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Jiaqiang Wang,1 Shuping Dong,1 Jianpo Zhang,2 Shilei Gao,1 Zhehuang Li,1 Po Li,1 Junhui Yuan,3 Zhichao Tian1 1Department of Bone and Soft Tissue, the Affiliated Cancer Hospital of Zhengzhou University and Henan Cancer Hospital, Zhengzhou, Henan Province, 450008, People’s Republic of China; 2Pathology Department, the Affiliated Cancer Hospital of Zhengzhou University and Henan Cancer Hospital, Zhengzhou, Henan Province, 450008, People’s Republic of China; 3Medical Imaging Department, the Affiliated Cancer Hospital of Zhengzhou University and Henan Cancer Hospital, Zhengzhou, Henan Province, 450008, People’s Republic of ChinaCorrespondence: Zhichao TianDepartment of Bone and Soft Tissue, the Affiliated Cancer Hospital of Zhengzhou University and Henan Cancer Hospital, Dongming Road, Zhengzhou, Henan Province, 450008, People’s Republic of ChinaTel +86-13592413731Fax +86-371-65961505Email tianzhichaoyy@163.comBackground: Although the annual incidence of undifferentiated pleomorphic sarcoma (UPS) is extremely low, it can be subdivided into different subtypes. UPS with fever of unknown origin (also known as neoplastic fever) is a specific subtype of UPS, which shows certain clinical features that differentiate it from other UPS subtypes. However, no studies have focused on this rare UPS subtype. This study retrospectively analyzed the clinical data of patients with UPS to provide a reference for the diagnosis and treatment of UPS with neoplastic fever.Methods: This study included patients with UPS who were diagnosed and treated between June 2012 and June 2018. We examined whether these patients had a history of neoplastic fever. The characteristics of patients with UPS with neoplastic fever were summarized and analyzed.Results: We reviewed the medical records of 183 patients with UPS. Seven (3.83%) of these patients had neoplastic fever. In patients with UPS with neoplastic fever, the primary lesions were located in the extremities and across the muscle space. In these patients, magnetic resonance imaging showed necrosis within the tumor body and extensive soft tissue edema around the tumor body. Patients with UPS with neoplastic fever had a lower metastasis rate (14.29% vs 44.94%) and a higher 3-year survival rate (85.71% vs 59.55%) than those without neoplastic fever.Conclusion: UPS with neoplastic fever is characterized by intratumoral necrosis and extensive edema of the surrounding soft tissues. Patients with UPS with neoplastic fever may have a better prognosis than those without neoplastic fever.Keywords: undifferentiated pleomorphic sarcoma, neoplastic fever, fever of unknown origin, sarcoma

Precompetitive collaborations on the development of new enabling technologies for conducting pharmaceutical research and development are becoming increasingly popular as pharmaceutical companies re...

In comparison to defect/doping induced activity in materials, transition metal borides with exposed metal atoms, large specific surface area, and high active site density show advantages as durable and efficient catalysts for specific electrochemical reactions. In this work, ReB2 for N2 reduction reaction (NRR) for ammonia (NH3) with a record-low limiting potential of UL = -0.05 V and high Faraday efficiency (FE) of 100% is screened out from a new class of TMB2. It is concluded that high pressure/temperature is favorable to N2 adsorption and kinetic barrier minimization; the maximal turnover frequency (TOF) at 700 K and 100 bar is 1.24 × 10-2 per s per site, which is comparable to that of the benchmark Fe3/Al2O3 catalysts, achieving an extremely fast reaction rate. In addition, crystal orbital Hamilton population (COHP) of *N2 reveals the intrinsic origin of N2 activation by analyzing the d-2π* interactions, and integrated COHP could be a quantitative descriptor to describe the N2 activation degree. It is evident that our results not only identify an efficient NRR electrocatalyst in particular, paving the way for sustainable NH3 production, but also explain the chemical and physical origin of the activity, advancing the design principle for catalysts for various reactions in general.

