Unraveling the relationship between Sr stoichiometry in Sr_(x)Fe_(1.5)Mo_(0.5)O_(6)-σ and its catalytic performance for high-temperature CO_(2) electrolysis

The solid oxide electrolytic cell(SOEC)is one of the most promising energy conversion and storage devices,which could convert CO_(2) to CO with high Faradaic efficiency and production rate.However,the lack of active and stable cathode materials impedes their practical applications.Here we focus on the promising perovskite oxide cathode material Sr_(2)Fe_(1.5)Mo_(0.5)O_(6)-σ,with the aim of understanding how A-atom stoichiometry and catalytic performance are linked.We find that increasing the strontium content in the perovskite improves the chemisorption of CO_(2) on its surface,forming a SrCO_(3) phase.This hinders the charge transfer and oxygen exchange processes.Simulta-neously,strontoium segregation to the cathode surface facilitates coking of the surface during CO_(2) electrolysis,which poisons the electrode.Consequently,a small number of Sr deficiencies are optimal for both electrochemical performance and long-term stability.Our results provide new insights for designing high-performance CO_(2) electrolysis cathode materials.

Essential oils and functional herbs for healthy aging

As total life expectancy increases, the prevalence of age-related diseases such as diabetes and Alzheimer's disease is also increasing. Many hypotheses about Alzheimer's disease have been developed, including cholinergic neuron damage, oxidative stress, and inflammation. Acetylcholine is a major neurotransmitter in the brain and cholinergic deficits leads to cognitive dysfunction and decline. Recent studies have linked diabetes as a risk factor in developing Alzheimer's disease and other types of dementia. The incidence of patients with type II diabetes and increased levels and activity of α-amylase is higher in patients with dementia. It has been shown that aromatherapy with essential oils from the mint family can improve cognitive performance in Alzheimer's disease patients. Selected monoterpenoids from these essential oils are reported to inhibit acetylcholinesterase, both in vitro and in vivo. Terpenoids are small, fat-soluble organic molecules that can transfer across nasal mucosa if inhaled, or penetrate through the skin after topical application, enter into the blood and cross the blood-brain barrier. Recent evidence supports the idea that the common constituents of essential oils also inhibit α-amylase, a starch digestive enzyme that plays an important role in the control of diabetes. The mint family is a fragrant plant family that contains most of the culinary herbs found in the Mediterranean diet. The Mediterranean diet is considered to be one of the healthiest diets in the world, and is found to be beneficial not only for the heart but also for the brain. Herbs used in this diet are rich in antioxidants that can prevent oxidative damage caused by free radicals. However, our study shows that they also contain biologically active compounds with potent α-amylase and acetylcholinesterase inhibitory activities. Consumption of fresh herbs can help boost memory and reduce sugar levels in the body. The use of herbs as a functional food could lead to significant improvements in health. Cognitive stimulation with medical food and medical herbs could delay development of cognitive decline, and improve the quality of life of Alzheimer's disease patients. This effect can be enhanced if combined with aromatherapy, topically or by inhalation, and/or by ingestion. Terpenes and terpenoids, the primary constituents of these essential oils are small, lipid soluble organic molecules that can be absorbed through the skin or across nasal mucosa into the systemic blood circulation. Many terpenes can also cross the blood-brain barrier. Therefore, topical application or inhalation of essential oils will also produce a systemic effect.

Ultrafine tuning of the pore size in zeolite A for efficient propyne removal from propylene

The removal of trace propyne(C_(3)H_(4))from propyne/propylene(C_(3)H_(4)/C_(3)H_(6))mixtures is a technical and challenging task during the production of polymer-grade propylene in view of their very similar size and physical properties.While some progress has been made,it is still very challenging to use some highly stable and commercially available porous materials via an energy-efficient adsorptive separation process.Herein,we report the ultrafine tuning of the pore apertures in type-A zeolites for the highly efficient removal of trace amounts of C_(3)H_(4)from C_(3)H_(4)/C_(3)H_(6)mixtures.The resulting ion-exchanged zeolite 5 A exhibits a large C_(3)H_(4)adsorption capacity(2.3 mmol g^(-1)under 10^(-4)MPa)and high C_(3)H_(4)/C_(3)H_(6)selectivity at room temperature,which were mainly attributed to the ultrafine-tuned pore size that selectively blocks C_(3)H_(6)molecules,while maintaining the stro ng adsorption of C_(3)H_(4)at low pressure region.High purity of C_(3)H_(6)(>99.9999%)can be directly obtained on this material under ambient conditions,as demonstrated by the experimental breakthrough curves obtained for both 1/99 and 0.1/99.9(V V)C_(3)H_(4)/C_(3)H_(6) mixtures.

