Theoretical Prediction of Superconductivity in Boron Kagome Monolayer:MB3(M=Be,Ca,Sr)and the Hydrogenated CaB3

Using first-principles calculations, we predict a new type of two-dimensional(2D) boride MB3(M = Be,Ca, Sr), constituted by boron kagome monolayer and the metal atoms adsorbed above the center of the boron hexagons. The band structures show that the three MB3compounds are metallic, thus the possible phononmediated superconductivity is explored. Based on the Eliashberg equation, for BeB3, CaB3, and SrB3, the calculated electron–phonon coupling constants λ are 0.46, 1.09, and 1.33, and the corresponding superconducting transition temperatures Tc are 3.2, 22.4, and 20.9 K, respectively. To explore superconductivity with higher transition temperature, hydrogenation and charge doping are further considered. The hydrogenated CaB3, i.e.,HCaB3, is stable, with the enhanced λ of 1.39 and a higher Tc of 39.3 K. Moreover, with further hole doping at the concentration of 5.8 × 1011hole/cm2, the Tc of HCaB3can be further increased to 44.2 K, exceeding the Mc Millan limit. The predicted MB3and HCaB3provide new platforms for investigating 2D superconductivity in boron kagome lattice since superconductivity based on monolayer boron kagome lattice has not been studied before.

Superconductivity Modulated by Carbonization and Hydrogenation in Two-Dimensional MXenes M2N(M=Mo,W)

The superconductivity of two-dimensional(2D)materials has extremely important research significance.To date,superconducting transition temperatures(T_(c))of 2D superconductors are still far from practical applications.Previously,2D MXene Mo_(2)N has been successfully synthesized[Urbankowski et al.Nanoscale 917722,(2017)].We systematically investigate the effects of carbonization and further hydrogenation on the stability,electronic property and superconductivity of 1T-and 2H-M_(2)N(M=Mo,W)based on first-principles calculations.The results show that the 1T-M_(2)N and 2H-M_(2)N(M=Mo,W)are all dynamically and thermodynamically stable after carbonization and further hydrogenation.After carbonization,Tc’s of 1T-M_(2)NC_(2)(M=Mo,W)are all increased,while Tc’s of 2H-M_(2)NC_(2)(M=Mo,W)are all decreased.By further hydrogenation,the Tc’s of 1T-and 2H-M_(2)NC2H2are all increased.Among all of these structures,Tcof 1T-Mo_(2)NC_(2)H_(2)is the highest one,reaching 42.7 K,and the corresponding electron-phonon coupling strengthλis 2.27.Therefore,hydrogenation is an effective method to modulate Tc’s of 2D M_(2)NC_(2)(M=Mo,W)materials.

Gut microbiota contributes to the distinction between two traditional Chinese medicine syndromes of ulcerative colitis

BACKGROUND Ulcerative colitis(UC)is considered to be closely associated with alteration of intestinal microorganisms.According to the traditional Chinese medicine(TCM)theory,UC can be divided into two disease syndromes called Pi-Xu-Shi-Yun(PXSY)and Da-Chang-Shi-Re(DCSR).The relationships among gut microbiota,TCM syndromes,and UC pathogenesis have not been well investigated.AIM To investigate the role of gut microbiota in UC and the distinction of microbiota dysbiosis between PXSY and DCSR syndromes.METHODS From May 2015 to February 2016,UC patients presenting to LongHua Hospital who met the established inclusion and exclusion criteria were enrolled in this retrospective study.Fresh stool specimens of UC patients with PXSY or DCSR were collected.The feces of the control group came from the health examination population of Longhua Hospital.The composition of gut bacterial communities in stool samples was determined by the pyrosequencing of 16S ribosomal RNA.The high-throughput sequencing reads were processed with QIIME,and biological functions were predicted using Phylogenetic Investigation of Communities by Reconstruction of Unobserved States.RESULTS The composition of gut bacterial communities in 93 stool samples(30 healthy controls,32 patients with PXSY syndrome,and 31 patients with DCSR syndrome)was determined by the pyrosequencing of 16S ribosomal RNA.Beta diversity showed that the composition of the microbiota was different among the three groups.At the family level,Porphyromonadaceae,Rikeneliaceae,and Lachnospiraceae significantly decreased while Enterococcus,Streptococcus,and other potential pathogens significantly increased in UC patients compared to healthy subjects.At the genus level,Parabacteroides,Dorea,and Ruminococcus decreased while Faeca-libacterium showed increased abundance in UC compared to healthy controls.Five differential taxa were identified between PXSY and DCSR syndromes.At the genus level,a significantly increased abundance of Streptococcus was observed in DCSR patients,while Lachnoclostridium increased in PXSY patients.The differential functional pathways of the gut microbiome between the PXSY and DCSR groups mainly included lipid metabolism,immunity,and the metabolism of polypeptides.CONCLUSION Our study suggests that the gut microbiota contributes to the distinction between the two TCM syndromes of UC.

