ChatGPT对终身学习的影响和启示

ChatGPT作为一种创新的人工智能对话代理,给终身学习的格局带来了颠覆性的变化。通过提供个性化和多元化的GPT学习体验,促进跨文化和跨境交流,扩大学习资源的可访问性和便利性,ChatGPT正在塑造人们在数字时代学习和成长的方式。基于ChatGPT强大功能,旨在分析ChatGPT对终身学习的影响,并探讨ChatGPT如何影响个人学习行为的发展和终身学习范式的转变。

Data secure transmission intelligent prediction algorithm for mobile industrial IoT networks

Mobile Industrial Internet of Things(IIoT)applications have achieved the explosive growth in recent years.The mobile IIoT has flourished and become the backbone of the industry,laying a solid foundation for the interconnection of all things.The variety of application scenarios has brought serious challenges to mobile IIoT networks,which face complex and changeable communication environments.Ensuring data secure transmission is critical for mobile IIoT networks.This paper investigates the data secure transmission performance prediction of mobile IIoT networks.To cut down computational complexity,we propose a data secure transmission scheme employing Transmit Antenna Selection(TAS).The novel secrecy performance expressions are first derived.Then,to realize real-time secrecy analysis,we design an improved Convolutional Neural Network(CNN)model,and propose an intelligent data secure transmission performance prediction algorithm.For mobile signals,the important features may be removed by the pooling layers.This will lead to negative effects on the secrecy performance prediction.A novel nine-layer improved CNN model is designed.Out of the input and output layers,it removes the pooling layer and contains six convolution layers.Elman,Back-Propagation(BP)and LeNet methods are employed to compare with the proposed algorithm.Through simulation analysis,good prediction accuracy is achieved by the CNN algorithm.The prediction accuracy obtains a 59%increase.

C-JNK信号通路对糖尿病大鼠心肌Ito钾通道重构的影响

目的研究c-JNK信号通路在糖尿病(DM)大鼠左室心肌细胞电压门控钾通道(Kv)重构中的作用和内在调控机制。方法将50只健康SD大鼠随机分为DM组[n=25,采用链尿佐菌素(STZ)诱导成模]和对照组(sham)(n=25)。应用全细胞膜片钳方法记录DM组与sham组大鼠心室肌瞬时外向钾电流(Ito);使用非放射性JNK激酶分析kit进行c-Jun活性测定。应用JNK抑制剂SP600125(10M)对DM大鼠心肌细胞进行体外孵育,观察孵育前后心肌细胞Ito的变化。用硫氧还蛋白还原酶(TrxR)抑制剂金诺芬(AF)对经JNK抑制剂SP600125孵育的大鼠心肌细胞进行处理,观察处理前后心肌细胞Ito的变化。应用抗Kv4.2抗体对Kv4.2的含量进行检测,检测结果使用UVP生物成像系统进行分析。结果DM组心肌JNK活性显著升高超过1倍,而Ito显著降低[Sham组:(31.2±3.4)pA/pF,n=16;DM组:(15.4±3.1)pA/pF,n=17;P<0.05]。DM大鼠心室肌细胞经JNK抑制剂SP600125(10 M)处理4 h后,Ito电流密度可恢复至Sham组水平[DM+SP600125组:(31.9±3.8)pA/pF,n=18;Sham组:(31.2±3.4)pA/pF,n=16;P<0.05];且sham组经SP600125处理后的最大Ito电流强度[(29.8±3.4)pA/pF,n=9]和未经处理的sham组无统计学差异。DM心肌经膜渗透性蛋白抑制剂JNKI-1(10 M)处理后,Ito密度也有显著增加,而sham组经相同处理后无改变。TrxR抑制剂AF显著抑制了SP600125对DM大鼠心肌Ito电流的增大作用[DM+AF+SP600125:(15.5±3.2)pA/pF,n=17],而AF对sham组Ito无明显影响。JNK抑制剂SP600125治疗后DM大鼠心肌的Kv4.2蛋白表达量显著增大,尽管未完全恢复到sham组心肌水平,但与先前在DM大鼠心肌所观察到的Ito电流改变一致。而JNK抑制并没有明显改变sham组心肌的Kv4.2蛋白表达量。结论DM大鼠心肌钾通道重构是氧化还原敏感的,可能通过持续性激活c-JNK信号通路促进Ito重构。在DM心肌中,JNK活性显著增高,Kv通道的电流密度降低;抑制JNK信号通路后可显著改善Kv通道重构,这一过程可能被硫氧还原蛋白系统所调控。

