A novel water-soluble AIE-based fluorescence probe with red emission for the sensitive detection of heparin in aqueous solution and human serum samples

Heparin is widely used to anticoagulation treatment in clinic, while the overdoses of heparin can cause potentially catastrophic complications. Thus, the selective and sensitive detection of heparin is of great importance. Herein, a novel water-soluble AIE-based fluorescent probe (TIBI) with red emission (650 nm) has been rationally developed to detect heparin by the electrostatic-interaction and ion replacing strategy. TIBI exhibited excellent selectivity and low detection limit (0.08 μM) for detection of heparin. Moreover, TIBI was successfully applied to detect heparin in complicated serum samples with satisfactory results. This study holds great promise for real time monitoring heparin in clinical application.     

Residue depletion of valnemulin in swine tissues after oral administration

The depletion profile of valnemulin (VLM) was studied in healthy piglets after oral administration of a premix. Thirty pigs were given doses of 7.5 mg/kg body weight/day in the feed for 21 days. One control and five medicated piglets were randomly selected for sacrifice at 0.25, 0.5, 1, 2 and 3 days post-treatment. The residue concentrations of VLM in swine muscle, liver and kidney were detected using high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). The highest residue concentrations of VLM were attained in 0.25 day, and all of the samples were below the maximum residue limit (MRL) recommended by the European Medical Evaluation Agency (EMEA) at 0.5 day post-treatment. The residue concentrations of swine liver were significantly higher than those of kidney and muscle, which indicated liver to be the target tissue for VLM. The withdrawal period of VLM with oral administration was 24 hours.     

Au nanoparticles based ultra-fast “Turn-On” fluorescent sensor for detection of biothiols and its application in living cell imaging

Au or other metal nanostructures have the ability to strongly quench the fluorescence of fluorophores.This feature has made AuNP-conjugates attractive for the construction of platforms for various bioanalytes to overcome the limitations of small molecule fluorophores(poor solubility,long reaction time).In this paper,an ultrafast "Turn-On" fluo rescent sensor for biothiols was constructed.The sensor is based on the fluorescent resonance energy transfer(FRET) effect between the fluorophore(PN) and AuNPs,which effectively quenches the fluorescence of the fluorophore.In the presence of thiols,PN is displaced and released from AuNP surfaces,and thus,the fluorescence is rapidly restored.The sensor features appreciable water solubility and ultrafast response time(a few seconds for Cys).In addition,it exhibits high selectivity and a detection limit as low as 12 nmol/L for Hcy.Moreover,the sensor presents good biocompatibility and has been successfully applied for imaging biothiols in living cells.     

Superhigh intrinsic proton conductivity in densely carboxylic covalent organic framework

Herein, we developed for the first time two carboxylic acid based intrinsic proton conductors (COOH-COF-1 and COOH-COF-2) via pre-assembly approach. The obtained COOH-COF-1 and COOH-COF-2 not only show outstanding chemical and thermal stabilities, but also exhibit superhigh intrinsic proton conductive behaviors. Especially, the intrinsic proton conductivity of COOH-COF-2 is up to 2.6 × 10⁻³ S/cm at 353 K and 98% RH, which is the highest value among all the reported acid functionalized COFs. This work lights up the way for the rational design of functional COFs with remarkably intrinsic proton conducting performance and related practical applications.     

双核有机锡（IV）配合物[Ph_3Sn(CH_3OH)O_2CC_6H_4CO_2(CH_3OH)-SnPh_3]·2CH_3OH和[Ph_3SnS_2CN(CH_2CH_2)_2NCS_2SnPh_3]·2CH_3OH的合成、表征和晶体结构

利用三苯基氯化锡和对苯二甲酸二钠、哌嗪荒酸二钠在甲醇中反应，合成了双 核有机锡（IV）配合物[Ph_3Sn(CH_3OH)O_2CC_6H_4CO_2(CH_3OH)SnPh_3]· 2CH_3OH和[Ph_3SnS_2CN(CH_2CH_2)_2NCS_2SnPh_3]·2CH_3OH（2）。通过元素分 析、红外光谱和核磁共振氢谱对其结构进行了表征。用X射线单晶衍测定了这两个 化合物的晶体结构。化合物质1为单斜晶系，空间群P2_1/n，a = 1.5199(5) nm， b = 0.9000(3) nm，c = 1.8206(6) nm，β=113.970(5)°，Z = 2，V = 2.2755 (13) nm~3，D_c = 1.413 g/cm~3，μ = 1.146 mm~(-1)，F(000) = 980，R_1 = 0.0353，wR_2 = 0.0606。化合物2为单斜晶系，空间群P2_1/c，a = 1.5066(5) nm，b = 1.0875(4) nm，c = 1.3542(5) nm，β=91.614(5)°，Z = 2，V = 2. 2178(14) nm~3，D_c = 1.498 g/cm~3，μ=1.351 mm~(-1)，F(000) = 1008，R_1 = 0.0401，wR_2 = 0.1148。在1和2的晶体中，锡原子呈五配位畸变三角双锥构型 。配合物1由未配位的甲醇分子通过氢键作用形成二维网状结构。     