Two Hybrid Methods Based on Rough Set Theory for Network Intrusion Detection

In this paper,we propose two intrusion detection methods which combine rough set theory and Fuzzy C-Means for network intrusion detection.The first step consists of feature selection which is based on rough set theory.The next phase is clustering by using Fuzzy C-Means.Rough set theory is an efficient tool for further reducing redundancy.Fuzzy C-Means allows the objects to belong to several clusters simultaneously,with different degrees of membership.To evaluate the performance of the introduced approaches,we apply them to the international Knowledge Discovery and Data mining intrusion detection dataset.In the experimentations,we compare the performance of two rough set theory based hybrid methods for network intrusion detection.Experimental results illustrate that our algorithms are accurate models for handling complex attack patterns in large network.And these two methods can increase the efficiency and reduce the dataset by looking for overlapping categories.

Strong-coupling superconductivity with Tc above 70 K in Be-decorated monolayer T-graphene

Using first-principles calculations,we predict a new type of two-dimensional(2D)beryllium(Be)-decorated T-graphene named BeC_(2),where Be atoms are inserted into C–C bonds linking the carbon tetrarings of T-graphene.The band structure shows that BeC_(2)is metallic,thus,the possible phonon-mediated superconductivity is explored based on the Eliashberg equation.The calculated electron-phonon coupling(EPC)constantλis up to 4.07,and the corresponding superconducting critical temperature(Tc)is 72.1 K,approaching the liquid nitrogen temperature.The reason for the high Tc is the strong EPC.And it is proved to be an anisotropic single-gap superconductor by analyzing the superconducting gap?kof BeC_(2).The electronic susceptibility calculation shows strong nesting effect in BeC_(2).Since rare 2D superconductors show such a strong EPC constantλwhich originates from the coupling between electrons in C-pzorbital and in-plane vibrations of Be and C atoms,the predicted BeC_(2)provides a new platform for investigating strong EPC 2D superconductor.

Altered gut microbiome in FUT2 loss-of-function mutants in support of personalized medicine for inflammatory bowel diseases

The FUT2 loss-of-function mutations are highly prevalent and are associated with inflammatory bowel disease(IBD).To investigate the impact of FUT2 loss-of-function mutation on the gut microbiota in patients with IBD,81 endoscopically confirmed IBD patients were genotyped and divided into 3 groups:homozygous for functional FUT2 genes(SeSe),with one copy of non-functional FUT2 gene(Sese),or homozygous for non-functional FUT2 genes(sese).Escherichia,which attaches to fucosylated glycoconjugates,was the only abundant genus exhibiting decreased abundance in sese patients.Compared with SeSe or Sese patients,sese patients exhibited higher abundance in CD8+inducing Alistipe and Phascolarctobacterium and Th17 inducing Erysipelotrichaceae UCG-003.Counter-intuitively,butyrate-producing bacteria were more abundant in sese patients.Consistently,metabolomics analysis found higher levels of butyrate in sese patients.Our data support the hypothesis that FUT2 loss-of-function mutation participates in the IBD pathogenesis by decreasing binding sites for adherent bacteria and thus altering the gut microbiota.Decreased abundances of adherent bacteria may allow the overgrowth of bacteria that induce inflammatory T cells,leading to intestinal inflammation.As FUT2 loss-of-function mutations are highly prevalent,the identification of T cell inducing bacteria in sese patients could be valuable for the development of personalized microbial intervention for IBD.