Preoperative predictors of short-term survival after hepatectomy for multinodular hepatocellular carcinoma

AIM:To investigate preoperative factors associated with poor short-term outcome after resection for multinodular hepatocellular carcinoma(HCC) and to assess the contraindication of patients for surgery.METHODS:We retrospectively analyzed 162 multinodular HCC patients with Child-Pugh A liver function who underwent surgical resection.The prognostic significance of preoperative factors was investigated by univariate analysis using the log-rank test and by multivariate analysis using the Cox proportional hazards model.Each independent risk factor was then assigned points to construct a scoring model to evaluate the indication for surgical intervention.A receiver operating characteristics(ROC) curve was constructed to assess the predictive ability of this system.RESULTS:The median overall survival was 38.3 mo(range:3-80 mo),while the median disease-free survival was 18.6 mo(range:1-79 mo).The 1-year mortality was 14%.Independent prognostic risk factors of 1-year death included prealbumin < 170 mg/L [hazard ratio(HR):5.531,P < 0.001],alkaline phosphatase > 129 U/L(HR:3.252,P = 0.005),fetoprotein > 20 g/L(HR:7.477,P = 0.011),total tumor size > 8 cm(HR:10.543;P < 0.001),platelet count < 100 × 109/L(HR:9.937,P < 0.001),and-glutamyl transpeptidase > 64 U/L(HR:3.791,P < 0.001).The scoring model had a strong ability to predict 1-year survival(area under ROC:0.925,P < 0.001).Patients with a score ≥ 5 had significantly poorer short-term outcome than those with a score < 5(1-year mortality:62% vs 5%,P < 0.001;1-year recurrence rate:86% vs 33%,P < 0.001).Patients with score ≥ 5 had greater possibility of microvascular invasion(P < 0.001),poor tumor differentiation(P = 0.003),liver cirrhosis with small nodules(P < 0.001),and intraoperative blood transfusion(P = 0.010).CONCLUSION:A composite preoperative scoring model can be used as an indication of prognosis of HCC patients after surgical resection.Resection should be considered with caution in patients with a score ≥ 5,which indicates a contraindication for surgery.

Lentivirus carrying the Atoh1 gene infects normal rat cochlea

Lentivirus carrying the Atohl gene can infect Corti＇s organ and express a hair-like cell surface marker in the supporting cell area. However, expression of the gene carried by adenovirus is instantaneous, which undoubtedly limits its clinical application. Lentivirus acts as a carrier that can stably and continuously express genes. In this study, the cochlear structure and hearing level were not affected, and Atohl gene carried by lentivirus promoted the production of hair-like cells in the cochlear supporting cell area. This led to expression of the hair-like cell surface marker myosin 7a 30 days after lentivirus carrying Atohl was microinjected into the cochlear round window of rats.

Re–Os geochronology of the Cambrian stage-2 and-3 boundary in Zhijin County, Guizhou Province, China

The black shale series that formed in the Ediacaran–Cambrian transition are important stratigraphic records of the co-evolution of the paleo-ocean,-climate,and-biology. In this study, we measured Re–Os isotopic compositions of the black shale in the Niutitang Formation from the Gezhongwu section in Zhijin, Guizhou Province.The samples had high Re and Os contents, with Re ranging from 21.27 to 312.78 ng/g and Os ranging from 0.455 to7.789 ng/g. The Re–Os isotope isochron age of 522.9 ± 8.6 Ma implies deposition of the Niutitang black shale predated the Chengjiang Fauna, providing an age constraint for the expansion of oceanic anoxia in the study area. The initial ^(187)Os/^(188)Os ratio of 0.826 ± 0.026 indicates that enhanced continental weathering might have triggered the exansion of the oceanic anoxia.

