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Background Lymphatic malformations are common congenital vascular lesions. Neither surgical resection nor other surgical treatments have been found to be effective for invasive cases. Recent research has suggested that sirolimus is effective in treating complex lymphatic malformations (LMs). We aimed to evaluate the effectiveness and safety of oral sirolimus for children living with LMs in our hospital. Methods Fifty-six cases of complex LMs treated with sirolimus were collected from Shanghai Children's Medical Centre between June 2016 and March 2019. All cases were confirmed either by pathology (44) or enhanced MRI (12). Following informed consent, sirolimus 0.8 mg/m2 bid was administered orally to participants and maintained at a trough concentration of 10–15 ng/ml. Children's ages at diagnosis were neonate to 16 years (mean 44.3 months). All children were followed up for 5 to 30 months, with a mean of 16.8 months. Results During the follow-up period, blood, liver and kidney function as well as disseminated intravascular coagulation was regularly reviewed in all 56 children. Enhanced MRI was regularly performed to evaluate therapeutic effects. Total effective rate (complete response or partial response) of LMs was 89.3% (50/56). No serious adverse reactions were found. Conclusion This study suggests that sirolimus is effective and tolerable for decreasing lesions in children with complex LMs, leading to fewer and more tolerable side effects. There is no need to pursue an excision rate to reduce unnecessary operative complications since adjuvant sirolimus therapy modifies the complex LMs clinical appearance and alleviates their symptoms. Type of study Clinical research. Level of evidence Level IV.

Large-scale seedling production aims to improve their production capacity and competitiveness by improving productivity, reducing labour costs, and eliminating labour-intensive production processes. With the pursuit of continuously improving productivity, the development of automatic seedling production has become a key technology. However, achieving the automatic separation of rootless collected seedlings into individual plants remains an important challenge because tender rootless seedlings need to be separated into individuals for feeding into seedling production equipment. In this study, a separator composed of subdivided air streams was developed to separate tender collected seedlings into individuals. The air streams for separation were generated by a jetting nozzle array of subdivided air streams at the base of the separator. By opening and closing different subdivided air stream nozzles, in turn, seedlings became suspended with some seedlings at the edge of the floating mass becoming separated. The separator was tested using aubergine and cucumber seedlings intended for grafting and for anthurium seedlings intended for cuttage transplanting. The results demonstrated that the separator could separate tender collected seedlings into individuals without causing damage. Moreover, the maximum separation rates for the collected seedlings were 11,070, 13,590, and 17,100 plants per hour for the aubergine, cucumber, and anthurium seedlings, respectively.

In the present study, a series of cycloalkyl[b]thiophenylnicotinamide derivatives against α-glucosidase were synthesized, and evaluated for their in vitro and in vivo anti-diabetic potential. Most of the synthetic analogues exhibited superior α-glucosidase inhibitory effects than the standard drug acarbose (IC

Automatic segmentation of abdominal organs in CT scans plays an important role in clinical practice. However, most existing benchmarks and datasets only focus on segmentation accuracy, while the model efficiency and its accuracy on the testing cases from different medical centers have not been evaluated. To comprehensively benchmark abdominal organ segmentation methods, we organized the first Fast and Low GPU memory Abdominal oRgan sEgmentation (FLARE) challenge, where the segmentation methods were encouraged to achieve high accuracy on the testing cases from different medical centers, fast inference speed, and low GPU memory consumption, simultaneously. The winning method surpassed the existing state-of-the-art method, achieving a 19× faster inference speed and reducing the GPU memory consumption by 60% with comparable accuracy. We provide a summary of the top methods, make their code and Docker containers publicly available, and give practical suggestions on building accurate and efficient abdominal organ segmentation models. The FLARE challenge remains open for future submissions through a live platform for benchmarking further methodology developments at https://flare.grand-challenge.org/.

