We report on commissioning experiments at the high-energy,high-temperature(HHT)target area at the GSI Helmholtzzentrum für Schwerionenforschung GmbH,Darmstadt,Germany,combining for the first time intense pulses o...We report on commissioning experiments at the high-energy,high-temperature(HHT)target area at the GSI Helmholtzzentrum für Schwerionenforschung GmbH,Darmstadt,Germany,combining for the first time intense pulses of heavy ions from the SIS18 synchrotron with high-energy laser pulses from the PHELIX laser facility.We demonstrate the use of X-ray diagnostic techniques based on intense laserdriven X-ray sources,which will allow probing of large samples volumetrically heated by the intense heavy-ion beams.A new target chamber as well as optical diagnostics for ion-beam characterization and fast pyrometric temperature measurements complement the experimental capabilities.This platform is designed for experiments at the future Facility for Antiproton and Ion Research in Europe GmbH(FAIR),where unprecedented ion-beam intensities will enable the generation of millimeter-sized samples under high-energy-density conditions.展开更多
The presence of heterozygous individuals in a population is crucial for maintaining genetic diversity,which can positively affect fitness and adaptability to environmental changes.While inbreeding generally reduces th...The presence of heterozygous individuals in a population is crucial for maintaining genetic diversity,which can positively affect fitness and adaptability to environmental changes.While inbreeding generally reduces the proportion of heterozygous individuals in a population,polyploidy tends to increase the proportion.North American Populus tremuloides is one of the most widely distributed and ecologically important tree species in the Northern Hemisphere.However,genetic variation in Mexican populations of P.tremuloides,including the genetic signatures of their adaptation to a variety of environments,remains largely uncharacterized.The aim of this study was to analyze how inbreeding coefficient(FIS)and ploidy are associated with clonal richness,population cover,climate and soil traits in 91 marginal to small,isolated populations of this tree species throughout its entire distribution in Mexico.Genetic variables were determined using 36,810 filtered SNPs derived from genome re-sequencing.We found that FIS was approximately between 0 and e1,indicating an extreme heterozygosity excess.One key contributor to the observed extreme heterozygosity excess was asexual reproduction,although ploidy levels cannot explain this excess.Analysis of all neutral SNPs showed that asexual reproduction was positively correlated with observed heterozygosity(Ho)but negatively correlated with expected heterozygosity(He).Analysis of outlier SNPs also showed that asexual reproductionwas positively correlated with Ho and negatively correlated with He,although this latter correlation was not significant.These findings support the presence of a Meselson effect.展开更多
The concentration of polychlorinated biphenyls （PCBs） in the urban air of Dalian, China was monitored from November 2009 to October 2010 with active high-volume sampler and semipermeable membrane device （SPMD） pas...The concentration of polychlorinated biphenyls （PCBs） in the urban air of Dalian, China was monitored from November 2009 to October 2010 with active high-volume sampler and semipermeable membrane device （SPMD） passive sampler. The concentration of PCBs （particle ＋ gas） （∑PCBs） ranged from 18.6 to 91.0 pg/m3, with an average of 50.9 pg/m3, and the most abundant dioxin-like PCB （DL-PCBs） was PCB118. The WHO-TEQ values of DL-PCBs were 3.6--22.1 fg/m3, with an average of 8.5 fg/m3, and PCB126 was the maximum contributor to ZTEQ. There was a much larger amount of PCBs in the gas phase than in the particulate phase. The dominant PCB components were lower and middle molecular weight PCBs. With increasing chlorination level, the concentration of the PCB congeners in the air decreased. The gas-particulate partitioning of PCBs was different for the four seasons. The gas- particulate partitioning coefficients （logKp） vs. subcooled liquid vapor pressures （logPL~） of PCBs had reasonable correlations for different sampling sites and seasons. The absorption mechanism contributed more to the gas-particulate partitioning process than adsorption. Correlation analysis of meteorological parameters with the concentration of PCBs was conducted using SPSS packages. The ambient temperature and atmospheric pressure were important factors influencing the concentration of PCBs in the air. The distribution pattern of the congeners of PCBs and the dominant contributors to DL-PCBs and TEQ in active samples and SPMDs passive samples were similar. SPMD mainly sequestrated gas phase PCBs.展开更多
