Plasma Nanoengineering of Bioresource-Derived Graphene Quantum Dots as Ultrasensitive Environmental Nanoprobes

Environmental contamination and energy shortage are among the most critical global issues that require urgent solutions to ensure sustainable ecological balance. Rapid and ultrasensitive monitoring of water quality against pollutant contaminations using a low-cost, easy-to-operate, and environmentally friendly technology is a promising yet not commonly available solution. Here, we demonstrate the effective use of plasma-converted natural bioresources for environmental monitoring. The energy-efficient microplasmas operated at ambient conditions are used to convert diverse bioresources, including fructose, chitosan, citric acid, lignin, cellulose, and starch, into heteroatom-doped graphene quantum dots (GQDs) with controlled structures and functionalities for applications as fluorescence-based environmental nanoprobes. The simple structure of citric acid enables the production of monodispersed 3.6 nm averaged-size GQDs with excitation-independent emissions, while the saccharides including fructose, chitosan, lignin, cellulose, and starch allow the synthesis of GQDs with excitation-dependent emissions due to broader size distribution. Moreover, the presence of heteroatoms such as N and/or S in the chemical structures of chitosan and lignin coupled with the highly reactive species generated by the plasma facilitates the one-step synthesis of N, S-codoped GQDs, which offer selective detection of toxic environmental contaminants with a low limit of detection of 7.4 nM. Our work provides an insight into the rapid and green fabrication of GQDs with tunable emissions from natural resources in a scalable and sustainable manner, which is expected to generate impact in the environmental safety, energy conversion and storage, nanocatalysis, and nanomedicine fields.

Resonance of a tension leg platform exited by third-harmonic force in nonlinear regular waves

The resonance of a floating tension leg platform (TLP) excited by the third-harmonic force of a regular wave is investigated based on fully nonlinear theory with a higher order boundary element method (BEM). The total wave elevation and the total velocity potential are separated into two parts, based on the incoming wave from infinity and the disturbed potential by the body. A numerical radiation condition is then applied at the far field to absorb the disturbed potential without affecting the incident potential. The BEM mesh on the free surface is generated only once at the initial time and the element nodes are rearranged subsequently without changing their connectivity by using a spring analysis method. Through some auxiliary functions, the mutual dependence of fluid/structure motions is decoupled, which allows the body acceleration to be obtained without the knowledge of the pressure distribution. Numerical simulation is carried out for the interaction of a floating TLP with waves. The focus is on the motion principally excited by higher harmonic wave forces. In particular, the resonance of the ISSC TLP generated by the third-order force at the triple wave frequency in regular waves is investigated, together with the tensions of the tendons.

The Sino-MONICA-Beijing Study: report on results between 1984 and 1986

The Beijing Heart Lung and Blood Vessel Medical Center has participated in the World Health Organisation MONICA project since 1981. Our study, named Sino-MONICA-Beijing, has been carried out in Beijing and covers a population approximately of 700,000. After a 2-year pilot study, the project started formally January 1, 1984. This paper presents the organization and methodology of the study, with emphasis on the monitoring system and on how events were found. The main results of the cardiovascular disease (CVD) event monitoring are as follows: average annual mortality from all causes, for the 3-year period of 1984-86 was 319/100,000 for men and 238/100,000 for women aged 25-64; from CVD 119/100,000 for men and 101/100,000 for women; from ischemic heart disease 29/100,000 for men and 14/100,000 for women; and from cerebrovascular disease 59/100,000 for men and 52/100,000 for women. Preliminary experience has shown that Sino-MONICA-Beijing is a well-standardized project of long-term surveillance of CVD in the communities of Beijing.

Significant down-regulation of alpha-albumin in human hepatoma and its implication

The potential association of alpha-albumin (ALF) with hepatocellular carcinoma (HCC) was investigated. Expression of ALF was significantly reduced in HCC tumor tissue as compared with the paired peritumor tissue from 16 patients and in four HCC cell lines as compared with normal hepatocytes. ALF mRNA was also down-expressed in circulating HCC cells compared to circulating normal hepatocytes. The proliferation of Hep3B cells was inhibited by over-expression of ALF. Taken together, ALF is significantly down-regulated in HCC, and this might facilitate the proliferation of HCC. Thus, detection of ALF mRNA, in addition to that of alpha-fetoprotein (AFP) mRNA, might help to distinguish normal or malignant hepatocytes in peripheral blood.

