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1.
Int J Med Robot ; : e2044, 2019 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-31674135

RESUMO

BACKGROUND: Robot-assisted puncture has gradually attracted more attention and practical clinical application. The lesion positioning and the needle positioning are the basis to ensure the accuracy of puncture and the key techniques in insertion operation. METHODS: A lesion positioning method is established which is realized only by the robot-CT system without using external positioning system, and an omnidirectional needle positioning method is also developed and realized by using VRCM, in order to make the puncture needle always keep pointing to the lesion point. A CT-guided surgical robotic system used for minimally invasive percutaneous lung is designed and the physical prototype is manufactured, to perform in-vitro experiments, thereby to validate the effectiveness of the lesion positioning method and the feasibility of omnidirectional needle positioning method. RESULTS: The accuracy of established lesion positioning method based on three non-collinear markers is within 3 mm, which is similar to that of the least squares method based on the five non-coplanar markers, but the positioning efficiency can be improved by about 40%, and the non-collinearity of markers is easier to be satisfied than non-coplanarity in practical applications. The average calculation error of the established positioning method is 0.997 mm. Moreover, the omnidirectional positioning of the puncture needle under the designed surgical robot is feasible. CONCLUSIONS: The designed surgical robot has good control accuracy and it can satisfy the requirements for use. The established lesion positioning method can provide a good precision basis for robot-assisted puncture surgery. The suitable insertion point and insertion posture can be determined by the developed omnidirectional needle positioning method. This work can provide theoretical reference for further study of path planning or autonomous positioning.

2.
Commun Biol ; 2: 389, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31667363

RESUMO

Billions of people have obesity-related metabolic syndromes such as diabetes and hyperlipidemia. Promoting the browning of white adipose tissue has been suggested as a potential strategy, but a drug still needs to be identified. Here, genetic deletion of activating transcription factor 3 (ATF3 -/- ) in mice under a high-fat diet (HFD) resulted in obesity and insulin resistance, which was abrogated by virus-mediated ATF3 restoration. ST32da, a synthetic ATF3 inducer isolated from Salvia miltiorrhiza, promoted ATF3 expression to downregulate adipokine genes and induce adipocyte browning by suppressing the carbohydrate-responsive element-binding protein-stearoyl-CoA desaturase-1 axis. Furthermore, ST32da increased white adipose tissue browning and reduced lipogenesis in HFD-induced obese mice. The anti-obesity efficacy of oral ST32da administration was similar to that of the clinical drug orlistat. Our study identified the ATF3 inducer ST32da as a promising therapeutic drug for treating diet-induced obesity and related metabolic disorders.

3.
Waste Manag ; 102: 56-64, 2019 Oct 24.
Artigo em Inglês | MEDLINE | ID: mdl-31669675

RESUMO

Radial oxygen loss (ROL) by the spreading root systems of vegetation can improve soil aeration for subsequent oxidation of methane (CH4) by microbes in landfill cover soils. This study proposes a theoretical model that elucidated the effects of ROL on microbial oxidation of CH4 to understand landfill gas transportation and oxidation in landfill cover soils. Parametric analyses were conducted to investigate the effects of root depth, root architecture, and ROL rate on the CH4 oxidation efficiency of landfill cover soils. The simulation results suggested that disregarding O2 emissions by plants root systems could underestimate the CH4 oxidation efficiency, especially when the water content ranged from 20% to 35%. Additionally, plants with a parabolic root architecture indicated 7-13% higher CH4 oxidation efficiency than other root architectures, i.e., uniform, triangular, and exponential. The CH4 oxidation efficiency increased rapidly at root depths less than 0.25 m. Therefore, plants characterized by a parabolic root architecture, longer root length, and higher ROL capacity should be selected as the preferred species for mitigating CH4 emissions from landfills in humid areas.

4.
Artigo em Inglês | MEDLINE | ID: mdl-31776910

RESUMO

Ammonia (NH3) volatilization from paddy soils is a main source of atmospheric NH3 and the magnitude is affected by many factors. Because of the complex field condition, it is difficult to identify the relative importance of individual factor on NH3 volatilization process in different locations and at different times. In this study, the grey relational entropy method was used to evaluate the relative impact of four main factors (i.e., nitrogen fertilizer application rate, NH4-N concentration, pH, and temperature of the floodwater) on NH3 volatilization loss from three different field experiments. The results demonstrated that floodwater NH4-N concentration was the most important factor governing NH3 volatilization process. Floodwater pH was the second most important factor, followed by temperature of the floodwater and nitrogen fertilizer application rate. We further validated the grey relational entropy method with NH3 volatilization loss data from other published study and confirmed the order of importance for the four factors. We hope the findings of this study will be helpful for guiding design to reduce paddy soil NH3 emission.