In this paper,we consider the use of blind deconvolution for optoacoustic(photoacoustic)imaging and investigate the performance of the method as means for increasing the resolution of the reconstructed image beyond th...In this paper,we consider the use of blind deconvolution for optoacoustic(photoacoustic)imaging and investigate the performance of the method as means for increasing the resolution of the reconstructed image beyond the physical restrictions of the system.The method is demonstrated with optoacoustic measurement obtained from six-day-old mice,imaged in the near-infrared using a broadband hydrophone in a circular scanning configuration.Wefind that estimates of the unknown point spread function,achieved by blind deconvolution,improve the resolution and contrast in the images and show promise for enhancing optoacoustic images.展开更多
Recently,a disruptive idea was reported about the discovery of a new type of battery named Liquid Displacement Battery(LDB)comprising liquid metal electrodes and molten salt electrolyte.This cell featured a novel conc...Recently,a disruptive idea was reported about the discovery of a new type of battery named Liquid Displacement Battery(LDB)comprising liquid metal electrodes and molten salt electrolyte.This cell featured a novel concept of a porous electronically conductive faradaic membrane instead of the traditional ion-selective ceramic membrane.LDBs are attractive for stationary storage applications but need mitigation against self-discharge.In the instant battery chemistry,Li|LiCl-PbCl_(2)|Pb,reducing the diffusion coefficient of lead ions can be a way forward and a solution can be the addition of Pb O to the electrolyte.The latter acts as a supplementary barrier and complements the function of the faradaic membrane.The remedial actions improved the cell’s coulombic efficiency from 92%to 97%without affecting the voltage efficiency.In addition,the limiting current density of a 500 m Ah cell increased from 575 to 831 m A cm;and the limiting power from 2.53 to 3.66 W.Finally,the effect of Pb O on the impedance and polarization of the cell was also studied.展开更多
Neoplastic cells are formed as a result of reprogramming the gene expression. It is only when these cells are classified as non-local by the normal cells that confrontation occurs, and thus cancer begins as a disease....Neoplastic cells are formed as a result of reprogramming the gene expression. It is only when these cells are classified as non-local by the normal cells that confrontation occurs, and thus cancer begins as a disease. The tumorogenic degradation of the skeletal muscle plays a highly important role in the pathomechanism of the disease. It transforms a diminishing differentiation into an increasing homeostatic disorder, and is forced to provide energy to the malignant cells. This characterizes the completed form of the pathomechanism. Blocking the pathomechanism is the goal of a therapy that can be realized on two levels: At the level of reprogramming of the gene expression, which initiates the formation of neoplastic cells, a “reprogramming” of the reprogramming of gene expression could be achieved by altering the genomic flow of information. Increased anabolism (corresponding to the nutrient surplus) as well as increased catabolism (corresponding to nutrient) could lead to respective changes of the flows of genomic information. These opposing flows in a patient could be expected to result in interference or a shearing effect. Patients with acromegaly exhibit a 9.25% increased neoplasia prevalence, whilst patients with hyperthyroidism have 8.41% increased neoplasia prevalence. Patients with acromegaly and hyperthyroidism have a lower prevalence of neoplasia of 3.30%, i.e. the chance of these patients not contracting cancer is three times greater than patients with either only acromegaly or only hyperthyroidism. At the level of tumorogenic degradation of skeletal muscle, inhibition of muscle degradation by means of hypertriglyceridemia results in a significant prolongation of the life of carcinoma patients. This is based on the fact that inhibition of muscle degradation occurs after infusion of triglyceride emulsion. In the case of S. sanguinis bacteremia, there may be an interaction between enzymes from S. sanguinis, from the digestive tract and from the tumor. The source of infection determines the inactivation of the tumor enzyme and thus suppresses tumor development.展开更多
