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This paper considers optimal control problem for networked control systems (NCSs) with Markovian packet dropouts. Since previous literatures generally consider the one-way Markovian packet dropouts, i.e., from the sensor to the estimator or from the controller to the actuator. To make a further study of this issue, we aim to give the complete solution to the control problem of the two-way Markovian packet dropouts, i.e., from the sensor to the estimator and from the controller to the actuator. Firstly, by applying the Pontryagin's maximum principle and mathematical induction method, a solution to the forward and backward stochastic difference equations (FBSDEs) is derived. Secondly, in virtue of the solution to the FBSDEs, we obtain the necessary and sufficient condition for the optimal control problem. Thirdly, the optimal controller is given based on the complete square method. Finally, numerical examples are proposed to illustrate the effectiveness of the theoretical results. [ABSTRACT FROM AUTHOR]

Abundant ancient seeds of plants in the genus Melilotus have been concurrently unearthed with grain crops and livestock bones from the Keyakekuduke beacon tower of the Tang Dynasty (AD 618–907) in Xinjiang, northwest China. This is the first time that a high concentration of Melilotus seeds has been found in archaeobotanical records in Xinjiang. Combined with the military nature of the site as well as the theoretical adequacy of using Melilotus plants as fodder, the high proportion of Melilotus remains is hypothesized to be an indication of its ancient use as army horse fodder with possible other applications. As a drought-tolerant plant adapted to high ambient temperatures, the use of Melilotus as a forage legume by ancient frontier soldiers might have been a judicious choice given local arid climatic conditions. [ABSTRACT FROM AUTHOR]

Understanding the role of agriculture in the development of human societies around the world is an important field of study with many unanswered questions. As a step toward that greater understanding, we have studied the archeobotanical remains at the Jingshuidun site in the mountainous areas of the lower reaches of the Yangtze River in southern Anhui Province which are part of the core area of rice cultivation today. Our analyses of macrobotanical remains and phytoliths formed the basis for the reconstruction of the subsistence economy of ancient humans at the Jingshuidun site from the late Neolithic to early historical times. When our data are combined with that of previous archeobotanical work, we obtain a clearer picture of the development of rice and millet agriculture in the southern Anhui Province region, as well as the spread of millet cultivation. Macrobotanical remains and phytoliths of domesticated rice are present in layers at the Jingshuidun site dated to 4874–4820 cal. yr B.P. (middle-late Liangzhu Period) and 2667–2568 cal. yr B.P. (late Western Zhou Dynasty to the early Spring and Autumn Period). Moreover, macrobotanical remains and phytoliths from the site document the earliest remains of foxtail millet (Setaria italica) in southern Anhui Province, from a layer dating to the late Western Zhou Dynasty and the early Spring and Autumn Period (2667-2568 cal. yr B.P.). These results suggest that the people occupying the Jingshuidun site used single rice farming as far back as 4874–4820 cal. yr B.P., and they began to plant millet by at least 2667–2568 cal. yr B.P., documenting the spread of millet agriculture to the southern area by that time. [ABSTRACT FROM AUTHOR]

The history and mechanisms of dust storms in northern China remain unclear owing to the paucity of reliable long-term, high-resolution geological records. In this study, we reconstructed the dust storm history of the last ~500 years in northern China, based on sedimentary coarse fraction (>63 µm) of a well-dated core from Lake Daihai, Inner Mongolia. The high-resolution data reveal three intervals of frequent dust storms: AD 1520–1580, AD 1610–1720, and AD 1870–2000. The dust storm events in the Lake Daihai area were broadly synchronous with those inferred from other historical or geological records and generally occurred during cold intervals. Changes in the intensity of Siberian High and the westerlies modulated by temperature variations are the likely major factors controlling dust storm dynamics. An interesting feature is that although the intensities of dust storms have been systematically increased during the recent warming period, a clear decreasing trend within this period is evident. The recent increase in average dust storm intensity may be ascribed to an increase in particle supply resulting from a rapid increase in human activity, whereas the weakening trend was likely caused by decreases in average wind speed resulting from the recent global warming. [ABSTRACT FROM AUTHOR]

