Dawei Qin

Nanohydrogels show great potential as efficient drug carriers due to their biocompatibility, low toxicity, and high water absorbability. In this paper, we prepared two O-carboxymethylated chitosan (OCMC)-based polymers functionalized with β-cyclodextrin (β-CD) and amino acid. The structures of the polymers were characterized by Fourier Transform In...

Camptothecin is a naturally occurred anticancer drug but exhibits limitations including poor aqueous solubility, low bioavailability, and high level of adverse drug reactions on normal organs. To overcome these problems, this paper developed a novel amphiphilic Lau-Leu-HES carrier using hydroxyethyl starch, lauric acid, and L-leucine as starting ma...

This study designed a pH-sensitive nanogel based on sodium alginate and chitosan. In order to improve the solubility of chitosan and reduce the toxicity caused by crosslinking agent, a specific synthetic pathway was designed. Structural modification of chitosan with various hydroxypropyl and carboxyl groups afforded a chitosan derivative (CHPCS), w...

A novel fluorescein-based probe FLA-Boe was developed for detecting H2O2. Modified by 2-Bromomethylphenylboronic acid pinacol ester, FLA-Boe is a Fluorescein derivative with eminent photostability and remarkable H2O2 sensitivity and selectivity. FLA-Boe was utilized to synthesize hydrogel sensors in the manner of guest–host interaction by taking ad...

The selective and efficient monitoring of mercury (Hg2+) contamination found in the environment and ecosystem has been carried out. Thus, a new 1,8‐naphthalimide‐based fluorescent probe NADP for the detection of Hg2+ based on a fluorescence enhancement strategy has been designed and synthesized. The NADP probe can detect Hg2+ with high selectivity...

A new phenothiazine‐based sensor PHE‐Ad for monitoring Hg2+ has been designed and synthesized based on the intramolecular charge transfer (ICT) mechanism. The probes were characterized by FTIR, 1H NMR, and HRMS, and their optical properties were detected by UV and FL. It's showed the probes detection of Hg2+ compared to other metal ions (Mg2+, Cu2+...

Many precedents prove that fluorescent probes are promising candidates for detection of metal ions in the environment and biological systems. Herein, two novel photoinduced electron transfer (PET)-based fluorescent probes, CH 3 -R6G and CN-R6G, were rationally synthesized by incorporating a triazolyl benzaldehyde moiety into the rhodamine 6G fluoro...

A highly effective method for the research and development of a novel macroscopic hydrogel sensor and bilayer hydrogel is reported. Based on Rhodamine 6G, an Hg2+ sensitive fluorescent functional monomer was synthesized, then the monomer was utilized to synthesize hydrogel sensors and bilayer hydrogels. Hydrogel sensor has prominent selectivity to...

Fe(II)-montmorillonites (Fe(II)-MMTs) were prepared by mixing solutions of Fe(II) and montmorillonite at pH 3.5. Two different Fe(II)-MMTs were prepared and the ferrous iron contents were 40 mg/L and 80 mg/L. All samples were characterized by XRD, FT-IR, TGA, DSC, and nitrogen adsorption. By nitrogen adsorption, the pore size can be obtained in the...

The objective of the current effort was to determine the efficacy of Fe(II)-montmorillonite (Fe(II)-MMT) as an adjuvant for specific targeted adsorption of phosphate. Specifically, Fe(II)-MMT was studied to combat hyperphosphatemia and anemia arising from chronic renal failure. The adsorption of phosphate over time, pH, and initial concentration wa...

High-resolution δ18O records from a Geladaindong mountain ice core spanning the period 1477-1982 were used to investigate past temperature variations in the Yangtze River source region of the central Tibetan Plateau (TP). Annual ice-core δ18O records were positively correlated with temperature data from nearby meteorological stations, suggesting th...

Two ice cores were retrieved from high elevations (~5800 m a.s.l.) at Mt. Nyainqêntanglha and Mt. Geladaindong in the southern and central Tibetan Plateau region. The combined tracer analysis of tritium (3H), 210Pb and mercury, along with other chemical records, provided multiple lines of evidence supporting that the two coring sites had not receiv...

To compare the pharmacokinetics and pharmacodynamics of antithymocyte globulins (ATGs) produced by two companies in the treatment of children with aplastic anemia (AA). Six children with acquired AA were divided into two groups. The patients in each group were treated with either R-ATG or F-ATG for 5 consecutive days. Venous blood samples were coll...

