Operative link on gastritis assessment stage is an appropriate predictor of early gastric cancer

AIM: To assess the predictive value of Operative Link on Gastritis Assessment (OLGA) and Operative Link on Gastric Intestinal Metaplasia Assessment (OLGIM) stages in gastric cancer.METHODS: A prospective study was conducted with 71 patients with early gastric cancer (EGC) and 156 patients with non-EGC. All patients underwent endoscopic examination and systematic biopsy. Outcome measures were assessed and compared, including the Japanese endoscopic gastric atrophy (EGA) classification method and the modified OLGA method as well as the modified OLGIM method. Helicobacter pylori (H. pylori) status was determined for all study participants. Stepwise logistic regression modeling was performed to analyze correlations between EGC and the EGA, OLGA and OLGIM methods.RESULTS: For patients with EGC and patients with non-EGC, the proportions of moderate-to-severe EGA cases were 64.8% and 44.9%, respectively (P = 0.005), the proportions of OLGA stages III-IV cases were 52.1% and 22.4%, respectively (P < 0.001), and the proportions of OLGIM stages III-IV cases were 42.3% and 19.9%, respectively (P < 0.001). OLGA stage and OLGIM stage were significantly related to EGA classification; specifically, logistic regression modeling showed significant correlations between EGC and moderate-to-severe EGA (OR = 1.95, 95% CI: 1.06-3.58, P = 0.031) and OLGA stages III-IV (OR = 3.14, 95%CI: 1.71-5.81, P < 0.001), but no significant correlation between EGC and OLGIM stages III-IV (P = 0.781). H. pylori infection rate was significantly higher in patients with moderate-to-severe EGA (75.0% vs 54.1%, P = 0.001) or OLGA/OLGIM stages III-IV (OLGA: 83.6% vs 55.8%, P < 0.001; OLGIM: 83.6% vs 57.8%, P < 0.001).CONCLUSION: OLGA classification is optimal for EGC screening. A surveillance program including OLGA stage and H. pylori infection status may facilitate early detection of gastric cancer.

Factors affecting occurrence of gastric varioliform lesions: A case-control study

AIM: To investigate the factors influencing the occurrence of gastric varioliform lesions(GVLs) and their possible link with gastric cancer.METHODS: A 1:1 matched case-control study was performed to retrospectively analyze data from 1638 chronic gastritis patients who had undergone gastroscopy at one of two Chinese hospitals between 2009 and 2014. Patients with GVLs(cases) were compared to those without such lesions(controls). Endoscopic and pathological findings were recorded, along with interview information on Helicobacter pylori(H. pylori) infection, medical, drug and family histories, lifestyle and eating habits. The association between each factor and the occurrence of GVLs was estimated, and then multivariate conditional logistic regression was used to evaluate the independent factors.RESULTS: The frequency and severity of glandular atrophy, intestinal metaplasia(IM) and low-grade intraepithelial neoplasia were significantly increased in the GVL group(P < 0.01). Overall analysis showed that H. pylori infection [3.051(2.157, 4.317), P <0.001], allergic respiratory diseases [3.636(2.183, 6.055), P < 0.001], work-related stress [2.019(1.568, 2.600), P < 0.001], irregular meals [2.300(1.462, 3.619), P < 0.001], high intake of spicy food [1.754(1.227, 2.507), P = 0.002] and high intake of fresh fruit [0.231(0.101, 0.529), P = 0.001] were significantly correlated with the occurrence of GVLs(positively, except for the latter). Stratified analyses indicated that pickled food consumption in patients over 50 years old [7.224(2.360, 22.115), P = 0.001] and excessive smoking in men [2.013(1.282, 3.163), P = 0.002] were also positively correlated, and that, for antral GVLs, vegetable consumption [0.491(0.311, 0.776), P = 0.002] was negatively correlated. CONCLUSION: Seven risk factors and two protective factors are determined for GVLs, which were found to be associated with premalignant abnormalities.

