code of the article have been uploaded to https://github.- com/JYY625/EACVP.git., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

Background: In recent years, multiple observational studies have confirmed the association between sleep traits and various human physiopathological states. However, the causal relationship between sleep traits and hypothalamic-pituitary-target gland axis (HPTGA) function remains unknown., Methods: We obtained summary statistics on sleep traits (insomnia, chronotype, and sleep duration (long and short)) from the UK Biobank database. Data related to the HPTGA functions were obtained from the publicly available database. Subsequently, a two-sample Mendelian randomization (MR) analysis was performed to investigate the causal relationship between different sleep traits and the HPTGA function. Reverse MR analysis was conducted to examine the direction of causality., Results: The MR analysis results suggested that chronotype is associated with decreased levels of six hormones in HPTGA. Sleep duration was causally associated with decreased levels of free thyroxine and progesterone. Both long and short sleep durations are detrimental to the secretion of prolactin-releasing peptide, somatostatin, and plasma cortisol, while short sleep duration can promote progesterone secretion. After gender stratification, we found that female reproductive function is more susceptible to the influence of unfavorable sleep traits., Conclusion: Our MR analysis indicated a significant causal association between chronotype and suppressed gonadal function in healthy adult humans, with no apparent gender-specific effect. Extreme sleep durations were also found to be detrimental to the maintenance of normal HPTGA secretion function. Compared to males, gonadal function in the female cohort is more susceptible to extreme sleep habits. Subsequent observational studies are urgently needed to confirm the underlying mechanisms., Competing Interests: There is no conflict of interest that could be perceived as prejudicing the impartiality of the research reported., (© 2024 Ren et al.)

Lymphatic system distributes in almost all vertebrate tissues and organs, and plays important roles in the regulation of body fluid balance, lipid absorption and immune monitoring. Although CuNPs or AgNPs accumulation has been reported to be closely associated with delayed hatching and motor dysfunction in zebrafish embryos, their biological effects on lymphangiogenesis remain unknown. In this study, thoracic duct was observed to be partially absent in both CuNPs and AgNPs stressed zebrafish larvae. Specifically, CuNPs stress induced hypermethylation of E2F7/8 binding sites on CCBE1 promoters via their producing ROS, thereby leading to the reduction of binding enrichment of E2F7/8 on CCBE1 promoter and its subsequently reduced expression, then resulting in defective lymphatic vessel formation. Differently, AgNPs stress induced down-regulated CCBE1 expression via down-regulating mRNA and protein levels of E2F7/8 transcription factors, thereby resulting in defective lymphatic vessel formation. This study may be the first to demonstrate that CuNPs and AgNPs damaged lymphangiogenesis during zebrafish embryogenesis, mechanistically, CuNPs epigenetically regulated the expression of lymphangiogenesis regulator CCBE1 via hypermethylating its promoter binding sites of E2F7/8, while AgNPs via regulating E2F7/8 expression. Meanwhile, overexpression of ccbe1 mRNA effectively rescued the lymphangiogenesis defects in both AgNPs and CuNPs stressed larvae, while overexpression of e2f7/8 mRNA effectively rescued the lymphangiogenesis defects in AgNPs rather than CuNPs stressed larvae. The results in this study will shed some light on the safety assessment of nanomaterials applied in medicine and on the ecological security assessments of nanomaterials. Video Abstract., (© 2024. The Author(s).)

As part of the central nervous system (CNS), the retina senses light and also conducts and processes visual impulses. The damaged development of the retina not only causes visual damage, but also leads to epilepsy, dementia and other brain diseases. Recently, we have reported that copper (Cu) overload induces retinal developmental defects and down-regulates microtubule (MT) genes during zebrafish embryogenesis, but whether the down-regulation of microtubule genes mediates Cu stress induced retinal developmental defects is still unknown. In this study, we found that microtubule gene stmn4 exhibited obviously reduced expression in the retina of Cu overload embryos. Furthermore, stmn4 deficiency (stmn4 -/- ) resulted in retinal defects similar to those seen in Cu overload embryos, while overexpression of stmn4 effectively rescued retinal defects and cell apoptosis occurred in the Cu overload embryos and larvae. Meanwhile, stmn4 deficient embryos and larvae exhibited reduced mature retinal cells, the down-regulated expression of microtubules and cell cycle-related genes, and the mitotic cell cycle arrests of the retinal cells, which subsequently tended to apoptosis independent on p53. The results of this study demonstrate that Cu stress might lead to retinal developmental defects via down-regulating expression of microtubule gene stmn4, and stmn4 deficiency leads to impaired cell cycle and the accumulation of retinal progenitor cells (RPCs) and their subsequent apoptosis. The study provides a certain referee for copper overload in regulating the retinal development in fish., (© 2024. The Author(s).)