The adsorption of Fe (II) onto montmorillonites was investigated through initial concentration, contact time, pH and temperature. During the whole adsorption process, the ascorbic acid (Vitamin C) was added as a kind of antioxidant, at the same time, deionized water (after boiling) and nitrogen protection were also used to avoid oxidation. The Fe2+...

By exploiting the different solubilities of triphenylphosphine in water, resins and organic solvents, porous melamine–formaldehyde (pMF) and porous urea–formaldehyde (pUF) resin materials could be successfully fabricated and used for adsorption of cadmium (II) (Cd(II)) cations. The obtained pMF and pUF materials had specific surface areas of 77.5 m...

Two ice cores were retrieved from high elevations (~ 5800 m a.s.l.) at Mt. Nyainqentanglha and Mt. Geladaindong in the southern to inland Tibetan Plateau. The combined analysis of tritium (3H), 210Pb, mercury tracers, along with other chemical records, revealed that the two coring sites had not received net ice accumulation since at least the 1950s...

In this paper, the volatile oil of Jia-Xiang chrysanthemum has been complexed with β-cyclodextrin (β-CD) by the saturated solution method, and the product has been characterized by thin layer chromatography, gas chromatograph, FTIR, differential scanning calorimetry and X-ray techniques. Chemical analyses indicate that characteristics of the volati...

In this work, a novel melamine‐formaldehyde‐Fe3O4 foam was prepared from a mixture containing melamine‐ethanolamine‐formaldehyde resin, melamine‐glycol‐formaldehyde resin and carboxylated Fe3O4 nanoparticles by microwave foaming method. The two resins were characterized by 13C‐NMR, respectively. The structures of foams, mechanical and fire‐retardan...

Two novel conjugated Schiff bases were prepared and characterized by IR, 1H NMR, and elementary analysis. Their fluorescence measurements indicated that both compounds have excellent performance on fluorescence emission, and the intensity of fluorescence emissions was enhanced sharply by adding Co2+. These compounds can be used as highly sensitive...

A high-frequency and precise ultrasonic sounder was used to record precipitated/deposited snow and drift events over a 3 yr period (17 January 2005 to 4 January 2008) at the Eagle automatic weather station (AWS) site. Through a comparison of the meteorological data with snow pit chemical/isotopic dating results, the snowdrift process effect during...

A series of macroporous beaded terpolymers with epoxy groups were synthesized by suspension polymerization with glycidyl methacrylate (GMA), ethylene glycol dimethacrylate (EGDMA), and the third monomers including styrene, methyl methacrylate, n-butyl acrylate (BA), butyl methacrylate (BMA), and 2-hydroxyethyl methacrylate for immobilization of Can...

In this work, two novel indole–hydrazone analogues were prepared by condensation reactions between 5-methoxyindole-3-carboxaldehyde and isobutyric acid hydrazide or hydrazine hydrate, respectively. The structural properties of the synthetic products were confirmed by FT-IR, 1H NMR, and elemental analysis, while the thermal stabilities and purities...

In this study, we evaluate the ability of the latest NASA GISS composition-climate model, GISS-E2-PUCCINI, to simulate the spatial distribution of snow BC (sBC) in the Arctic relative to present-day observations. Radiative forcing due to BC deposition onto Arctic snow and sea ice is also estimated. Two sets of model simulations are analyzed, where...

In this study, we focus on the latest NASA GISS composition-climate model to evaluate its performance in simulating the spatial distribution of snow BC (sBC) in the Arctic relative to present observations. The radiative forcing due to BC deposition to the Arctic snow and sea ice is also estimated. Two sets of model simulations have been done in the...

Some new star-shaped polydentate ligands were synthesized using 2,4,6-tris(p-formylphenoxy)-1,3,5-triazine as a template and were characterized by infrared, H NMR, and C NMR spectra and elemental analysis. These products may form polynuclear complexes with metal ions, and the complexes may possess potential applications in the area of electromateri...

The Indian Ocean Experiments (INDOEX) first reported the Atmospheric Brown Clouds (ABCs) to the public in 1999. And black carbon (BC), which was particularly concerned in ABCs, not only acted the significant roles of reducing solar radiation, warming its surrounding atmosphere, and changing precipitation pattern, but also accelerated the Himalayan...

A simple pathway for the preparation of D-cycloserine is presented. The intermediates and D-cycloserine were characterized by FT-IR, (1)H-NMR spectra and elemental analysis. D-Cycloserine can inhibit the growth of Mycobacterium tuberculosis and can be used as a second-line drug for the treatment of tuberculosis, especially for the use in developing...