5.
iScience ; 22: 133-146, 2019 Nov 09.
Artigo em Inglês | MEDLINE | ID: mdl-31765994

RESUMO

All-optical physiology (AOP) manipulates and reports neuronal activities with light, allowing for interrogation of neuronal functional connections with high spatiotemporal resolution. However, contemporary high-speed AOP platforms are limited to single-depth or discrete multi-plane recordings that are not suitable for studying functional connections among densely packed small neurons, such as neurons in Drosophila brains. Here, we constructed a 3D AOP platform by incorporating single-photon point stimulation and two-photon high-speed volumetric recordings with a tunable acoustic gradient-index (TAG) lens. We demonstrated the platform effectiveness by studying the anterior visual pathway (AVP) of Drosophila. We achieved functional observation of spatiotemporal coding and the strengths of calcium-sensitive connections between anterior optic tubercle (AOTU) sub-compartments and >70 tightly assembled 2-µm bulb (BU) microglomeruli in 3D coordinates with a single trial. Our work aids the establishment of in vivo 3D functional connectomes in neuron-dense brain areas.

6.
Cell Rep ; 29(9): 2634-2645.e5, 2019 Nov 26.
Artigo em Inglês | MEDLINE | ID: mdl-31775034

RESUMO

The transcription factor interferon regulatory factor 4 (IRF4) is critical for the development, maintenance, and function of plasma cells. The mechanism by which IRF4 exerts its action in mature plasma cells has been elusive due to the death of all such cells upon IRF4 loss. While we identify apoptosis as a critical pathway for the death of plasma cells caused by IRF4 loss, we also determine that IRF4 did not regulate the intrinsic apoptotic pathway directly. By using an inducible IRF4 deletion system in the presence of the overexpression of anti-apoptotic BCL2, we identify genes whose expression is coordinated by IRF4 and that in turn specify plasma cell identity and mitochondrial homeostasis.

7.
Cell Rep ; 29(8): 2257-2269.e6, 2019 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-31747599

RESUMO

Despite the key role that antibodies play in protection, the cellular processes mediating the acquisition of humoral immunity against malaria are not fully understood. Using an infection model of severe malaria, we find that germinal center (GC) B cells upregulate the transcription factor T-bet during infection. Molecular and cellular analyses reveal that T-bet in B cells is required not only for IgG2c switching but also favors commitment of B cells to the dark zone of the GC. T-bet was found to regulate the expression of Rgs13 and CXCR3, both of which contribute to the impaired GC polarization observed in the absence of T-bet, resulting in reduced IghV gene mutations and lower antibody avidity. These results demonstrate that T-bet modulates GC dynamics, thereby promoting the differentiation of B cells with increased affinity for antigen.

8.
Anal Chem ; 2019 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-31751515

RESUMO

Single-cell metabolomics could be used to discover the chemical strategies of cells for coping with chemical or environmental stress because metabolomics provides a more immediate and dynamic picture of cell functionality. However, these small-molecule metabolites are the most difficult to measure because they characterize rapid metabolic dynamics, structural diversity, and incapac-ity to achieve signal amplification or labelling. In order to solve above problems, we presented a surface-enhanced Raman scatter-ing (SERS)-microfluidic droplet platform to realize the label-free simultaneous analysis of multiplexed metabolites at the single-cell level via a versatile magnetic SERS substrate composed by silver nanoparticles (AgNPs, 30 nm) decorated 400 nm Fe3O4 mag-netic microspheres. This metal-magnetic composite substrate is beneficial to efficient adsorption of single cell metabolite, fast sepa-ration from complex matrixes, and high SERS sensitivity. Also, endocytosis effect can be fully prohibited due to its relatively large size. This work achieves label-free, non-destructive, simultaneous determination of three single-cell metabolites: pyruvate, adenosine triphosphate (ATP) and lactate, owing to their intrinsic SERS fingerprints. The "hot spots" effect induced by the mag-netic aggregation of Ag@Fe3O4 allows highly sensitive SERS detection. Encapsulating metabolites in such a limited and isolated droplet volume accelerates the process of diffusion and adsorption equilibriums. Activation with saponin for metabolites was as-sessed on different cell lines. The SERS-microdroplet platform is a powerful tool for exploring single-cell heterogeneity at the metabolic level.