Cold is one of the main abiotic stresses in temperate fruit crops, affecting the yield and fruit quality of apple in China and European countries. The plant receptor-like kinase FERONIA is widely reported to be involved in abiotic stresses. However, its function in apple cold resistance remains unknown. Modification of cell wall components and accumulation of soluble sugars and amino acids are important strategies by which plants cope with cold. In this study, expression of the apple FERONIA receptor-like kinase gene MdMRLK2 was rapidly induced by cold. Apple plants overexpressing MdMRLK2 (35S:MdMRLK2) showed enhanced cold resistance relative to the wild type. Under cold conditions, 35S:MdMRLK2 apple plants had higher amounts of water insoluble pectin, lignin, cellulose, and hemicellulose, which may have resulted from reduced activities of polygalacturonase, pectinate lyase, pectinesterase, and cellulase. More soluble sugars and free amino acids and less photosystem damage were also observed in 35S:MdMRLK2 apple plants. Intriguingly, MdMRLK2 interacted with the transcription factor MdMYBPA1 and promoted its binding to MdANS and MdUFGT promoters, leading to more anthocyanin biosynthesis, particularly under cold conditions. These findings complemented the function of apple FERONIA MdMRLK2 responding to cold resistance., (© 2023 Society for Experimental Biology and John Wiley & Sons Ltd.)

Human leukocyte antigen (HLA) plays a vital role in immunomodulatory function. Studies have shown that immunotherapy based on non-classical HLA has essential applications in cancer, COVID-19, and allergic diseases. However, there are few deep learning methods to predict non-classical HLA alleles. In this work, an adaptive dual-attention network named DapNet-HLA is established based on existing datasets. Firstly, amino acid sequences are transformed into digital vectors by looking up the table. To overcome the feature sparsity problem caused by unique one-hot encoding, the fused word embedding method is used to map each amino acid to a low-dimensional word vector optimized with the training of the classifier. Then, we use the GCB (group convolution block), SENet attention (squeeze-and-excitation networks), BiLSTM (bidirectional long short-term memory network), and Bahdanau attention mechanism to construct the classifier. The use of SENet can make the weight of the effective feature map high, so that the model can be trained to achieve better results. Attention mechanism is an Encoder-Decoder model used to improve the effectiveness of RNN, LSTM or GRU (gated recurrent neural network). The ablation experiment shows that DapNet-HLA has the best adaptability for five datasets. On the five test datasets, the ACC index and MCC index of DapNet-HLA are 4.89% and 0.0933 higher than the comparison method, respectively. According to the ROC curve and PR curve verified by the 5-fold cross-validation, the AUC value of each fold has a slight fluctuation, which proves the robustness of the DapNet-HLA. The codes and datasets are accessible at https://github.com/JYY625/DapNet-HLA., Competing Interests: Declaration of competing interest The authors declare that they have no conflict of interest., (Copyright © 2023 Elsevier Inc. All rights reserved.)

The purpose of this study was to measure the vestibular function and plasma fibrinogen level in the nitroglycerin (NTG)-induced chronic migraine rats, and explore the effect of defibrinogenation on migraine and associated vestibular dysfunction. The chronic migraine rat model was built by recurrent NTG injection. Batroxobin was administrated as a defibrinogenating drug. We measured the mechanical withdrawal threshold, vestibular function, and fibrinogen level of the rats 30 min before and 2 h following the model establishment, as well as 1 h after batroxobin administration. The results showed that vestibular function was impaired in NTG-induced chronic migraine rats. The fibrinogen levels were increased following repeated NTG injections. However, defibrinogenation did not affect either aggravating or alleviating mechanical hyperalgesia or vestibular dysfunction in the migraine model rats. These findings suggest that the NTG-induced chronic migraine rat model can be used for research on migraine-associated vestibular symptoms. Albeit the association between elevated fibrinogen levels and migraine attacks can be observed, the role of excessive fibrinogen in the pathogenesis of chronic migraine is yet to be determined., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Zhang, Zhao, Jing, Han, Ma, Yu and Diao.)

