Effect of cetyltrimethylammonium bromide on morphology and porous structure of mesoporous hydroxyapatite

The mesoporous hydroxyapatite （HA） was synthesized by hydrothermal method utilizing cationic surfactant cetyltrimethylammonium bromide （CTAB） as template. The crystalline phase, morphology and porous structure were characterized respectively by different detecting techniques. The results reveal that the particles are highly crystalline hydroxyapatite phase. The surfactant has little influence on the morphology of the crystals, but affects the porous structure obviously. The sample without CTAB has a low surface area not exceeding 33 m^2/g, and no distinct pores can be observed by TEM. While the samples obtained with the surfactant get better parameters. Numerous open-ended pores centered at 2-7 nm spread unequally on the surface of the hydroxyapatite nanorods. The N2 adsorption-desorption experiments show type IV isotherms with distinct hysteresis loops, illustrating the presence of mesoporous structure. When the mole ratio of CTAB to HA is 1：2, the sample has the largest surface area of 97.1 m^2/g and pore volume of 0.466 cm^3/g.

Rational construction of thermally stable single atom catalysts:From atomic structure to practical applications

As a new frontier in catalysis field,single-atom catalysts(SACs)hold unique electronic structure and high atom utilization,which have displayed unprecedented activity and selectivity toward a wide range of catalytic reactions.However,many reported SACs are susceptible to Ostwald ripening process in high temperature environment or long-term catalytic application,which will cause sintering and deactivation.This is due to the weak interaction between the metal atom and supports.The regeneration and recycling of deactivated catalysts will greatly increase the time and economic cost of industrial production.Therefore,it is necessary to develop SACs with excellent thermal stability to meet the industrial demands.Here,we discuss the fundamental comprehension of the stability of thermally stable SACs obtained from different synthesis methods.The influences of the speciation of metal centers and coordination environments on thermal stability are summarized.The importance of using novel in situ and operando characterizations to reveal dynamic structural evolution under synthesis and reaction conditions and to identify active sites of thermally stable SACs is highlighted.The mechanistic understanding of the unique role of thermally stable SACs in thermocatalytic application is also discussed.At last,a brief perspective on the remaining challenges and future directions of thermally stable SACs is presented.

Er^(3+)-activated silica inverse opals synthesized by the solgel method

We present the details of the sol-gel processing used to realize inverse silica opal,where the silica was activated with 0.3 mol% of Er3+ ions. The template(direct opal) was obtained assembling polystyrene spheres of the dimensions of 260 nm by means of a vertical deposition technique. The Er3+-activated silica inverse opal was obtained infiltrating,into the void of the template,the silica sol doped with Er3+ ions and subsequently removing the polystyrene spheres by means of calcinations. Scanning electron microscope showed that the inverse opals possess a fcc structure with a air hollows of about 210 nm and a photonic band gap,in the visible range,was observed from reflectance measurements. Spectroscopic properties of Er3+-activated silica inverse opal were investigated by luminescence spectroscopy,where,upon excitation at 514.5 nm,an emission of 4I13/2 → 4I15/2 of Er3+ ions transition with a 21 nm bandwidth was observed. Moreover the 4I13/2 level decay curve presents a single-exponential profile,with a measured lifetime of 18 ms,corresponding a high quantum efficiency of the system.

Preparation, characterization and catalytic performance of single-atom catalysts

Supported and colloidal single‐atom catalysts(SACs),which possess excellent catalytic properties,are particularly important in both fundamental studies and practical applications.The progress made in the preparation methods,characterization,catalytic performances and mechanisms of SACs anchored to metal oxides,two‐dimensional materials and the surface of metal nanoclusters(NCs)are reviewed.The different techniques for SAC fabrication,including conventional solution methods based on co‐precipitation,incipient wetness co‐impregnation,and the chemical vapor deposition method,as well as the newer atom layer deposition(ALD)and galvanic replacement methods,are summarized.The main results from experimental and theoretical studies of various catalytic reactions over SACs,including oxidation reactions,hydrogenation,water gas shift,photocatalytic H2evolution and electrochemical reactions,are also discussed.Moreover,the electronic properties of the single atoms and their interactions with the supports are described to assist in understanding the origin of the high catalytic activity and selectivity of SACs.Finally,possible future research directions of SACs and their applications are proposed.

