Exploring the topographical pattern beneath the water surface: Global bathymetric volume-area-height curves(BVAH) of inland surface water bodies

Global inland surface water bodies such as lakes and reservoirs,important components of the hydrosphere and ecosphere,are increasingly affected by climate change.Generating bathymetric volume-areaheight (BVAH) curves for global inland surface water bodies can enhance our understanding of their topography and climate impacts.However,accurately quantifying the topographic patterns of these water bodies remains challenging due to the difficulties in collecting comprehensive bathymetric data.Therefore,we collected and processed over 2000 bathymetric maps of global water bodies from over 50 different data sources and then developed the BVAH model.Finally,the BVAH hydrological curves of 16671 global inland surface water bodies (larger than 10 km~2) were generated.The results include but are not limited to (1) For most targeted water bodies,area (A) and volume (V) exhibit significant power function relationships with surface heights (H),with optimal power values quantified as 1.42 for A and 2.42 for V.(2) The BVAH model outperforms GLOBathy in estimating area and volume changes,achieving higher correlation coefficients (CC) of approximately 0.962 for the area and 0.991 for volume,and demonstrating lower percentages of root mean squared errors (PRMSE) around 10.9% for the area and 4.8% for volume.(3) In the case study of the Xizang Plateau and various large global reservoirs,the BVAH curve database can capture dynamic volume changes.As a unified simulation of the bathymetric topographical patterns,our bathymetric dataset and corresponding BVAH curve database have great potential to contribute to effective water resource management and ecological conservation efforts worldwide.

Prevalence and associated risk factors of Helicobacter pylori infection in community households in Lanzhou city

BACKGROUND Helicobacter pylori(H.pylori)infection exhibits a familial clustering phenomenon.AIM To investigate the prevalence of H.pylori infection,identify associated factors,and analyze patterns of transmission within families residing in the community.METHODS From July 2021 to September 2021,a total of 191 families(519 people)in two randomly chosen community health service centers in the Chengguan District of Lanzhou in Gansu Province,were recruited to fill out questionnaires and tested for H.pylori infection.Individuals were followed up again from April 2023 and June 2023 to test for H.pylori infection.The relationship between variables and H.pylori infection was analyzed using logistic regression and generalized linear mixed models.RESULTS In 2021,the individual-based H.pylori infection rate was found to be 47.0%(244/519),which decreased to 38.1%(177/464)in 2023.Additionally,the rate of individual-based H.pylori new infection was 22.8%(55/241).The family-based H.pylori infection rate in 2021 was 76.9%(147/191),which decreased to 67.1%(116/173)in 2023,and the rate of family-based H.pylori new infection was 38.6%(17/44).Individual H.pylori infection was positively correlated with age,body mass index(BMI),eating food that was excessively hot,frequent acid reflux,bloating,and halitosis symptoms,and negatively correlated with family size and nut consumption.New individual H.pylori infection was positively correlated with BMI,other types of family structures,drinking purified water,and frequent heartburn symptoms,while negatively correlated with the use of refrigerators and following a regular eating schedule.A larger living area was an independent protective factor for H.pylori infection in households.Frequently consuming excessively hot food and symptoms of halitosis were independent risk factors for H.pylori infection in individuals;frequent consumption of nuts was an independent protective factor for H.pylori infection.Other types of family structure,drinking purified water,and frequent heartburn symptoms were independent risk factors for new individual H.pylori infection;the use of a refrigerator was an independent protective factor for new H.pylori infections.CONCLUSION The household H.pylori infection rate in Lanzhou is relatively high and linked to socio-demographic factors and lifestyles.Eradication efforts and control of related risk factors are recommended in the general population.