We present in situ measurements of spectrally resolved X-ray scattering and X-ray diffraction from monocrystalline diamond samples heatedwith an intense pulse of heavy ions.In this way,we determine the samples’heatin...We present in situ measurements of spectrally resolved X-ray scattering and X-ray diffraction from monocrystalline diamond samples heatedwith an intense pulse of heavy ions.In this way,we determine the samples’heating dynamics and their microscopic and macroscopic structuralintegrity over a timespan of several microseconds.Connecting the ratio of elastic to inelastic scattering with state-of-the-art density functionaltheory molecular dynamics simulations allows the inference of average temperatures around 1300 K,in agreement with predictions fromstopping power calculations.The simultaneous diffraction measurements show no hints of any volumetric graphitization of the material,butdo indicate the onset of fracture in the diamond sample.Our experiments pave the way for future studies at the Facility for Antiproton andIon Research,where a substantially increased intensity of the heavy ion beam will be available.展开更多
PURPOSE. To study some functional candidate genes in cataract families of Indi an descent. METHODS. Nine Indian families, clinically documented to have congeni tal/childhood cataracts, were screened for mutations in c...PURPOSE. To study some functional candidate genes in cataract families of Indi an descent. METHODS. Nine Indian families, clinically documented to have congeni tal/childhood cataracts, were screened for mutations in candidate genes such as CRYG (A→D), CRYBB2, and GJA8 by PCR analyses and sequencing. Genomic DNA sample s of either probands or any representative affected member of each family were P CR amplified and sequenced commercially. Documentation of single nucleotide poly morphisms (SNPs) and candidate mutations was done through BLAST SEARCH(http://ww w.ncbi.nlm.nih.gov/ blast/Blast.- cgi?). RESULTS. Several single nucleotide polymorphisms in CRYG, CRYBB2, and G JA8 genes were observed. Because they do not co-segregate with the phenotype, t hey were excluded as candidates for the cataract formation in these patients. However, a substitution (W151C in exon 6 of CRYBB2) was identi fied as the most likely causative mutation underlying the phenotype of central n uclear cataract in all affected members of family C176. Protein structural inter pretations demonstrated that no major structural alterations could be predicted and that even the hydrogen bonds to the neighboring Leu166 were unchanged. Surpr isingly, hydropathy analysis of the mutant βB2-crystallin featuring the amino acids at position 147 to 155, further increased the hydrophobicity, which might impair the solubility of the mutant protein. Finally, the Cys residue at positio n 151 might possibly be involved in intramolecular disulphide bridges with other cysteines during translation, possibly leading to dramatic structural changes. CONCLUSIONS. Exon 6 of CRYBB2 appears to be a critical region susceptible for mu tations leading to lens opacity.展开更多
BACKGROUND: An association between exposure to vehicular traffic in urban areas and the exacerbation of cardiovascular disease has been suggested in previous studies. This study was designed to assess whether exposure...BACKGROUND: An association between exposure to vehicular traffic in urban areas and the exacerbation of cardiovascular disease has been suggested in previous studies. This study was designed to assess whether exposure to traffic can trigger myocardial infarction. METHODS: We conducted a case-crossover study in which cases of myocardial infarction were identified with the use of data from the Cooperative Health Research in the Region of Augsburg Myocardial Infarction Registry in Augsburg, in southern Germany, for the period from February 1999 to July 2001. There were 691 subjects for whom the date and time of the myocardial infarction were known who had survived for at least 24 hours after the event, completed the registry’s standardized interview, and provided information on factors that may have triggered the myocardial infarction. Data on subjects’activities during the four days preceding the onset of Symptoms were collected with the use of patient diaries. RESULTS: An association was found between exposure to traffic and the onset of a myocardial infarction within one hour afterward(odds ratio, 2.92; 95 percent confidence interval, 2.22 to 3.83; P< 0.001). The time the subjects spent in cars, on public transportation, or on motorcycles or bicycles was consistently linked with an increase in the risk of myocardial infarction. Adjusting for the level of exercise on a bicycle or for getting up in the morning changed the estimated effect of exposure to traffic only slightly(odds ratio for myocardial infarction, 2.73; 95 percent confidence interval, 2.06 to 3.61; P< 0.001). The subject’s use of a car was the most common source of exposure to traffic; nevertheless, there was also an association between time spent on public transportation and the onset of a myocardial infarction one hour later. CONCLUSIONS: Transient exposure to traffic may increase the risk of myocardial infarction in susceptible persons.展开更多