Is sentinel lymph node biopsy necessary for the patients diagnosed with breast ductal carcinoma in situ using core needle biopsy or vacuum-assisted biopsy as the initial diagnostic method？

Axillary lymph node status is one of the most important prognostic indicator of survival for breast cancer, especially in ductal carcinoma in situ （DCIS）. The purpose of this study was to investigate whether sentinel lymph node biopsy （SLNB） should be performed in patients with an initial diagnosis of DCIS. Methods： A retrospective study was performed of 124 patients with an initial diagnosis of DCIS between March 2000 and June 2014. The patients were treated with either SLNB or axillary node dissection during the surgery, and we compared the clinicopathologic characteristics, image features, and immunohistochemical results. Results： Eighty-two patients （66.1%） had pure DCIS and 25 （20.2%） had DCIS with microinvasion （DCISM）, 17 （13.7%） updated to invasive breast cancer （IBC）. 115 patients （92.7%） underwent SLNB, among them, 70 patients （56.5%） underwent axillary node dissection. 3 of 115 patients （2.6%） had a positive sentinel lymph node, only 1 （1.4%） of 70 patients had axillary lymph node metastasis, in 84 patients （66.7%） who were diagnosed DCIS by core needle biopsy （CNB） and vacuum-assisted biopsy （VAB）. 26 patients （31.0%） were upstaged into IBC or DCISM in the final histological diagnosis. The statistically significant factors predictive of underestimation were large tumor size, microcalcifications, comedo necrosis, positive Her-2 status, negative estrogen receptor status. Conclusion： The metastasis of sentinel lymph nodes in pure DCIS is very low, but the underestimation of invasive carcinoma in patients with an initial diagnosis of DCIS is an usual incident, especially in the cases when DCIS is diagnosed by CNB or VAB. Our findings suggest patients presenting with a preoperative diagnosis of DCIS associated with large tumor sizes, microcalcifications, comedo necrosis, positive Her-2 status, negative ER status are more likely to be DCISM and IBC in final diagnosis. SLNB should be performed in this part of patients.

Predicting intrinsic disorder in proteins： an overview

The discovery of intrinsically disordered proteins （IDP） （i.e., biologically active proteins that do not possess stable secondary and/or tertiary structures） came as an unexpected surprise, as the existence of such proteins is in contradiction to the traditional ＂sequence →structure →function＂ paradigm. Accurate prediction of a protein＇s predisposition to be intrinsically disordered is a necessary prerequisite for the further understanding of principles and mechanisms of protein folding and function, and is a key for the elaboration of a new structural and functional hierarchy of proteins. Therefore, prediction of IDPs has attracted the attention of many researchers, and a number of prediction tools have been developed. Predictions of disorder, in turn, are playing major roles in directing laboratory experiments that are leading to the discovery of ever more disordered proteins, and thereby leading to a positive feedback loop in the investigation of these proteins. In this review of algorithms for intrinsic disorder prediction, the basic concepts of various prediction methods for IDPs are summarized, the strengths and shortcomings of many of the methods are analyzed, and the difficulties and directions of future development of IDP prediction techniques are discussed.

Design and Synthesis of Novel Fluorine-containing Acrylates

A series of novel fluorine-containing acrylates 6a-6g were synthesized via the condensation of ethyl cyanoacetate and trifluoroacetic anhydride, followed by chloridization and the coupling reaction with amines. These new compounds exhibited some biological activity as preliminary bioassay indicated. A plausible reaction mechanism was outlined and discussed.

Colorectal cancer lymph node staining by activated carbon nanoparticles suspension in vivo or methylene blue in vitro

AIM:To investigate whether activated carbon nanoparticles suspension(ACNS) or methylene blue(MB) can increase the detected number of lymph nodes in colorectal cancer.METHODS:Sixty-seven of 72 colorectal cancer patients treated at our hospital fulfilled the inclusion criteria of the study which was conducted from December 2010 to February 2012.Seven patients refused to participate.Eventually,60 patients were included,and randomly assigned to three groups(20 in each group):ACNS group(group A),MB group(group B) and non-stained conventional surgical group(group C).In group A,patients received subserosal injection of 1 mL ACNS in a 4-quadrant region around the mass.In group B,the main artery of specimen was identified and isolated after the specimen was removed,and 2 mL MB was slowly injected into the isolated,stretched and fixed vessel.In group C,no ACNS and MB were injected.All the mesentery lymph nodes were isolated and removed systematically by visually inspecting and palpating the adipose tissue.RESULTS:No difference was observed among the three groups in age,gender,tumor location,tumor diameter,T-stage,degree of differentiation,postoperative complications and peritoneal drainage retention time.The total number of detected lymph nodes was 535,476 and 223 in the three groups,respectively.The mean number of detected lymph nodes per patient was significantly higher in group A than in group C(26.8 ± 8.4 vs 12.2 ± 3.2,P < 0.001).Similarly,there were significantly more lymph nodes detected in group B than in group C(23.8 ± 6.9 vs 12.2 ± 3.2,P < 0.001).However,there was no significant difference between group A and group B.There were 50,46 and 32 metastatic lymph nodes dissected in 13 patients of group A,10 patients of group B and 11 patients of group C,without significant differences among the three groups.Eleven of the 60 patients had insufficient number of detected lymph nodes(< 12).Only one patient with T 4a rectal cancer had 10 lymph nodes detected in group B,the other 10 patients were all from group C.Based on the different diameter categories,the number of detected lymph nodes in groups A and B was significantly higher than in group C.However,there was no statistically significant difference between group A and group B.The metastatic lymph nodes were not significant different among the three groups.Similarly,tumor location,T stage and tumor differentiation did not affect the staining results.Body mass index was a minor influencing factor in the two different staining methods.The stained lymph nodes can easily be identified from the mesenteric adipose tissues,and the staining time for lymph nodes was not significantly different compared with unstained group.None of the patients in groups A and B had drug-related complications.CONCLUSION:Both activated carbon nanoparticles suspension in vivo and methylene blue in vitro can be used as tracers to increase the detected number of lymph nodes in colorectal cancer.

