Genomic characterization of peritoneal lavage cytology-positive gastric cancer

Objective: Positive peritoneal lavege cytology(CY1) gastric cancer is featured by dismal prognosis, with high risks of peritoneal metastasis. However, there is a lack of evidence on pathogenic mechanism and signature of CY1and there is a continuous debate on CY1 therapy. Therefore, exploring the mechanism of CY1 is crucial for treatment strategies and targets for CY1 gastric cancer.Methods: In order to figure out specific driver genes and marker genes of CY1 gastric cancer, and ultimately offer clues for potential marker and risk assessment of CY1, 17 cytology-positive gastric cancer patients and 31matched cytology-negative gastric cancer patients were enrolled in this study. The enrollment criteria were based on the results of diagnostic laparoscopy staging and cytology inspection of exfoliated cells. Whole exome sequencing was then performed on tumor samples to evaluate genomic characterization of cytology-positive gastric cancer.Results: Least absolute shrinkage and selection operator(LASSO) algorithm identified 43 cytology-positive marker genes, while Mut Sig CV identified 42 cytology-positive specific driver genes. CD3G and CDKL2 were both driver and marker genes of CY1. Regarding mutational signatures, driver gene mutation and tumor subclone architecture, no significant differences were observed between CY1 and negative peritoneal lavege cytology(CY0).Conclusions: There might not be distinct differences between CY1 and CY0, and CY1 might represent the progression of CY0 gastric cancer rather than constituting an independent subtype. This genomic analysis will thus provide key molecular insights into CY1, which may have a direct effect on treatment recommendations for CY1and CY0 patients, and provides opportunities for genome-guided clinical trials and drug development.

Phase transition-induced superstructures ofβ-Sn films with atomic-scale thickness

The ultrathinβ-Sn(001)films have attracted tremendous attention owing to its topological superconductivity(TSC),which hosts Majorana bound state(MBSs)for quantum computation.Recently,β-Sn(001)thin films have been successfully fabricated via phase transition engineering.However,the understanding of structural phase transition ofβ-Sn(001)thin films is still elusive.Here,we report the direct growth of ultrathinβ-Sn(001)films epitaxially on the highly oriented pyrolytic graphite(HOPG)substrate and the characterization of intricate structural-transition-induced superstructures.The morphology was obtained by using atomic force microscopy(AFM)and low-temperature scanning tunneling microscopy(STM),indicating a structure-related bilayer-by-bilayer growth mode.The ultrathinβ-Sn film was made of multiple domains with various superstructures.Both high-symmetric and distorted superstructures were observed in the atomic-resolution STM images of these domains.The formation mechanism of these superstructures was further discussed based on the structural phase transition ofβtoα-Sn at the atomic-scale thickness.Our work not only brings a deep understanding of the structural phase transition of Sn film at the two-dimensional limit,but also paves a way to investigate their structure-sensitive topological properties.

Epitaxial growth of antimony nanofilms on HOPG and thermal desorption to control the film thickness

Group-V elemental nanofilms were predicted to exhibit interesting physical properties such as nontrivial topological properties due to their strong spin-orbit coupling,the quantum confinement,and surface effect.It was reported that the ultrathin Sb nanofilms can undergo a series of topological transitions as a function of the film thickness h:from a topological semimetal(h>7.8 nm)to a topological insulator(7.8 nm>h>2.7 nm),then a quantum spin Hall(QSH)phase(2.7 nm>h>1.0 nm)and a topological trivial semiconductor(h<1.0 nm).Here,we report a comprehensive investigation on the epitaxial growth of Sb nanofilms on highly oriented pyrolytic graphite(HOPG)substrate and the controllable thermal desorption to achieve their specific thickness.The morphology,thickness,atomic structure,and thermal-strain effect of the Sb nanofilms were characterized by a combination study of scanning electron microscopy(SEM),atomic force microscopy(AFM),and scanning tunneling microscopy(STM).The realization of Sb nanofilms with specific thickness paves the way for the further exploring their thickness-dependent topological phase transitions and exotic physical properties.

Gastric ulcer treated using an elastic traction ring combined with clip: A case report

BACKGROUND There is a high annual incidence of acute,nonvariceal upper gastrointestinal bleeding in Chinese adults.Early endoscopic intervention can reduce rates of rebleeding,surgery,and mortality.The metal clip is the most common method for establishing homeostasis;however,it possesses several limitations.In patients with bleeding secondary to large gastric ulcers,the clip will often fail to stop the bleeding.This article highlights the use of an elastic traction ring as a novel hemostatic method for patients with upper gastrointestinal bleeding.CASE SUMMARY An elderly male presented to the emergency room with complaints of hematemesis and melena.Endoscopic examination revealed an ulcer(Forrest IIa)in the lesser curvature of the gastric antrum.Six tissue clips and one elastic traction ring were inserted into the stomach cavity to suture the ulcer.The patient recovered quickly without postoperative gastrointestinal bleeding.Two months later,the patient's ulcer was significantly healed.CONCLUSION To our best knowledge,this is the first report to demonstrate the safety and efficacy of elastic traction rings for upper gastrointestinal bleeding.Elastic traction rings should be considered a routine therapeutic modality for patients with upper gastrointestinal bleeds.