新型离子型有机锡化合物{[Ph~2Sn]~2[2,6-Py(CO~2)]~3H~2O}^2^-.[HNEt~3]^+~2的合成、表征、性质及晶体结构

利用三苯基氯化锡和2,6-吡啶二甲酸在三乙胺存在下以1:1摩尔比反应,合成了离子型有机锡化合物{[Ph~2Sn]~2[2,6-Py(CO~2)]~3H~2O}^2^-[HNEt~3]^+~2。通过元素分析、红外光谱和核磁共振氢谱对其结构进行了表征。用X射线单晶衍射测定了该化合物的晶体结构。化合物为单斜晶系,空间群P2~1/n,a=1.7073(7)nm,b=1.7447(7)nm,c=2.5333(10)nm,β=109.694(7)°,Z=4,V=6.824(5)nm^3,D~c=1.282g/cm^3,μ=0.793mm^-^1,F(000)=2696,R~1=0.0563,WR~2=0.1539。化合物中两个锡原子呈七配位畸变五角双锥构型。生物活性测试结果表明,该化合物具有较强的体外抗肿瘤活性。     

On discontinuous motions in systems with unilateral constraints

Mechanical systems with a finite number of degrees of freedom, subject to one or more unilateral geometric constraints, are considered. Apart from the main forms of motion—flying, supported motion and non-degenerate collisions—such systems also show more complex, discontinuous motions, including infinitely many impacts in any neighbourhood of the starting time. These motions are possible not only when no continuous motions exist, but also together with continuous motions [1]. It is proved that, in the case of ideal constraints, if the reactions of the constraints at the starting time are non-zero, there cannot be any discontinuous motion. In systems with dry friction there is yet another type of discontinuity, namely, tangential impact at zero approach velocity. Sufficient conditions for continuity of the motion are derived for this case also. The conditions are verified with examples that use the usual models of impact.     

High ionic conductivity of hydrated Li0.5FeOCl

Iron oxychloride has been lithiated by the reaction with n-butyllithium and thereafter exposed to air. Lithium intercalation increases several orders of magnitude of the electrical conductivity of the pristine material although the intercalate remains a semiconductor. This phase, after being exposed to atmospheric humidity becomes an ionic conductor, with a conductivity comparable to that of some molten salts, and does not show electronic conduction in the whole range of temperatures of measurement (150–300 K), a strong non-Arrhenius behaviour being observed. Impedance spectroscopy and NMR techniques, among others, have been used to follow this behaviour.     

A New Lie Algebra and a Way to Generate Multiple Integrable Couplings

A new higher-dimensional Lie algebra is constructed, which is used to generate multiple integrable couplings simultaneously. From this, we come to a general approach for seeking multi-integrable couplings of the known integrable soliton equations.     

Identification of the tannins in traditional Chinese medicine Paeoniae Radix Alba by UHPLC-Q-Exactive Orbitrap MS

Paeoniae Radix Alba (PRA, dried root of Paeonia lactiflora Pall.) is a widely used as traditional Chinese medicine and tannins are one of their main bioactive ingredients. However, there are rarely systematically investigated in this study. This study aimed to establish a rapid, high selective, high sensitive and effective method based on UHPLC-Q-Exactive Orbitrap MS for simultaneous identification the tannins in PRA. Separation was performed on Thermo Scientific Hypersil GOLD™ aQ (100 mm × 2.1 mm, 1.9 μm) using gradient elution consist of 0.1% formic acid acetonitrile and 0.1% formic acid water as the mobile phase at a flow rate of 0.3 mL/min. The mass spectrometer was operated with Q-Exactive Orbitrap spectrometer in negative ion mode. Finally, a total of 106 constituents were identified in PRA by UHPLC-Q-Exactive Orbitrap MS, 75 of those were reported from PRA for the first time. This result laid the foundation for in-depth research on the material basis efficacy and provided scientific basis for the selection of quality marker of PRA.