放射肿瘤学临床实习教学的研究与探讨

近年来，恶性肿瘤逐渐成为危害人类健康的主要杀手。目前，恶性肿瘤治疗已经进入综合治疗时代，据统计在全部恶性肿瘤中，45％的患者可以被治愈，其中22％经手术治愈，18％经放射治疗治愈，5％经化疗治愈。而且，约70％的肿瘤病人需要接受不同程度的放射治疗，以治愈肿瘤、缓解症状或改善生活质量。因此，放射治疗作为基本治疗手段之一，在恶性肿瘤治疗中的地位越来越重要。

Expression and significance of Musashi-1 in gastric cancer and precancerous lesions

AIM:To investigate expression of stem cell marker Musashi-1(Msi-1)in relationship to tumorigenesis and progression of intestinal-type gastric cancer(GC).METHODS:Endoscopic biopsy specimens and surgical specimens were obtained,including 54 cases of intestinal-type GC,41 high-grade intraepithelial neoplasia,57low-grade intraepithelial neoplasia,31 intestinal metaplasia,and 36 normal gastric mucosa.Specimens were fixed in 10%paraformaldehyde,conventionally dehydrated,embedded in paraffin,and sliced in 4-μm-thick serial sections.Two-step immunohistochemical staining was used to detect Msi-1 and proliferating cell nuclear antigen(PCNA)expression.Correlation analysis was conducted between Msi-1 and PCNA expression.The relationship between Msi-1 expression and clinicopathological parameters of GC was analyzed statistically.RESULTS:There were significant differences in Msi-1and PCNA expression in different pathological tissues(χ2=15.37,P<0.01;χ2=115.36,P<0.01).Msi-1and PCNA-positive cells were restricted to the isthmus of normal gastric glands.Expression levels of Msi-1and PCNA in intestinal metaplasia were significantly higher than in normal mucosa(U=392.0,P<0.05;U=40.50,P<0.01),whereas there was no significant difference compared to low or high-grade intraepithelial neoplasia.Msi-1 and PCNA expression in intestinaltype GC was higher than in high-grade intraepithelial neoplasia(U=798.0,P<0.05;U=688.0,P<0.01).There was a significantly positive correlation between Msi-1 and PCNA expression(rs=0.20,P<0.01).Msi-1expression in GC tissues was correlated with their lymph node metastasis and tumor node metastasis stage(χ2=12.62,P<0.01;χ2=11.24,P<0.05),but not with depth of invasion and the presence of distant metastasis.CONCLUSION:Msi-1-positive cells may play a key role in the early events of gastric carcinogenesis and may be involved in invasion and metastasis of GC.

Propofol vs midazolam plus fentanyl for upper gastrointestinal endomicroscopy:A randomized trial

AIM:To compare the endomicroscopic image quality of integrated confocal laser endomicroscopy(iCLE)and sedation efficacy of propofolvs midazolam plus fentanyl(M/F).METHODS:Consecutive outpatients undergoing iCLE were prospectively recruited and randomized to the propofol group(P group)or M/F group.The patient,performing endoscopist and endoscopic assistant were blinded to the randomization.The quality of endomicro-scopic images and anesthetic efficacy outcomes were blindly evaluated after iCLE examination.RESULTS:There were significantly more good quality endomicroscopic images in the propofol group than in the M/F group(72.75%vs 52.89%,P<0.001).The diagnostic accuracy for upper gastrointestinal mucosal lesions using confocal laser endomicroscopy favors the P group,although this did not reach statistical significance.Adverse events and patient assessment were not significantly different for M/F vs propofol except for more frequent intraprocedural recall with M/F.Procedure duration and sedation times were significantly longer in the M/F group,while the scores of endoscopist,anesthetist and assistant assessment were all significantly better in the P group.CONCLUSION:Sedation with propofol might increase the proportion of good quality endomicroscopic images,and may result in improved procedural efficacy and diagnostic accuracy during iCLE examination.