To reveal the differences in energy exchange between a degraded alpine meadow (DM) and an artificial pasture (AP, that was artificially planted with Elymus nutans on the ploughed degraded meadow), the energy partitioning and its biophysical controls were compared between the two study sites in the Three-River Source Region (TRSR) on the Qinghai-Tibetan Plateau. The mean maximum leaf area index (LAI) for AP and DM was 2.66 and 1.08 m2 m−2, respectively. The net radiation (Rn), sensible heat flux (H), latent heat flux (λE), and soil heat flux (G) showed similar seasonal changes for the two study sites; no obvious differences in energy partitioning were noted between AP and DM during the non-growing season. However, during the growing season, Rn of DM was about 5.4% higher than that of AP, although almost the same downward shortwave and longwave radiation was received at both sites. Moreover, the mean albedo (α) of DM was lower by 0.02 than that of AP, and the mean soil surface temperature of DM was 4.1 °C lower than that of AP. The partitioning of available energy into H and λE of DM differed markedly from those of AP, and the λE/Rn ratio of DM was 16.4% higher than that of AP, whereas the H/Rn ratio of the former was 20.9% lower than that of the latter during the growing season. The growing season (annual) mean Bowen ratio (β) was 0.69 ± 0.04 and 0.90 ± 0.03 (2.38 ± 0.09 and 2.93 ± 0.12) at DM and AP, respectively, indicating that more available energy of DM was used for λE in comparison with that for AP. The difference in vegetation was considered to be the major factor leading to differences in the energy partitioning between the two sites. The results of the case study suggest that meadow degradation increases water loss through evapotranspiration and that enlarging the area of artificial pasture can increase the plant productivity and improve the water conservation capacity in this region.

Prorocentrum lima is a typical diarrheic shellfish poisoning (DSP) toxin-producing benthic dinoflagellate usually found attached to or associated with macrophytes, floating detritus, debris, or other substrates. In this paper, to gain a deeper understanding of the molecular and cellular responses to N limitation in P. lima, transcriptome profiling was performed. We found that most genes related to photosynthesis, porphyrin and chlorophyll metabolism were down-regulated following N limitation, while some genes concerning fatty acid biosynthesis, starch synthesis and ubiquitin pathway were up-regulated. Meanwhile, ABC transports ABCB1 and ABCG2 and glutathione S-transferase were up-regulated under N-limited conditions. These transcriptomic data were further corroborated by the biochemical analyses which revealed that starch, lipid content was increased, while photosynthetic efficiency was decreased. In addition, TEM analysis demonstrated that chloroplasts appeared smaller and were less abundant, while a major fraction of the cell volume was occupied by lipid bodies and starch granules, and thylakoid was twisted in the cells. Taking together, we proposed that N limitation could induce the accumulation of neutral lipid and starch in P. lima cells for carbon fixation trough recycling chloroplast membranes by autophagy. ABCB and ABCG transporters might be involved in the transport of DSP toxins. Our findings might provide global information for the response or adaptation of P. lima to N limitation.

A series of novel aralkyl piperazine derivatives were synthesized, and evaluated for their serotonin reuptake inhibitory and 5-HT1A/5-HT7 receptors affinities activity. Antidepressant activities in vivo of the compounds were screened using the forced swimming test (FST) and tail suspension test (TST). The results indicated that compounds 21k (RUI, IC50 = 31 nM; 5-HT1A, 5-HT7, ki = 62, 12 nM) and 21n (RUI, IC50 = 25 nM; 5-HT1A, 5-HT7, ki = 28, 3.3 nM) exhibited high affinities for the 5-HT1A/5-HT7 receptors coupled with potent serotonin reuptake inhibition. Specifically, the most promising compound 21n possessed a good oral pharmacokinetic properties and an acceptable hERG profile, and showed potent antidepressant-like effect in the FST and TST models.

Shrubs are important plant species in grassland ecosystems worldwide, and their density and cover have been gradually increasing globally. However, the interaction effect of grazing and aridity on population recruitment and population growth of shrub species in grasslands has not been examined explicitly. We examined sapling establishment, sexual recruitment, population mortality, and population growth of Caragana stenophylla along a climatic aridity gradient and a grazing intensity gradient in the Inner Mongolia Steppe, using manipulative field experiments. Sapling establishment, sapling height, and sexual recruitment of C. stenophylla decreased as climatic aridity and grazing intensity increased. The negative effects of grazing on sapling establishment and sexual recruitment gradually increased as climatic aridity increased. The effect of climatic aridity and grazing on population mortality was influenced by sexual recruitment. In the combined treatments of climatic aridity and grazing, population mortality was relatively high when sexual recruitment was relatively high, while population mortality increased as climatic aridity and grazing increased when sexual recruitment was relatively low. C. stenophylla population increased under relatively low drought stress and mild grazing but declined under strong drought stress and/or severe grazing. Our results suggested that to maintain viable Caragana populations, appropriate grazing policies must be made according to climate aridity gradient.