Join us on an amazing journey towards next-generation treatments for CNS disorders:Launch of Neuroprotection,a new high-quality journal in translational neuroscience

Translational medicine in neurodegenerative and neurovascular diseases is approaching a breakthrough point.Recent years have led to dramatic progress in both experimental and clinical research.Based on a much better and continuously increasing understanding of disease mechanisms,progression and pathophysiology,new therapies with an improved translational potential to protect tissue either against acute or chronic degeneration and even approaches potentially capable of repairing damaged brain tissue are emerging.

Tetradentate Pt(Ⅱ)complex as a singlet exciton sensitizing host for highly efficient green fluorescent organic light-emitting diodes

Efficient green fluorescent organic light-emitting diodes were designed with a phosphorescent metal complex as a singlet exciton sensitizing host(SESH)for achieving high efficiency and low efficiency roll-off through exciton and polaron management.Tetradentate Pt(Ⅱ)complex(Pt-Trz)possessing a tetradentate ligand with a bulky blocking group not only suppresses the severe formation of excimer or dimer itself but also transfers radiative excitons to fluorescent dopant effectively.The SESH assisted fluorescence(SESHF)device with Pt-Trz as the host exhibits the maximum external quantum efficiency of 13.3%and a lower efficiency roll-off compared with exciplex host device which is a general approach for harvesting triplet excitons.Numerical exciton dynamics modeling unravels that the SESHF device effectively utilizes triplet excitons in the host by intersystem crossing and resonance energy transfer from the triplet state of the host to the singlet state of the terminal emitter.Bimolecular quenching rates of the SESHF device are reduced by 11 times for triplet-triplet annihilation and 1.8 times for tripletpolaron annihilation compared with the exciplex device,which demonstrates that Pt-Trz could be a platform to be used as an efficient host for fluorophores.

纳米团簇晶体的制备和结构研究

利用表面调制“幻数团簇”的方法制备出Al、Ga和In的纳米团簇人造晶体。这种方法是用Si(111) 7× 7表面作为“模板”生长尺寸相同和分布有序的纳米团簇。通过扫描隧道显微镜 (STM )原位分析结合第一性原理计算确定了金属纳米团簇的原子结构以及这些结构的形成机理。我们的研究表明对生长动力学的精确控制是制备团簇晶体的关键所在。此外 ,这种方法并不局限于制备某一种金属团簇。人造纳米团簇具有高的热稳定性和独特的结构使它们有希望在实际中得到广泛的应用。

氮气、氧气和空气水合物的合成及其拉曼光谱特征

在-20℃和不同的压力下,在实验室内分别合成了氮气水合物(16MPa)、氧气水合物(13MPa)和空气水合物(15MPa),并对其N—N和O—O键伸缩振动的拉曼光谱特征进行了研究。结果表明,人工合成的水合物中的N—N和O—O键的拉曼位移与天然的空气水合物中的数据十分接近。在氮气水合物和空气水合物中,N—N键的拉曼峰值均为2322.4cm-1;O—O键的拉曼峰值在氧气水合物和空气水合物保持一致,均为1547.8cm-1。空气水合物分解的拉曼谱图表明,它不是氮气水合物和氧气水合物组成的混合物,而是由氮分子和氧分子共同生成的单一水合物,氮分子和氧分子同时进入水合物的大笼和小笼中。与空气中的氮、氧比例相比,水合物中氧分子明显富集,氮分子和氧分子的比例为2.4∶1。

银岛膜表面胸腺嘧啶吸附行为的表面增强拉曼光谱和表面增强红外光谱研究

利用激光刻蚀法制备了具有"化学纯净"表面的银岛膜,该岛膜有很好的表面增强特性。利用表面增强拉曼光谱和表面增强红外光谱对胸腺嘧啶分子在银岛膜表面的吸附状态进行了对比研究。表面增强拉曼光谱中CN和C—O伸缩振动模式的出现表明胸腺嘧啶分子由原来的酮式结构变成了烯醇式结构;C(4)O伸缩振动谱带明显增强和N(3)的去质子化异构体特征峰的存在证明胸腺嘧啶分子是通过O(8)和N(3)的共同作用倾斜地吸附在银岛膜表面。对10-5 mol.L-1胸腺嘧啶在银岛膜表面上的红外光谱利用欧米采样器进行了反射法测量,发现其红外吸收增强了200倍。红外信号分析的结果支持了胸腺嘧啶分子通过O(8)与银表面发生相互作用的论断,同时也可得出胸腺嘧啶倾斜地吸附在银岛膜表面的结论。