Diagnosing Helicobacter pylori infection in vivo by novel endoscopic techniques

Infection with Helicobacter pylori(H.pylori)is a worldwide problem.Endoscopic observation of H.pylori infection in vivo would be helpful to obtain an immediate diagnosis.The aim of this review is to describe recent advances in endoscopic technology and to review the available literature pertaining to its clinical application in H.pylori infection.Endoscopic visualization of H.pylori infection is not always feasible using conventional endoscopy.Thus,advanced endoscopic techniques have been developed with the aim of providing a precise and‘‘real-time’’endoscopic diagnosis.Recently,new endoscopic techniques such as magnifying endoscopy,narrow band imaging,I-Scan,endocytoscopy and endomicroscopy help focus examination of the stomach to diagnose disease in a time-efficient manner,and the analysis of mucosal surface details is beginning to resemble histologic examination.The new detailed images have enabled endoscopists to observe microscopic structures,such as gastric pit patterns,microvessels and cell morphology.Accordingly,endoscopic prediction of H.pylori infection is possible by analysis of surface architecture of the mucosa,which influences the clinical management.These endoscopic techniques might lead us to easier diagnosis and treatment of H.pylorirelated diseases.

Magnified and enhanced computed virtual chromoendoscopy in gastric neoplasia: A feasibility study

AIM: To evaluate the feasibility of a new computed virtual chromoendoscopy (CVC) device (M i-scan) in the diagnosis of gastric neoplasia. METHODS: Patients with superficial lesions no larger than 1.0 cm found during high definition endoscopy were included. Those with advanced or obviously protruded or depressed lesions, lesions larger than 1.0 cm and/or lesions which were not amenable to observation by zoom function were excluded. The endoscopist was required to give the real-time descriptions of surface pit patterns of the lesions, based on surface pattern classification of enhanced magnification endoscopy. According to previous reports, types Ⅰ-Ⅲ represent nonneoplastic lesions, and types Ⅳ-Ⅴ represent neoplastic lesions. Diagnosis with M i-scan and biopsy was performed before histopathological diagnosis. Magnified images of gastric lesions with and without enhancement were collected for further analysis. The diagnostic yield of real-time M i-scan and effects on magnification image quality by tone enhancement (TE), surface enhancement (SE) and color enhancement (CE) were calculated. The selected images were sent to another endoscopist. The endoscopist rated the image quality of each lesion at 3 levels. Ratings of image quality were based on visualization of pit pattern, vessel and demarcation line. RESULTS: One hundred and eighty-three patients were recruited. Five patients were excluded for advanced gastric lesions, 1 patient was excluded for poor preparation and 2 patients were excluded for superficial lesions larger than 1.0 cm; 132 patients were excluded for no lesions found by high definition endoscopy. In the end, 43 patients with 43 lesions were included. Histopathology revealed 10 inflammation, 14 atrophy, 10 metaplasia, 1 low grade dysplasia (LGD), 5 high grade dysplasia (HGD) and 3 cancers. For 7 lesions classified into type Ⅰ, histopathology revealed 6 atrophy and 1 metaplasia; for 10 lesions classified into type Ⅱ, histopathology revealed 2 inflammation, 7 atrophy and 1 metaplasia; for 10 lesions classified into type Ⅲ, histopathology revealed 1 inflammation, 8 metaplasia and 1 LGD; for 9 lesions classified into type Ⅳ, histopathology revealed 4 inflammation, 1 atrophy and 4 HGD; for 7 lesions classified into type Ⅴ, histopathology revealed 3 inflammation, 1 HGD and 3 cancers. A total of 172 still images, including 43 images by white light (MWL) and 129 images by M i-scan (43 with TE, 43 with SE and 43 with CE), were selected and sent to the endoscopist who did the analysis. General image quality of M i-scan with TE and SE was significantly better than that of MWL (TE, 4.55 ± 1.07; SE, 4.30 ± 1.02; MWL, 3.25 ± 0.99; P < 0.001). Visualization of pit pattern was significantly improved by M i-scan with SE (1.93 ± 0.25 vs 1.50 ± 0.50, P < 0.001). Microvessel visualization was significantly improved by M i-scan with TE (1.23 ± 0.78 vs 0.76 ± 0.73, P < 0.001). Demarcation line visualization was improved by M i-scan with both TE and SE (TE, 1.75 ± 0.52; SE, 1.56 ± 0.59; MWL, 0.98 ± 0.44; P < 0.001). M i-scan with CE did not show any significant improvements of image quality in general or in the 3 key parameters. Although M i-scan with TE and SE slightly increased the diagnostic yield of MWL, there was no significant difference (P > 0.1). CONCLUSION: Although digital enhancement improves the image quality of magnification endoscopy, its value in improving the diagnostic yield seems to be limited.