Predictive value of neutrophil infiltration as a marker of Helicobacter pylori infection

AIM： To evaluate the predictive value of neutrophil in- filtration as a marker of Helicobacter pylori （H. pyloni） infection. METHODS： A total of 315 patients with dyspepsia symptoms who underwent upper gastrointestinal en- doscopy were enrolled in this study. Biopsies were evaluated using the updated Sydney system. The medication history of all patients in the preceding 4 wk was recorded. The diagnosis of H. pylori infection was based on 13C-urea breath test at least 4 wk after with- drawal of antisecretory drugs, antibiotics and related drugs. For the patients with subtotal gastrectomy, the diagnosis of H. pylori infection was based on anti-H. pylori immunoglobulin G （IgG） antibody. Serum anti-H. pylori IgG antibody was measured by enzyme-linked immunosorbent assays （Biohit, Finland）. RESULTS： The sensitivity, specificity, positive predic- tive value and negative predictive value of neutrophil infiltration in the diagnosis ofH, pylorlinfection were 92.3%, 83.5%, 77.4% and 94.7%, respectively. Neu- trophil infiltration of gastric mucosa in the histological analysis was strongly associated withH, pylorlinfection （77.4% vs 5.3% in the neutrophil infiltration negative group, P = 0.000）. Moderate neutrophil infiltration was more frequent in H. pylorl infection when compared to mild infiltration （81.8% and 75%, respectively）, but did not reach statistical significance. For those patients with negative rapid urease test, H. pylori was detected in 73.2% of patients with positive neutrophil infiltration on histology. In patients with subtotal gastrectomy, the diagnostic accuracy of neutrophil infiltration in H. pylori infection was 50%. CONCLUSION： Neutrophil infiltration is closely associ- ated withH, pylori and may be recognized as a sign of this infection.

Preparation of Molecularly Imprinted Composites Initiated by Hemin/Graphene Hybrid Nanosheets and Its Application in Detection of Sulfamethoxazole

Molecularly imprinted polymers(MIPs)exhibit high selectivity resulting from imprinted cavities and superior performance from functional materials,which have attracted much attention in many fields.However,the combination of MIPs film and functional materials is a great challenge.In this study,hemin/graphene hybrid nanosheets(H-GNs)were used to initiate the imprinted polymerization by catalyzing the generation of free radicals.Thus,MIPs using sulfamethoxazole as the template was directly prepared on the surface of H-GNs without any film modification.Most importantly,the template could be absorbed on the H-GNs to enhance the number of imprinted sites per unit surface area,which could improve the selectivity of MIPs film.Thus,the composites could exhibit high adsorption capacity(29.4 mg/g),imprinting factor(4.2)and excellent conductivity,which were modified on the surface of electrode for rapid,selective and sensitive detection of sulfamethoxazole in food and serum samples.The linear range was changed from 5μg/kg to 1 mg/g and the limit of detection was 1.2μg/kg.This sensor was free from interference caused by analogues of sulfamethoxazole,which provides a novel insight for the preparation of MIPs-based sensor and its application in food safety monitoring and human exposure study.

A subset of ulcerative colitis with positive proteinase-3 antineutrophil cytoplasmic antibody

A small subset of patients with active ulcerative colitis is non-responsive to major known non-biological therapies. We reported 5 patients with positive serum proteinase-3 antineutrophil cytoplasmic antibody (PR3-ANCA) and tried to (1) identify the common clinical features of these patients; (2) investigate the efficacy of a novel therapy using a Chinese medicine compound; and (3) attract more gastroenterologists to be engaged in further study of this subset of patients. The common manifestations of disease in these 5 patients included recurrent bloody diarrhea and inflammatory lesions involving the entire colorectal mucosa. Initial treatment with intravenous methylprednisolone successfully induced remission. Four of these 5 patients were steroid-dependence, and immunosuppressants, such as azathioprine and cyclophosphamide, were in effective. In 3 patients, only the particular Chinese medicine compound could induce and maintain remission. One patient underwent colectomy. No vascular inflammatory lesions were found by histopathological examination. Although more cases are needed for confirmation, our study indicates thatulcerative colitis with positive PR3-ANCA may belong to a subtype of refractory ulcerative colitis. The particular Chinese medicine compound used in our study is by far the most effective in the management of these patients, with additional advantages of having no noticeable side-effects and less financial burden.