9.
J Mol Cell Cardiol ; 2019 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-31751567

RESUMO

Cardiotoxicity is a well-known adverse effect of doxorubicin (Dox) administration, but the underlying molecular mechanism of this effect is not fully understood. Over the past two decades, considerable efforts have focused on the potential molecular targets of cardiotoxicity in the hope that novel targeted therapies will be generated to attenuate Dox-induced cardiotoxicity. Here, we provide a comprehensive overview of genetically modified animals that show enhanced or reduced susceptibility to the cardiotoxic effects of Dox. We focused on the process by which the molecules involved in DNA damage, oxidative stress, apoptosis, autophagy and necrosis are affected in the presence of Dox. We also present a protein-protein interaction network and explain the contribution of the components to the process of Dox-induced cardiotoxicity. More importantly, data from the literature have indicated that PI3Kγ and Rac1 are potential targets with therapeutic advantages in cancer therapy; molecules that target these proteins can simultaneously attenuate Dox-induced cardiotoxicity and enhance its anticancer activity. This review highlights the potential molecular targets that are critical regulators involved in Dox-mediated cardiotoxicity, thus providing further insight into the development of potential treatment strategies to prevent the cardiotoxic effects and enhance the anticancer efficiency of Dox in cancer patients.

10.
Sci Total Environ ; 701: 134424, 2019 Sep 12.
Artigo em Inglês | MEDLINE | ID: mdl-31726412

RESUMO

Over use of N fertilizers, most commonly as urea, had been seriously concerned as a major source of radiative N (Nr) for severe environment impacts through leaching, volatilization, and N2O emission from fertilized croplands. It had been well known that biochar could enhance N retention and use efficiency by crops in amended croplands. In this study, a granular biochar-mineral urea composite (Bio-MUC) was obtained by blending urea with green waste biochar supplemented with clay minerals of bentonite and sepiolite. This Bio-MUC material was firstly characterized by microscopic analyses with FTIR, SEM-EDS and STEM, subsequently tested for N leaching in water in column experiment and for N supply for maize in pot culture, compared to conventional urea fertilizer (UF). Microscopic analyses indicated binding of urea N to particle surfaces of biochar and clay minerals in the Bio-MUC composite. In the leaching experiment over 30 days, cumulative N release as NH4+-N and of dissolved organic carbon (DOC) was significantly smaller by >70% and by 8% from the Bio-MUC than from UF. In pot culture with maize growing for 50 days, total fresh shoot was enhanced by 14% but fresh root by 25% under Bio-MUC compared to UF. This study suggested that N in the Bio-MUC was shown slow releasing in water but maize growth promoting in soil, relative to conventional urea. Such effect could be related mainly to N retention by binding to biochar/mineral surfaces and partly by carbon bonds of urea to biochar in the Bio-MUC. Therefore, biochar from agro-wastes could be used for blending urea as combined organo/mineral urea to replace mineral urea so as to reduce N use and impacts on global Nr. Of course, how such biochar combined urea would impact N process in soil-plant systems deserve further field studies.

11.
Emerg Infect Dis ; 25(12): 2205-2214, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31742507

RESUMO

According to the government of China, reported cases of pertussis have increased remarkably and are still increasing. To determine the genetic relatedness of Bordetella pertussis strains, we compared multilocus variable-number tandem-repeat analysis (MLVA) results for isolates from China with those from Western countries. Among 335 isolates from China, the most common virulence-associated genotype was ptxA1/ptxC1/ptxP1/prn1/fim2-1/fim3A/tcfA2, which was more frequent among isolates from northern than southern China. Isolates of this genotype were highly resistant to erythromycin. We identified 36 ptxP3 strains mainly harboring ptxA1 and prn2 (35/36); ptxP3 strains were sensitive to erythromycin and were less frequently from northern China. For all isolates, the sulfamethoxazole/trimethoprim MIC was low, indicating that this drug should be recommended for patients infected with erythromycin-resistant B. pertussis. MLVA of 150 clinical isolates identified 13 MLVA types, including 3 predominant types. Our results show that isolates circulating in China differ from those in Western countries.