A favorable impact of preoperative FPLC chemotherapy on patients with gastric cardia cancer

The aim of this study is to evaluate the effects of preoperative chemotherapy with fluorouracili polyphase liposome composita pro orale (FPLC) on the tumour cells and the survival rate of the patients with gastric cardia cancer. Sixty patients with gastric cardia cancer were randomly divided into two groups. Thirty patients were treated with FPLC prior to surgical resection, the other 30, as controls, did not receive the preoperative chemotherapy. Pathological responses of the tumours to the FPLC chemotherapy were determined by gross and microscopic assessments of tumour size, tumour emboli, cell degeneration and necrosis. Expressions of nm23 and CD44 were detected by flow cytometry. All patients were followed up to 5 years. In the FPLC-treated patients, the tumour size (p<0. 01), the number of tumour emboli (p=0.04) and the intensity of CD44 expression (p<0.001), were significantly reduced, while cell degeneration (p<0.001), necrosis (p<0.01) and the expression of nm23 (p<0.001) were increased, when compared with those observations seen in the controls. The postoperative 5-year survival rate was 40% in the FPLC-treated group and 23% in the controls (p=0.17). Preoperative FPLC chemotherapy might improve the survival rate of patients with gastric cardia cancer by inhibiting tumour proliferative, invasive and metastatic activities, and stimulating the patient's immune system.

A favorable impact of preoperative FPLC chemotherapy on patients with gastric cardia cancer

The aim of this study is to evaluate the effects of preoperative chemotherapy with fluorouracili polyphase liposome composita pro orale (FPLC) on the tumour cells and the survival rate of the patients with gastric cardia cancer. Sixty patients with gastric cardia cancer were randomly divided into two groups. Thirty patients were treated with FPLC prior to surgical resection, the other 30, as controls, did not receive the preoperative chemotherapy. Pathological responses of the tumours to the FPLC chemotherapy were determined by gross and microscopic assessments of tumour size, tumour emboli, cell degeneration and necrosis. Expressions of nm23 and CD44 were detected by flow cytometry. All patients were followed up to 5 years. In the FPLC-treated patients, the tumour size (p<0. 01), the number of tumour emboli (p=0.04) and the intensity of CD44 expression (p<0.001), were significantly reduced, while cell degeneration (p<0.001), necrosis (p<0.01) and the expression of nm23 (p<0.001) were increased, when compared with those observations seen in the controls. The postoperative 5-year survival rate was 40% in the FPLC-treated group and 23% in the controls (p=0.17). Preoperative FPLC chemotherapy might improve the survival rate of patients with gastric cardia cancer by inhibiting tumour proliferative, invasive and metastatic activities, and stimulating the patient's immune system.

beta-arrestin differentially regulates the chemokine receptor CXCR4-mediated signaling and receptor internalization, and this implicates multiple interaction sites between beta-arrestin and CXCR4

The chemokine receptor CXCR4 has recently been shown to be a co-receptor involved in the entry of human immunodeficiency virus type 1 into target cells. This study shows that coexpression of beta-arrestin with CXCR4 in human embryonic kidney 293 cells attenuated chemokine-stimulated G protein activation and inhibition of cAMP production. Truncation of the C-terminal 34 amino acids of CXCR4 (CXCR4-T) abolished the effects of beta-arrestin on CXCR4/G protein signaling, indicating the functional interaction of the receptor C terminus with beta-arrestin. On the other hand, receptor internalization and the subsequent activation of extracellular signal-regulated kinases were significantly promoted by coexpression of beta-arrestin with CXCR4, whereas the C-terminal truncation of CXCR4 did not affect this regulation of beta-arrestin, suggesting that beta-arrestin can functionally interact with CXCR4 with or without the C terminus. Moreover, beta(2)V54D, the dominant inhibitory mutant of beta-arrestin 2, exerted no effects on CXCR4/G protein signaling, but strongly influenced receptor internalization and extracellular signal-regulated kinase activation. Further cross-linking experiments demonstrated that beta-arrestin as well as beta(2)V54D could physically contact both CXCR4 and CXCR4-T. Glutathione S-transferase pull-down assay showed that beta-arrestin was able to bind efficiently in vitro to both the third intracellular loop and the 34-amino acid C terminus of CXCR4. Taken together, our data clearly establish that beta-arrestin can effectively regulate different functions of CXCR4 and that this is mediated through its distinct interactions with the C terminus and other regions including the third loop of CXCR4.