Jiaqiang Wang,1 Shilei Gao,1 Yonghao Yang,2 Xu Liu,1 Peng Zhang,1 Shuping Dong,1 Xin Wang,1 Weitao Yao1 1Department of Orthopedics, The Affiliated Cancer Hospital of Zhengzhou University and Henan Cancer Hospital, Zhengzhou, Henan Province, 450008, People’s Republic of China; 2Department of Immunotherapy, The Affiliated Cancer Hospital of Zhengzhou University and Henan Cancer Hospital, Zhengzhou, Henan Province, 450008, People’s Republic of ChinaCorrespondence: Jiaqiang WangDepartment of Orthopaedics, The Affiliated Cancer Hospital of Zhengzhou University and Henan Cancer Hospital, Zhengzhou, Henan Province, 450008, People’s Republic of ChinaTel +86-18737187831Fax +86-371-65961505Email doctorwangjiaqiang@126.comPurpose: Advanced clear cell sarcoma (CCS) is a rare subtype of sarcoma with few effective treatments. Evidence shows that apatinib is efficacious and safe for CCS. This study aimed to assess the safety and efficacy of apatinib and/or camrelizumab (a PD-1 inhibitor) in treating advanced CCS.Methods: We retrospectively reviewed 12 patients with advanced CCS who received apatinib and/or camrelizumab therapy between November 2018 and July 2021. Standard descriptive statistics were employed for continuous variables and categorical variables (number and percentage).Results: Of the 12 CCS patients, 3 had a partial response (PR), and 4 had stable disease (SD). Among the 5 patients treated with apatinib monotherapy, 1 PR and 2 SD were found, and the addition or replacement of camrelizumab after progressive disease (PD) did not work. In the 4 patients who received apatinib plus camrelizumab combination therapy, 1 PR and 1 SD were found. All 3 patients who received camrelizumab first had PD, and 1 PR and 1 SD were found after adding apatinib. Grade 3 or 4 adverse events were significantly more common in the apatinib plus camrelizumab combination therapy than in the apatinib or camrelizumab monotherapy, and these included increased aspartate aminotransferase and increased alanine aminotransferase levels.Conclusion: Apatinib has promising effectiveness for CCS. Camrelizumab efficacy for the treatment of clear cell sarcoma is inconclusive. The efficacy of apatinib and PD-1 inhibitors in CCS need to be further investigated in prospective clinical trials.Keywords: clear cell sarcoma, apatinib, camrelizumab, sarcoma, tyrosine kinase inhibitor, PD-1 inhibitor

The antioxidant natural product sulforaphane (SFN) is an oil with poor aqueous and thermal stability. Recent work with SFN has sought to optimize methods of formulation for oral and topical administration. Herein we report the design of new analogs of SFN with the goal of improving stability and drug-like properties. Lead compounds were selected based on potency in a cellular screen and physicochemical properties. Among these, 12 had good aqueous solubility, permeability and long-term solid-state stability at 23 °C. Compound 12 also displayed comparable or better efficacy in cellular assays relative to SFN and had in vivo activity in a mouse cigarette smoke challenge model of acute oxidative stress.

Guiyu, China, is well-known for the crude disposal of electronic waste (EW) and severe persistent organic pollutants (POPs). Therefore, in this study, the occurrence, composition, and source of polybrominated diphenyl ethers (PBDEs), 2,2',4,4',5,5'-hexabromobiphenyl (BB153), some novel brominated flame retardants (NBFRs), Dechlorane Plus (DP) and polybrominated dibenzo-p-dioxins/dibenzofurans (PBDD/Fs) in farmland soils covering Guiyu were studied. In EW disposal area soils, PBDEs were the most abundant FRs, with concentrations of 13-1014 ng g-1. The primary PBDE sources were technical Penta- and Deca-BDE mixtures in northern and southern Guiyu, respectively. The levels of BB153 were relatively low, possibly because it has been banned in the 1970s. The concentrations of hexabromobenzene (HBB) were 0.048-3.3 ng g-1, while pentabromoethylbenzene (PBEB) was almost not detected in the soils. Two alternatives to commercial PBDEs, decabromodiphenyl ethane (DBDPE) and 1,2-bis(2,4,6-tribromophenoxy) ethane (BTBPE), were the primary NBFRs, with concentrations of 1.8-153 ng g-1 and 0.43-15 ng g-1, respectively. DP was another primary FR, with concentrations of 0.57-146 ng g-1. Moreover, syn-DP and anti-DP isomers were not stereoselectively decomposed during the EW disposal process and were therefore present in their original fractions in the soils. The levels of PBDD/Fs in EW disposal area soils were 2.5-17 pg TEQ g-1. 1,2,3,4,6,7,8-HpBDF and OBDF were the dominant congeners, mainly derived from processing, pyrolysis and combustion of BFRs. The regional distribution of pollutants was shown to be related to the disposal manner of EW, with their open thermal disposal tending to release more highly brominated compounds such as BDE209, DBDPE, and 1,2,3,4,6,7,8-HpBDF. Additionally, some riverbank sites were heavily polluted because of nearby point sources, downwind Simapu (SMP) town without EW disposal activity was also contaminated by these pollutants.

