Atmospheric deposition of heavy metals in the Pearl River Delta, China

Author name used in this publication: C. S. C. WongAuthor name used in this publication: X. D. LiAuthor name used in this publication: G. ZhangAuthor name used in this publication: S. H. QiAuthor name used in this publication: X. Z. Peng2002-2003 > Academic research: refereed > Publication in refereed journalAccepted ManuscriptPublishe

Heavy metals in agricultural soils of the Pearl River Delta, South China

Author name used in this publication: S. C. WongAuthor name used in this publication: X. D. LiAuthor name used in this publication: G. ZhangAuthor name used in this publication: S. H. QiAuthor name used in this publication: Y. S. Min2001-2002 > Academic research: refereed > Publication in refereed journalAccepted ManuscriptPublishe

Relaxed stability conditions based on Taylor series membership functions for polynomial fuzzy-model-based control systems

© 2014 IEEE. In this paper, we investigate the stability of polynomial fuzzy-model-based (PFMB) control systems, aiming to relax stability conditions by considering the information of membership functions. To facilitate the stability analysis, we propose a general form of approximated membership functions, which is implemented by Taylor series expansion. Taylor series membership functions (TSMF) can be brought into stability conditions such that the relation between membership grades and system states is expressed. To further reduce the con-servativeness, different types of information are taken into account: the boundary of membership functions, the property of membership functions, and the boundary of operating domain. Stability conditions are obtained from Lyapunov stability theory by sum of squares (SOS) approach. Simulation examples demonstrate the effect of each piece of information

Domain freezing in potassium dihydrogen phosphate, triglycine sulfate, and CuAlZnNi

The temperature dependence of the dielectric constant and dissipation in potassium dihydrogen phosphate (KDP), its deuterated compound (DKDP), triglycine sulfate (TGS), and TGS doped with α-alanine (LATGS) has been studied at various frequencies. It is found that the relaxation time of domain freezing in KDP and DKDP in the kHz range can be described by the Vogel-Fulcher relation. Evidence of domain freezing in TGS is presented through an analysis of relaxation time related to domain walls and a comparison between TGS and LATGS. Studies of internal friction and compliance show preliminary evidence of domain freezing in CuAlZnNi alloy. A domain-freezing model is proposed based upon the collective pinning of randomly distributed pinning centers to domain walls. Some key experiments related to domain freezing, such as (1) the Vogel-Fulcher relation for relaxation time; (2) the size effect of domain freezing; (3) two kinds of relaxation in low- and high-frequency ranges, respectively; and (4) the dependence of TF on defect density and applied field, etc., are explained.published_or_final_versio

Effects of Scorpion Venom Heat-Resistant Protein on Seizure Behavior and Expression of Proenkephalin in Rats with Kainate-Induced Epilepsy