Gene transfer into primary cultures of fetal neural stem cells by a recombinant adenovirus carrying the gene for green fluorescent protein

Objective: To evaluate the transduction efficiency of a recombinant adenovirus carrying the gene for green fluorescent protein (Ad-GFP) into the primary cultures of fetal neural stem cells (NSCs) by the expression of GFP. Methods: The Ad-GFP was constructed by homologous recombination in bacteria with the AdEasy system; NSCs were isolated from rat fetal hippocampus and cultured as neurosphere suspensions. After infection with the recombinant Ad-GFP, NSCs were examined with a fluorescent microscopy and a flow cytometry for their expression of GFP. Results: After the viral infection, flow cytometry analysis revealed that the percentage of GFP-positive cells was as high as 97.05%. The infected NSCs sustained the GFP expression for above 4 weeks. After differentiated into astrocytes or neurons, they continued to express GFP efficiently. Conclusion: We have success- fully constructed a viral vector Ad-GFP that can efficiently infect the primary NSCs. The reporter gene was showed fully and sustained expression in the infected cells as well as their differentiated progenies.

Novel m.4268T>C mutation in the mitochondrial tRNA^(Ile) gene is associated with hearing loss in two Chinese families

BACKGROUND Herein,we report the genetic,clinical,molecular and biochemical features of two Han Chinese pedigrees with suggested maternally transmitted non-syndromic hearing loss.AIM To investigate the pathophysiology of hearing loss associated with mitochondrial tRNA mutations.METHODS Sixteen subjects from two Chinese families with hearing loss underwent clinical,genetic,molecular,and biochemical evaluations.Biochemical characterizations included the measurements of tRNA levels using lymphoblastoid cell lines derived from five affected matrilineal relatives of these families and three control subjects.RESULTS Three of the 16 matrilineal relatives in these families exhibited a variable seriousness and age-at-onset(8 years)of deafness.Analysis of mtDNA mutation identified the novel homoplasmic tRNA^(Ile) 4268T>C mutation in two families both belonging to haplogroup D4j.The 4268T>C mutation is located in a highly conserved base pairing(6U–67A)of tRNA^(Ile).The elimination of 6U–67A basepairing may change the tRNA^(Ile) metabolism.Functional mutation was supported by an approximately 64.6%reduction in the level of tRNA^(Ile) observed in the lymphoblastoid cell lines with the 4268T>C mutation,in contrast to the wild-type cell lines.The reduced level of tRNA was below the proposed threshold for normal respiration in lymphoblastoid cells.However,genotyping analysis did not detect any mutations in the prominent deafness-causing gene GJB2 in any members of the family.CONCLUSION These data show that the novel tRNA^(Ile) 4268T>C mutation was involved in maternally transmitted deafness.However,epigenetic,other genetic,or environmental factors may be attributed to the phenotypic variability.These findings will be useful for understanding families with maternally inherited deafness.

MICROW AVE-INDUCED THERMOA COUSTIC IMAGING FOR EARLY BREAST CA NCER DETECTION

Microwave induced thermoacoustic tomography(TAT)is a noninvasive,nonionizing modality based on the inherent differences in microwave absorpt ion of malignant breast tissues and normal adipose dominated breast tissues.In this paper,a TAT system based on multielement acquisition system was built to receive signals.Slices from different layers in the sample were composed into a three-dimensional(3D)volume.Based on the 3D volume,inherent differences in microw ave absorption bet ween different biological tisues can be converted into structure information.Our experimental results of some minicked and human tumors indicate that TAT may potentially be used to detect early-stage breast cancers with high contrast.