Endoscopic papillary large balloon dilation with or without sphincterotomy for large bile duct stones removal:Short-term and long-tem outcomes

To the Editor:Simplifying the endoscopic procedures and reducing the procedure time are necessary,while guaranteeing that the stone retrieval efficacy is an important prerequisite for minimizing the risk of complications after endoscopic retrograde cholangiopancreatography(ERCP).Compared with endoscopic sphincterotomy(EST),which can effectively extract common bile duct stones,endoscopic papillary balloon dilatation(EPBD)causes less bleeding and perforation and preserves the function of sphincter of Oddi[1,2].However,in comparison with EST,EPBD is related to a higher risk of pancreatitis[2,3].Retrieving large bile duct stones(≥10 mm)using the conventional techniques EST and EPBD is difficult.The use of EST combined with endoscopic papillary large balloon dilation(EPLBD)for bile duct stone removal was first introduced by Ersoz et al.[4],and this innovation has become useful in patients with large or difficult stones.In addition,removing the bile duct stones should be considered urgent.Especially,EPLBD procedure is appropriate for patients with unfavorable anatomy for EST,such as those who underwent Roux-en-Y or Billroth II gastrectomy[5].

A Novel Magnetic Carbon Based Catalyst Synthesized from Reed Straw and Electric Furnace Dust for Biodiesel Production

In the era of serious greenhouse gas emission and energy shortage,it is necessary to use solid waste to prepare new renewable materials.In this work,the potential application of reed straw and electric furnace dust was explored.Firstly,magnetic carbon carrier(EFD&C)was prepared by high temperature calcination,and then magnetic carbon catalyst(SM@EFD&C)was prepared by activation of sodium methoxide.The catalyst was used to prepare biodiesel by transesterification reaction to test its activity and stability.Reed biochar,EFD&C and SM@EFD&C were detected by Diffraction of X-rays(XRD),Fourier transform infrared(FT-IR),Inductively coupled plasma(ICP),Scanning electron microscope(SEM),Transmission electron microscope(TEM),Brunauer-Emmett-Teller(BET),Vibrating sample magnetometer(VSM),Temperature programmed desorption of CO_(2)(CO_(2)-TPD)and Thermogravimetric analysis(TG-DTG).The results showed that SM@EFD&C catalyst had some characteristics including porous structure,easy adsorption and better magnetism.Under the reaction conditions of 65℃for 2 h with 6 wt%catalyst and methanol/oil molar ratio of 15:1,the biodiesel yields from reed biochar and EFD&C were only 4.88 wt%and 0.03 wt%,respectively,while the yield from SM@EFD&C catalyst reached 93.14 wt%(89.84 wt%after 7 cycles)under the same conditions,which proved that it had good catalytic activity and stability when used in biodiesel production.This study is of great significance of carbon dioxide emission reduction and environmental protection.