Scorpion venom is a traditional antiepileptic medicine in Asia. We examined the effects of scorpion venom heat-resistant protein (SVHRP) on seizure behavior of rats with kainate-induced epilepsy and expression of proenkephalin (pENK) in their hippocampus. Subcutaneous injections of convulsive doses of kainic acid (KA, 10 mg/kg) evoked acute epileptic seizures; the intensity of such seizures was measured after subsequent injections of lower (subthreshold in the norm) doses of KA (5 mg/kg). Scorpion venom heat-resistant protein in a dose of 125 mg/kg was given in a part of the animals through i.p. injections daily during 10 days; rats of the control groups were injected with normal saline. Behavioral indices were measured, and the hippocampus was taken for pENK mRNA estimation by RTPCR analysis. The mean behavioral score of seizure sensitivity in the SVHRP-treated group was smaller significantly (P < 0.05) compared to that in the control group (1.19 vs 2.93). The pENK mRNA level was dramatically greater in hippocampal neurons of KA-treated rats with a high seizure sensitivity, while in the SVHRP-treated group the respective index was significantly lower. Thus, SVHRP inhibits behavior seizures in epilepsy and reverses the abnormally increased pENK mRNA in hippocampal neurons of such animalsОтрута скорпіона є традиційним антиепілептичним терапевтичним засобом в Азії. Ми вивчали вплив термостійкого протеїну з отрути скорпіона (ТСПОС) на судорожну поведінку щурів з викликаною каїнатом епілепсією та на експресію проенкефаліну (пEНК) у їх гіпокампі. Підшкірні ін’єкції «конвульсивних» доз каїнової кислоти (КК, 10 мг/кг) призводили до розвитку гострих епілептичних судом; інтенсивність таких судом вимірювали після наступних ін’єкцій КК (5 мг/кг, підпорогова доза в нормі). Частина тварин отримувала ТСПОС у дозі 125 мкг/кг шляхом внутрішньоочеревинних ін’єкцій щоденно протягом 10 днів; щурам контрольної групи вводили фізіологічний розчин. Вимірювали поведінкові показники; гіпокамп ізолювали для подальшої оцінки пEНК мРНК з використанням RT-PCR-аналізу. Усереднені поведінкові показники судомної чутливості в групі тварин, котрі отримували ТСПОС, були істотно нижче (P < 0.05) таких у контрольній групі (1.19 проти 2.93). У нейронах гіпокампа щурів із високою судомною чутливістю, котрі отримували КК, рівень пЕНК мРНК був істотно вищим, тоді як у тварин з ін’єкціями ТСПОС відповідний показник був значно нижчим. Отже, ТСПОС гальмує поведінкові судоми при епілепсії та різко зменшує аномально збільшений рівень пEНК мРНК у нейронах гіпокампа таких тварин

Tunable Multifunctional Topological Insulators in Ternary Heusler Compounds

Recently the Quantum Spin Hall effect (QSH) was theoretically predicted and experimentally realized in a quantum wells based on binary semiconductor HgTe[1-3]. QSH state and topological insulators are the new states of quantum matter interesting both for fundamental condensed matter physics and material science[1-11]. Many of Heusler compounds with C1b structure are ternary semiconductors which are structurally and electronically related to the binary semiconductors. The diversity of Heusler materials opens wide possibilities for tuning the band gap and setting the desired band inversion by choosing compounds with appropriate hybridization strength (by lattice parameter) and the magnitude of spin-orbit coupling (by the atomic charge). Based on the first-principle calculations we demonstrate that around fifty Heusler compounds show the band inversion similar to HgTe. The topological state in these zero-gap semiconductors can be created by applying strain or by designing an appropriate quantum well structure, similar to the case of HgTe. Many of these ternary zero-gap semiconductors (LnAuPb, LnPdBi, LnPtSb and LnPtBi) contain the rare earth element Ln which can realize additional properties ranging from superconductivity (e. g. LaPtBi[12]) to magnetism (e. g. GdPtBi[13]) and heavy-fermion behavior (e. g. YbPtBi[14]). These properties can open new research directions in realizing the quantized anomalous Hall effect and topological superconductors.Comment: 20 pages, 5 figure

Evolution of oligomeric state through allosteric pathways that mimic ligand binding.

Evolution and design of protein complexes are almost always viewed through the lens of amino acid mutations at protein interfaces. We showed previously that residues not involved in the physical interaction between proteins make important contributions to oligomerization by acting indirectly or allosterically. In this work, we sought to investigate the mechanism by which allosteric mutations act, using the example of the PyrR family of pyrimidine operon attenuators. In this family, a perfectly sequence-conserved helix that forms a tetrameric interface is exposed as solvent-accessible surface in dimeric orthologs. This means that mutations must be acting from a distance to destabilize the interface. We identified 11 key mutations controlling oligomeric state, all distant from the interfaces and outside ligand-binding pockets. Finally, we show that the key mutations introduce conformational changes equivalent to the conformational shift between the free versus nucleotide-bound conformations of the proteins.This is the accepted manuscript. The final version is available from AAAS at http://www.sciencemag.org/content/346/6216/1254346.abstract

Disparities and risks of sexually transmissible infections among men who have sex with men in China: a meta-analysis and data synthesis.