Evidence challenging the causal role of gut microbiota in inflammatory bowel diseases

Recently,Bourgonje et al.[1]investigated the antibody epitope repertoire in patients with inflammatory bowel diseases(IBD)[1].Using the high-throughput phage-display immunoprecipitation sequencing(PhIP-Seq)method,they made several significant findings,including elevated antibody reactivities against bacterial flagellins in patients with Crohn’s disease(CD)and the effectiveness of the antibody epitope pattern in differentiating between CD/ulcerative colitis and healthy controls[1].

In silico design of novel proton-pump inhibitors with reduced adverse effects

The development of new proton-pump inhibitors (PPIs) with less adverse effects by lowering the pKa values of nitrogen atoms in pyrimidine rings has been previously suggested by our group. In this work, we proposed that new PPIs should have the following features:(1) number of ring II = number of ring I+ 1;(2) preferably five, six, or seven-membered heteroatomic ring for stability;and (3) 1<pKa1<4. Six molecular scaffolds based on the aforementioned criteria were constructed, and R groups were extracted from compounds in extensive data sources. A virtual molecule dataset was established, and the pKa values of specific atoms on the molecules in the dataset were calculated to select the molecules with required pKa values. Drug-likeness screening was further conducted to obtain the candidates that significantly reduced the adverse effects of long-term PPI use. This study provided insights and tools for designing targeted molecules in silico that are suitable for practical applications.

Lock-up function of fluorine enhances photovoltaic performance of polythiophene

Three model polythiophenes,PTCBT,PTCFBT and PFTCBT,have been synthesized to investigate the effect of fluorination on photovoltaic performance of polythiothenes.Compared with PTCBT,PFTCBT with F atom on TC unit shows a narrower optical bandgap(1.79 eV),higher crystallinity,and ideal morphology in the active layer,leading to a higher short-circuit current density(J_(SC))of 11.84 mA/cm^2 and a power conversion efficiency(PCE)of 5.93%.The lock-up function of fluorine enhances polythiophene backbone planarity and molecular packing.

Systematic review of experiences and effects of integrating post-abortion family planning services into existing health system worldwide

Objective To systematic review and analyze the practices and effects of integrating post-abortion family planning （PAFP） services into existing health system worldwide in order to inform the future interventions to deliver PAFP in China. Methods A systematic search for relevant published and unpublished literature was conducted. Based on a set of criteria, citation and full text were screened, related data were extracted. Findings of included studies were reviewed and analyzed using a textual narrative approach to synthesis. Results A total of 28 studies were included in the synthesis. The studies were published between 1995 and 2008 and covered 20 countries. Some countries were in the stage of piloting post-abortion care （PAC）/PAFP intervention, while others were either from piloting to scaling up or examined how well a pilot PAC/PAFP intervention and resulting improvements were able to be maintained over the long term in the same intervention site. Most studies examined initiatives that were implemented at public sectors from tertiary, secondary to primary health facilities, while a few were imple- mented at private sectors. Efforts of integrating PAFP into existing health system from health system perspectives such as funding the programs, training of trainer （TOT） training or on the job training of physicians and mid-level service provider, expan- sion the range of contraceptive methods available including a few free distribution of contraceptives, improving data collection including cost analysis in a few countries,service guidelines provided to health professionals, supportive supervision at program sites to ensure quality of care, and leadership from government to strengthen PAC/ PAFP service by revising or developing a new national policy. Effects of those intervention programs included that 2 studies decreased abortion rates, 7 studies improved modern contraceptive use, 1 study improved women＇s knowledge on sexual ＆ reproductive health, and 5 studies reported women＇s high satisfaction rate with receiving PAC/PAFP services. Conclusion Each study was conducted within a cultural legal social and religious framework. There might be no single set of best practices that can be put forward as a model to integrate PAFP into existing health system in China. These areas should be taken into account in our future intervention including government＇s optimization and complement to the regulations related to abortion, contraception and PAFP, capacity building for service provider, continuous efforts to improve the quality of PAFP service, and accessibility of multiple contraceptive methods for married as well as unmarried youth.