12.
J Exp Med ; 2019 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-31699822

RESUMO

Blood-brain barrier (BBB) dysfunction has been suggested to play an important role in epilepsy. However, the mechanism mediating the transition from cerebrovascular damage to epilepsy remains unknown. Here, we report that endothelial cyclin-dependent kinase 5 (CDK5) is a central regulator of neuronal excitability. Endothelial-specific Cdk5 knockout led to spontaneous seizures in mice. Knockout mice showed increased endothelial chemokine (C-X-C motif) ligand 1 (Cxcl1) expression, decreased astrocytic glutamate reuptake through the glutamate transporter 1 (GLT1), and increased glutamate synaptic function. Ceftriaxone restored astrocytic GLT1 function and inhibited seizures in endothelial Cdk5-deficient mice, and these effects were also reversed after silencing Cxcl1 in endothelial cells and its receptor chemokine (C-X-C motif) receptor 2 (Cxcr2) in astrocytes, respectively, in the CA1 by AAV transfection. These results reveal a previously unknown link between cerebrovascular factors and epileptogenesis and provide a rationale for targeting endothelial signaling as a potential treatment for epilepsy.

13.
Bioorg Chem ; : 103391, 2019 Nov 09.
Artigo em Inglês | MEDLINE | ID: mdl-31761409

RESUMO

Thermostability of monoclonal antibodies (mAbs) and antibody-drug conjugates (ADCs), as a critical property of biotherapeutics, is important for their physicochemical processes, pharmacodynamics, and pharmacokinetics. Fc glycosylation of mAbs plays a crucial role in antibody functions including thermostability, however, due to the lack of homogeneous glycosylation for comparison, the precise impact of glycoforms on thermostability of mAbs and ADCs remains challenging to elucidate. In this paper, we employed the technique of differential scanning fluorimetry (DSF) to investigate the thermostability of Fc domains, glycoengineered mAbs, and ADCs, carrying well-defined N-glycan structures for comparison. The results revealed that high-mannose-type N-glycans dramatically reduce the Tm value of Fc, compared to complex-type N-glycans. We also found that core-fucose contributes to the thermostability of mAbs, and the unnatural modification on non-reducing end of biantennary N-glycan can compensate the reduced stability of afucosylated mAbs and maintain the advantage of enhanced antibody-dependent cell-mediated cytotoxicity (ADCC). DSF analysis of lysine-linked and glycosite-specific ADCs indicated that thermostability of glycan-linked ADCs is reduced, but it could be improved by using an optimized linkage. This work provides an in-depth analysis on thermostability of mAbs and ADCs with homogeneous glycoforms, and also proposes new strategies for optimizing glycoengineered mAbs and glycosite-specific ADCs using unnatural glycan and stabilized linkage.

14.
BMJ ; 367: l5919, 2019 11 14.
Artigo em Inglês | MEDLINE | ID: mdl-31727627

RESUMO

OBJECTIVE: To assess the efficacy and safety of different endoscopic surgical treatments for benign prostatic hyperplasia. DESIGN: Systematic review and network meta-analysis of randomised controlled trials. DATA SOURCES: A comprehensive search of PubMed, Embase, and Cochrane databases from inception to 31 March 2019. STUDY SELECTION: Randomised controlled trials comparing vapourisation, resection, and enucleation of the prostate using monopolar, bipolar, or various laser systems (holmium, thulium, potassium titanyl phosphate, or diode) as surgical treatments for benign prostatic hyperplasia. The primary outcomes were the maximal flow rate (Qmax) and international prostate symptoms score (IPSS) at 12 months after surgical treatment. Secondary outcomes were Qmax and IPSS values at 6, 24, and 36 months after surgical treatment; perioperative parameters; and surgical complications. DATA EXTRACTION AND SYNTHESIS: Two independent reviewers extracted the study data and performed quality assessments using the Cochrane Risk of Bias Tool. The effect sizes were summarised using weighted mean differences for continuous outcomes and odds ratios for binary outcomes. Frequentist approach to the network meta-analysis was used to estimate comparative effects and safety. Ranking probabilities of each treatment were also calculated. RESULTS: 109 trials with a total of 13 676 participants were identified. Nine surgical treatments were evaluated. Enucleation achieved better Qmax and IPSS values than resection and vapourisation methods at six and 12 months after surgical treatment, and the difference maintained up to 24 and 36 months after surgical treatment. For Qmax at 12 months after surgical treatment, the best three methods compared with monopolar transurethral resection of the prostate (TURP) were bipolar enucleation (mean difference 2.42 mL/s (95% confidence interval 1.11 to 3.73)), diode laser enucleation (1.86 (-0.17 to 3.88)), and holmium laser enucleation (1.07 (0.07 to 2.08)). The worst performing method was diode laser vapourisation (-1.90 (-5.07 to 1.27)). The results of IPSS at 12 months after treatment were similar to Qmax at 12 months after treatment. The best three methods, versus monopolar TURP, were diode laser enucleation (mean difference -1.00 (-2.41 to 0.40)), bipolar enucleation (0.87 (-1.80 to 0.07)), and holmium laser enucleation (-0.84 (-1.51 to 0.58)). The worst performing method was diode laser vapourisation (1.30 (-1.16 to 3.76)). Eight new methods were better at controlling bleeding than monopolar TURP, resulting in a shorter catheterisation duration, reduced postoperative haemoglobin declination, fewer clot retention events, and lower blood transfusion rate. However, short term transient urinary incontinence might still be a concern for enucleation methods, compared with resection methods (odds ratio 1.92, 1.39 to 2.65). No substantial inconsistency between direct and indirect evidence was detected in primary or secondary outcomes. CONCLUSION: Eight new endoscopic surgical methods for benign prostatic hyperplasia appeared to be superior in safety compared with monopolar TURP. Among these new treatments, enucleation methods showed better Qmax and IPSS values than vapourisation and resection methods. STUDY REGISTRATION: CRD42018099583.