BACKGROUND: Sexually transmitted infections (STIs), including Hepatitis B and C virus, are emerging public health risks in China, especially among men who have sex with men (MSM). This study aims to assess the magnitude and risks of STIs among Chinese MSM. METHODS: Chinese and English peer-reviewed articles were searched in five electronic databases from January 2000 to February 2013. Pooled prevalence estimates for each STI infection were calculated using meta-analysis. Infection risks of STIs in MSM, HIV-positive MSM and male sex workers (MSW) were obtained. This review followed the PRISMA guidelines and was registered in PROSPERO. RESULTS: Eighty-eight articles (11 in English and 77 in Chinese) investigating 35,203 MSM in 28 provinces were included in this review. The prevalence levels of STIs among MSM were 6.3% (95% CI: 3.5-11.0%) for chlamydia, 1.5% (0.7-2.9%) for genital wart, 1.9% (1.3-2.7%) for gonorrhoea, 8.9% (7.8-10.2%) for hepatitis B (HBV), 1.2% (1.0-1.6%) for hepatitis C (HCV), 66.3% (57.4-74.1%) for human papillomavirus (HPV), 10.6% (6.2-17.6%) for herpes simplex virus (HSV-2) and 4.3% (3.2-5.8%) for Ureaplasma urealyticum. HIV-positive MSM have consistently higher odds of all these infections than the broader MSM population. As a subgroup of MSM, MSW were 2.5 (1.4-4.7), 5.7 (2.7-12.3), and 2.2 (1.4-3.7) times more likely to be infected with chlamydia, gonorrhoea and HCV than the broader MSM population, respectively. CONCLUSION: Prevalence levels of STIs among MSW were significantly higher than the broader MSM population. Co-infection of HIV and STIs were prevalent among Chinese MSM. Integration of HIV and STIs healthcare and surveillance systems is essential in providing effective HIV/STIs preventive measures and treatments. TRIAL REGISTRATION: PROSPERO NO: CRD42013003721

The disposition and pharmacokinetics of Dioscorea nipponica Makino extract in rats

This study was aimed to investigate the disposition and pharmacokinetics of the total saponins of dioscorea (TSD) in rats. Male Sprague-Dawley rats were orally administrated with 3H labeled TSD at a single dose ratio of 80 mg TSD per 1 kg rat. Blood samples and feces were collected at different time points to measure the level of TSD activity. At the final time point, determination of the disposition of TSD in lung, kidney, heart, liver, adrenal, and small intestine were performed. From the blood samples' emission of radioactivity, pharmacokinetic parameters were derived as T1/2 = 33.33 ± 4.48 h, T max = 6.5 ± 0.71 h, AUC = 119400 ± 421097.67, and C max = 2643.33 ± 192.26 dpm/ml. There was 51.609% of 3H labeled substance excreted in 24 h. These results suggested that blood concentration of 3H-TSD was extremely low and the majority of TSD was excreted in the feces. The TSD was extensively distributed to multitissues. The radioactivity level was measured to be the highest in the liver, adrenal gland, and wall of the gastrointestinal tract. The radioactivity of TSD was still being detected in blood after 96 h. This showed TSD was excreted in vivo very slowly. © 2008 Academic Journals.published_or_final_versio

Regulating Ion Diffusion and Stability in Amorphous Thiosilicate-Based Solid Electrolytes Through Edge-Sharing Local Structures

\ua9 2024 The Author(s). Advanced Energy Materials published by Wiley-VCH GmbH. Amorphous solid-state electrolytes (SSEs) play a pivotal role as fundamental components within all-solid-state lithium batteries, yet their understanding lags behind that of crystalline materials. In this work, a novel amorphous SSE 5Li2S-3SiS2 (mol %) with a high ionic conductivity of 1.2 mS cm−1 is first reported. The silicon and sulfur atoms in the edge-sharing Si2S64− are less attracted to lithium compared to the SiS44− anion, which is expected to facilitate the lithium ions conduction in SSEs. More importantly, the relationship between the material properties and local structure in the amorphous thiosilicate SSEs is revealed, particularly highlighting the desirable edge-sharing local structure. The Si2S64− presents better stability with Li metal. This work offers an important guideline in the development of anion frameworks in amorphous sulfide SSEs for high-performance all-solid-state lithium metal batteries