A rapid and sensitive liquid chromatography method was developed and validated for the simultaneous determination of 21 free amino acids in nasal feeding nutrition after liquid extraction-derivatization. The analytes were extracted by PEG/EtOH (60/40, v/v), concentrated by a Dowex Monosphere 650C cation-exchange resin and derivatized using phenyl isothiocyanate (PITC). The separation was carried out on a reversed-phase Shimadzu Inertsil ODS-3 column with component A 10 mmol L−1 phosphate buffer solution (pH 6.5) and B acetonitrile/methanol/water (40/45/15, v/v/v). The optimal separation of 21 amino acids was obtained within 15 min. The average recoveries of 21 amino acids spiked at 3 concentrations (0.5, 2.0 and 10.0 µmol L−1) were in the range of 62.49–82.54%. Limits of detections (LODs) varied from 0.002 to 0.038 µmol L−1 and limits of quantifications (LOQs) ranged from 0.01 to 0.19 µmol L−1. This rapid and sensitive method has been successfully applied for the analysis of nasal feeding nutrition from Chinese markets, and the contents of free amino acids in these samples are very different. [ABSTRACT FROM AUTHOR]

The South Aisikexiaer Cemetery, located in the Hami Basin of Xinjiang, northwest China, has been dated to around 2700 to 2400 BP. The arid conditions of the Hami region allow for the preservation through desiccation of a large amount of botanical materials, with 14 different taxa identified by systematic archaeobotanical study. Naked barley (Hordeum vulgare var. coeleste) was the only cereal type identified. Barley may be cultivated in the oases around the cemetery and threshed to obtain grains for foodstuff. Broken stems of barley were by-products of threshing and possibly consumed as binder for wall construction. Woody plants mainly include Populus euphratica, Tamarix sp. and Salix sp. Timbers of P. euphratica were the most important wooden materials for local inhabitants, used in the construction of tombs and fabrication of wooden articles. The remaining wild herbaceous plants are dominated by Aristida grandiglumis. Culms of A. grandiglumis may have been specially collected for livestock fodder and used as filling material of roof thatch on tomb. Stems of Phragmites australis were used in mat weaving. The diversity of plant remains, and their uses give insight into the adaptive strategies of the South Aisikexiaer population to arid environment in the Hami Basin during the early Iron Age. [ABSTRACT FROM AUTHOR]

The Gumugou Cemetery is located in the Lop Nor region of the Tarim Basin in Xinjiang, northwest China. Radiocarbon dating found the site to be 3800 years BP. Due to the exceptionally arid conditions, most of the plant remains are well-preserved. Morphological and anatomical studies suggest that the plant remains consist of: Triticum cf. aestivum, Phragmites australis, Populus euphratica, Ephedra sp., as well as Typha sp. These ancient plants imply that the indigenous people lived in oases surrounded by extensive desert. Caryopses of T. cf. aestivum might have been used as funeral objects of the mummies as well as a subsidiary food source of the inhabitants, while the wild plants were used in other aspects of daily life. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the safety and efficacy of three-dimensional (3D) navigation-guided polymethylmethacrylate (PMMA)-augmented thoracic and lumbar pedicle screw fixation for the osteoporotic patients. Methods: 27 consecutive osteoporosis patients with a variety of spinal disorders who underwent 3D navigation-guided PMMA-augmented pedicle screw fixation were evaluated clinically and radiologically in the perioperative and 1-year follow-up period. The improvement of Japanese Orthopaedic Association (JOA) scores was analyzed. PMMA leakage and other complications were inspected intraoperatively and postoperatively. Screw loosening and bone fusion were evaluated radiographically during follow-up. Results: 8 patients had thoracic and lumbar fractures; 18 patients had degenerative spinal disorders; one patient had revision surgery. One patient died of postoperative pneumonia. Each of the other 26 patients was followed up regularly at 3, 6, 12 and 18 months postoperatively. The mean therapeutic improvement rate is 39.6 % evaluated by JOA scores. 2 patients (7.4 %) had leakage into the spinal canal in front of the posterior longitudinal ligament and two patients (7.4 %) had leakage into the prevertebral soft tissue inspected by the postoperative CT scans. No pedicle cortex breach and cement leakage surrounding pedicle cortex were observed. None of patients complained of dyspnoea and showed evidence of pulmonary embolism. Bone fusions were found in 20 patients (bony fusion rate 76.9 %) at the 12-month follow-up and no screw loosening occurs. Conclusion: The results show favorable outcome using 3D navigation-guided PMMA-augmented thoracic and lumbar pedicle screw fixation for the osteoporosis patients both clinically and radiologically. [ABSTRACT FROM AUTHOR]