Objective: The present study aimed to explore the pathogenesis of the ascending sudden sensorineural hearing (SSNHL) loss by comparing the clinical characteristics and prognosis of acute low-frequency hearing loss (ALFHL) and ascending SSNHL., Methods: A total of 43 patients with ALFHL and 122 patients with ascending SSNHL were enrolled in this study. First, the prognosis of patients with ALFHL and ascending SSNHL were compared, and the prognostic factors of AFHL and ascending SSNHL were analyzed., Results: Acute low-frequency hearing loss and ascending SSNHL have no remarkable difference in complete recovery rate. Compared to ascending SSNHL, ALFHL has younger onset age, female prevalence, lower hearing threshold, shorter time from onset to recovery, and a lower proportion of combined tinnitus. The PTA at admission and delay from onset to therapy were significantly related to the prognosis of patients with ascending SSNHL, while only delay from onset to therapy was significantly related to the prognosis of patients with ALFHL. The majority of patients with ascending SSNHL and ALFHL recovered completely within 10 days from onset., Conclusion: Audiogram shape plays a critical role in the prognosis of SSNHL. Ascending SSNHL and ALFHL may share a common pathological mechanism., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Diao, Chen, Jing and Ma.)

Purpose: To investigate the risk factors for residual dizziness (RD) in patients with benign paroxysmal positional vertigo (BPPV) after successful repositioning., Methods: Searches were performed in PubMed, Embase, Cochrane library, Web of Science, Chinese National Knowledge Infrastructure, and Sino Med up to March 7, 2021 and references of relevant articles were screened. Data from eligible studies were meta-analyzed using Stata version 16.0 and Review Manager 5.4., Results: In this systematic review and meta-analysis of 4487 patients from 31 studies, the prevalence of RD was 43.0% (95% CI 39.0-48.0%). Age (MD 4.17; 95% CI 2.13-6.21, P = 0.000), female gender (OR = 1.28, 95% CI 1.11-1.47, P = 0.001), secondary BPPV (OR 1.88; 95% CI 1.27-2.77, P = 0.001), a longer duration of BPPV before treatment (MD 3.45; 95% CI 1.87-5.02, P = 0.000), abnormal ocular vestibular evoked myogenic potential (OVEMP, OR 4.34; 95% CI 2.78-6.78, P = 0.000), abnormal cervical vestibular evoked myogenic potential (CVEMP, OR 2.48; 95% CI 1.54-3.99, P = 0.000), higher Dizziness Handicap Index (DHI) score before treatment (MD 10.88; 95% CI 5.96-15.80, P = 0.000), anxiety (OR 9.58; 95% CI 6.32-14.52, P = 0.000), osteopenia (OR = 4.40, 95% CI 2.17-8.96, P = 0.000), onset in winter (OR 7.27; 95% CI 2.38-22.24, P = 0.001) and with a history of BPPV (OR 1.79; 95% CI 1.06-3.04, P = 0.03) are the risk factors for RD in patients with BPPV after successful repositioning. The affected side, location or type of semicircular involvement, hyperlipidemia, diabetes, hypertension, heart disease, migraine, sleep disorders, canalolithiasis/cupulolithiasis, the number of times the canalith repositioning procedures (CRPs) were performed and number of vertigo attacks did not correlate with the occurrence of RD., Conclusions: Despite successful treatment, nearly half of the BPPV patients developed RD. RD seems to be a syndrome caused by multiple factors. The pathogenesis of most factors can be explained by psychological and/or physical disorders. Early recognition of these risk factors contributes to the prevention and treatment of RD., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