Carbazole-based polymer bearing phthalocyanine groups with moderate glass transition temperature (Tg) for photorefractive purpose was prepared via esterification reaction. The precursor polymer (P1) and the resultant polymer (P2) were identified by means of 1H NMR, FT-IR, UV–vis, GPC and DSC. This approach was facile, and the analysis demonstrated...

A Mount Everest ice core analyzed at high resolution for major and trace elements (Sr, Cs, Ba, La, Ce, Pr, Nd, Sm, Eu, Tb, Dy, Ho, Er, Tm, Yb, Lu, Bi, U, Tl, Al, S, Ca, Ti, V, Cr, Mn, Fe, Co) and spanning the period A.D. 1650-2002 is used to investigate the sources of and variations in atmospheric dust through time. The chemical composition of dust...

Rod-like SBA-15 mesoporous material was synthesized using amphiphilic Pluronic polymer surfactant P123 (EO20PO70EO20) as structure-directing agent. The sample was characterized by SEM, TEM, SAXRD, N2 adsorption–desorption isotherms and FT-IR spectra. It had a high specific surface area of 490m2g−1, a total pore volume of 1.04cm3g−1 and a pore diame...

Major outcomes of Working Group I, IPCC AR4 (2007), as well as the recent understandings from our regional climatic assessments in China were summarized. Changes of cryosphere in China, one of the major components in regional climate system, is specifically reviewed. Under the global/regional warming, all components of cryosphere in China (Tibetan P...

Ground-based measurements are essential for understanding alpine glacier dynamics, especially in remote regions where in-situ measurements are extremely limited. The meteorological and radiative fluxes were measured over the accumulation area on the East Rongbuk Glacier, Mt. Qomolangma (the Mt. Everest) at elevation of 6,560 m a.s.l. Measurements w...

During 2004-2006, black carbon concentrations were measured in the snow and ice sampled from the glaciers in west China. The investigated regions could be aligned as follows based on the BC concentrations in the surface snow for the glaciers: the Tianshan Mountains > the central Tibetan Plateau (TP) > the Pamirs > the Qilian Mountians > the Himalay...

In-situ Fourier Transform infrared (FTIR) spectroscopy was employed to investigate the kinetics of the non-catalyzed polycondensation reaction between toluene-2,4-diisocyanate (TDI) and polyether diol. By monitoring the decrease in the NCO absorption band of TDI, the kinetic constants at different temperatures in the range from 50°C to 90°C were ob...

We assess the correspondence of reanalysis air temperatures from ERA-40, NCEP-1, and NCEP-2 with homogenized observational data from China for 1958-2001 and 1979-2001. Results indicate that climatologies for annual ERA-40, NCEP-1, and NCEP-2 air temperatures are lower than observations by -0.93°C, -2.78°C, and -2.27C, respectively. Large negative d...

A continuous measurement for black carbon (hereafter "BC") in a 40 m shallow ice core retrieved from the East Rongbuk Glacier (hereafter "ERG") in the northeast saddle of Mt. Qomolangma (Everest) provided the first historical record of BC deposition during the past ~50 yrs in the high Himalyas. Apparent increasing trend (smooth average) of BC conce...

A useful and potential chelating agent, 2,4,6-triamino-1,3,5-triazine-N,N,N‘,N‘,N",N"-hexaacetic acid (melamine hexaacetic acid), was synthesised by nucleophilic substitution through three steps and its structure was confirmed by IR, 1H NMR, 13C NMR and elemental analyses. The chelation value of melamine hexaacetic acid was determined, by calcium o...

Mt. Everest is relatively inaccessible and little is known about its meteorology. On 27 April 2005, an automaticweather station was displayed on the north column (28°01′0.95″N, 86°57′48.4″E, 6523 masl) of Mt. Everest. This paper summarizes the meteorological data collected from 1 May to 22 July 2005. The measured variables included long-wave radiat...

A highly resolved Mt. Everest ice core reveals a decrease in marine and increase in continental air masses related to relatively high summer surface pressure over Mongolia, and reduction in northward incursions of the summer South Asian monsoon since ∼1400 AD. Previously published proxy records from lower sites south of the Himalayas indicate stren...

Mount Qomolangma, the highest peak on Earth, is often referred to as the third pole of the globe. The Nyainqentanglha is one of the closest remote parts of mountain range north to the Himalayas. As such the two places are relatively inaccessible on the southern Tibetan Plateau and little is known about their meteorology. In 2003, an auto weather st...