Gastric cancer (GC) is the third leading cause of cancer-related mortality worldwide. Oxysterol-binding protein-related protein 8 (ORP8) functions as a sterol sensor that regulates a number of cellular functions. We showed that ORP8 expression was significantly lower in GC tissues and cells. Overexpression of ORP8 significantly inhibited GC cell proliferation in several GC cells. The formation of colonies in AGS cells was inhibited by the overexpression of ORP8. Moreover, overexpression of ORP8 significantly decreased implanted tumor growth in nude mice. Overexpression of ORP8 resulted in a significant increase in CHOP and GRP78 expression and the phosphorylation of PERK, indicating the occurrence of ER stress. Inhibition of ER stress by 4-PBA notably suppressed overexpression of ORP8-induced decrease of GC cell proliferation, formation of colonies, and implanted tumor growth. Overexpression of ORP8 resulted in a significant decrease in Wnt3a and β-catenin expression, and activation of Wnt signaling by HLY78 markedly blocked overexpression of ORP8-induced decrease in GC cell proliferation, formation of colonies, and implanted tumor growth. 4-PBA inhibited overexpression of ORP8-induced decrease in Wnt signaling. Furthermore, overexpression of ORP8 resulted in significant activation of mitochondrial apoptotic events and increase in apoptosis, which was inhibited by 4-PBA and HLY78. Induction of ER stress, inhibition of Wnt signaling, and apoptotic cell death were involved in ORP8-induced inhibition of GC cell proliferation. These findings indicate that downregulation of ORP8 plays a pivotal role in the progression of GC, and it may be a novel therapeutic target in the treatment of GC.

Cisplatin resistance has long been a major problem that restricts its use. A novel paradigm in tumor biology suggests that gastric tumor chemo-resistance is driven by gastric cancer stem cell-like (GCSCs). Growing evidence has indicated that microRNAs (miRNAs) contributes to chemo-resistance in gastric cancer (GC). Here, Lgr5+ cells derived from gastric cancer cell lines displayed stem cell-like features. Flow cytometry demonstrated the presence of a variable fraction of Lgr5 in 19 out of 20 GC specimens. By comparing the miRNA expression profiles of Lgr5+ GCSCs and Lrg5- cells, we established the upregulation of miR-132 in Lgr5+ GCSCs. The enhanced miR-132 expression correlated chemo-resistance in GC patients. Kaplan-Meier survival curve showed that patients with low miR-132 expression survived obviously longer. Functional assays results indicated that miR-132 promoted cisplatin resistance in Lgr5+ GCSCs in vitro and in vivo. Further dual-luciferase reporter gene assays revealed that SIRT1 was the direct target of miR-132. The expression of miR-132 was inversely correlated with SIRT1 in gastric cancer specimens. Furthermore, through PCR array we discovered ABCG2 was one of the downstream targets of SIRT1. Overexpression of SIRT1 down-regulated ABCG2 expression by promoting the de-acetylation of the transcription factor CREB. CREB was further activated ABCG2 via binding to the promoter of ABCG2 to induce transcription. Thus, we concluded that miR-132 regulated SIRT1/CREB/ABCG2 signaling pathway contributing to the cisplatin resistance and might serve as a novel therapeutic target against gastric cancer.