The morphology, microstructure, and chemical composition of a variety of particles emitted from coal-fired power plants, steel plants, and vehicle exhausts, which are possible sources of particulate matter (PM) in the atmosphere, were investigated by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) and compared with particle samples collected from urban atmosphere to identify the best footprint or the suitable indicator relating the existence of studied particles and their possible emitters by the morphology, microstructure, and chemical composition of the particles. The investigation indicated that the particles from these three sources are different in morphology, microstructure, and chemical composition. Sphere aggregates were generally the most abundant components, with silicon and aluminum as major elements. The urban air particulate contained particles similar to those observed in the power plant, steel plant, and vehicle exhaust samples suggesting that all three sources are contributing to the pollution in the city. [ABSTRACT FROM AUTHOR]

In this paper, the impact of the viaduct on flow and traffic exhausting particles dispersion within urban street canyons was numerically simulated using a computational fluid dynamics (CFD) model. Two-dimensional flow and dispersion of particles from traffic exhausts were modeled using the standard k- ∈ turbulence model. The street canyons with a viaduct at different widths and different heights above the ground are simulated. The results show that the airflow in street canyon is evidently influenced by the viaduct: The position of the main vortex center is changed, especially there are two strong vortexes when the viaduct is placed at 10 m height above the ground. It is found based on the study of the particles number concentrations (PNCs) that the viaduct may mitigate the pollution level in the street canyon sometimes. The impact of the viaduct width on PNCs is stronger than that of the height. The study of PNDs reveals that the mean PNCs at the wall of upwind building increase when a viaduct is placed in street canyon. In addition, it is found based on the study of mean particles residence time (PRT) that the removal of the particles strongly correlates to the mean PNCs. The results indicate that the viaduct is an important factor to influence the flow patterns and particles dispersion in street canyons. [ABSTRACT FROM AUTHOR]

Refractive-index (phase-contrast) radiology was able to detect lung tumors less than 1 mm in live mice. Significant micromorphology differences were observed in the microradiographs between normal, inflamed, and lung cancer tissues. This was made possible by the high phase contrast and by the fast image taking that reduces the motion blur. The detection of cancer and inflammation areas by phase contrast microradiology and microtomography was validated by bioluminescence and histopathological analysis. The smallest tumor detected is less than 1 mm with accuracy better than 1 × 10 mm. This level of performance is currently suitable for animal studies, while further developments are required for clinical application. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

In order to explore the mechanism of moss as air pollution biomonitor, the moss samples were exposed in a pollution site of Shanghai Institute of Steel Research (SISR) and a control site of Shanghai Institute of Applied Physics (SIAP) simultaneously for one month. The concentrations of trace elements in the micro areas of leaf and stem, as well as in the whole moss tissue, were determined using synchrotron radiation X-ray fluorescence (SRXRF) method. The distributions of some metal elements such as Pb, Cu, Fe, Ni, Mn, Zn, Ca and K in the leaf surface and the stem slice were obtained. The results showed that the metallic ions were not evenly distributed after adsorption. In particular, some elements of K, Ni, Fe, Pb, etc., were concentrated in the leaf apex and the intermediate rib. Under pollution condition, the excessive Pb was adsorbed and deposited in the leaf. It caused serious damage to plant growth and ultrastructure, also suppressed moss' normal absorption to the nutritive elements of K, Ca, etc. [ABSTRACT FROM AUTHOR]

The atmospheric particulate matter samples were collected in Shanghai, China. The X-ray absorption near-edge structure (XANES) spectra of Cr, Mn, Cu and Zn were measured. The XANES spectroscopy was used as a fingerprint to compare with that of reference materials to obtain speciation information. The oxidation state of these elements and main chemical components in the samples were described using the method. The results show that in our samples the oxidation state of Cr is trivalent, Mn mainly exists in the divalent state, Cu also exists in the divalent state, and Zn mainly exists in the zinc sulfate. For the XANES spectra of samples with different particle size and from different sampling site, we did not find their obvious differences. When we compared the XANES spectra of our samples with those of standard reference material SRM 1648, we found that they are similar in regards to the determined elements. The elemental concentrations in the samples were determined by proton induced X-ray emission (PIXE). The difference of elemental concentrations was observed in the different samples. [ABSTRACT FROM AUTHOR]