Assuntos
Hiperplasia Prostática/cirurgia , Ressecção Transuretral da Próstata , Humanos , Masculino , Avaliação de Resultados (Cuidados de Saúde) , Ressecção Transuretral da Próstata/efeitos adversos , Ressecção Transuretral da Próstata/métodos , Ressecção Transuretral da Próstata/estatística & dados numéricos , Resultado do Tratamento
16.
Artigo em Inglês | MEDLINE | ID: mdl-31709485

RESUMO

Biochar has been considered as a promising soil amendment for improving fertility and mitigating N2O emission from the arable land. However, biochar's effectiveness in acidic tea soil and underlying mechanisms are largely unknown. We conducted a short-term microcosm experiment using two biochars (1% w/w, LB, generated from legume and NLB, non-legume biomass, respectively) to investigate the effects of biochar amendments on soil chemical properties, N2O emission, and microbial community in an acidic soil. Soil and headspace gas samples were taken on 1, 10, and 30 day's incubation. Biochar amendment increased soil pH and DOC, however, significantly reduced soil inorganic N. Both biochars at ~ 1% addition had little effect on microbial CO2 respiration but suppressed soil N2O emission by ~ 40% during the incubation. The divergence in N2O efflux rates between soils with and without biochar addition aligned to some degree with changes in soil pH, inorganic N, and dissolved organic C (DOC). We also found that biochar addition significantly modified the fungal community structure, in particular the relative abundance of members of Ascomycota, but not the bacterial community. Furthermore, the copy number of nosZ, the gene encoding N2O reductase, was significantly greater in biochar-amended soils than the soil alone. Our findings contribute to better understanding of the impact of biochar on the soil chemical properties, soil N2O emission, and microbial community and the consequences of soil biochar amendment for improving the health of acidic tea soil.

17.
Lasers Surg Med ; 2019 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-31709596

RESUMO

BACKGROUND AND OBJECTIVE: Vulvar intraepithelial neoplasia (VIN), a precancerous lesion, is difficult to treat by excision or ablation due to high recurrence rates. Photodynamic therapy (PDT) is a minimally invasive therapeutic procedure and is now widely used to treat non-melanoma skin diseases. However, the clinical response rates of VIN to single PDT are unstable. The reason may be the limited light penetration into deep tissues. OBJECTIVE: To retrospectively evaluate the clinical response and recurrence of VIN after combined treatment with superficial shaving and PDT. STUDY DESIGN/MATERIALS AND METHODS: Seventeen patients with VIN were enrolled. All patients had multifocal high-grade VIN that had failed to respond to various therapies. Superficial shaving was performed only once and prior to the first 5-aminolaevulinic acid (5-ALA)-PDT cycle. Generally, the procedure of 5-ALA PDT for each patient was performed in three sessions. Clinical response, recurrence, cosmetic outcomes, adverse events, patient satisfaction, quality of life, and mental health were assessed. The expression of p16 and Ki-67 in pre- and post-treatment tissue was detected. RESULTS: A clinical response of 94% was observed in 17 patients, who were administered combination therapy, over an observation period of 12 months. Approximately, 71% of patients had excellent cosmetic outcomes. All patients had satisfactory therapeutic effects and significant improvements in quality of life and mental health. Downregulation of p16 and Ki-67 may have been correlated with recurrence after 5-ALA-PDT. CONCLUSION: Combined treatment with superficial shaving and 5-ALA-PDT is a safe and effective option for VIN. In particular, combination therapy is recommended for patients with large, multifocal, high-grade lesions; repeated recurrence; and strong willingness to maintain vulvar configuration and function. Lasers Surg. Med. © 2019 Wiley Periodicals, Inc.