Cellulose nanocrystals (CNCs) are most commonly prepared by sulfuric acid hydrolysis of a purified cellulose starting material but the effects of hydrolysis conditions on CNC yield and properties are incompletely understood. In this study, we use a rotatable central composite experimental design to elucidate parameter interactions between three design factors, acid concentration (x1), hydrolysis temperature (x2), and hydrolysis time (x3), over a broad range of process conditions and determine their effect on yield and sulfate group density. Parameter ranges are 55–65 wt.% for x1, 45–65 °C for x2, and 30–180 min for x3. Regression models of the experimental yield data reveal significant two-factor interactions of x1 with each x2 and x3, whereas x2 has no significant two-factor interaction with x3. The models predict maximum yields of 66–69% at optimum process conditions of 57–58 wt.% (x1), 64–67 °C (x2), and 134–156 min (x3). At these conditions, the sulfate group density is predicted to be between 241 and 265 mmol/kg. The sulfate group density is linearly dependent on acid concentration and hydrolysis temperature and not dependent on hydrolysis time. Maximum sulfate group density can only be achieved at the expense of yield. The results presented here provide a foundation for subsequent, sequential optimization using narrower parameter ranges, allowing further optimization of the hydrolysis conditions and potentially enabling higher yield.

The study evaluates cellulose nanocrystals (CNCs) as nanocarriers for targeted, intracellular delivery of molecular agents. CNCs were labeled with fluorescein-5′-isothiocyanate as an imaging agent and conjugated to folic acid (FA) as a targeting ligand. The CNC conjugates were characterized by UV–vis spectroscopy, ζ-potential analysis, dynamic light scattering, and atomic force microscopy. Cellular binding/uptake of the FA-conjugated CNCs by KB and MDA-MB-468 cells was quantified with cellular uptake assays. Internalization of the particles was confirmed by confocal microscopy. Uptake mechanisms were determined by inhibition studies with chlorpromazine and genistein. Binding affinity was qualitatively assessed with a free folate inhibition assay. Both KB and MDA-MB-468 cells exhibited significant and folate-receptor specific binding/uptake of FA-conjugated CNCs. Clathrin-mediated endocytosis was a significant uptake mechanism in both cell types, whereas caveolae-mediated endocytosis only played a significant role in MDA-MB-468 cells. Uptake inhibition of FA-conjugated CNCs by KB cells required high concentrations (>1 mM) of free FA. The observed FR-specific internalization of FA-conjugated CNCs by FR-positive cancer cells and tumors and their remarkable high affinity for the FR demonstrate the great potential of CNCs as novel nanocarriers for imaging agents and chemotherapeutics in the early detection and treatment of cancer.

A one-year-long aerosol characterization study was conducted from July 2002 through July 2003, in Beijing, China. Twenty-four hour PM2.5 and PM10 filter samples were collected, and about 50 aerosol samples of each type were obtained. Organic, elemental, and total carbon, levoglucosan and other organic compounds, and inorganic ionic species were measured. The overall mean PM mass concentrations were 99 and 175 mu g/m(3) for PM2.5 and PM10, respectively. Total carbon was the main component in both PM2.5 and PM10, with overall mean concentrations of 21 and 30 mu g/m(3), respectively. Of the organic compounds measured, levoglucosan exhibited the highest levels (overall mean of 0.31 mu g/m(3) in PM2.5 and of 0.40 ng/m(3) in PM10). Sulfate was the most prominent inorganic ionic species, with overall mean levels of 15.6 and 17.0 mu g/m(3) in PM2.5 and PM10, respectively. Most components measured were predominantly present in the PM2.5 size fraction; the overall mean PM2.5/PM10 ratio was typically in the range of 0.7-0.8, but this ratio was only 0.55 for the PM mass and for Ca2+ it was as low as 0.19. In PM2.5, total carbon exhibited relatively larger concentration levels (30 mu g/m(3)) in winter than in the other seasons. K+ also exhibited a relatively high concentration level in the winter season, with 2.3 mu g/m(3) in PM2.5. The contribution from biomass burning to K+ in PM2.5 was estimated on the basis of the levoglucosan data and the minimum K+/levoglucosan ratios obtained throughout the year; it was found that the contribution was largest in autumn, with 44%.