Study Region Three-River Source Region, Qinghai-Tibetan Plateau, China. Study Focus Evapotranspiration (ET) is often the largest loss of water from grassland ecosystems and consists of two constituents: evaporation (E) and transpiration (T), but it is very difficult to separate E and T. In this study, we used an energy balance model (Shuttleworth-Wallace) and a water balance model (SOILWAT2) to estimate the water budget variables over a 10-year period (2007–2016) in a degraded alpine meadow in the Three-River Source Region on the Qinghai-Tibetan Plateau. New Hydrological Insights for the Region The models produced contrasting patterns of precipitation and ET partitioning at the study site. Precipitation partitioning by SW2 resulted in substantial fluxes of both ET and deep drainage, while ET estimated by SW consumed almost all precipitation. ET was partitioned by the models into different annual E and T fluxes as well as different monthly and annual T/ET. Our study site located in an important water source region suggests that its water balance would contribute to drainage which aligns better with SW2 results. The surprising discrepancies between the models in the partitioning of precipitation into T, E, and deep drainage, however, is limiting our understanding and management of the degraded site and will require future work to reconcile.

A series of arylalkanol and aralkyl piperazine derivatives have been synthesized and evaluated for 5-HT reuptake inhibitory abilities and binding affinities at the 5-HT 1A /5-HT 7 receptors. Antidepressant activities of the compounds in vivo were screened using the forced swimming test (FST). The results indicated that the compound 8j exhibited high affinities for the 5-HT 1A /5-HT 7 receptors (5-HT 1A , k i = 0.84 nM; 5-HT 7 , k i = 12 nM) coupling with moderate 5-HT reuptake inhibitory activity (RUI, IC 50 = 100 nM) and showed a marked antidepressant-like activity in the FST model.

To understand the possible influence of substrate degradation on the drug-loading system of magnesium alloy-based drug-eluting stents, a rapamycin drug-loading poly(lactic-co-glycolic acid) coating was prepared on Mg-Nd-Zn-Zr stents for a systematic investigation in a phosphate buffer system. Mg degradation accelerated the drug release kinetics prominently, which was mainly attributed to H2 evolution in the diffusion-controlled phase while thereafter to PLGA erosion. Although physiochemical stability of the released rapamycin was partially deteriorated by magnesium degradation, the drug-loading system on magnesium substrates exhibited a more potent long-term inhibition on smooth muscle cell proliferation in vitro as compared to drug-loaded stainless steel.

Dual physically cross-linked hydrogels, which are triggered by cationic latexes as hydrophobic association and ionic crosslinking centers, were easily fabricated via a one-pot in situ polymerization method. First, the hydrophobic alkyl chains of hydrophobic monomers are adsorbed on the surface of latex microspheres and stabilized in the presence of surfactants, forming hydrophobic association centers as the first physical crosslinking points. Meanwhile, the anionic sulfate radicals dissociated by persulphate are attracted towards the cationic molecular chains of latex microspheres through ionic interactions, forming the secondary physical crosslinking centers, and initiate the copolymerization between acrylamide and hydrophobic vinyl monomers. The fabricated hydrogel exhibited high tensile strength of 1.32MPa, a remarkable toughness of 4.53MJm-3, excellent self-recovery properties and fatigue resistance. Therefore, the current work provides a promising strategy for designing novel hydrogels via multiple physical interactions and devoid of any chemical crosslinking. The novel design of hydrogels can enhance their mechanical properties and expand their biomedical applications.