Endogenous delta-opioid and ORL1 receptors couple to phosphorylation and activation of p38 MAPK in NG108-15 cells and this is regulated by protein kinase A and protein kinase C

The p38 mitogen-activated protein kinase (MAPK) cascade transduces multiple extracellular signals from cell surface to nucleus and is employed in cellular responses to cellular stresses and apoptotic regulation. The involvement of the p38 MAPK cascade in opioid- and opioid receptor-like receptor-1 (ORL1) receptor-mediated signal transduction was examined in NG108-15 neuroblastoma x glioma hybrid cells. Stimulation of endogenous delta-opioid receptor (DOR) or ORL1 resulted in activation of p38 MAPK. It also induced the activation of extracellular signal-regulated kinases (ERKs), another member of the MAPK family, with slower kinetics. Activation of p38 MAPK was abolished by selective antagonists of DOR or ORL1, pretreatment with pertussis toxin, or SB203580, a specific inhibitor of p38 MAPK. Inhibition of p38 MAPK had no significant effect on opioid-induced ERK activation, indicating that p38 MAPK activity was not required for ERK activation, though its stimulation preceded ERK activation. Inhibition of protein kinase A (PKA) strongly diminished p38 activation mediated by DOR or ORL1 but had no significant effect on ERK activation, and protein kinase C (PKC) inhibitors potentiated stimulation of p38 while inhibiting activation of ERKs. Taken together, our results provide the first evidence for coupling of DOR and ORL1 to the p38 MAPK cascade and clearly demonstrate that receptor-mediated activation of p38 MAPK both involves PKA and is negatively regulated by PKC.

Five-transmembrane domains appear sufficient for a G protein-coupled receptor: functional five-transmembrane domain chemokine receptors

The putative seven-transmembrane (TM) domains have been the structural hallmark for the superfamily of heterotrimeric G protein-coupled receptors (GPCRs) that regulate a variety of cellular functions by mediating a large number of extracellular signals. Five-TM GPCR mutants of chemokine receptor CCR5 and CXCR4, the N-terminal segment of which connected directly to TM3 as a result of a deletion of TM1-2 and the first intracellular and extracellular loops, have been obtained in this study. Laser confocal microscopy and flow cytometry analysis revealed that these five-TM mutant GPCRs were expressed stably on the cell surface after transfection into human embryonic kidney 293 cells. The five-TM CCR5 and CXCR4 functioned as normal chemokine receptors in mediating chemokine-stimulated chemotaxis, Ca2+ influx, and activation of pertussis toxin-sensitive G proteins. Like the wild-type GPCRs, the five-TM mutant receptors also underwent agonist-dependent internalization and desensitization and were subjected to regulation by GPCR kinases and arrestins. Our study indicates that five-TM domains, at least in the case of CCR5 and CXCR4, appear to meet the minimum structural requirements for a functional GPCR and suggests possible existence of functional five-TM GPCRs in nature during evolution.

[Epidemiological characteristics of stroke in 16 provinces of China]

Epidemiological survey was conducted, according to diagnostic standard from WHO-MONICA project, on stroke events in 16 provinces of China. There were significant differences in geographical distribution of morbidity and mortality of stroke events. The morbidity and mortality were higher in northern China than in southern China (P < 0.001). The differences of morbidity varied from 11 to 14 times. The morbidity and mortality were higher in man than in woman (P < 0.01 or P < 0.05) and were higher in rural areas than in cities. The geographical differences in the morbidity and mortality for stroke may be related to many factors, and may be in parallel with the hypertension prevalence rate, which was higher in northern China than in Southern China. The age of patients with stroke was younger in northern China than in southern China (P < 0.01). The frequency of cerebral hemorrhage was higher in southern China than in northern China.

Hybridization to an anti-activated platelet monoclonal antibody enhances fibrinolytic potency on urokinase

The B-chain of urokinase (UK) was covalently linked by disulfide bond to the Fab fragment of an anti-human activated platelet monoclonal antibody (SZ-51). The UK-SZ-51 conjugate retained the original binding specificity of its parent antibody, and produced about a 5-fold enhancement in clot lysis in plasma over that of the urokinase in vitro. Whereas UK significantly decreased the concentration of fibrinogen in plasma clot assay supernatants, UK-SZ-51 did not.