Cellulose nanocrystals are rod-shaped, crystalline nanoparticles that have shown prom-ise in a number of industrial applications for their unique chemical and physical properties. However, investigations of their abilities in the biomedical field are limited. The goal of this study is to show the potential use of folic acid-conjugated cellulose nanocrystals in the potentiation of irreversible electroporation-induced cell death in folate receptor (FR)-positive cancers. We optimized key pulse parameters including pulse duration, intensity, and incubation time with nanoparticles prior to electroporation. FR-positive cancer cells, KB and MDA-MB-468, were preincubated with cellulose nanocrystals (CNCs) conjugated with the targeting molecule folic acid (FA), 10 and 20 min respectively, prior to application of the optimized pulse electric field (PEF), 600 and 500 V/cm respectively. We have shown cellulose nanocrystals’ ability to potentiate a new technique for tumor ablation, irreversible electroporation. Pre-incubation with FA-conjugated CNCs (CNC-FA) has shown a significant increase in cytotoxicity induced by irreversible electroporation in FR-positive cancer cells, KB and MDA-MB-468. Non-targeted CNCs (CNC-COOH) did not potentiate IRE when preincubated at the same parameters as previously stated in these cell types. In addition, CNC-FA did not potentiate irreversible electroporation-induced cytotoxicity in a FR-negative cancer cell type, A549. Without changing irreversible electroporation parameters it is possible to increase the cytotoxic effect on FR-positive cancer cells by exploiting the specific binding of FA to the FR, while not causing further damage to FR-negative tissue.

Direct individual analysis using Scanning Electron Microscopy combined with online observation was conducted to examine the S-rich particles in PM2.5 of two typical polluted haze episodes in summer and winter from 2014 to 2015 in Beijing. Four major types of S-rich particles, including secondary CaSO4 particles (mainly observed in summer), S-rich mineral particles (SRM), S-rich water droplets (SRW) and (C, O, S)-rich particles (COS) were identified.We found the different typical morphologies and element distributions of S-rich particles and considered that (C, O, S)-rich particles had two major mixing states in different seasons. On the basis of the S-rich particles’ relative abundances, S concentrations and their relationships with PM2.5 as well as the seasonal comparison, we revealed that the S-participated formation degrees of SRM and SRW would enhance with increasing PM2.5 concentration. Moreover, C-rich matter and sulfate had seasonally different but significant impacts on the formation of COS. Open image in new window

We carried out short-term continuous monitoring of Asian dust every 2 hours in Beijing, China and Nagasaki, Japan and performed chemical analyses during 2 events where there were large differences in the characteristics of the Asian dust blowing into Nagasaki. The first involved typical Asian dust that originated in the Mongolian Gobi Desert on March 30, 2007 (abbreviated to TAD 2007). The second involved a polluted air parcel that arrived in Japan along with Asian dust on May 8, 2007. By comparing temporal changes in PM10 and particulate sulfur (sulfate ions) concentrations with the timing of the Asian dust arrival, we found in the April event (TAD 2007) that the polluted air parcel covering Beijing did not mix with an air parcel containing TAD 2007 coming from the north. In the May event, we inferred that mixing of the polluted air parcel and an air parcel containing Asian dust had occurred. The composition of aerosol particles in the air parcel reaching Nagasaki in the April event reflected the chemical composition of TAD 2007 itself, whereas that of the May event had high concentrations of chemical components originating in anthropogenic pollution, such as sulfate ions, zinc, lead and other heavy metals.