Decreasing Pin1 suppresses telomerase activity by NF-κB in HCT116 cells colorectal carcinoma

Objective： The aim of our study was to investigate the effect of Pin 1 on the telomerase activity in human colorectal carcinoma HCT116 cells. Methods： Firstly, we transfected plasmid pGenesil-l-Pinl （p-shRNA） using liposome （Lipofectamine 2000） into colorectal cancer HCT-116 cells to down-regulate the expression of Pin1. To detect the apoptotic rate of HCT116 cells was by cytometry （FCM）. The expression of Pin1 and hTERT at RNA levels in human colorectal cancer HCT116 cells were determined by RT-PCR. To evaluate the activity of telomerase was by TRAP-silver staining. The subcellular localization and accumulative level of p-NF-κB/p65 protein at the nuclear was detected by Immunofluorescence and Western blotting. The DNA-binding activity of NF-κB/p65 was detected by electrophoretic mobility shift assay （EMSA）. Results： Using liposome into colorectal cancer HCT-116 cells, and down-regulate the expression of Pin1 （0.392 ± 0.072-fold; P = 0.001）, and the apoptotic rate was increased （11.40% ± 1.54%; P 〈 0.05）. Compared with transfected p-CON cell group, in transfected p-shRNA cell group, the transcription of hTERT was lower （0.171 ±0.060-fold; P = 0.001） by quantitative real-time RT-PCR, and the results of TRAP-silver staining analysis suggested that the telomerase activity was significantly declined （0.384 ± 0.015-fold; P 〈 0.05）. Furthermore, it was demonstrated by Immunofluorescence that p-NF-κB/p65 had a nuclear localization, and the level of p-NF-κB/p65 protein at the nuclear was reduced with silencing the expression of Pin1 by Western blotting. Using EMSA, it was suggested that NF-κB/p65 was able to bind to hTERT promoter, and the direct interaction was declined with silencing the expression of Pin1. Conclusion： Taken together, silencing Pin1 may suppress activity of telomerase and the expression of hTERT by inhibiting NF-κB/p65 activity and reducing the combination of NF-κB/p65 and hTERT gene promoter.

给蛇口戴个帽

在手竿主线与竿梢蛇口线的连接上，不少钓友采用“活结法”。即在主线一端10厘米处回折后打上下两个结，组装时将食指、中指插入两结间后翻转勾出一活扣，然后将它套在事先已在竿梢蛇口线末端打好的一死结后方拉紧即可。此种连接方法十分实用，但美中不足的是在垂钓过程中有松脱的可能，

Structure for energy cycle: a unique status of the second law of thermodynamics for living systems

Distinguishing things from beings, or matters from lives, is a fundamental question. Extending E. Schr?dinger's neg-entropy and I. Prigogine's dissipative structure, we propose a chemical kinetic view that the earliest "live" process is embedded essentially in a special interaction between a pair of specific components under a particular, corresponding environmental conditions. The interaction exists as an inter-molecular-force-bond complex(IMFBC) that couples two separate chemical processes: one is the spontaneous formation of the IMFBC driven by a decrease of Gibbs free energy as a dissipative process; while the other is the disassembly of the IMFBC driven thermodynamically by free energy input from the environment. The two chemical processes coupled by the IMFBC originated independently and were considered non-living on Earth, but the IMFBC coupling of the two can be considered as the earliest form of metabolism: the first landmark on the path from things to a being. The dynamic formation and disassembly of the IMFBC, as a composite individual, follows a principle designated as "… structure for energy for structure for energy…", the cycle continues; and for short it will be referred to as "structure for energy cycle". With additional features derived from this starting point, the IMFBC-centered "live" process spontaneously evolved into more complex living organisms with the characteristics currently known.