Microstructure and Mechanical Properties of AZ91D Magnesium Alloy Recycled from Scraps by Hot-press/extrusion

A large number of scraps are produced in the fabrication process of magnesium alloy products. It is necessary to recycle these scraps for the development and scale application of magnesium alloys. In this research,a method for recycling AZ91D magnesium alloy scraps fabricated by hot-press / extrusion was studied. Mechanical properties and microstructure of the recycled specimens were investigated. Microstructural analyses were performed by using the techniques of optical microscopy and scanning electron microscopy. Microstructural observations reveal that the recycled specimens consisted of fine grains when adopting the extrusion temperature of 400- 450 ℃,the extrusion ratio of( 25- 100) ∶ 1 and the extrusion rate of 0. 10- 0. 20 mm / s. Ultimate tensile strength and elongation to failure increased with the increase of the extrusion temperature,the extrusion ratio and the extrusion rate,respectively. Recycled specimens reached the highest ultimate tensile strength of average 361. 47 MPa and the highest elongation to failure of average 11. 55% when adopting the hot-press,the extrusion temperature of 400± 5 ℃,the extrusion ratio of 100 ∶ 1 and the extrusion rate of 0. 15 mm / s. The shape of bonding interface was tightly relation with the ultimate tensile strength. When the bonding interface formed continuous curves,the ultimate tensile strength decreased almost linearly with increasing the average width of the bonding interface. When the bonding interface formed discontinuous curves,the ultimate tensile strength increased almost linearly with the increase the proportion of the fine bonding length accounting for the measured interface length. Ultimate tensile strength of the recycled specimens could be calculated by using the forecastable equation.

Effect of boron on microstructure and mechanical properties of cast Ti-44Al6-Nb ingots

In order to improve the mechanical properties of Ti Al alloys, especially the ductility at room temperature, and to study the effect of boron(B) on Ti Al alloys, different contents(0, 0.1, 0.3, 0.6, 0.9, 1.2, at.%) of B were added into Ti-44Al-6Nb alloys to prepare ingots. The surface quality, macrostructure, microstructure, compressive properties and fracture surface of the ingots were studied. The results show that B has little influence on the surface quality except that there are some dark spots on the surface when the content of B is 0.9%. B can refine the grains. The average grain size decrease from about 0.8 mm to 0.088 mm with increasing B content. Meanwhile, the grain morphology of these ingots changes from big equiaxed grains with lamellars to fine equiaxed grains. When the content of B is 1.2%, the primary Ti B2 phase forms in the liquid phase and increases the nucleation rate, leading to further refinement of the grains. The compressive testing results show that B can increase the strength and the ductility, the compressive strength and compressibility can reach 2,037.8 MPa and 26.7% from 1,156.2 MPa and 10.2% when the boron content is 0.6%, which is resulted from grain refining and grain boundary strengthening. It is found that the compressive strength and the compressibility are relatively stable when the B content is more than 0.3%.

Entanglement properties of GHZ and W superposition state and its decayed states

We use the generalized Wootters formula, the positive partial transpose(PPT) criterion and the matched entanglement witness, to detect entanglement of three-qubit GHZ and W superposition state and its decayed states. It shows that the results of the generalized Wootters formula in the part near the W state are tight. In the other parts, the PPT criterion is superior to the generalized Wootters formula. Furthermore, we investigate the relationship between entanglement and coherence.

Microstructure and microhardness of Ti-48Al alloy prepared by rapid solidification

To improve the microstructure and microhardness,Ti-48Al(at.%)alloy was rapidly solidified by melt spinning under different cooling rates.The microstructure and microhardness of rapidly solidified Ti-48Al alloy were systematically investigated.Results show that the average lamellar colony size of the alloy reduces from 60.6μm to 11μm as the cooling rate increases from 2.3×105 to 5.1×105 K·s-1,caused by the increase of nucleation rate at a higher cooling rate.At the high cooling rate of(4.3-5.1)×105 K·s-1,theαphase is the primary phase,and a few metastableαphases are reserved,which then transform intoα2 phase and subsequently lead to the formation ofα2 equiaxed grain.The lamellar spacing also decreases with the increase of cooling rate.The relationship between lamellar spacing(d)and cooling rate(v)is d=33.6v-1.34.The microhardness increases with the increase of cooling rate because the refined lamellar spacing and grain size can improve the microhardness.

Maternal inappropriate calcium intake aggravates dietary-induced obesity in male offspring by affecting the differentiation potential of mesenchymal stem cells