Attenuated plasmodium sporozoite expressing MAGE-A3 induces antigen-specific CD8+ T cell response against lung cancer in mice

Objective: Cancer vaccines that rely on tumor antigen-specific CD8^+ T cell responses, are promising anti-cancer adjuvant immunotherapies. This study investigated whether genetically attenuated Plasmodium sporozoite(GAS) could be used as a novel vector to induce antigen-specific CD8^+ T cell responses against lung cancer.Methods: We constructed GAS/MAGE-A3, a recombinant GAS engineered to express the lung cancer-specific antigen, melanomaassociated antigen 3(MAGE-A3), and assessed its therapeutic effects against lung cancer.Results: Robust parasite-specific CD8αlow CD11ahigh and CD49dhigh CD11ahigh CD4^+ T cell responses as well as a MAGE-A3-specific CD8^+ T cell response were induced in GAS/MAGE-A3-immunized mice. Adoptive transfer of GAS/MAGE-A3-induced CD8^+ T cells from HLA-A2 transgenic mice into lung cancer-bearing nude mice inhibited tumor growth and prolonged survival.Conclusions: These findings demonstrate that GAS/MAGE-A3 induces a strong MAGE-A3-specific CD8^+ T cell response against lung cancer in vivo, and indicate that GAS is a novel and efficacious antigen delivery vector for antitumor immunotherapy.

Extranasopharyngeal angiofibroma in children:A case report

BACKGROUND Sporadic cases of extranasopharyngeal angiofibroma in children,especially preschool children,have been reported in the literature.CASE SUMMARY We present a case of extranasopharyngeal angiofibroma in a 4-year-old boy.The presenting symptoms,imaging findings,treatment,histological appearance,and follow-up data are described in detail.For this patient,we performed embolization on two occasions,and then,resected the tumor completely.During the treatment,the patient developed a soft-palate perforation due to aseptic necrosis.However,the healing ability was good,and the perforation healed spontaneously.We additionally reviewed all pediatric cases of extranasopharyngeal angiofibroma published up to 30 June 2020 in the PubMed,Baidu Scholar,Scopus,and Web of Science databases.We identified 45 pediatric patients[average(10.98±4.86),boys 39(86.7%)].The highest proportion of cases occurred in adolescence[22(48.9%)].The top three sites of occurrence of extranasopharyngeal angiofibroma in children were the maxillary sinus,nasal septum,and inferior turbinate.CONCLUSION Extranasopharyngeal angiofibromas can occur throughout childhood,and predominantly present with nasal obstruction and spontaneous rhinorrhagia.

Petrogenesis and Economic Potential of the Sangong MaficUltramafic Intrusion in the Eastern Tianshan, Central Asian Orogenic Belt: Constraints from Mineral, Whole-Rock, and PGE Geochemistry

The Sangong Cu-Ni sulfide mineralized mafic-ultramafic intrusion is located on the southern margin of the Bogeda-Harlik belt,eastern Tianshan,China.The intrusion is a well-differentiated complex and is comprised of leucogabbro,gabbro,olivine gabbro,Pl-bearing peridotite,and Pl-bearing pyroxenite.The Pl-bearing pyroxenite hosts both irregularly disseminated sulfide and round droplet sulfide.The intrusive rocks have a wide range of SiO_(2)(42.1 wt.%-50.48 wt.%)and MgO(6.21 wt.%-22.11 wt.%),and are enriched in light rare earth elements(LREE),large-ion lithophile elements(LILE;e.g.,Rb,Ba,Sr,and Pb),and palladium platinum group elements(PPGE)but depleted in high-field-strength elements(HFSE;e.g.,Nb,Ta,and Ti)and iridium PGEs(IPGE).These geochemical characteristics indicate that the Sangong mafic-ultramafic intrusion was derived from high degree of partial melting of depleted mantle and interacted with subduction-related material.The low Pd/Ir(3.21-27.44)but high Ni/Cu(1.64-24.16)ratios,combined with the olivine crystals with low Fo(60.88-78.65)and Ni(54.99 ppm-1688.87 ppm)concentrations suggest that the parental magma of the Sangong intrusion were likely high MgO basaltic in composition that experienced extensive evolution prior emplacement.The Ce/Pb ratios(5.8-13.6)and Nb/U ratios(11.6-30.3)of the intrusive rocks all range between MORB and crustal values,the Nb/Yb and Th/Yb values are close to the lower crust values,together with the low Se/S ratios[(17-100)×10^(-6))]suggest that the magma experienced assimilation not only in mantle source but also in conduit,but the degree of crustal contamination is limited.The Cu/Pd ratios of the rocks range from 3.9×10^(4) to 10.8×10^(4),and the Cu/Zr ratios of Pl-bearing pyroxenite in the Sangong intrusion are>1,combined with the presence of sulfide droplets in the Pl-bearing pyroxenite,indicating the parental magma experienced sulfide saturation and the economical ore bodies may present in the depth of the intrusion.Furthermore,given the discovery of the Baixintan and Yueyawan deposits,we propose the DananhuHarlik belt as an essential prospecting target for Cu-Ni mineralization in North Xinjiang.