Conductive hydrogels as wearable devices meet the basic demands of mechanical flexibility and smart sensing. However, achieving a combination of adequate skin adhesion, long-term stability and visible human-sensor interface are still challengeable. Here, a simple and effective strategy was proposed to fabricate “all-in-one” hydrolyzed keratin protein-modified polyacrylamide composite hydrogel transducer. Hydrolyzed keratin endowed hydrogel with lower modulus and ultra-stretchability to minimize wearing-related tension and discomfort. Specially, robust skin adhesion was obtained to achieve precise sensing without delamination. Impressively, the hydrogel had high transparency and exhibited wide-range temperature tolerance (−20 °C to 50 °C). Besides, the hydrogel with stable conductivity was extremely sensitive to pressure and strain at a wide range. As a result, the obtained transducer could not only detect human motion, respiratory mode and vocal-cord vibration, but also identify handwriting and facial expression. This work shed a new light on the design of next-generation skin-like electronic devices with applications in human-machine interface, ionic skin, artificial intelligence and healthcare monitoring.

This paper builds a dual isolation system for suppressing the micro-vibration due to flywheel of optical satellite. The advantages of this system compared to the single-layer vibration isolation system are: 1) the layout of flywheels is more compact, which improves the utilization rate of structure; 2) the load path of the perturbation of flywheel is extended; 3) the attenuation rate of vibration in high frequency band is improved. The transmissibility of force is discussed and the decay time of precession associated with the flywheel gyroscopic effect is analyzed. The suitable cut-off frequencies of isolators are designed in consideration of the precession decay time and the first-order natural frequency of the satellite during launch process. The influence of flywheel micro-vibration on camera with and without isolation is compared by on-ground optical imaging test. The RMS of pixel offset attenuates obviously under dual isolation and the maximum attenuation rate reaches 69.0%. The pixel offset value under dual isolation is less than 0.1 pixels, indicating the feasibility of dual isolation system for flywheel.

An experimental investigation of the single event upset (SEU) susceptibility for heavy ions at tilted incidence was performed. The differences of SEU cross-sections between tilted incidence and normal incidence at equivalent effective linear energy transfer were 21% and 57% for the silicon-on-insulator (SOI) static random access memories (SRAMs) of 0.5 μm and 0.18 μm feature size, respectively. The difference of SEU cross-section raised dramatically with increasing tilt angle for SOI SRAM of deep-submicron technology. The result of CREME-MC simulation for tilted irradiation of the sensitive volume indicates that the energy deposition spectrum has a substantial tail extending into the low energy region. The experimental results show that the influence of edge effects on SEU susceptibility cannot be ignored in particular with device scaling down.

Hirschsprung's disease (HD) is a congenital malformation of the gastrointestinal tract characterized by the absence of the distal enteric nervous system. Hirschsprung-associated enterocolitis (HAEC) is severe life threatening complication of HD. The disease pathogenesis is still unclear, but evidences suggest that the intestinal microbiota may play important role in the development of HD and HAEC. Because microbial abundance and diversity might differ in HD patients with enterocolitis, we sought to generate comparative metagenomic signatures to characterize the structure of the microbiome in HD patients with and without enterocolitis. Our experimental design is to enroll four HD patients (two with enterocolitis and two without enterocolitis). The microbiome was characterized by 16S rRNA gene, and the data obtained will be used to taxonomically classify and compare community structure among different samples. We found that the structure of the microbiome within HAEC patients are differ from those without enterocolitis. This study helps us to understand microbial contributions to the etiology of Hirschsprung-associated enterocolitis.

A series of novel aralkyl piperazine and piperidine derivatives were synthesized, and evaluated for their serotonin reuptake inhibitory and 5-HT1A/5-HT7 receptors affinities activity. Antidepressant activities in vivo of the selective compound were screened using the forced swimming test (FST) and tail suspension test (TST). The results indicated that compound 19a exhibited high affinities for the 5-HT1A/5-HT7 receptors (5-HT1A, Ki = 12 nM; 5-HT7, Ki = 3.2 nM) coupled with potent serotonin reuptake inhibition (IC50 = 14 nM) and showed a marked antidepressant-like effect in the FST and TST models.