TAM receptors:two pathways to regulate adult neurogenesis

Introduction of neurogenesis： Neurogenesis is a process charac- terized by the production and differentiation of new neurons from neural stem cells （Emsley et al., 2005）. This was previously thought to occur in prenatal and early postnatal development only; how- ever, several studies have shown that it occurs continuously in our adult brains as well, mainly in the lateral ventricles of the brain, the lining of the subventricular zone （SVZ）, and the subgranular zone （SGZ） of the dentate gyrus （part of the hippocampal complex）. Neurogenesis may also be induced in the adult brain by injury or degeneration of the central nervous system （CNS）. In this instance, new neurons have been found in other parts of the brain, such as in the neocortex, amygdala, substantia nigra and tegmentum of the midrain, the brain stem and spinal cord （Wang and Jin, 2014）. There are numerous steps involved in differentiating neural stem cells into fully-grown neurons, starting with stem cell proliferation, then migration and survival, followed by commitment to neuronal lineage, and lastly the assimilation of the new neurons into existing brain circuits, ranging from up in the neocortex to down in the spinal cord. Neurogenesis is a dynamic process that is modulated by several factors, both intrinsic and extrinsic, such as growth and transcriptional factors, cell surface receptors, signal transduction molecules, and cytokine or chemokines. In adult brains, physio- logical as well as pathological conditions can affect neurogenesis. Neural stem cell proliferation and neuronal differentiation can be inhibited by infection or invoked inflammation. The interruption of neurogenesis in adult brains leads to hippocampus-dependent learning and behavior impairment （Yan et al., 2007）.

Effect of Daicong solution on hippocampal muscarinic receptors 1 and 3 gene expression in a rat model of Alzheimer’s disease

BACKGROUND： It has been previously shown that the muscarinic （M） receptor is involved in brain arousal and selective attention, mood, and motor coordination. OBJECTIVE： To explore the effects of various intragastric Daicong doses on hippocampal MI and M3 receptor gene expression in a rat model of Alzheimer＇s disease. DESIGN, TIME AND SETTING： A randomized cellular and molecular biology experiment, conducted at the Molecular Immunology Laboratory in Shandong between October 2006 and April 2007. MATERIALS： Fifty 22-month old Sprague Dawley rats, weighing 250-300 g were used for this experiment. Kainic acid was used to lesion the nucleus basalis to establish a rat model of Alzheimer＇s disease. The components of Daicong solution were as follows： ginseng, rehmannia dride rhizome, anemarrhena, and radix astragali. The solution was provided by the Affiliated Hospital to Weifang Medical College, according to preparation techniques of extracting liquid for traditional Chinese medicine （1 g crude drug/mL solution）. Kainic acid was provided by Professor Xiuyan Li at Weifang Medical College. METHODS： The rats were randomly divided into 5 groups, 10 rats in each group. Four groups were used for model establishment, and the fifth group served as a normal control group. Three of the model groups were intragastrically administered 5, 10, and 20 g/kg/d Daicong solution, and an additional model group and normal control group received normal saline （10 mL/kg/d）. Drugs were administered over a time period of one month. MAIN OUTCOME MEASURES： Four days after model establishment, Morris water maze was used to measure learning and memory capabilities. RT-PCR was used to detect the effect of Daicong solution on mRNA expression of M1 and M3 receptor in the hippocampus of all groups. RESULTS： Fifty rats were included in the final analysis, without any loss. M1 and M3 receptor mRNA expression was decreased in the model group, compared to the normal control group （P 〈 0.05）. Upon Daicong administration （10 g/kg/d and 20 g/kg/d）, M1 and M3 receptor mRNA expression significantly increased in the hippocampus, compared to the model group （P 〈 0.05）. M1 and M3 mRNA expression was greatest in the 10 g/kg/d group. CONCLUSION： A 10 g/kg/d solution of Daicong can improve M1 and M3 receptor mRNA expression in the hippocampus of a rat model of Alzheimer＇s disease.

The Pythium periplocum elicitin PpEli2 confers broad-spectrum disease resistance by triggering a novel receptor-dependent immune pathway in plants

Elicitins are microbe-associated molecular patterns produced by oomycetes to elicit plant defense.It is still unclear whether elicitins derived from non-pathogenic oomycetes can be used as bioactive molecules for disease control.Here,for the first time we identify and characterize an elicitin named PpEli2 from the soil-borne oomycete Pythium periplocum,which is a non-pathogenic mycoparasite colonizing the root ecosystem of diverse plant species.Perceived by a novel cell surface receptor-like protein,REli,that is conserved in various plants(e.g.tomato,pepper,soybean),PpEli2 can induce hypersensitive response cell death and an immunity response in Nicotiana benthamiana.Meanwhile,PpEli2 enhances the interaction between REli and its co-receptor BAK1.The receptor-dependent immune response triggered by PpEli2 is able to protect various plant species against Phytophthora and fungal infections.Collectively,our work reveals the potential agricultural application of non-pathogenic elicitins and their receptors in conferring broad-spectrum resistance for plant protection.