Atmospheric aerosols were collected during the scientific expedition to Mt. Qomolangma (Everest) in May-June, 2005. The elemental concentrations of the aerosols were determined by inductively coupled plasma mass spectrometry. This yielded data for the concentration of 14 elements: Na, Mg, Al, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, and Pb. The mean elemental concentrations were generally comparable with those from central Asia and the Arctic, while much higher than those from Antarctic. Size, morphology, and chemical composition of 900 individual aerosol particles were determined by scanning electron microscopy and energy-dispersive X-ray microanalysis. Based on morphology and elemental composition, the particles were clustered into eight groups: soot (8%), tar ball (3%), alumosilicates/silica (55%), calcium sulfate (16%), Ca/Mg carbonate (2%), Fe/Ti-rich particles (3%), Pb-rich particles (1%), and biological particles (12%). The sampling site, located at 6,520 m in the Himalayas, is particularly remote and located at high altitude. Nonetheless, high aerosol enrichment factors for copper, chromium, lead, nickel, vanadium, and zinc all suggest the influence of long-range transported pollution, while enrichment in calcium and the presence of alumino-silicates in individual particle analyses indicates a distinct mineral dust influence. The backward air mass trajectories showed that the northwestern part of India may contribute to the atmospheric aerosol in the central high Himalayas.

Using Monte Carlo simulation, the geometric and matrix effects on intensity and intensity ratio measured by EPMA were investigated for both synthetic particles and biomass burning particles. Three particulate standards, KCl, K2SO4, KHSO4, were prepared and measured along with biomass burning particles. The modified CASINO program (University of Sherbrooke, Quebec, Canada) at the University of Antwerp, Belgium was used. The relative intensities obtained by the UA version of the CASINO program appear to be in line with those from experiments. The CASINO program and iterative procedures were applied to quantitatively determinate the atomic fraction of K, Cl and S in particulate standard and real samples. After correcting the geometric and matrix effects, the atomic fraction ratio of K to Cl in KCl sample was found to be 1.007±0.025, 0.996±0.013 and 1.011±0.019 for experiments with high voltages of 15, 20 and 25 keV, respectively. The same procedure was also applied to K2SO4 and KHSO4 standard particle sample. The atomic fraction ratio of K to S was 1.945±0.049 (25 keV) for K2SO4 and 1.014±0.072 (20 keV) for KHSO4. These ratios obtained are close to the theoretic values 1 or 2. Reasonable data were obtained for biomass burning particles, indicating that it is possible to perform chemical speciation.

More and more evidence has demonstrated that astrocyte elevated gene-1 (AEG-1) is tightly associated with progression, metastasis, and unfavorable prognosis in many malignancies. However, the potential biological role of AEG-1 in gastric carcinoma (GC) has not been thoroughly delineated. In the current study, we found that AEG-1 mRNA and protein levels in GC tissues were significantly higher than those in normal gastric mucosa (P

Chemical incompatibility and relatively weak interaction between lignocellulosic fibers and synthetic polymers have made studies of wood fiber-thermoplastic composite more challenging. In this study, adsorption of 2-hydroxypropyltrimethylammonium xylans onto rod-like cellulose nanocrystals are investigated by zeta-potential measurements, and polarized and depolarized dynamic light scattering as a factor for better understanding of lignocellulosic fibers and cellulose nanocrystals. Zeta-potential measurements show xylan derivative adsorption onto cellulose nanocrystals. Decay time distributions of the ternary system and binary system from dynamic light scattering show that aggregates exist in the binary system and they disappear in the ternary system. At low 2-hydroxypropyltrimethylammonium xylan concentrations relative to that of cellulose nanocrystal, xylan derivatives adsorbed onto some of the cellulose nanocrystal. Hence, more xylan derivatives adsorbed onto cellulose nanocrystal increased with increasing xylan derivative concentration. Also, the concentration dependence of the ratio of the rotational diffusion coefficient to the translational diffusion coefficient revealed a strong adsorptive interaction between xylan derivatives and the cellulose nanocrystals.