A novel multi-state bogie system reliability evaluation approach by extended d-MC model for high-speed trains

Bogie is a pivotal system and plays a critical part in the safety and reliability management of high-speed rail.However,the available bogie system reliability analysis methods lack the consideration of multi-state characteristics,and the common multi-state reliability analysis methods,being an NP-hard problem,lead to low efficiency.In order to overcome these drawbacks,this paper proposes a novel multi-state rail train bogie system reliability analysis approach based on the extended d-MC model.Three different function interactions within the bogie system are considered to build the multi-state bogie system flow network model.Meanwhile,an extended d-MC model is established to remove unnecessary d-MC candidates and duplicates,which greatly enhances the computing efficiency.The bogie system reliability is calculated,and examples are provided.Numerical experiments are carried out for the different operational conditions of the bogie system and are used to test the practicability of the method proposed in this article;it is found that this method outperforms a newly developed method in solving multi-state reliability problems.

AIFM1 variants associated with auditory neuropathy spectrum disorder cause apoptosis due to impaired apoptosis-inducing factor dimerization

Auditory neuropathy spectrum disorder(ANSD)represents a variety of sensorineural deafness conditions characterized by abnormal inner hair cells and/or auditory nerve function,but with the preservation of outer hair cell function.ANSD represents up to 15%of individuals with hearing impairments.Through mutation screening,bioinformatic analysis and expression studies,we have previously identified several apoptosis-inducing factor(AIF)mitochondria-associated 1(AIFM1)variants in ANSD families and in some other sporadic cases.Here,to elucidate the pathogenic mechanisms underlying each AIFM1 variant,we generated AIF-null cells using the clustered regularly interspersed short palindromic repeats(CRISPR)/CRISPR-associated protein 9(Cas9)system and constructed AIF-wild type(WT)and AIF-mutant(mut)(p.T260A,p.R422W,and p.R451Q)stable transfection cell lines.We then analyzed AIF structure,coenzyme-binding affinity,apoptosis,and other aspects.Results revealed that these variants resulted in impaired dimerization,compromising AIF function.The reduction reaction of AIF variants had proceeded slower than that of AIF-WT.The average levels of AIF dimerization in AIF variant cells were only 34.5%-49.7%of that of AIF-WT cells,resulting in caspase-independent apoptosis.The average percentage of apoptotic cells in the variants was 12.3%-17.9%,which was significantly higher than that(6.9%-7.4%)in controls.However,nicotinamide adenine dinucleotide(NADH)treatment promoted the reduction of apoptosis by rescuing AIF dimerization in AIF variant cells.Our findings show that the impairment of AIF dimerization by AIFM1 variants causes apoptosis contributing to ANSD,and introduce NADH as a potential drug for ANSD treatment.Our results help elucidate the mechanisms of ANSD and may lead to the provision of novel therapies.