Egg-associated secretions from the brown planthopper(Nilaparvata lugens)activate rice immune responses

The brown planthopper(BPH,Nilaparvata lugens)is a notorious sap-sucking insect pest that damages rice(Oryza sativa)plants throughout Asia.During BPH feeding,saliva enters rice plant tissues,whereas during oviposition egg-associated secretions(EAS)are deposited in damaged plant tissue.Dynamic changes in rice to planthopper salivary effectors have been widely reported.However,the effects of EAS from planthopper on rice immunity remains largely unexplored.In this study,we found that both infestation of rice by gravid BPH female adults and treatment with the EAS elicited a strong and rapid accumulation of jasmonic acid(JA),JA-isoleucine,and hydrogen peroxide in rice.EAS enhanced plant defenses not only in rice but also in tobacco,and these impaired the performance of BPH on rice,as well as the performance of aphids and whiteflies on tobacco.High-throughput proteome sequencing of EAS led to 110 proteins being identified and 53 proteins with 2 or more unique peptides being detected.Some proteins from BPH EAS were also found in the salivary proteome from herbivores,suggesting potential evolutionary conservation of effector functions across feeding and oviposition;however,others were only identified in EAS,and these are likely specifically related to oviposition.These findings point to novel proteins affecting interactions between planthoppers and rice during oviposition,providing an additional source of information for effector studies.

渥曼青霉素对胶质瘤细胞U251的辐射增敏作用

目的利用渥曼青霉素（wortmannin,WM）抑制人恶性胶质瘤细胞U251磷脂酰肌醇-3-激酶（PI3K）通路的活性,探讨对U251细胞辐射敏感性的影响及可能的作用机制.方法 采用10μmol/L WM预处理U251 2 h,并接受10 Gy X射线照射,检测PI3K/Akt信号通路的活性、集落形成率和凋亡的变化;通过Western blot方法检测凋亡相关蛋白活化型Caspase-3、Bax、Bcl-2及XIAP表达的变化.结果 10 μmol/L WM预处理2h,明显抑制了U251细胞phospho-Akt的表达（t=0.000 1,P＜0.01）.WM预处理联合X射线照射后,U251细胞的凋亡率由对照组和单纯照射组的（2.14±1.32）％和（11.5±2.9）％增加到（22.6±3.8）％,差异具有统计学意义（t=0.009 3、0.002 7,P＜0.01）;集落形成率由对照组和单纯照射组的（88.54±4.76）％和（56.31±4.05）％降低到（12.25±9.59）％（t=0.000 03、0.000 2,P＜0.01）;同时伴随着凋亡相关蛋白活化型Caspase-3表达显著增加,Bax/Bcl-2的比值明显增高以及XIAP的显著降低.结论 WM通过抑制PI3 K/Akt信号通路活性,增加凋亡蛋白Caspase-3的活化和Bax/Bcl-2比值,下调凋亡抑制蛋白XIAP来增强恶性胶质瘤细胞的辐射敏感性.