Pulmonary endarterectomy (PEA) is an effective treatment for chronic thromboembolic pulmonary hypertension (CTEPH) by dissecting the residual thrombus from the native vessel wall. The goal of PEA is to improve pulmonary hemodynamics and right ventricular dysfunction, and thus increase exercise capacity, alleviate symptoms and decrease mortality. The aim of this study, accordingly, was to assess the ability of echocardiography to provide a mechanism to monitor the time course of RV functional improvement after PEA.Twenty-six consecutive adult patients who underwent PEA for CTEPH were included in the study. All the patients underwent transthoracic echocardiography and right heart catheterization before surgery. Follow-up echocardiography was performed within 3, 12, and 24 months of surgery. The parameters of right ventricle were compared with baseline data.In all cases, the RV was enlarged and systolic function was impaired before surgery. RV systolic pressure fell from 92±16 mm Hg before surgery to 41±9 mm Hg by the 3 month post-PEA follow-up (P0.001). RV end-diastolic area and end-systolic area likewise decreased from 35.8±4.4 cm(2) to 26.6±4.8 cm(2) (P0.001) and from 27.1±3.8 cm(2) to 17.9±3.8 cm(2) (P0.001), respectively. The RV myocardial performance index also decreased from a ratio of 0.8±0.1 to 0.5±0.1 (P0.001). The tricuspid annular plane systolic excursion increased from 8.8±0.6mm to 10.1±0.9 mm (P0.001). Tricuspid regurgitation (TR) improved from a mean grade of 3.1±0.5 to 2.2±0.7 (P0.001). At the 12 and 24 month follow-up examinations, RV systolic pressure and function remained improved, respectively. The RV systolic pressure remained above 50 mmHg in only two cases.In patients with CTEPH who undergo PEA, echocardiography is a useful tool for the evaluation of RV function. Echocardiographic measurements of RV size, systolic pressure, systolic function, and TR show significant improvement, and this effect is sustained for up to 24 months after surgery.

Objectives To investigate the influence of catgut implantation at acupoints on leptin resistance (LR) and insulin resistance (IR) in the simple obesity rat. Methods Rats were made obese with high-fat diets, after which surgical catgut was implanted at Zusanli (ST 36) and Neiting (ST 44) acupoints once a week for 4 weeks (implantation group). Rats from the implantation group were compared with normal rats and unoperated obese rats (control group). Gene expression of the leptin receptor (OB-R) was evaluated using RT-PCR and northern blot. Serum and hypothalamus leptin and insulin (INS) levels were determined by radioimmunoassay. Body weight, Lee's index, body fat, serum and hypothalamus leptin and INS levels, and hypothalamic OB-R gene expression were determined before and after treatment. Results Body weights, Lee's index, body fat, and serum leptin and INS levels were significantly higher in obese than in normal rats. Hypothalamic leptin and INS levels and OB-R gene expression were significantly lower in obese rats. Catgut implantation at acupoint promoted weight loss and decreased serum leptin and INS levels. Hypothalamic leptin and INS levels and OB-R gene expression increased significantly. Conclusions Catgut implantation at acupoint adjusts central and peripheral leptin and promotes hypothalamic OB-R gene expression. This may be an important method for regulation of LR, IR and abnormal endocrinology and metabolism.

Using satellite-observed Normalized Difference Vegetation Index (NDVI) data and Rotated Empirical Orthogonal Function (REOF) method, we analyzed the spatio-temporal variation of vegetation during growing seasons from May to September in the Three-River Source Region, alpine meadow in the Qinghai-Tibetan Plateau from 1982 to 2006. We found that NDVI in the centre and east of the region, where the vegetation cover is low, showed a consistent but slight increase before 2003 and remarkable increase in 2004 and 2005. Impact factors analysis indicted that among air temperature, precipitation, humid index, soil surface temperature, and soil temperature at 10 cm and 20 cm depth, annual variation of NDVI was highly positive correlated with the soil surface temperature of the period from March to July. Further analysis revealed that the correlation between the vegetation and temperature was insignificant before 1995, but statistically significant from 1995. The study indicates that temperature is the major controlling factor of vegetation change in the Three-River Source Region, and the currently increase of temperature may increase vegetation coverage and/or density in the area. In addition, ecological restoration project started from 2005 in Three-River Source Region has a certain role in promoting the recovery of vegetation. (C) 2011 Elsevier B.V. All rights reserved.