18.
Nat Commun ; 10(1): 5117, 2019 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-31712651

RESUMO

The integration of luminescence and chirality in easy-scalable metal-organic frameworks gives rise to the development of advanced luminescent sensors. To date, the synthesis of chiral metal-organic frameworks is poorly predictable and their chirality primarily originates from components that constitute the frameworks. By contrast, the introduction of chirality into the pores of metal-organic frameworks has not been explored to the best of our knowledge. Here, we demonstrate that chirality can be introduced into an anionic Zn-based metal-organic framework via simple cation exchange, yielding dual luminescent centers comprised of the ligand and Tb3+ ions, accompanied by a chiral center in the pores. This bifunctional material shows enantioselectivity luminescent sensing for a mixture of stereoisomers, demonstrated for Cinchonine and Cinchonidine epimers and amino alcohol enantiomers, from which the quantitative determination of the stereoisomeric excess has been obtained. This study paves a pathway for the design of multifunctional metal-organic framework systems as a useful method for rapid sensing of chiral molecules.

19.
BMC Genomics ; 20(1): 792, 2019 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-31666003

RESUMO

BACKGROUND: The mitogenomes of 12 teleost fish of the bothid family (order Pleuronectiformes) indicated that the genomic-scale rearrangements characterized in previous work. A novel mechanism of genomic rearrangement called the Dimer-Mitogenome and Non-Random Loss (DMNL) model was used to account for the rearrangement found in one of these bothids, Crossorhombus azureus. RESULTS: The 18,170 bp mitogenome of G. polyophthalmus contains 37 genes, two control regions (CRs), and the origin of replication of the L-strand (OL). This mitogenome is characterized by genomic-scale rearrangements: genes located on the L-strand are grouped in an 8-gene cluster (Q-A-C-Y-S1-ND6-E-P) that does not include tRNA-N; genes found on the H-strand are grouped together (F-12S … CytB-T) except for tRNA-D that was translocated inside the 8-gene L-strand cluster. Compared to non-rearranged mitogenomes of teleost fishes, gene organization in the mitogenome of G. polyophthalmus and in that of the other 12 bothids characterized thus far is very similar. These rearrangements could be sorted into four types (Type I, II, III and IV), differing in the particular combination of the CR, tRNA-D gene and 8-gene cluster and the shuffling of tRNA-V. The DMNL model was used to account for all but one gene rearrangement found in all 13 bothid mitogenomes. Translocation of tRNA-D most likely occurred after the DMNL process in 10 bothid mitogenomes and could have occurred either before or after DMNL in the three other species. During the DMNL process, the tRNA-N gene was retained rather than the expected tRNA-N' gene. tRNA-N appears to assist in or act as OL function when the OL secondary structure could not be formed from intergenic sequences. A striking finding was that each of the non-transcribed genes has degenerated to a shorter intergenic spacer during the DMNL process. These findings highlight a rare phenomenon in teleost fish. CONCLUSIONS: This result provides significant evidence to support the existence of dynamic dimeric mitogenomes and the DMNL model as the mechanism of gene rearrangement in bothid mitogenomes, which not only promotes the understanding of mitogenome structural diversity, but also sheds light on mechanisms of mitochondrial genome rearrangement and replication.

20.
Opt Express ; 27(20): 27797-27806, 2019 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-31684541

RESUMO

An actively Q-switched dual-wavelength intracavity Raman laser based on a coaxially pumped dual-crystal (Nd:YAG and b-cut Nd:YAP) fundamental configuration was theoretically and experimentally investigated. Stable dual-wavelength Stokes output at 1176 nm and 1195 nm was subsequently obtained by the Raman conversion from an a-cut YVO4 crystal. A total average power of 1.8 W was produced at 10 kHz pulse repetition frequency under an incident diode pump power of 15.8 W, in which the power levels at the two Stokes wavelengths were nearly equivalent. The power proportion and the interval between the dual-wavelength Stokes pulses could be manipulated actively by changing the pump focal position or pump wavelength.

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