Zircon U-Pb geochronology of the Chinese continental crust: a preliminary analysis of the Elsevier science database

The amount of zircon U-Pb geochronological data for China has grown rapidly in recent years.Nearly 410,000 items of zircon U-Pb geochronological data,representing more than 7,000 relevant articles in the Elsevier Science Database,have been collected to a database in this research.Statistics on the ages and absolute errors of these collated data,yielded smallest standard errors for(206Pb/238U),(207Pb/235U),and(207Pb/206Pb)ages within respective time intervals of<1388.96 Ma,1388.96–3282.52 Ma,and>3282.52 Ma.The ages and their absolute errors were determined using three main geochronology methods,based on laser ablation inductively coupled mass spectrometer(LA-ICP-MS),sensitive high-resolution ion microprobe(SHRIMP),and secondary ion mass spectrometer(SIMS)measurements.We compared the influence of these different methods on errors for each age interval.In addition,using a Gaussian model of multi-peak fitting of zircon U-Pb age frequencies,we identified seven growth peaks in zircons from the Chinese continental crust,which are 48.60 Ma,131.49 Ma,249.91 Ma,444.27 Ma,835.95 Ma,1860.65 Ma,and 2505.54 Ma.It is clear that there are correspondences between these ages and various geological events,namely,the Wutai movement,Lvliang movement,Jinning movement,Caledonian movement,Indo-China movement,Yanshan movement,and Himalayaorogeny movement,respectively.The time and spatial distributions of these zircons correspond to distinct geological events on the Chinese continent,reflecting its crustal evolution.

Step-edge controlled fast growth of wafer-scale MoSe_(2)films by MOCVD

Two-dimensional(2D)transition metal dichalcogenides(TMDCs),due to their unique physical properties,have a wide range of applications in the next generation of electronics,optoelectronics,and valleytronics.Large-scale preparation of high-quality TMDCs films is critical to realize these potential applications.Here we report a study on metal-organic chemical vapor deposition(MOCVD)growth of wafer-scale MoSe_(2)films guided by the crystalline step edges of miscut sapphire wafers.We established that the nucleation density and growth rate of MoSe_(2)films were positively correlated with the step-edge density and negatively with the growth temperature.At a certain temperature,the MoSe_(2)domains on the substrate with high step-edge density grow faster than that with low density.As a result,wafer-scale and continuous MoSe_(2)films can be formed in a short duration(30 min).The MoSe_(2)films are of high crystalline quality,as confirmed by systematic Raman and photoluminescence(PL)measurements.The results provide an important methodology for the rapid growth of wafer-scale TMDCs,which may promote the application of 2D semiconductors.

Role of BDNF in the taste system

Neurotrophins are a family of proteins that regulate neural survival, development, function and plasticity in the central and the peripheral nervous system. There are four neurotrophins： NGF, BDNF, NT-3 and NT-4. Among them, BDNF is mostly studied in the taste system due to its high expression. Recent studies have shown BDNF play an important role in the developmental and mature taste system, by regulating survival of taste cells and geniculate ganglion neurons, and maintaining and guiding taste nerve innervations. These studies imply BDNF has great potentialities for therapeutic usage to enhance sensory regeneration following nerve injury, with aging, and in some neurodegenerative diseases.

Crustal evolution events in the Chinese continent: evidence from a zircon U-Pb database

The zircon U-Pb chronology database provides a good opportunity to obtain important zircon growth peak periods in the Earth’s history so as to study the origin and evolution of the crust.It should be noted that research preference affects the objectivity of zircon sampling,leading to hot data in the database and age statistics.To evaluate the influence of hot data on statistical results,the W and Y indexes are introduced.Using a Gaussian model of multipeak fitting of zircon U-Pb age frequencies,we identify seven major growth peaks in zircons from the Chinese continental crust,which are 2498.95,1855.82,828.88,444.29,249.46,131.96,and 58.21 Ma.Due to differences in the time scales of zircon growth peaks,these peaks can be divided into two categories:first-order zircon growth peaks(Ⅰ)and second-order zircon growth peaks(Ⅱ),which represent longer and shorter time scales,perhaps due to different kinds of geological dynamics,respectively.In addition,there are clear correspondences between these ages and various geological events recognized by most scholars,namely,the Wutai orogeny,Lvliang orogeny,Jinning orogeny,Caledonian orogeny,Indosinian orogeny,Yanshanian orogeny,and Himalayan orogeny,respectively.