In this study, we investigated the influence of temperature on the bioaccumulation and depuration of Crassostrea gigas exposed to Cd associated with its molecular responses. Oysters were acclimatized to different temperatures (10 °C, 15 °C, 20 °C, 25 °C, and 30 °C) for 14 d and then exposed to 10 μg/L Cd for 28 d, followed by a depuration period of 35 d. Oysters were sampled for chemical analysis by inductively coupled plasma mass spectrometry (ICP-MS) and for mRNA quantification by qPCR. In the digestive gland, gill, and mantle, the cadmium concentration at 10 °C was significantly lower than that at 25 °C and 30 °C in both the whole experiments. The use of a two-compartment model showed that the uptake rate k 1 in the above three tissues increased with increasing temperatures ranging from 15 to 25 °C. The fastest elimination rates and shortest half-lives were observed at 15-25 °C. The induction of metallothionein (MT) only occurred in the digestive gland at 15 °C and 20 °C at the end of the accumulation phase. In the mantle and gills, the expression of P-glycoprotein (P-gp) was significantly induced at the end of the accumulation phase and significantly inhibited at the end of the depuration phase. In the digestive gland, the expression of P-gp was induced at the end of both the accumulation and depuration phases. Heat shock protein (hsp70) expression exhibited an overall increasing trend throughout the experiment., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Objective: Benign paroxysmal positional vertigo (BPPV) has a high recurrence rate, but the risk factor-associated recurrence are elusive., Methods: Searches were performed in PubMed, Embase, Cochrane library, Web of science, Chinese National Knowledge Infrastructure, and Sino Med up to November 3, 2019. The effect size was analyzed by odds ratio and 95% CI. Data from eligible studies were meta-analyzed using Stata version 15.0., Results: Our search resulted in a total of 4076 hits. Twenty-four outcomes of sixty articles were included in the meta-analysis. Risk factors for the recurrence of BPPV included female gender, age (≥65years), hyperlipidemia, diabetes, hypertension, migraine, cervical spondylosis, osteopenia/osteoporosis, head trauma, otitis media, abnormal vestibular evoked myogenic potential, and long use of computers. No significant differences were found in side, type of the involved semicircular canals, smoking, alcohol consumption, stroke, ear surgery, duration of vertigo before treatment, the times of repositioning, Meniere disease, sleep disorders, hypercholesterolemia, and 25-hydroxy vitamin D., Conclusion: These findings strengthen clinical awareness of early warning to identify patients with potential relapse risk of BPPV and clinicians should counsel patients regarding the importance of follow-up after diagnosis of BPPV.

To explore whether patients with unilateral idiopathic sudden sensorineural hearing loss (uISSNHL) have normal speech in noise (SIN) perception under different masking conditions after complete recovery of pure tone audiometry. Eight completely recovered uISSNHL patients were enrolled in ISSNHL group, while 8 normal-hearing adults matched with age, gender, and education experience were selected as the control group. Each group was tested SIN under four masking conditions, including noise and speech maskings with and without spatial separation cues. For both ISSNHL and control groups a two-way ANOVA showed a statistically significant effect of masking type (p = 0.007 vs p = 0.012). A significant effect of perceived spatial separation (p < 0.001 vs p < 0.001). A significant interaction between masking type and perceived spatial separation was found (p < 0.001 vs p < 0.001). A paired sample T-test showed that the SIN perception of the control group was statistically significant lower than that of ISSNHL patients only under speech masking without spatial separation cues (p = 0.011). There were still abnormalities in the auditory center shortly after complete recovery in the ISSNHL group (within 2 weeks). However, the auditory periphery and higher-level ability to use spatial cues was normal., (© 2022. The Author(s).)

Objective: This study aimed to find bilateral vestibulopathy（BVP） patients in outpatients with unsteadiness and investigate their clinical characteristics. Methods: According to the common manifestation and etiologies of BVP, 2075 outpatients who were diagnosed as imbalance, follow up on chemotherapy, bilateral Menière's disease, systemic lupus erythematosus（SLE） and vasculitis from January 2018 to October 2019 were searched based on the hospital information system. After completing a telephone screening interview, eligible individuals whose symptoms were in consistent with the diagnostic criteria of BVP were scheduled for questionnaires and video head impulse test（vHIT）. Results: A total of 131 patients replied and complained chronic unsteadiness. The response rates of patients with bilateral Menière's disease, chemotherapy, SLE and vasculitis were 10.0%, 0%, 0.3% and 1.2%, respectively. Unsteadiness is uncommon or mild in outpatients with vasculitis, SLE and chemotherapy. Twenty-nine patients presented with typical symptoms of BVP and only 3 were diagnosed as BVP after vHIT. The horizontal vHIT gain was significantly lower among patients who reported very severe life impact than those reported mild to severe impact in older patients, as well as in male patients（both P <0.01）. However, no significant differences were noted in younger and female patients（ P =0.396, 0.180, respectively）. Conclusion: BVP accounts for 2.3% in outpatients with unsteadiness, and only 10.3% of patients who presents with typical symptoms meet the diagnostic criteria, suggesting vestibular function test is of great significance in making diagnosis., Competing Interests: The authors of this article and the planning committee members and staff have no relevant financial relationships with commercial interests to disclose., (Copyright© by the Editorial Department of Journal of Clinical Otorhinolaryngology Head and Neck Surgery.)