BACKGROUND The effects of inappropriate dietary calcium intake in early life on later obesity have not been fully elucidated.AIM To raise the mechanism of maternal calcium intake on the multi-differentiation potential of mesenchymal stem cells among their male offspring.METHODS Four-week-old female C57BL/6N mice were fed by deficient,low,normal and excessive calcium reproductive diets throughout pregnancy and lactation.Bone MSCs(BMSCs)were obtained from 7-day-old male offspring to measure the adipogenic differentiation potential by the Wnt/β-catenin signaling pathway.The other weaning male pups were fed a high-fat diet for 16 wk,along with normalfat diet as the control.Then the serum was collected for the measurement of biochemical indicators.Meanwhile,the adipose tissues were excised to analyze the adipocyte sizes and inflammatory infiltration.And the target gene expressions on the adipogenic differentiation and Wnt/β-catenin signaling pathway in the adipose tissues and BMSCs were determined by real-time reverse transcription polymerase chain reaction.RESULTS Compared with the control group,maternal deficient,low and excessive calcium intake during pregnancy and lactation aggravated dietary-induced obesity,with larger adipocytes,more serious inflammatory infiltration and higher serum metabolism indicators by interfering with higher expressions of adipogenic differentiation(PPARγ,C/EBPα,Fabp4,LPL,Adiponectin,Resistin and/or Leptin)among their male offspring(P<0.05).And there were significantly different expression of similar specific genes in the BMSCs to successfully polarize adipogenic differentiation and suppress osteogenic differentiation in vivo and in vitro,respectively(P<0.05).Meanwhile,it was accompanied by more significant disorders on the expressions of Wnt/β-catenin signaling pathway both in BMSCs and adulthood adipose tissues among the offspring from maternal inappropriate dietary calcium intake groups.CONCLUSION Early-life abnormal dietary calcium intake might program the adipogenic differentiation potential of BMSCs from male offspring,with significant expressions on the Wnt/β-catenin signaling pathway to aggravate high-fat-diet-induced obesity in adulthood.

Effect of total glucosides of paeony on serum cytokines in patients with psoriasis and its clinical efficacy:A meta-analysis

Objective:To evaluate the relationship between the changes of inflammatory cytokines and clinical efficacy in patients with psoriasis treated with Total glucosides of paeony by Meta analyses,and to explore the microcosmic mechanism of effective treatment of psoriasis with Total glucosides of paeony from the point of view of evidence-based medicine.Methods:The databases of CNKI,Wanfang,VIP,SinoMed,PuMed,Embase and Cochrane Library were searched by computer,and the time range was from the establishment of the database to May 2020.After screening,data extraction and bias risk assessment,Revman5.3 software was used for statistical analysis.Results:A total of 998 patients were included in 11 clinical studies,including 502 patients in the trial group and 496 patients in the control group.The results of Meta analysis showed that there was significant difference in the expression of cytokines between the two groups(MD=-10.97,95%Cl[-15.56,-6.37]).The effective rate of treatment(OR=3.57,95%Cl[2.58,4.94])and the decrease of PASI score(MD=-4.55,95%Cl[-5.91,-3.20])in the combined use of Total glucosides of paeony group were superior to those in the control group.Conclusion:Total glucosides of paeony can regulate immune and inflammatory response and improve skin lesions by inhibiting the expression of cytokines such as IL-2,IL-8,IL-23 and TNF-αin serum of patients with psoriasis.In view of the low overall quality of the included studies,larger samples and higher quality clinical trials are still needed to obtain more sufficient evidence.

Effect and mechanism of N-acetylcysteine on adjuvant arthritis rats

Objective:To investigate the anti-inflammatory effects of N-Acetylcysteine(NAC)on adjuvant arthritis(AA)rats and the changes of Toll-like receptor 2(TLR2)-inflammatory factors.Methods:50 SD rats,randomly divided into 10 control groups,40 AA model group,after 10 d,which were divided into model group,NAC groups gave low,medium and high dose NAC(lavage respectively 50,100,200 mg/kg)for 16 d,joint swelling degree and arthritis index evaluation NAC therapeutic effect on AA rats;Immunohistochemical staining and Western blot were used to observe the expression of TLR2 protein in synovial tissue of joints.Serum levels of TNF-α,IL-1βand IL-10 were detected by ELISA.Results:Compared with the control group,the joint swelling and arthritis index in the model group were significant,and the joint swelling and arthritis index in the NAC treatment groups were significantly reduced(P<0.05,P<0.01).The expression of TLR2 protein in the synovial tissue of NAC treatment groups was decreased,inflammatory factors TNF-αand IL-1βwere decreased,and IL-10 was increased(P<0.01).Conclusion:NAC can improve the symptoms of arthritis in AA rats,and its mechanism may be related to inhibition of TLR2 and regulation of downstream inflammatory factor pathways in AA rats.