Elongated nanoparticles have recently been shown to have distinct advantages over spherical ones in targeted drug delivery applications. In addition to their oblong geometry, their lack of cytotoxicity and numerous surface hydroxyl groups make cellulose nanocrystals (CNCs) promising drug delivery vectors. Herein we report the synthesis of folic acid-conjugated CNCs for the targeted delivery of chemotherapeutic agents to folate receptor-positive cancer cells. Folate receptor-mediated cellular binding/uptake of the conjugate was demonstrated on human (DBTRG-05MG, H4) and rat (C6) brain tumor cells. Folate receptor expression of the cells was verified by immunofluorescence staining. Cellular binding/uptake of the conjugate by DBTRG-05MG, H4, and C6 cells was 1452, 975, and 46 times higher, respectively, than that of nontargeted CNCs. The uptake mechanism was determined by preincubation of the cells with the uptake inhibitors chlorpromazine or genistein. DBTRG-05MG and C6 cells internalized the conjugate primarily via caveolae-mediated endocytosis, whereas H4 cells internalized the conjugate primarily via clathrin-mediated endocytosis.

The occurrence and characteristics of 2,3,7,8-substituted polybrominated and polychlorinated dibenzo-p-dioxins and dibenzofurans (PBDD/F and PCDD/F) from various combustion and metallurgic industrial thermal processes were investigated. PBDD/F levels from metallurgic processes (TEQ) concentrations from 0.14 to 1.5 ng Nm(-3), mass concentrations from 0.56 to 5.8 ng Nm(-3)) were markedly higher than those from combustion processes (TEQ) concentrations from 0.010 to 0.054 ng Nm(-3), mass concentrations from 0.025 to 0.15 ng Nm(-3)). This indicated that metallurgic processes could be important sources of PBDD/F. Consequently, more attention should be paid to the metallurgical emission sources in addition to combustion of brominated flame retardants (BFRs) and related products. Specific isomeric patterns for PCDD/F from various industrial sources were highly consistent, while PBDD/F patterns were not. This revealed that PCDD/F might form through a common mechanism such as de novo synthesis mechanism, while PBDD/F might form by different mechanisms in thermal processes such as precursor mechanisms. Finally, an approach to identify the PBDD/F sources in ambient air by using the PBDD/F to PCDD/F ratio was developed.

Even after its being phased out in gasoline in the late 90s, lead (Pb) is still present at relatively high levels in the atmosphere of Beijing, China (0.10–0.18 μg m −3 ). Its origin is subject to debate as several distinct sources may contribute to the observed pollution levels. This study proposes to constrain the origin(s) of Pb and strontium (Sr) in aerosols, by coupling both Pb and Sr isotope systematics. The characterisation of the main pollution sources (road traffic, smelters, metal refining plants, coal combustion, cement factories, and soil erosion) shows that they can unambiguously be discriminated by the multi-isotope approach ( 206 Pb/ 204 Pb and 87 Sr/ 86 Sr). The study of total suspended particulates (TSP) and fine particles (PM 2.5 ) from Beijing and its vicinity indicates that both size fractions are controlled by the same sources. Lead isotopes indicate that metal refining plants are the major source of atmospheric lead, followed by thermal power stations and other coal combustion processes. The role of this latter source is confirmed by the study of strontium isotopes. Occasionally, emissions from cement plants and/or input from soil alteration are isotopically detectable.

A brief review of principal methods of analysis of trace nitro-polycyclic aromatic hydrocarbons(NO 2 -PAHs) used for past ten years in our laboratories in diesel exhaust particulate, air particulate commercial carbon black and reaction products, etc. is presented

Two series of size-selective aerosol samples, PM2.5 and PM10, were collected in Beijing from July 2002 to July 2003. The samples were analyzed for levoglucosan and related saccharidic compounds, organic and elemental carbon, and ionic species. Levoglucosan and related saccharidic compounds were mostly present in the fine size fraction. The contribution from biomass burning to the carbonaceous aerosol in Beijing was estimated; biomass burning was responsible for 18–38% of the PM2.5 organic carbon and for 14–32% of the PM10 organic carbon. The biomass burning marker levoglucosan was present all year round in Beijing. High levoglucosan concentrations in October and November were attributed to corn field burning and burning of fallen leaves, while the high level observed on 7 May 2003 was tracked back to a boreal forest fire more than 1000 km away in northeastern China. The biomass burning contribution to the Beijing aerosol is made up of two parts, a background component, which is due to biofuel burning all year round in the neighboring countryside households, and a superimposed component from seasonal crop burning events and wild fires.