Lipopolysaccharide (LPS) plays a critical role in the pathogenesis of sepsis due to gram-negative bacterial infections. Therefore, LPS-neutralizing molecules could have important clinical applications. Our previous work showed, CLP19, an analogue peptide derived from limulus anti-LPS factor (LALF), possessed the capacity to neutralize LPS and thereby inhibit the LPS-induced responses. However, potential cytotoxicity of CLP19 was also found, especially when added to human red blood cells. Accordingly we further developed two peptides (designated as CLP19-1 and CLP19-2) by single- and double-point amino acid substitution of CLP19, respectively, in order to reduce its toxicity and meanwhile retain the anti-LPS activity. In this study, the LPS-detoxifying effectiveness of these peptides was evaluated both in vitro and in vivo. CLP19-1 was found to dose-dependently neutralize LPS in vitro, with significantly lower hemolysis of red blood cells as compared with CLP19. Further in vivo tests verified that CLP19-1 exerted significant protective effects on mice against LPS, characterized by significantly improved survival, decreasing of tumor necrosis factor alpha (TNF-α) serum level and alleviation of tissue injury. Our work indicates that CLP19-1 is worthy of further study as potential anti-LPS agents for the management of sepsis.

Due to the difficulty in spinal cord regeneration with biological methods, the microelectronic neural bridge, a new concept based on microelectronic technology, is presented. The microelectronic system has been realized in the forms of hybrid and integrated circuits. The integrated circuits for neural signal detection, stimulation, and regeneration are realized in a CMOS process. In animal experiments with 100 toads, 48 rats, and 3 rabbits, nerve signals have been successfully detected from spinal cords and sciatic nerves, and functional electrical stimulation has been carried out for spinal cords and sciatic nerves. When the microelectronic system is bridged between the controlling and stimulated nerve, the relevant motion of legs and nerve signal waveforms, which are stimulated by the evoked or spontaneous nerve signal through such a system, have been observed. Therefore, the feasibility of the presented method was demonstrated.

Endotoxin, also known as lipopolysaccharide (LPS), is the major mediator of septic shock due to Gram-negative bacterial infections. Recently, much attention has been focused on cationic peptides which possess the potential to detoxify LPS. Limulus anti-LPS factor (LALF), a protein found in the horseshoe crab ( Limulus polyphemus ), has been proved with striking anti-LPS effects. We synthesized a cyclic peptide (CLP-19), and then investigated its bioactivity both in vitro and in vivo . The ability of CLP-19 to neutralize LPS in vitro was tested using a Limulus amebocyte lysate (LAL) assay and the LPS-binding affinity was measured with an affinity biosensor method. The synthetic peptide LALF 31–52 (residues 31 to 52 of LALF) was used as the positive control peptide in this study. It was found that CLP-19 exhibited the significant activity to antagonize LPS without observable cytotoxicity effect on mouse macrophages. CLP-19 directly bound to LPS, and neutralized it in a dose-dependent manner in the LAL assay. Moreover, CLP-19 also showed the remarkable ability to protect mice from lethal LPS attack and to inhibit the LPS-induced tumor necrosis factor alpha (TNF-α) release by decreasing serum LPS in vivo . Our work suggests that this peptide is worthy of further investigation as a potential anti-LPS agent in the treatment of septic shock.

We monitored UVA, UVB, and solar radiation from August 2001 to 2003 on the northern Qinghai-Tibetan Plateau to characterize the diurnal and seasonal variations of UV radiation on the world's highest plateau. Daily UVB radiation and the ratio of UVB to total solar radiation increased significantly when the atmospheric ozone concentration decreased as estimated by the total ozone mapping spectrometer (TOMS), as well as when cloud coverage decreased. The UVB/UVA ratio also showed a significant increase when the TOMS ozone concentration decreased in the morning. The seasonal variation pattern of UVB, however, was closely correlated with solar elevation but was little affected by the seasonal pattern of the atmospheric ozone amount. Compared to observations from the central plateau, the magnitude of the UVB increase attributed to ozone depletion was smaller at the northern edge. The study suggests that the temporal variation of ground UV radiation is determined by both solar elevation and the ozone amount, but the spatial difference on the plateau is likely to be ascribed mainly to the spatial variation of the ozone amount. (c) 2007 Published by Elsevier B.V.