Two Himalayan ice cores display a factor-two decreasing trend of air content over the past two millennia, in contrast to the relatively stable values in Greenland and Antarctica ice cores over the same period. Because the air content can be related with the relative frequency and intensity of melt phenomena, its variations along the Himalayan ice c...

It is shown that the Ramsey number r(K 2,s+1 ,K 1,n )≤n+sn+(s+3)/2+o(1)forlargen, and r(K 2,s+1 ,K 1,n )∈(q-1) 2 s+1,(q-1) 2 s+2, where n=(q-1) 2 s-q+2 and q is a prime power such that 2∣(q-1).

A 108m ice core collected in 2002 from the col of the East Rongbuk Glacier at the northeast slope of Mt. Everest (6518 m a.s.l.) spanning the past millennium has been sampled at high-resolution (3cm/sample) and analyzed for trace elements (Sr, Cs, Ba, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Bi, U, As, Tl, Li, Al, S, Ca, Ti, V, Cr, M...

A 108m high-resolution ice core drilled to bedrock from the East Rongbuk Col of Mt. Everest covers the last 1500 years. Analysis indicates a weakening of the Asian monsoon since 1600 AD. Empirical orthogonal function (EOF) analysis on the major ion (Na+, K+, Mg2+, Ca2+, Cl-, NO3-, SO42-) and deltaD timeseries demonstrates that the Everest site is i...

Two Himalayan ice cores display a factor-two decreasing trend of air content over the past two millennia, in contrast to the relatively stable values in Greenland and Antarctica ice cores over the same period. Because the air content can be related with the relative frequency and intensity of melt phenomena, its variations along the Himalayan ice c...

Delta D and net accumulation records covering the period AD 1952-1998 were reconstructed using a 29.5 m ice core from the col of the Lanong Glacier (5850 m a.s.l.) on the eastern saddle of Mt. Nianquentanglha, southern Tibetan Plateau (TP). Using NCEP/NCAR Reanalysis data, we investigate the relationships between ice core records and primary compon...

Glaciers around the globe provide a unique medium for investigating the temporal and spatial variation of dust deposition. Here we investigate the spatial and seasonal distribution of eolian dust deposition in central Asia through the analysis of concentrations and size distributions of insoluble particles (over the size range 1–22 μm diameter) in...

Glaciochemical records recovered from an 80.4 m ice core in the East Rongbuk (ER) Glacier (elevation: 6450 m) on the northern slope of Mt. Everest provide a reconstructing of past climate for the period AD 1846–1997. Empirical orthogonal function (EOF) analysis on the eight major ion (SO42−, Mg2+, Ca2+, Na+, Cl−, NH4+, K+, and NO3−) time-series rev...

A 51.85 m ice core collected from site LGB65 (accumulation rate 127 kg m1, mean annual temperature 97 Chinese First Antarctic Inland Expedition has been analysed for chemical composition and oxygen isotope ratio. Based on the high definition of seasonal variations of major ions, the ice core was dated with errors within ± 3 years. The continuous su...

The hypothesis being tested in the present study is that increased anisotropic properties occurs in the remodeled post-infarction heart due to spatial alterations in Kv channels expression and K(+) currents of the remodeled myocardium. Three to 4 weeks post myocardial infarction (MI) in the rat, we measured the two components of the outward K(+) cu...

An NH4+ record covering the period AD1846-1997 was reconstructed using an 80.4 m ice core from East Rongbuk Glacier on Mt. Everest. Variations in NH4+ are characterized by a dramatic increase since the 1950s. The highest NH4+ concentrations occur in the 1980s. They are about two-fold more than those in the first half of 20th century. EOF analysis o...

During 1997 summer, fresh snow samples were collected from four snowfall events from the elevation of 5800 to 7000 m in the Dasuopu Glacier region on the northern slope of Mt. Xixabangma (28 degrees 33'N, 85 degrees 44'E), in order to understand the elevation distribution of the middle/upper tropospheric components in the remote region. The correla...

The chemistry of fresh snow samples collected in August and September, 1998 from Mount Everest was studied and compared with other fresh snow samples collected in different seasons in this region. The results indicated that major species in precipitation were very low in late summer in Mount Everest region and may be representative of the backgroun...

T-type Ca2+ currents (I(Ca-T)) are present in neonatal rat myocytes but is not detected in adult ventricular myocytes. The present study was designed to investigate the expression of the T-type Ca2+ channel gene and current in post-infarction remodeled hypertrophied rat left ventricle (LV). We compared the expression of T-type Ca2+ channel gene alp...