The total nitrogen (TN) and water-soluble nitrogenous ions were determined by using CHN Elemental Analyzer and ion chromatography method, respectively, from November 24, 1998 to February 12, 1999 in Beijing. The average concentrations of TN, NH(4) (+) and NO(3) (-) were 10.62 microg N m(-3), 6.67 microg m(-3) and 10.01 microg m(-3), respectively. The total inorganic nitrogen (IN) calculated from NH(4) (+) and NO(3) (-) was 7.45 microg N m(-3), accounting for 70% of TN, i.e., 30% of TN existed as organic nitrogen form (ON). The correlation between ON and other pollution tracers showed that, coal combustion, biomass burning, soil humic matter and secondary formation were the important sources of ON in particulate matter in Beijing.

Cellulose nanocrystals are promising candidates for applications in nanomedicine. To enable the use of fluorescence techniques in in vitro and in vivo studies, cellulose nanocrystals were labeled with fluorescein-5‘-isothiocyanate (FITC) via a three-step reaction, involving epoxy activation of the nanocrystal surface, opening of the epoxy rings with ammonium hydroxide, and coupling of FITC molecules to the primary amino groups. The FITC content of the labeled cellulose nanocrystals was determined by UV/vis spectroscopy. A FITC content of 0.03 mmol/g of cellulose, equivalent to 5 FITC moieties per 1000 anhydroglucose units, was obtained using the described method.

Scanning electron microscopy–energy dispersive X-ray analysis (SEM–EDX) was used for the analysis of 2500 single particles in five atmospheric aerosol samples collected during the spring and summer of 2000 in Beijing, China. Mineral dust appeared to be the dominant particles during an Asian dust episode, while in other circumstances mineral dust and S-containing particles constituted the major particle components. During anthropogenic pollution episodes in the summer, a large abundance of S-containing particles featured the atmospheric aerosol. Chemical and size distribution characteristics are discussed for Ca–S, K–S and Ca–K–S particle classes. Formation of Ca–K–S and other S-containing particle classes with high abundance was closely related to meteorological conditions such as relative humidity and cloud coverage. Simple and composite sulfate particles with an elongated crystalline morphology were detected which appear to be indicative of aqueous phase oxidation, such as in-cloud processing for sulfate formation pathway.

There is growing evidence that filamentous nanoparticles offer advantages over spherical ones in drug delivery applications. The purpose of this study was to assess the potential of rod-like, plant-derived cellulose nanocrystals (CNCs) for nanomedical uses. Besides a nonspherical morphology, their facile bioconjugation, surface hydrophilicity and small size render CNCs promising drug carriers. The cytotoxicity of CNCs against nine different cell lines (HBMEC, bEnd.3, RAW 264.7, MCF-10A, MDA-MB-231, MDA-MB-468, KB, PC-3 and C6) was determined by MTT and LDH assay. CNCs showed no cytotoxic effects against any of these cell lines in the concentration range and exposure time studied (0–50 μg/mL and 48 h, respectively). Cellular uptake of fluorescein-5′-isothiocyanate-labeled CNCs by these cell lines, quantified with a fluorescence microplate reader, was minimal. The lack of cytotoxicity and the low nonspecific cellular uptake support our hypothesis that CNCs are good candidates for nanomedical applications.

A method was developed for the analysis of mutagenic nitroarenes in carbon black. The procedure included extraction, pre-separation column chromatography on silica gel, and determination by high-performance liquid chromatography (HPLC) using a diode-array detector. Different solvents, such as dichloromethane, benzene, toluene, and chlorobenzene were used for the extraction of carbon black. It was found that chlorobenzene yielded the highest amount of extracted material. The pre-separation, the optimization of the HPLC separation, the selection of detection wavelengths, and the calibration curve are discussed. 3-Nitro-9-fluorenone was detected in a treated carbon black, which is used for making carbon ink. The identification of peaks in the sample chromatograms was confirmed by comparing the retention time and the UV spectra with those of standards.