基于丝网印刷和光固化油墨制备具有角度变色效应的光子晶体防伪图案

具有角度变色效应的光子晶体图案是一种新型防伪材料.虽然该材料的制备方法早有报道,但鲜有研究工作聚焦于发展低成本、规模化、高效可控的制备技术与工艺.本论文发展了一种结合丝网印刷和光固化过程的新制备方法,以SiO_(2)胶粒/单体为油墨,通过丝印在基材表面构筑图案,并利用紫外光固化最终形成光子晶体图案.通过综合评估光子晶体油墨的固化速度、所制墨迹的角度变色能力、结构色分布均匀性、机械及化学稳定性,从“丙烯酸酯型”、“丙烯酰胺型”、“烯烃型”活性单体中筛选出适于制造光子晶体油墨的单体主料和辅料.此外,通过系统研究丝印模板目数对涂层厚度和印刷分辨率的影响,确定了实现最优结构色强度和图案精度的制备条件.最后,论文提出几种光子晶体防伪图案的设计方案,可实现单色图案随角度变色、双色图案特定角度单色化、层叠图案交替显现等动态视觉效果.

Somatic genetic aberrations in gallbladder cancer: comparison between Chinese and US patients

Background:Gallbladder cancer(GBC)is often diagnosed at an advanced stage with limited therapeutic options and poor prognosis.The five-year survival rate of this cancer when diagnosed at an advanced stage is below 5%,and the median survival time is less than a year with standard gemcitabine-based chemotherapy.Survival benefit with second-line treatment is unknown.Thus,there is an urgent need for novel treatment strategies and targeted therapy based on next generation sequencing(NGS)may be of value.Methods:Comprehensive genomic profiling(CGP)was performed with NGS panel on paraffin-embedded tumors from a cohort of 108 Chinese and 107 US GBC patients.Clinical data were collected using an IRB approved protocol from a single-center in US and from China.Results:In Chinese and US GBC cohorts,an average of 6.4 vs.3.8 genomic alterations(GAs)were identified per patient.The most frequent alterations were TP53(69.4%),CDKN2A/B(26%),ERBB2(18.5%),PIK3CA(17%)and CCNE1(13%)in Chinese cohort,TP53(57.9%),CDKN2A/B(25%),SMAD4(17%),ARID1A(14%),PIK3CA(14%)and ERBB2(13.1%)in US patients.NFE2L2 mutations were present in 6.5%of Chinese patients and not observed in the US cohort.Interestingly,ERBB2 genetic aberrations were significantly associated with better pathological tumor differentiation and tended to co-occurrence with CDKN2A/B mutations in both the Chinese and US GBC cases.Out of the top 9 dysregulated genetic pathways in cancer,Chinese patients harbored more frequent mutations in ERBB genes(30.6%vs.19.0%,P=0.04).High frequency of PI3K/mTOR pathway variations was observed in both Chinese(37%)and US cohort(33%)(P=0.5).Additionally,both Chinese and US GBC patients exhibited a relatively high tumor mutational burden(TMB)(17.6%and 17.0%,respectively).In the Chinese cohort,a significant association was seen between direct repair gene alterations and TMB≥10 muts/Mb(P=0.004).Conclusions:In our study,over 83%Chinese and 68%US GBC patients had actionable alterations that could potentially guide and influence personalized treatment options.The identification of high TMB,ERBB2,CDKN2A/B,PI3K/mTOR pathway and DNA repair mutations indicated that both Chinese and US GBC patients may benefit from targeted or immune checkpoint inhibitors.

Real-space visualization of intercalated water phases at the hydrophobic graphene interface with atomic force microscopy

The phase behavior of water is a topic of perpetual interest due to its reinai kable anomalous properties and importance to biology,material science,geoscience,nanoscience,etc.It is predicted confined water at interface can exist in large amounts of crystalline or amorphous states.However,the experimental evidence of coexistence of liquid water phases at interface is still insufficient.Here,a special folding few-layers graphene film was elaborate prepared to form a hydrophobic/hydrophobic interface,which can provide a suited platform to study the structure and properties of confined liquid water.The real-space visualization of intercalated water layers phases at the folding interface is obtained using advanced atomic force microscopy(AFM).The folding graphene interface displays complicated internal interfacial characteristics.The intercalated water molecules present themselves as two phases,low-density liquid(LDL,solid-like)and high-density liquid(HDL,liquid-like),according to their specific mechanical properties taken in two multifrequency-AFM(MF-AFM)modes.Furthermore,the water molecules structural evolution is demonstrated in a series of continuous MF-AFM measurements.The work preliminary confirms the existence of two liquid phases of water in real space and will inspire further experimental work to deeply understanding their liquid dynamics behavior.