ClCN光解过程激发态势能面的MCSCF方法研究

利用MCSCF(MC9/12),双ζ极化基组(DZP)计算了ClCN分子线型离解过程基态~1∑^+及激发态~1∏_(1),~1∏_(2)、~1∑^-、~1△、~1∑^+等和弯曲构型离解过程激发态~1A″,~1A″等的势能曲线及势能面。最低单重激发态~1∏_(1)—~1A″_(0)势能面,在分子光解过程中不与其它激发态势能面相交。论证了该分子光解过程最可能的通道是:由分子平衡构型的X^1∑^+态激发到~1∏_(1)-~1A″_(0)态得到基态分子碎片CN(X^2∑^+)+Cl(~2P)。从激发态的势能面得到分子光解经历了一个大角度弯曲过程的结论,说明了交叉分子束实验事实—ClCN分子光解碎片的转动能量分布反转。

Defensin expression in chronic pouchitis in patients with ulcerative colitis or familial adenomatous polyposis coli

瞄准：当在在为家庭腺瘤息肉病关口 i (FAP ) 的 proctocolectomy 以后的病人是稀罕的时， Pouchitis 在小袋外科以后在开始的 10 年期间与 ulcerative 在多达 50% 病人在 ileoanal 小袋发展症候群。Defensins 是天生的免疫系统的主要部件并且在胃肠的微生物引起的动态平衡起一个重要作用。小袋 defensin 和 cytokine 表示与小袋发炎的状态被相关在 pouchitis 学习他们的角色。方法：有 ulcerative 和 FAP 症候群的病人在外科以后与小袋被成层进组，小袋没有或与 pouchitis。从从健康的肠或从有 ulcerative 的病人的正常终端回肠的终端回肠的活体检视用作控制。从小袋和控制的 mRNA 为 defensin 和 cytokine 表示被分析。结果：defensins 的表示在外科以后立即在所有小袋被增加，与控制的回肠相比。开始，在 ulcerative 的小袋比 FAP 小袋揭示了更高的 defensin 表示。Defensin 表示在两个耐心的组衰退了并且与 ulcerative 在病人在 pouchitis 稍微再增加了。没有 pouchitis 的 FAP 小袋有 beta-defensin hBD-1 的强壮的表示，当所有另外的 defensins 在底层留下了时。在 ulcerative 小袋的 Cytokine 表示高，当 FAP 小袋仅仅在外科以后显示出中等提高的 cytokines 时。结论：pouchitis 的开发除了 cytokines 的高表示在 ulcerative 与减少的 defensin 表示相关。在 FAP 小袋的 pouchitis 的低发生与低 cytokine 层次联合与 hBD-1 beta-defensin 的增加的表示相关。

Metastatic pattern in esophageal and gastric cancer:Influenced by site and histology

BACKGROUND Detailed information on metastatic patterns in of patients with esophageal and gastric cancer is limited.Early recognition of metastases is important to avoid futile locoregional treatments.Furthermore,knowledge on metastatic patterns is necessary for further development of personalized treatment modalities.AIM To gain insight into the metastatic pattern of gastroesophageal cancer.METHODS A nationwide retrospective autopsy study of 3876 patients with adenocarcinoma(AC)or squamous cell carcinoma(SCC)of the esophagus or stomach between 1990 and 2017 was performed.Only patient with metastases were included for analysis.The metastatic pattern was analyzed according to the primary tumor location and histological subtype.RESULTS Metastatic disease was found in 268 esophageal and 331 gastric cancer patients.In esophageal cancer,the most common metastatic locations were liver(56%),distant lymph nodes(53%)and lung(50%).Esophageal AC showed more frequently metastases to the peritoneum and bone compared with esophageal SCC.In gastric cancer,the most common metastatic locations were distant lymph nodes(56%),liver(53%)and peritoneum(51%).Intestinal-type AC of the stomach showed metastases to the liver more frequently,whereas metastases to the bone,female reproductive organs and colorectum were observed more frequently in diffuse-type gastric AC.CONCLUSION This study showed differences in metastatic patterns of patients with esophageal and gastric cancer according to the primary tumor location and histological subtype.