Inspired by the active-site structure of the [NiFe] hydrogenase, we have computationally designed the iron complex [P(tBu) 2 N(tBu) 2 )Fe(CN)2 CO] by using an experimentally ready-made diphosphine ligand with pendant amines for the hydrogenation of CO2 to methanol. Density functional theory calculations indicate that the rate-determining step in the whole catalytic reaction is the direct hydride transfer from the Fe center to the carbon atom in the formic acid with a total free energy barrier of 28.4 kcal mol(-1) in aqueous solution. Such a barrier indicates that the designed iron complex is a promising low-cost catalyst for the formation of methanol from CO2 and H2 under mild conditions. The key role of the diphosphine ligand with pendent amine groups in the reaction is the assistance of the cleavage of H2 by forming a Fe-H(δ-) ⋅⋅⋅H(δ+) -N dihydrogen bond in a fashion of frustrated Lewis pairs., (© 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

The hydrogenation of ethyl acetate to ethanol catalyzed by SNS pincer ruthenium complexes was computationally investigated by using DFT. Different from a previously proposed mechanism with fac-[(SNS)Ru(PPh 3 )(H) 2 ] (5') as the catalyst, an unexpected direct hydride transfer mechanism with a mer-SNS ruthenium complex as the catalyst, and two cascade catalytic cycles for hydrogenations of ethyl acetate to aldehyde and aldehyde to ethanol, is proposed base on our calculations. The new mechanism features ethanol-assisted proton transfer for H 2 cleavage, direct hydride transfer from ruthenium to the carbonyl carbon, and C-OEt bond cleavage. Calculation results indicate that the rate-determining step in the whole catalytic reaction is the transfer of a hydride from ruthenium to the carbonyl carbon of ethyl acetate, with a total free energy barrier of only 26.9 kcal mol -1 , which is consistent with experimental observations and significantly lower than the relative free energy of an intermediate in a previously postulated mechanism with 5' as the catalyst., (© 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Objective: To compare the vertigo controlling situation between the endolymphatic sac decompression(ELSD) and semicircular canal occlusion (SCO) in stage 4 Ménière disease., Method: Fourteen patients who underwent endolymphatic sac decompression and 9 patients who underwent semicircular canal occlusion from 2009 to 2013 were followed. All patients has complete preoperative examination and postoperative follow-up., Result: The vetigo control of the patients underwent endolymphatic sac decompression: completely control 35.7%; basic control 28.6%; partly control 14.3%; the vetigo control of the patients underwent semicircular canal occlusion: completely control 88.9%; basic control 11.1%., Conclusion: ELSD and SCO are alternative methods for the patients of stage 4. SCO has a much highter complete vertigo control rate. For the patients without practical listening, SCO is a better choice.

Objective: To analyze the false-negative proportion and reasons of positioning test in benign paroxysmal positional vertigo (BPPV)., Method: Sixty-eight cases were reviewed and analyzed during February to April 2009. All patients had typical clinical history of BPPV and diagnosed by positioning test,and all were treated with PRM successfully. If positioning test at the first time were negative, examinations repeated after either head shaking or return visits., Result: Thirteen patients (19.12%) appeared false-negative in positoning test, and 11 cases showed typical nystagmus after head shaking,while 2 cases were diagnosed by return visitis the next day. There were no statistically difference between false-negative group and positive group in age (P > 0.05), gender (P > 0.05), course of disease (P > 0.05) and types of semi-circular canal (P > 0.05)., Conclusion: Re-examinations after head shaking or return visits are useful for the diagnosis in the suspected BPPV patients who have negative positioning test.