The study on elemental speciation in atmospheric particulate matter (PM) is important for understanding the formation and origin of pollution and evaluating their toxicity. In this paper, the speciation of iron in atmospheric PM was investigated with extended X-ray absorption fine structure (EXAFS) spectra based on synchrotron radiation. The chemical components of PM can be calculated by regression analysis of EXAFS spectra. This is a non-destructive method. In order to have knowledge of the influence of chemical components on EXAFS spectra, we prepared a series of mixed reference samples, and proved the precision of method is good. The PM samples with different particle sizes and from different sampling sites were collected in Shanghai, China. The chemical components of the samples were calculated by regression analysis of EXAFS spectra. The results show that the iron in all PM samples mainly consist of Fe2O3, Fe3O4 and Fe2(SO4)3, but their proportions are different in different samples. The changes of components among PM samples were observed preliminarily. The concentrations of iron in the samples were determined by proton-induced X-ray emission (PIXE) technique. It is observed that the concentrations of iron in the samples of iron and steel industrial district were much higher than those of other districts, and chemical components were also different from those of others. [ABSTRACT FROM AUTHOR]

Three human liver tissue samples (∼5 mm ⊗ 40 mm ⊗ 20 nun) were excised from a cancer patient's liver during surgery. The microradiology analysis was performed with a non-standard approach on a synchrotron. High-resolution refractive-index edge-enhanced microradiographs that cover a larger volume of the liver tissue sample were obtained. The cancer tissue and normal tissue could be clearly identified and distinguished based on their different textures. Furthermore, new blood vessel hyperplasia was found near the cancer area. Blood vessels with a diameter smaller than 20 μm could be identified. These findings were fully consistent with the histopathological examination of the same area. Microradiographs of the newly formed blood vessels at different angles were also obtained. This result shows that it is possible to further develop this approach into a technique of microradiographic imaging for clinic diagnosis of liver cancer at the early stage. [ABSTRACT FROM AUTHOR]

The iron-containing atmospheric particulate matter collected from a tunnel and downtown in Shanghai were analyzed by Mössbauer spectroscopy; their chemical composition, size of particles and concentration were determined. X-ray absorption near-edge structure measurements and the nuclear microprobes were performed to supplement the identification of the chemical compositions of iron compounds. In addition, the transformation of the iron compound in air was discussed [ABSTRACT FROM AUTHOR]

Diabetes mellitus is characterized by hyperglycemia and is closely related to trace elements. Quite a few pregnant women suffer from impaired glucose tolerance (IGT) or gestational diabetes mellitus (GDM). Investigation of the changes of elemental contents in serum of the pregnant women with IGT and GDM is significant in the etiological research and cure of the diseases. In the present work, the elements Cu, Zn, Ca, Sr, Mg, P, Fe, and Al in the serum of pregnant women were determined. The elemental contents in different experimental groups were compared. Also, the correlation between elemental contents and gestational period was observed. The results showed that compared with normal pregnant women, the Cu contents in serum of pregnant women with GDM increased, but Zn contents had a decreasing trend. In addition, for all pregnant women, the Ca contents in serum had an obvious inverse correlation with gestational period. [ABSTRACT FROM AUTHOR]

This article deals with an osteoporosis model using New Zealand rabbits in order to study the function of inorganic elements for women patients with osteoporosis. Thirty cases of iliac crests were collected and determined using the neutron activation analysis technique. The results show that the fluorine concentrations in the experimental group are higher than those in the control group and that the magnesium concentrations are significantly lower ( p<0.001), but the concentrations of potassium, sodium, calcium, barium, manganese, and strontium show no significant differences. Combined with the serum biochemical markers of bone formation and resorption, the physiological functions of some metal elements in bone are also discussed. [ABSTRACT FROM AUTHOR]

More than 30 aerosol samples were collected from 1 place near Zaojiaban Road (downtown of Shanghai) and 1 village near Jiading country (suburb) by a stacked-filter air sampler. The coarse particulates (>2.5 µm) and the fine particulates (PM2.5) and their unsoluble parts were analyzed by proton-induced X-ray emission. The cytotoxicity of particulates from the two places was evaluated by malondialdehyde (MDA) and thiazolyl blue (MTT) methods. The results show that the transition metal Fe, Cr, and Mn compounds from downtown are more easily soluble than those from the suburb, both in coarse and fine particulates, and the S content is much higher in particulates from downtown than that from the suburb. The cytotoxicity of the particulates from downtown is higher than that from the suburb and the cytotoxicity of acidified particulates is significantly higher than that of the controls. Because there are higher-soluble transition metal compounds that can induce free radicals in acidified particulates, the soluble transition metals may be one of the main factors for cytotoxicity. [ABSTRACT FROM AUTHOR]