Comprehensive molecular profiling of extrahepatic cholangiocarcinoma in Chinese population and potential targets for clinical practice

Background:Cholangiocarcinoma(CCA)is a diverse group of malignancies arising from the intra-or extrahepatic biliary epithelium and characterized by its late diagnosis and fatal outcome.Extrahepatic cholangiocarcinoma(ECC)accounts for 90%of CCA.However,little is known about the comprehensive genomic alterations of ECC in Chinese population for providing clinical managements especially targeted therapy.Methods:Comprehensive genomic profiling(CGP)was performed with next generation sequencing panel on paraffin-embedded tumor from a cohort of 80 Chinese ECC patients.Results:The most frequently altered genes were TP53(68%),KRAS(46%),SMAD4(22%),ARID1A(20%)and CDKN2A(19%).Mutual exclusivity was observed between multiple genes including ARID1A:TP53,KRAS:LRP1B and NF2:TP53.Genetic alterations with potential therapeutic implications were identified in 43%of patients.The top three actionable alterations include CDKN2A(n=11),BRAF(n=5)and ERBB2(n=4).Potentially actionable alterations were mainly enriched in the G1-S transition,homologous recombination repair,MAPK/ERK pathway.Conclusions:This is the largest data set of ECC cases providing a comprehensive view on genetic alterations in Chinese population which differs significantly from a US cohort,and indicates the potential clinical implications for targeted therapies.

Confined reaction inside nanotubes： New approach to mesoporous g-C3N4 photocatalysts

Mesoporous g-C3N4 nanorods （NRs） are synthesized through the nano-confined thermal condensation of cyanamide in silica nanotubes （NTs） with porous shells.The gas bubbles retained during condensation and the limited cyanamide precursor inside the silica NTs lead to the formation of mesoporous g-C3N4.This nano-confined reaction is an alternative method to the traditional templating process for the synthesis of mesoporous materials.The as-prepared mesoporous g-C3N4 NRs exhibit remarkably improved photocatalytic activity and high stability in water splitting and degradation of Rhodamine B compared with bulk g-C3N4.

Epitaxial fabrication of AgTe monolayer on Ag(111)and the sequential growth of Te film

Transition-metal chalcogenides(TMCs)materials have attracted increasing interest both for fundamental research and industrial applications.Among all these materials,two-dimensional(2D)compounds with honeycomb-like structure possess exotic electronic structures.Here,we report a systematic study of TMC monolayer AgTe fabricated by direct depositing Te on the surface of Ag(111)and annealing.Few intrinsic defects are observed and studied by scanning tunneling microscopy,indicating that there are two kinds of AgTe domains and they can form gliding twin-boundary.Then,the monolayer AgTe can serve as the template for the following growth of Te film.Meanwhile,some Te atoms are observed in the form of chains on the top of the bottom Te film.Our findings in this work might provide insightful guide for the epitaxial growth of 2D materials for study of novel physical properties and for future quantum devices.

Toplayer-dependent crystallographic orientation imaging in the bilayer two-dimensional materials with transverse shear microscopy

Nanocontact properties of two-dimensional(2D)materials are closely dependent on their unique nanomechanical systems,such as the number of atomic layers and the supporting substrate.Here,we report a direct observation of toplayer-dependent crystallographic orientation imaging of 2D materials with the transverse shear microscopy(TSM).Three typical nanomechanical systems,MoS_(2) on the amorphous SiO_(2)/Si,graphene on the amorphous SiO_(2)/Si,and MoS_(2) on the crystallized Al_(2)O_(3),have been investigated in detail.This experimental observation reveals that puckering behaviour mainly occurs on the top layer of 2D materials,which is attributed to its direct contact adhesion with the AFM tip.Furthermore,the result of crystallographic orientation imaging of MoS_(2)/SiO_(2)/Si and MoS_(2)/Al_(2)O_(3) indicated that the underlying crystalline substrates almost do not contribute to the puckering effect of 2D materials.Our work directly revealed the top layer dependent puckering properties of 2D material,and demonstrate the general applications of TSM in the bilayer 2D systems.

Advanced atomic force microscopies and their applications in two-dimensional materials:a review

Scanning probe microscopy(SPM)allows the spatial imaging,measurement,and manipulation of nano and atomic scale surfaces in real space.In the last two decades,numerous advanced and functional SPM methods,particularly atomic force microscopy(AFM),have been developed and applied in various research fields,from mapping sample morphology to measuring physical properties.Herein,we review the recent progress in functional AFM methods and their applications in studies of two-dimensional(2D)materials,particularly their interfacial physical properties on the substrates.This review can inspire more exciting application works using advanced AFM modes in the 2D and functional materials fields.