Clinical Observations on 100 Cases of Ulcerative Colitis Treated with the Method of Clearing Away Heat,Expelling Dampness,Promoting Blood Circulation and Healing Ulcer

Objective： To observe the clinical therapeutic effect of dampness, promoting blood circulation and healing ulcer on the method of clearing away heat, expelling ulcerative colitis. Methods： The 100 cases were randomly divided into a control group of 45 cases treated with retention enema of the enterosoluble tablet sulfasalazine once every evening and a treatment group of 55 cases treated with retention enema of the decoction for clearing away heat, expelling dampness, promoting blood circulation and healing ulcer once every evening. The patients in both groups orally took Chinese drug for basic treatment for 30 days as a course. After treatment, the clinical therapeutic effects in the 2 groups were compared and changed symptoms in intestinal mucosa were observed under endoscope. Results： The total effective rate of treatment group was better in relieving symptoms of TCM syndrome （90.9%） and intestinal mucosa （83.3%） than that of control group （68.9%, 56.3%） （P〈0.01 or P〈0.05）. Conclusion： With good therapeutic effect on ulcerative colitis, Qinghua Huoxue Lianyang therapy （clearing away heat, expelling dampness, promoting blood circulation and healing ulcer） can obviously repair intestinal mucosa.

A simple electrochemical method for conversion of Pt wires to Pt concave icosahedra and nanocubes on carbon paper for electrocatalytic hydrogen evolution

In the controlled synthesis of noble metal nanostructures using wet-chemical methods, normally, metal salts/complexes are used as precursors, and surfactants/ligands are used to tune/stabilize the morphology of nanostructures. Here, we develop a facile electrochemical method to directly convert Pt wires to Pt concave icosahedra and nanocubes on carbon paper through the linear sweep voltammetry in a classic three-electrode electrochemical cell. The Pt wire, carbon paper and Ag/AgCl(3 mol L-1 KCl) are used as the counter, working and reference electrodes, respectively.Impressively, the formed Pt nanostructures exhibit better electrocatalytic activity towards the hydrogen evolution compared to the commercial Pt/C catalyst. This work provides a simple and effective way for direct conversion of Pt wires into well-defined Pt nanocrystals with clean surface. We believe it can also be used for preparation of other metal nanocrystals,such as Au and Pd, from their bulk materials, which could exhibit various promising applications.

On the Tangent Bundle of a Hypersurface in a Riemannian Manifold

Let （Mn, g） and （N^n＋1, G） be Riemannian manifolds. Let TMn and TN^n＋1 be the associated tangent bundles. Let f ： （M^n, g） → （N^＋1, G） be an isometrical immersion with g = f^＊G, F = （f, df） ： （TM^n,g） → （TN^n＋1, Gs） be the isometrical immersion with g= F＊Gs where （df）x ： TxM → Tf（x）N for any x∈ M is the differential map, and Gs be the Sasaki metric on TN induced from G. This paper deals with the geometry of TM^n as a submanifold of TN^n＋1 by the moving frame method. The authors firstly study the extrinsic geometry of TMn in TN^n＋1. Then the integrability of the induced almost complex structure of TM is discussed.

Upper crustal P-wave velocity structure beneath two volcanic areas in northern Iran

Detailed information about the crustal structure is essential for better understanding the occurrence and mechanisms of earthquakes and volcanoes.Here we present a study of the upper crustal P-wave velocity structure of two seismically and volcanically active areas in northern Iran using the two-dimensional Pg travel time tomography method.The imaging results suggest low velocities in the upper crust beneath the Damavand and Sahand-Sabalan volcanic areas in the central and western parts of northern Iran,respectively.The upper crustal low velocities in these two areas roughly coincide with previously imaged low Pn velocity anomalies,suggesting that the Late Cenozoic volcanic activity was probably caused by the upwelling of hot materials from the mantle.The image feature of the Pg velocity structure beneath the Sahand-Sabalan volcanic area further indicates that the hot materials stored in the upper crust beneath Sahand may be larger in size than those stored beneath Sabalan.Comparison of the Pg velocity images with the earthquake distribution in north Iran suggests that earthquakes mainly occur at moderately low velocity or low to high velocity boundary areas instead of significantly low or high velocity regions.The anisotropy results show that the Pg wave fast direction is consistent with the GPS direction at high Pg velocity areas and the fast direction is inconsistent with the GPS direction but consistent with the strike direction of faults at low velocity areas.Our new upper crustal structural images provide the basic observation for better understanding of the regional seismicity and volcanism,and link the surface geological phenomena to deep crustal and mantle processes associated with the active tectonics in northern Iran.