Investigation of ultrafast dynamics of CdTe quantum dots by femtosecond fluorescence up-conversion spectroscopy

The ultrafast carrier relaxation processes in CdTe quantum dots are investigated by femtosecond fluorescence upconversion spectroscopy.Photo-excited hole relaxing to the edge of the forbidden gap takes a maximal time of ～ 1.6 ps with exciting at 400 nm,depending on the state of the photo-excited hole.The shallow trapped states and deep trap states in the forbidden gap are confirmed for CdTe quantum dots.In addition,Auger relaxation of trapped carriers is observed to occur with a time constant of ～ 5 ps.A schematic model of photodynamics is established based on the results of the spectroscopy studies.Our work demonstrates that femtosecond fluorescence up-conversion spectroscopy is a suitable and effective tool in studying the transportation and conversion dynamics of photon energy in a nanosystem.

Candidate colorectal cancer predisposing gene variants in Chinese early-onset and familial cases

AIM: To investigate whether whole-exome sequencing may serve as an efficient method to identify known or novel colorectal cancer(CRC) predisposing genes in early-onset or familial CRC cases.METHODS: We performed whole-exome sequencing in 23 Chinese patients from 21 families with nonpolyposis CRC diagnosed at ≤ 40 years of age, or from multiple affected CRC families with at least 1 firstdegree relative diagnosed with CRC at ≤ 55 years of age.Genomic DNA from blood was enriched for exome sequences using the Sure Select Human All Exon Kit, version 2(Agilent Technologies) and sequencing was performed on an Illumina Hi Seq 2000 platform.Data were processed through an analytical pipeline to search for rare germline variants in known or novel CRC predisposing genes.RESULTS: In total, 32 germline variants in 23 genes were identified and confirmed by Sanger sequencing.In 6 of the 21 families(29%), we identified 7 mutations in 3 known CRC predisposing genes including MLH1(5 patients), MSH2(1 patient), and MUTYH(biallelic, 1 patient), five of which were reported as pathogenic.Inthe remaining 15 families, we identified 20 rare and novel potentially deleterious variants in 19 genes, six of which were truncating mutations.One previously unreported variant identified in a conserved region of EIF2AK4(p.Glu738_Asp739insA rgA rg) was found to represent a local Chinese variant, which was significantly enriched in our early-onset CRC patient cohort compared to a control cohort of 100 healthy Chinese individuals scored negative by colonoscopy(33.3% vs 7%, P < 0.001).CONCLUSION: Whole-exome sequencing of early-onset or familial CRC cases serves as an efficient method to identify known and potential pathogenic variants in established and novel candidate CRC predisposing genes.

红外吸收峰的位置波动:归因于单一谱带的频移还是重叠谱带相对强度的变化?

红外吸收峰的位置波动可能由单一谱带的实际频移或是邻近重叠谱带相对强度的变化而产生。本文通过主成分分析法(PCA)有力地证明了光谱位置波动的根源往往归因于后一种机理。PCA能灵敏有效地区分单一谱带的实际频移与由重叠谱带相对强度变化所产生的最大峰移。对于由分子相互作用强度变化所诱导,并在振动光谱领域较为常见的所谓"带移"的概念,往往由于其隐含了谱带的固有频移而有些概念误导。在许多红外光谱中,峰极大值表面的位移,一般产生于两条重叠谱带相对贡献的变化,而不是分子相互作用强度变化所诱导的单一谱带的缓慢频移。这个观点可以帮助我们解释振动光谱所探测到的分子相互作用。

Metabolomic changes in fatty liver can be modified by dietary protein and calcium during energy restriction

AIM: To characterise the effect of energy restriction (ER) on liver lipid and primary metabolite profile by using metabolomic approach. We also investigated whether the effect of energy restriction can be further enhanced by modif ication of dietary protein source and calcium. METHODS: Liver metabolomic profile of lean and obese C57Bl/6J mice (n = 10/group) were compared with two groups of weight-reduced mice. ER was performed on control diet and whey protein-based high-calcium diet (whey + Ca). The metabolomicanalyses were performed using the UPLC/MS based lipidomic platform and the HPLC/MS/MS based primary metabolite platform. RESULTS: ER on both diets significantly reduced hepatic lipid accumulation and lipid droplet size, while only whey + Ca diet significantly decreased blood glucose (P < 0.001) and serum insulin (P < 0.01). In hepatic lipid species the biggest reduction was in the level of triacylglycerols and ceramides while the level of cholesterol esters was significantly increased during ER. Interestingly, diacylglycerol to phospholipid ratio, an indicator of relative amount of diabetogenic diglyceride species, was increased in the control ER group, but decreased in the whey + Ca ER group (P < 0.001, vs obese). ER on whey + Ca diet also totally reversed the obesity induced increase in the relative level of lipotoxic ceramides (P < 0.001, vs obese; P > 0.05, vs lean). These changes were accompanied with up-regulated TCA cycle and pentose phosphate pathway metabolites. CONCLUSION: ER-induced changes on hepatic metabolomic profile can be significantly affected by dietary protein source. The therapeutic potential of whey protein and calcium should be further studied.