Objective: Through a prospective cohort study, to assess the clinical efficacy of methylprednisolone (MP) and dexamethasone (DXM) in treatment of all-frequency sudden hearing loss., Methods: A total of 76 cases of all-frequency sudden hearing loss were included in this study and divided into two groups. The MP group (n = 40) was treated with MP 40 mg qd, for 5 days, combined with conventional treatment. The DXM group (n = 36) was treated with DXM 10 mg qd, for 5 days, combined with conventional treatment. The total period of treatment was 14 days., Results: After the treatment for 14 days, in the MP group,17 cases were cured (42.5%), 7 cases were markedly improved (17.5%), 9 cases were effective (22.5%), and 7 cases were invalid (17.5%), the total effective rate was 82.5%. As for the patients in the DXM group, 13 cases were cured (36.1%), 6 cases were markedly improved (16.7%), 8 cases were effective (24.2%), and 9 cases were invalid (25%), the total effective rate was 75.0%. The pure tone audiometry in all-frequency was improved (31.5 ± 17.8) dB in the MP group, and (33.1 ± 24.2) dB in the DXM group. The speech recognition rate was improved (41.7 ± 29.8) %, and (42.0 ± 39.1) % in the DXM group. There were no significant differences between two groups., Conclusion: There is no significant difference of therapeutic efficacy between the low-dose MP group and High-dose DXM group.

Objective: To investigate the effecacy of cochlear implantation (CI) improving hearing of Lermoyez's syndrome, we retrospectively analyzed a case of Lermoyez's syndrome whose left ear was extremely severe sensorineural deafness and right ear was severe sensorineural deafness., Method: The patient had completed preoperative audiological examination , vestibular function and imaging examination, then was carried out bilateral endolymphatic sac decompression and left side CI. Follow up after the surgery., Result: The vertigo could be controlled very well after the bilateral endolymphatic sac decompression surgery, but the hearing loss couldn't be control, so CI was carried out to improve hearing and speech recognition rate. The contralateral hearing also improved significantly after the operation., Conclusion: Endolymphatic sac decompression can effectively control. Ménière's disease in patients with vertigo attacks. CI can improve patients' hearing, and speech recognition rate and, also could improve the quality of life. CI was the first choice for the patient of 4 stage Ménière's disease.

Objective: Analyzing different types of concomitant vertigo in sudden deafness (SD) patients with different hearing loss types, exploring different pathogenesis of SD and concomitant vertigo., Method: The clinical data of 121 SD cases during 2007. 12 - 2009. 4 were retrospectively analyzed. Detailed information including age, sex, history and hearing level were recorded. According to the standard of China Medical Association,all patients were classified into five sub-groups based on audiogram types: low frequency SD, high frequency SD, flat frequency SD and total SD. The proportion of vertigo in different SD types were calculated and analyzed by statistical method., Result: Among all 121 cases, 45 cases with concomitant vertigo, the proportion in different SD types was 42.9%, 47.1%, 23.6% and 51.4%, respectively. By chi-square test, P < 0.05, the proportion in the flat type was statistically lower than that of the other types. 23 patients were diagnosed as true vertigo. The vertigo incidence in different SD types had no statistical difference., Conclusion: Vaso factor and viral infection played different roles in different SD types. Discussing concomitant vertigo could help understand SD and otogenic vertigo.

Objective: Comparison of the bithermal test in benign paroxysmal positional vertigo (BPPV) before and after particle repositioning maneuver (PRM), identify the possible mechanisms of canal paralysis in BPPV., Method: Ninety-six BPPV cases during 2005-2008 were randomly divided into two groups: 52 cases were carried bithermal test before PRM, and the other 44 cases were carried after successful PRM. According to the canal paresis(CP) > or = 20%, subdivided each patients group the normal semicircular canal (SC) function group and the paresis SC function group. Compared the ratio of paresis SC function between the subgroups., Result: Except the ages of the first group were younger than the second group, the gender rate, semicircular canal involved, side involved, course of the disease, recurrent attacks were all equal between the two groups. Using chi square test to compare the ratio of paresis SC between the two groups (t = 0.654, P < 0.05), the differences between the two groups were not statistical., Conclusion: PRM has no influence to the bithermal test in BPPV. The mechanisms of the paresis SC function may be the extensive pathological changes in the vestibular system. The floating otolith has little effect on the dynamic of the endolymph.

Objective: To evaluate expressions of NF-kappaB p65 in laryngeal carcinoma and normal mucous membrane and its clinical significance., Method: The immunohistochemical method and the in situ hybridization were employed in detecting the NF-kappaB p65 expressions in surgical specimen from 48 laryngeal carcinoma and 20 normal mucous membrane., Result: (1) The expression of NF kappaB p65 was higher than in normal laryngeal mucous membrane. (2) Positive expression of NF-kappaB p65 correlated with the development of distant metastasis., Conclusion: The results of the study show that the NF-kappaB p65 protein is a significant predictor of survival in laryngeal carcinoma patients.