Study on the mechanism of Salvia miltiorrhiza-Pueraria lobata in the treatment of type 2 diabetes mellitus based on network pharmacology

Objective:To explore the synergistic mechanism of salvia miltiorrhiza and Pueraria lobata of multi-component,multi-target and multi-pathway in the treatment of type 2 diabetes mellitus(T2DM).Methods:The chemical components of Salvia miltiorrhiza and Pueraria lobata were queried and screened through the pharmacological database and analysis platform of traditional Chinese medicine system,and the chemical components were predicted by SwissTargetPrediction database.At the same time,the related targets of T2DM were searched and screened from GeneCards,TTD,DrugBank and Disgenet databases.The chemical composition targets and disease targets are intersected,and the PPI network of intersection targets is constructed by using STRING11.0 database,and the PPI network nodes are screened to get the key targets.The GO function and KEGG pathway enrichment analysis of the key targets are carried out.Results:A total of 70 chemical constituents and 51 key targets for the interaction between chemical components and diseases were obtained through retrieval and screening.After enrichment and analysis of 51 key targets,a total of 71 cellular components,85 molecular functions,559 biological processes and 137 signal pathways were obtained.The treatment of T2DM with Salvia miltiorrhiza and Pueraria lobata may be related to AGE-RAGE,Pl3K-Akt,ErbB,insulin resistance,HIF-1 and other signal pathways.Conclusion:This study preliminarily reveals the action mechanism of Salvia miltiorrhiza and Pueraria lobata on the treatment of T2DM with multi-components,multi-targets and multi-pathways,which provides a certain basis for the study of the molecular mechanism of Salvia miltiorrhiza and Pueraria lobata pairs.

Molecular docking and big-data bioinformatics predict the mechanisms of action of the active ingredients of Ganoderma lucidum in treating lung cancer

Background:This study pioneers a network pharmacology-based approach and in silico molecular docking and visualization approaches to predict the potential molecular mechanisms involved in treatment of lung cancer with Lingzhi(Ganoderma lucidum).Methods:The active ingredients of Ganoderma lucidum were screened in the Traditional Chinese Medicine Systems Pharmacology database,and corresponding potential targets of these active ingredients were queried.Then potential targets for the treatment of lung cancer were separately queried using the GeneCards database.The overlapping targets of the active ingredients and lung cancer treatment were further analyzed in silico by calculating degree values and conducting literature searches.A protein-protein interaction network was constructed for these overlapping targets using the STRING database,and a“drug-ingredient-target”network was created using Cytoscape 3.7.1 software.Gene ontology and Kyoto Encyclopedia of Genes and Genomes(KEGG)enrichment analyses were performed for key targets using Metascape.Finally,the key molecules were examined using molecular docking in Autodock 3.7 software,and the representative docking results were visualized using PyMol software.Results:A total of 14 active ingredients were identified,including 3 key ingredients(ganolucidic acid E,ergosta-4,6,8(14),22-tetraene-3-one,and beta-sitosterol)and 8 key targets.Gene ontology analysis and KEGG enrichment showed that Ganoderma lucidum may act on 10 key signaling pathways,such as the neuroactive ligand-receptor interaction pathway,calcium signaling pathway,and cyclic adenosine monophosphate signaling pathway,to regulate neuroactivity,ion homeostasis,and other processes,thus inhibiting the progression of lung cancer.Molecular docking results predicted that among the 8 key targets,mu-type opioid receptor,transforming growth factor beta-1 proprotein,and apoptosis regulator BAX exhibit better docking with these ligands.Conclusion:The preliminary results of this study identified potential active ingredients of Ganoderma lucidum for the treatment of lung cancer,and putative mechanisms of action,which could provide a theoretical basis for further experimental studies on anticancer efficacy.

Microstructure and mechanical properties of Ti44Al6Nb alloys with different cerium contents

Ti44A16 Nb-based alloy ingots with different cerium(Ce)contents(0,0.05,0.10,0.15,0.20;at%)were prepared by non-consumable vacuum arc smelting furnace(WK-Ⅱ).The surface quality,macrostructure,microstructure,compressive properties and fracture morphology of these ingots were studied.The results show that Ce has few influences on the surface quality.Ce can refine grain size and the average grain size decreases from 0.50 to 0.19 mm with the increase of Ce content.Meanwhile,the microstructure morphology of these ingots changes from large lamellar microstructure to dual-phase microstructure.With addition of Ce,CeO and AlCe3 are formed during melting and solidifying,which act as the core of heterogeneous nucleation and refine the grain.The compressive testing results show that Ce can improve strength and ductility.The ultimate compressive strength increases from 1156.2 to 1472.2 MPa with Ce content increasing from 0 at%to 0.20 at%.The compression ratio is improved from 10.2%to 15.3%with Ce content increasing from 0 at%to 0.10 at%.The refined crystalline strengthening and grain boundary strengthening are the main reasons for the improvement of compressive property.