Gestational diabetes is one of the most common diseases in pregnancy. In the present work, the possible relationship between serum selenium concentration and gestational diabetes was investigated. Blood samples of 234 pregnant women were collected, including 98 subjects with impaired glucose tolerance (IGT), 46 subjects with gestational diabetes mellitus (GDM), and 90 normal pregnant women (NPW). An additional 17 samples of normal women of fertile age (NW) were collected for comparison. The hydride generation atomic fluorescence spectrometry was used for selenium determination. The mean serum selenium levels obtained for each group were 0.0741±0.0167 mg/L for NPW, 0.0631±0.0132 mg/L for IGT, 0.0635±0.0120 mg/L for GDM, and 0.108±0.0170 mg/L for NW. Serum selenium levels were significantly lower in pregnant woman with IGT ( p<0.001) and GDM ( p<0.001) than in NPW. Furthermore, an inverse correlation between the serum selenium concentration and the gestational period was also observed. Selenium supplementation during gestation for pregnant women, especially with IGT and GDM, should be considered. [ABSTRACT FROM AUTHOR]

Focuses on a study which explored the distribution of inorganic substances in bone, and provided scientific basis for prevention and therapy of osteoporosis using the synchroton radiation X-ray fluorescence microprobe technique. Materials and methods; Results and discussion; Conclusions.

The samples of PM2.5 and PM10 inhalable particulate matter had been collected during the period of December 2002–January 2003 at nineteen representative sites of Shanghai urban and suburb area in order to investigate the chemical characterization of aerosol particle in winter. The samples were analyzed to determine the average concentrations for up to twenty elements by means of particle induced X-ray emission (PIXE). It was found that the average elemental concentrations in the urban center are higher than those in the suburb, except for Ti and P. The particulate mass data demonstrate that the ratio range of PM2.5/PM10 is from 0.32 to 0.85 and its average ratio is 0.6. The result of the enrichment factor shows that the inhalable particles may be divided into two categories, i.e., soil elements from the earth crust and anthropogenic pollution elements. It is noticed that toxic or harmful elements such as S, As, Pb, Ni, Mn and Se are enriched mainly in fine particles with diameter less than 2.5 μm. The fingerprints of major pollution sources such as coal (or oil) burning, vehicle exhaust emission and industry are also presented and discussed. [ABSTRACT FROM AUTHOR]

The tunable photoluminescence (PL) of nitrogen-doped carbon dots (NCDs) has attracted much attention in recent years while the specific mechanism is still in dispute. Herein, NCDs with yellow emission were successfully synthesized via a facile hydrothermal approach. Three kinds of post-treatment routes were investigated to verify the influence of surface states on the PL emission of NCDs including solvent-dependent, reduced-reaction and metal-enhanced effect. The interaction mechanism was studied by absorption spectrum, structural characterizations, steady-state and time-resolved spectroscopy. When dispersed in different solvents, the as-prepared NCDs show tunable emission and PL enhancement attributed to hydrogen bonding between solvents and NCDs. Besides, the addition of NaBH4 can induce the reduction of the C=O bonds existing in original NCDs to C–O bonds and thus result in the enhancement of the intrinsic (n–π*) emission. Moreover, metal-enhanced fluorescence of NCDs can also be observed when adding Ag+ into initial NCD solution, which might be ascribed to aggregation-induced emission enhancement. These results for post-treated NCDs demonstrate that surface functional groups are responsible for PL emission and provide new possibilities like multi-image sensing and lighting application. [ABSTRACT FROM AUTHOR]

In this letter, dual-emissive and color-tunable Mn-doped InP/ZnS quantum dots (Mn:InP/ZnS QDs) with the absolute photoluminescence quantum yield (PL QY) up to 78% were successfully synthesized via a growth-doping method. The dual emission of Mn:InP/ZnS QDs is composed of intrinsic emission and Mn-doped emission, which can be tuned by different Mn/In ratios. With the increase of Mn dopant concentration, the intrinsic emission shows a red shift from 485 to 524 nm. The new class of dual-emissive QDs provides potential for future application in white LED. [ABSTRACT FROM AUTHOR]

A correction to the article "Detecting Small Lung Tumors in Mouse Models by Refractive-Index Microradiology" that was published in a 2011 issue is presented.