A study was carried out to examine the effect of dynamic photosynthetically active photon flux density (PPFD) on photoinhibition and energy use in three herbaceous species, prostrate Saussurea superba, erect-leaved S. katochaete, and half-erect-leaved Gentiana straminea, from the Qinghai-Tibet Plateau. Chlorophyll fluorescence response was measured under each of three sets of high-low PPFD combinations: 1700-0, 1400-300, and 1200-500 mu mol m(-2) s(-1), illuminating in four dynamic frequencies: 1, 5, 15, and 60 cycles per 2 h. The total light exposure time was 2h and the integrated PPFD was the same in all treatments. The highest frequency of PPFD fluctuation resulted in the lowest photochemical activity, the highest level of non-photochemical quenching, and the greatest decrease of F-v/F-m (maximal photochemical efficiency of PSII). The 5 and 15 cycles per 2h treatments resulted in higher photochemical activity than the 1 cycle per 2h treatment. The 1700-0 PPFD combination led to the lowest photochemical activity and more serious photoinhibition in all species. S. superba usually exhibited the highest photochemical activity and CO2 uptake rate, the lowest reduction of F-v/F-m,F- and the smallest fraction of energy in thermal dissipation. With similar fractions of thermal dissipation, S. katochaete had relatively less photoinhibition than G. straminea owing to effective F-o quenching. The results suggest that high frequency of fluctuating PPFD generally results in photoinhibition, which is more serious under periods of irradiation with high light intensity. (c) 2005 Elsevier B.V. All rights reserved.

The wind tunnel experiments is conducted to get inspiration for understanding the mechanism of the asymmetric flow pattern and developing an innovative flow control technique for a slender body at high angle of attack. The bi-stable situation of the side forces is observed, which could be easily switched by a tiny disturbances either from coming flow or from artificial disturbances at nose tip (including manufacturing defect). In turbulent flows the side forces switched randomly between positive and negative. There exists a hysteresis loop of side force with the rolling angle. A rod in front of the slender body is used to change the vortex pattern, which could be kept even the rod is moved out from the stream. A miniature strake attached to the nose tip of the model can be moved to different circumferential position. When the strake is stationary, the hysteresis loop disappears and the side force does not change with the turbulent fluctuation of coming flow. The results from dynamic measurements of section side force indicates that when the strake swung at lower frequency the side force can follow the cadence of the swinging strake. With increasing frequency, the magnitude of the side force decreases. At still high frequency, the side force diminishes to zero. If the strake is swinging, while the middle position can be changed to different circumferential angle ϕs on either left or right side, the side forces can be changed proportionally with the angle ϕs. On the basis of the experimental results, the mechanism of the asymmetry is discussed.

To reveal the potential contribution of grassland ecosystems to climate change, we examined the energy exchange over an alpine Kobresia meadow on the northeastern Qinghai-Tibetan Plateau. The annual pattern of energy exchange showed a clear distinction between periods of frozen soil with the daily mean soil temperature at 5 cm (T-s5 L 0 D C) and non-frozen soil (T-s5 G 0 D C). More than 80% of net radiation was converted to sensible heat (H) during the frozen soil period, but H varied considerably with the change in vegetation during the non-frozen soil period. Three different sub-periods were further distinguished for the later period: (1) the pre-growth period with Bowen ratio (b) G 1 was characterized by a high b of 3.0 in average and the rapid increase of net radiation associated with the increases of H, latent heat (LE) and soil heat; (2) during the Growth period when b L 1, the LE was high but H fluxes was low with b changing between 0.3 and 0.4; (3) the post-growth period with average b of 3.6 when H increased again and reached a second maximum around early October. The seasonal pattern suggests that the phenology of the vegetation and the soil water content were the major factors affecting the energy partitioning in the alpine meadow ecosystem. C 2005 Elsevier B.V. All rights reserved.