[The changes in alpha-granule membrane protein (GMP-140) on plasma membrane of platelets during cardiopulmonary bypass]

The degree of activation and damage of platelets during various stages of cardiopulmonary bypass (CPB) was studied with monoclonal antibody SZ-51 specific for an alpha-granule membrane protein (GMP-140) on the surface of activated platelets. The number of platelets fell significantly at the commencement of CPB and reached the minimum at the end of CPB; GMP-140 molecules on the platelet surface increased significantly after the commencement of CPB and reached the peak between the ending of bypass and administration of protamine and returned to normal level at 2 hours postoperatively, however, the concentration of GMP-140 in plasma began increasing at the end of CPB and reached the peak at 2 hours postoperatively and became normal at 24 to 48 hours after operation. The results indicate that platelet activation and damaging occur during CPB.

[Chemical constituents from stems of Oplopanax elatus Nakai]

Five constituents were isolated from the stems of Oplopanax elatus. They were identified as syringin, daucosterol, beta-sitosterol, L-rhamnose and surcose.

[Observation of platelet activation in coronary heart disease]

A monoclonal antibody specific for alpha-granule membrane protein (GMP-140) of platelets was used to evaluate the platelet activation degree in 16 cases with acute myocardial infarction (AMI) and 14 cases with unstable angina (UA). The number of GMP-140 molecules on platelet surface reached the highest 48 hours after AMI attack and returned to baseline at the seventh day. The concentration of GMP-140 in plasma began to increase at the first day and decreased to normal at the tenth day. The degree of platelet activation in patients with UA is less than that of AMI.

Thrombus imaging in dogs with a monoclonal antibody (SZ-51) specific for activated human platelets

To specifically detect the localization of thrombus in vivo, we prepared a monoclonal antibody (McAb) SZ-51 specific for an alpha-granule membrane protein (GMP-140) on the surface of activated human platelets. The thrombus binding rate in vitro was 80 +/- 5% for 131I-SZ-51 and 4.4 +/- 0.5% for 131I-nonimmune IgG. Owing to the crossreaction of McAb SZ-51 with the activated platelets of dogs, thrombus in the femoral artery and vein of dogs was formed and imaged with single photon emission computerized tomography (SPECT). The ratio of thrombus to blood radioactivity (T/B) was 2.1, 4.8, 14.0 and 18.0 at 1, 2, 3 and 4 hours after injection of 131I-SZ-51 (0.6 mCi, 50 micrograms) into the arterial thrombus respectively, while the T/B ratio was 1.7, 2.2, 5.3 and 8.0 for venous one. The injection of 131I-nonimmune IgG at the same doses yielded a T/B ratio of 1.2 +/- 0.3 at each time period for both arterial and venous thrombi. These findings were in good agreement with the counting of removed thrombi 24 hours after the injection of radiotracer. The ratio was 21.7 and 2.6 for the 131I-SZ-51 in the arterial and venous thrombus, respectively. However, there were only 1.48 and 1.6 for the 131I-nonimmune IgG. These results indicate the great potentiality of McAb SZ-51 in application to detection of thrombi in vivo.

Stroke in China (Sino-MONICA-Beijing study) 1984-1986

We present here the results of the Sino-MONICA-Beijing stroke study based on 700,000 Beijing residents in 1984-1986. To compare incidence rates for stroke with other communities and countries, we adopted the criteria of the WHO Collaborative Study of 17 centers which used the same definition and methodology as was used in this study. Over the 3-year period of the study, 2,593 stroke events were registered in the 25- to 74-year age-group. The incidence rate for all strokes was 189.5/100,000 and the incidence rate for first strokes was 133.6/100,000. Men had a significantly higher incidence rate than women (all strokes 219.7/100,000 for male vs. 160.5/100,000 for female, OR = 1.32, 99% limits 1.19-1.46; first strokes 151.6/100,000 for male vs. 116.4/100,000 for female, OR = 1.25, 99% limits 1.11-1.42). In comparison with other studies, age-adjusted incidence rate of stroke in Beijing was higher than in other countries, especially for hemorrhagic stroke. The proportion of hemorrhagic stroke related to other types of stroke was also higher in Beijing. Further analysis of the cases confirmed by computerized tomography also supported this finding. Unlike the incidence rates, the 4-week case fatality rate for women, 39.5%, was higher than for men, 32.8%. This finding was confirmed by a multiple logistic analysis controlling for age (p less than 0.001) and for previous stroke (p less than 0.001). The adjusted sex difference is also significant (OR = 1.37, p less than 0.001). In addition, results showed that men had a higher hospitalization rate than women. More women than men were treated at home, possibly indicating better medical care for men.