Observation of Refractive Index Line Shape in Ultrafast XUV Transient Absorption Spectroscopy

Ultrafast extreme ultraviolet (XUV) transient absorption spectroscopy measures the time- and frequencydependent light losses after light–matter interactions. In the linear region, the matter response to an XUV light field is usually determined by the complex refractive index ̃n. The absorption signal is directly related to the imaginary part of ̃n, namely, the absorption index. The real part of ̃n refers to the real refractive index, which describes the chromatic dispersion of an optical material. However, the real refractive index information is usually not available in conventional absorption experiments. Here, we investigate the refractive index line shape in ultrafast XUV transient absorption spectroscopy by using a scheme that the XUV pulse traverses the target gas jet off-center. The jet has a density gradient in the direction perpendicular to the gas injection direction, which induces deflection on the XUV radiation. Our experimental and theoretical results show that the shape of the frequency-dependent XUV deflection spectra reproduces the refractive index line profile. A typical dispersive refractive index line shape is measured for a single-peak absorption;an additional shoulder structure appears for a doublet absorption.Moreover, the refractive index line shape is controlled by introducing a later-arrived near-infrared pulse to modify the phase of the XUV free induction decay, resulting in different XUV deflection spectra. The results promote our understanding of matter-induced absorption and deflection in ultrafast XUV spectroscopy.

GDF15 negatively regulates chemosensitivity via TGFBR2-AKT pathway-dependent metabolism in esophageal squamous cell carcinoma

Treating patients with esophageal squamous cell carcinoma(ESCC)is challenging due to the high chemoresistance.Growth differentiation factor 15(GDF15)is crucial in the development of various types of tumors and negatively related to the prognosis of ESCC patients according to our previous research.In this study,the link between GDF15 and chemotherapy resistance in ESCC was further explored.The relationship between GDF15 and the chemotherapy response was investigated through in vitro and in vivo studies.ESCC patients with high levels of GDF15 expression showed an inferior chemotherapeutic response.GDF15 improved the tolerance of ESCC cell lines to low-dose cisplatin by regulating AKT phosphorylation via TGFBR2.Through an in vivo study,we further validated that the anti-GDF15 antibody improved the tumor inhibition effect of cisplatin.Metabolomics showed that GDF15 could alter cellular metabolism and enhance the expression of UGT1A.AKT and TGFBR2 inhibition resulted in the reversal of the GDF15-induced expression of UGT1A,indicating that TGFBR2-AKT pathway-dependent metabolic pathways were involved in the resistance of ESCC cells to cisplatin.The present investigation suggests that a high level of GDF15 expression leads to ESCC chemoresistance and that GDF15 can be targeted during chemotherapy,resulting in beneficial therapeutic outcomes.

Multi-component system maintenance optimization of a rail transit train based on opportunistic correlations

ln order to deal with the problems of insufficient or excessive maintenance in the current maintenance activities of China transit trains,this paper develops a novel multi-component system maintenance optimization approach based on an opportunistic correlation model.Based on the minimal reliability and failure rate change rule of each train component,the novel proposed maintenance optimization benefits from an improved opportunistic maintenance model with system structure correlation,fault correlation and reliability correlation under imperfect maintenance.Then,different maintenance modes can be determined by a proposed mainte-nance factor under the different conditions of components.Specifically,the reliability threshold of each component is also considered to optimize the maintenance cost by the system reliability and operational availability of the train.Furthermore,as the mentioned problem belongs to the NP-Hard optimization problems,a modified particle swarm optimization(PSO)with the improvement of inertia weight is proposed to cope with the optimization problem.Based on a specific case under the practical recorded failure data,the analysis shows that the proposed model and approach can effectively cut the maintenance cost.