Efficient capture of C_(2)H_(2)from CO_(2)and C_(n)H_(4)by a novel fluorinated anion pillared MOF with flexible molecular sieving effect

The efficient separation of acetylene(C_(2)H_(2))from carbon dioxide(CO_(2))and CnH_(4)(n=1 and 2)to manufacture high purity C_(2)H_(2)and recover other light hydrocarbons is technologically important,while posing significant challenges.Herein,we reported a new TiF62−anion(TIFSIX)pillared metal-organic framework(MOF)ZNU-5(ZNU=Zhejiang Normal University)with ultramicropores for highly selective C_(2)H_(2)capture with low adsorption heat through gate opening based molecular sieving effect.ZNU-5 takes up a large amount of C_(2)H_(2)(128.6 cm^(3)/g)at 1.0 bar and 298 K but excludes CO_(2),CH_(4),and C_(2)H_(4).Such high capacity has never been realized in MOFs with molecular sieving.The breakthrough experiments further confirmed the highly selective C_(2)H_(2)separation performance from multi-component gas mixtures.3.3,2.8,and 2.2 mmol/g of C_(2)H_(2)is captured at ZNU-5 from equimolar C_(2)H_(2)/CO_(2),C_(2)H_(2)/CO_(2)/CH_(4),and C_(2)H_(2)/CO_(2)/CH_(4)/C_(2)H_(4)mixtures,respectively.Furthermore,2.6,2.0,and 1.5 mmol/g of>98%purity C_(2)H_(2)can be recycled from the desorption process.Combining high working capacity,low adsorption heat,as well as good recyclability,ZNU-5 is promising for C_(2)H_(2)purification.

Th-MOF showing six-fold imide-sealed pockets for middle-sizeseparation of propane from natural gas

Separation of propane from natural gas is of great importance to industry.However,in light of size-based separation,there still lacks effective method to directly separate propane from natural gas,due to the comparable physical properties for these light alkanes(C1–C4)and the middle size of propane.In this work,we found that a new Th-metal-organic framework(MOF)could be an ideal solution for this issue.The Th-MOF takes UiO-66-type structure,but with the pocket sealed by six-fold imide groups;this not only precisely reduces the size of pocket to exactly match propane,but also enhances the host–guest interactions through multiple(C)H(^(δ+))∙∙∙(^(δ−))O(C)interactions.As a result,highly selective adsorption of propane over methane,ethane,and butane was observed,implying unique middle-size separation.The actual separation was confirmed by breakthrough experiments of simulated natural gas,confirming its superior application in direct separation of propane from natural gas.The separation mechanism,as unveiled by both theoretical calculation and comparative experiments,is due to the six-fold imide-sealed pocket that could effectively distinguish propane from other light alkanes through both size effect and host–guest interactions.

Reaction mechanism of hydrogen activation by frustrated Lewis pairs

Typically, a Lewis acid and a Lewis base can react with each other and form a classical Lewis adduct. The neutralization reaction can however be prevented by ligating the acid and base with bulky substituents and the resulting complex is known as a "frustrated Lewis pair"(FLP). Since the Lewis acid and base reactivity remains in the formed complex, FLPs can display interesting chemical activities, with promising applications in catalysis. For example, FLPs were shown to function as the first metal-free catalyst for molecular hydrogen activation. This, and other recent applications of FLPs, have opened a new thriving research field. In this short-review, we recapitulate the computational and experimental studies of the H_2 activation by FLPs. We discuss the thus-far uncovered mechanistic aspects, including pre-organization of FLPs,the reaction paths for the activation, the polarization of He H bond and other factors affecting the reactivity. We aim to provide a rather complete mechanistic picture of the H_2 activation by FLPs, which has been under debate for decades since the first discovery of FLPs. This review is meant as a starting point for future studies and a guideline for industrial applications.