Precise detection of multipartite entanglement in four- qubit Greenberger-Horne-Zeilinger diagonal states

We propose a method of constructing the separability criteria for multipartite quantum states on the basis of entanglement witnesses. The entanglement witnesses are obtained by finding the maximal expectation values of Hermitian operators and then optimizing over all possible Hermitian operators. We derive a set of tripartite separability criteria for the four-qubit Greenberger-Horne-Zeilinger （GHZ） diagonal states. The derived criterion set contains four criteria that are necessary and sufficient for the tripartite separability of the highly symmetric four-qubit GHZ diagonal states; the criteria completely account for the numerically obtained boundaries of the tripartite separable state set. One of the criteria is just the tripartite separability criterion of the four-qubit generalized Werner states.

Diagnostic value of optic disc retinal nerve fiber layer thickness for diabetic peripheral neuropathy

Objective:To investigate the value of optic disc retinal nerve fiber layer(RNFL)thickness in the diagnosis of diabetic peripheral neuropathy(DPN).Methods:Ninety patients with type 2 diabetes,including 60 patients without DPN(NDPN group)and 30 patients with DPN(DPN group),and 30 healthy participants(normal group)were enrolled.Optical coherence tomography(OCT)was used to measure the four quadrants and the overall average RNFL thickness of the optic disc.The receiver operator characteristic curve was drawn and the area under the curve(AUC)was calculated to evaluate the diagnostic value of RNFL thickness in the optic disc area for DPN.Results:The RNFL thickness of the DPN group was thinner than those of the normal and NDPN groups in the overall average((101.07±12.40)μm vs.(111.07±6.99)μm and(109.25±6.90)μm),superior quadrant((123.00±19.04)μm vs.(138.93±14.16)μm and(134.47±14.34)μm),and inferior quadrant((129.37±17.50)μm vs.(143.60±12.22)μm and(144.48±14.10)μm),and the differences were statistically significant.The diagnostic efficiencies of the overall average,superior quadrant,and inferior quadrant RNFL thicknesses,and a combined index of superior and inferior quadrant RNFL thicknesses were similar,and the AUCs were 0.739(95%confidence interval(CI)0.635–0.826),0.683(95%CI 0.576–0.778),0.755(95%CI 0.652–0.840),and 0.773(95%CI 0.672–0.854),respectively.The diagnostic sensitivity of RNFL thickness in the superior quadrant reached 93.33%.Conclusions:The thickness of the RNFL in the optic disc can be used as a diagnostic method for DPN.

Entanglement witnesses of four-qubit tripartite separable quantum states

A quantum entangled state is easily disturbed by noise and degenerates into a separable state.Compared to the entanglement with bipartite quantum systems,less progress has been made for the entanglement with multipartite quantum systems.For tripartite separability of a four-qubit system,we propose two entanglement witnesses,each of which corresponds to a necessary condition of tripartite separability.For the four-qubit GHZ state mixed with a W state and white noise,we prove that the necessary conditions of tripartite separability are also sufficient at W states side.

Separability of evolving W state in a noise environment

Entanglement is an important resource for quantum information processing.We provide a new entanglement witness to detect the entanglement of an evolving W state.Our results show that the new entanglement witness matches the evolving W state better than other witnesses or methods.The new witness significantly improves the performance of entanglement detection for some three-qubit states.

Recent developments of nanomaterials-based conductive type methane sensors

Methane is an explosive gas in coalmines and needs to be monitored by methane sensors.Conductivetype methane sensors are small,simple and stable,and they are very promising for mining safety or home safety applications.They can even be employed in mining Internet of things if the power consumption can be lowered down to few milliwatts.Many researches of nanomaterialsbased conductive-type methane sensors have been reported recently.This review intends to present a comprehensive and critical summary on the recent progresses in the nanomaterials-based conductive-type methane sensors field.Many excellent methane-sensitive nanomaterials will be present,such as SnO2,ZnO,TiO2,WO3,carbon nanotubes,graphene,rare earth metal-based perovskite oxides and their hybrids.Particular attention is given to the synthetic methods of the nanomaterials,sensing mechanisms of the nanomaterials and the relationship between the sensing performance and the structures and components of the nanomaterials.Finally,the future trends and perspectives of nanomaterials-based conductive-type methane sensors are proposed.