Modification of laser-induced state in atomic attosecond transient absorption by the XUV pulse pair

Attosecond transient absorption(ATA)has been developed as an all-optical technique for probing electron dynamics in matter.Here we present a scheme that can modify the laserinduced state and the corresponding ATA spectrum via excitation by a pair of XUV attosecond pulses and by a time-delayed mid-infrared(MIR)laser probe.Different from the scheme of the electronic excitation by a single XUV attosecond pulse,the application of a pair of XUV pulses provides extra degrees of freedom,such as the time delay and the intensity ratio between two XUV pulses,which make it possible to adjust the pump process,resulting in the modification of the ATA spectrum.We show that by varying the time delay between the two XUV pulses,the population of the dark state and the ATA spectrum of the laser-induced state have periodic modulations.We also demonstrate that the peak of the ATA spectrum of the laser-induced state appears at a fixed time delay between the XUV pair and the MIR laser when the intensity ratio is large,and it changes with the time delay when the intensity ratio is small,which can be related to either one of two peaks in the population of the dark state.

Significance of the auditory meatus inferior wall cartilage in the surgical treatment of congenital first branchial cleft anomalies in children

Objective To investigate the clinical significance of the inferior wall cartilage of the auditory meatus in surgical treatment of congenital first branchial cleft anomalies(CFBCAs)in children.Methods Twenty children diagnosed with CFBCAs who underwent surgery between December 2018 and June 2022 at our hospital were retrospectively analyzed and classified according to their Work lesion type.The guiding significance of the inferior wall cartilage in the surgical treatment of CFBCAs was summarized by investigating the adjacent relationships of the surgical lesions with the external auditory canal and facial nerve.Results Of the 20 patients,16 were classified as Work type Ⅰ and 4 as Work type Ⅱ.The lesions were adjacent to the inferior wall cartilage of the auditory meatus in all children.Work type Ⅰ lesions were located in the upper lateral aspect and were not adjacent to the facial nerve.Work type Ⅱ lesions were located in the inferior-medial region of the facial nerve.The lesions were completely resected in all children.One patient experienced recurrence 3 months postoperatively because of a residual endochondral fistula.No patients developed facial paralysis or other complications.Conclusions The inferior wall cartilage of the auditory meatus may help to the identify the initial lesion of the CFBCAs and can be regarded as a guiding anatomical structure.These lesions can be completely resected.For resection of Work type II first branchial cleft lesions,the surgical incision can be narrower,and can be precisely positioned with the assistance of endoscope.

New Re-Os Isotopic Constrains on the Formation of the Metalliferous Deposits of the Lower Cambrian Niutitang Formation

The Terreneuvian Epoch（541-521 Ma）is also an important period for metallogenesis in South China, as was represented by the widespread occurrences of Ni-Mo polymetallic layers on the antecedent shallow platform margin and the V-enriched black shales in deeper slope-basin settings. In this study, we have measured Re-Os isochron ages of Ni-Mo polymetallic layers（Songlin, Niuchang, Sancha, Chuanpengwan）, V-rich black shales（Bahuang）, and non-metalliferous black shales（Shuidong） in the basal Niutitang Formation in Guizhou and Hunan province, South China. The Ni-Mo polymetallic layers and V-enriched black shales have similar Re-Os isochron ages, suggesting concurrent deposition of these two types of metalliferous ores. This suggestion is consistent with the traditional stratigraphic correlation by using the nodular phosphorite bed directly underlying these metalliferous layers as a stratigraphic marker. Furthermore, the metalliferous ores and non-metalliferous black shales have similar initial ^（187）Os/^（188） Os ratios of 0.8-0.9, arguing for a dominant seawater origin with minor contribution of hydrothermal activity. Furthermore, Re-Os isotopic data also imply that Ni-Mo and V ore might have derived from the same source. We suggest that the spatial distribution of metalliferous ores can be explained by the development of non-sulfidic anoxic-suboxic wedge（NSASW） in the slope-basin and sulfidic wedge in the previous platform margin. Upwelling of deep water first transects the mildly reduced, organic rich NSASW, in which V（V） is reduced to V（IV）, and is preferentially removed from seawater by organometallic complex formation. As a result, V-rich black shale deposits in the slope-basin of Yangtze Platform. Further movement of deep water into the sulfidic platform margin results in Ni-Mo polymetallic layer formation.