The production of pyruvate using enzymatic methods is a valuable process for its cheap substrate, high conversion ratio, simple composition of reaction, and convenience of recovery. Cell-free extracts from Pseudomonas putida SM-6 that contain both lactate oxidase (LOD) and catalase were employed as catalysts for biocatalysis. In order to obtain an efficient and cost-effective biocatalyst, the cultivation of P. putida SM-6 both in shake flask and at bioreactor level was investigated. On enzyme production, the suitability of glucose instead of lactate as a carbon source was studied. Maximum LOD production occurred when a mixture of lactate and glucose was used as a carbon source. Lactate was assimilated first and the increase of nitrogen concentration had a positive effect on cell growth and glucose assimilation. The optimum cultivation temperature was 29–31 °C, and the neutral or basic initial medium pH was in favor of both cell growth and LOD production. The interrelation between various process parameters was evaluated for the cultivation of P. putida SM-6 in submerged culture. Using a fed-batch cultivation strategy in a 2-l bioreactor, an increase in cell mass was achieved but without a concomitant increase in LOD production compared with cultivation in shake flask. Bioconversion of lactate to pyruvate was carried out using cell-free extract acquired by cell disruption of P. putida SM-6. Ethylenediaminetetraacetic acid (EDTA) was added into the biocatalytic system to prohibit the degradation of pyruvate by other enzymes in the cell-free extract. As a result, on a preparative scale, cell-free extract which contained 3.04 mg/ml crude enzyme (10.0 U/ml LOD, 877 U/ml catalase) produced pyruvate of 423 mM from dl -lactate of 660 mM in a reaction period of 22 h. The molar conversion yield of pyruvate on the basis of the amount of lactate consumed was 0.80 g/g.

We used the eddy covariance method to measure the M exchange between the atmosphere and an alpine meadow ecosystem (37degrees29-45'N, 101degrees12-23'E, 3250m a.s.l.) on the Qinghai-Tibetan Plateau, China in the 2001 and 2002 growing seasons. The maximum rates Of CO2 uptake and release derived from the diurnal course Of CO2 flux (FCO2) were -10.8 and 4.4 mumol m(-2) s(-1), respectively, indicating a relatively high net carbon sequestration potential as compared to subalpine coniferous forest at similar elevation and latitude. The largest daily CO2 uptake was 3.9 g cm(-2) per day on 7 July 2002, which is less than half of those reported for lowland grassland and forest at similar latitudes. The daily CO2 uptake during the measurement period indicated that the alpine ecosystem might behave as a sink of atmospheric M during the growing season if the carbon lost due to grazing is not significant. The daytime CO2 uptake was linearly correlated with the daily photosynthetic photon flux density each month. The nighttime averaged F-CO2 showed a positive exponential correlation with the soil temperature, but apparently negative correlation with the soil water content. (C) 2004 Elsevier B.V. All rights reserved.

The Qinghai-Tibet Plateau is characterized by extremely high radiation, which may induce down-regulation of photosynthesis in plants living in this alpine ecosystem. To clarify whether photoinhibition occurs in the alpine environment and to discern its underlying mechanisms, we examined photosynthetic gas exchange and fluorescence emission in response to the changes in photosynthetic photon flux density (PPFD) and leaf temperature under natural regimes for two herbaceous species: prostrate Saussurea superba and erect-leaved Saussurea katochaete from altitude 3250 m on the Qinghai-Tibet Plateau. S. superba intercepted a higher maximum PPFD and experienced much higher leaf temperature than the erect-leaved S. katochaete. S. superba exhibited a much higher light saturation point for photosynthesis than S. katochaete. Under controlled conditions, the former species had higher CO2 uptake rates and neither species showed obvious photosynthetic down-regulation at high PPFD. Under natural environmental conditions, however, apparent photoinhibition, indicated by reduced electron transport rate (ETR), was evident at high PPFD for both species. After a night frost, the photochemistry of S. katochaete was depressed markedly in the early morning and recovered by mid-day. After a frost-free night, it was high in the morning and low at noon due to high radiation. S. superba did not respond to the night frost in terms of daytime photochemical pattern. In both species, photochemical depression was aggravated by high leaf temperature and the erect species was more sensitive to high temperature. This study suggests that the high radiation on the Qinghai-Tibet Plateau is likely to induce rapidly reversible photoinhibition, which is related closely to plant architecture. Photochemistry in the prostrate species seems able to tolerate higher PPFD, without obvious suppression, than the erect species. (C) 2003 Elsevier Science B.V. All rights reserved.

A well-defined NHC–Pd(II)–Im complex was proved to be an efficient catalyst for the Hiyama reaction of a variety of aryl chlorides with aryltrimethoxysilanes. Under the optimal conditions, all reactions took place smoothly to give the corresponding coupling products in moderate to high yields.