PCDD/Fs in the urban air of Dalian,China were monitored with high-volume active sampler from November 2009 to October 2010.The concentration of Cl 4-8 DD/Fs ranged from 3065 to 49538 fg m-3,with an average of 10249 fg...PCDD/Fs in the urban air of Dalian,China were monitored with high-volume active sampler from November 2009 to October 2010.The concentration of Cl 4-8 DD/Fs ranged from 3065 to 49538 fg m-3,with an average of 10249 fg m-3.The international toxic equivalents(I-TEQ) value of that was 61.8 1182 fg m-3,with an average of 235 fg m-3,which was comparable to those in the other urban locations around the world.It was found that the Cl 4 8 DD/Fs appeared to be present mainly in the particle phase during winter,spring and autumn,while during summer which were dominantly in gas phase.The ratio of Cl 4-8 DD/Fs present in particle phase increased with the increasing level of chlorination.The concentrations of PCDFs and PCDDs decreased with the increase of chlorinated level,while the concentrations of 2,3,7,8-PCDDs congeners increased with the increase of chlorination level.The homolog profiles of the concentrations of PCDFs presented were higher than those of the PCDDs,which indicated the PCDD/Fs pollution source of the air in Dalian was characteristic for thermal source pollution.The correlation analysis of meteorological parameters with the concentrations of Cl 4-8 CDD/Fs was conducted using SPSS packages,and it was found that the ambient temperature and atmospheric pressure were important factors influence the concentration of PCDD/Fs in the air.The respiratory risk and intake dioxins of the residents around the sampling sites were studied in the paper.It was found that Junge-Pankow model was much more accurate in predicting the gas-particle partitioning behavior of PCDD/Fs homologues during winter,while the Harner-Bidleman model shows better agreement with the measured data during winter and summer.展开更多
Background Most orthopedic surgeons prefer spica cast immobilization in children for 4 to 12 weeks after surgical hip reconstruction in children with developmental hip dysplasia.This challenging treatment may be assoc...Background Most orthopedic surgeons prefer spica cast immobilization in children for 4 to 12 weeks after surgical hip reconstruction in children with developmental hip dysplasia.This challenging treatment may be associated with complica-tions.Studies are lacking that focus on early mobilization without casting for postoperative care after hip reconstruction.Methods Twenty-seven children(3.4±2.0 years),including 33 hips with developmental hip dysplasia(DDH)and dislocation of the hip(Tonnis grade 1 to 4),who underwent hip reconstruction(Dega acetabuloplasty,varisation-derotation osteotomy and facultative open reduction)were retrospectively included in this study.Postoperatively the patients were placed in an individual foam shell with 30 degrees of hip abduction,hip extension,and neutral rotation.Early mobilization physiotherapy was performed within the first few days after the surgery under epidural anaesthesia.Full weight bearing was allowed after 3-4 weeks.All children received a clinical examination and radiographic evaluation before and after surgical intervention.The follow-up period was 12.3±2.9 months.Results On average,the postoperative acetabular index decreased significantly from 36.9 to 21.7 degrees and the center-edge angle increased from 9.9 to 28.6 degrees.All hips had reached Tonnis grade 1 at the time of the last follow-up.No complications such as dislocation of the bone wedge,avascular necrosis of the acetabulum or femur,lack of non-union,or nerve injury,were reported.Conclusions In this cohort study,hip reconstruction was successful according to clinical and radiographic outcome param-eters after early mobilization without cast therapy.Early mobilization may be used as an alternative treatment option after hip reconstruction in DDH.展开更多
Background Equinus is a common deformity in children with bilateral spastic cerebral palsy (BSCP).While dynamic equinus usually is treated by conservative therapy,fixed contractures need surgical correction.To choose ...Background Equinus is a common deformity in children with bilateral spastic cerebral palsy (BSCP).While dynamic equinus usually is treated by conservative therapy,fixed contractures need surgical correction.To choose the appropriate surgical method,it is important to discriminate between isolated gastrocnemius shortening and combined gastrosoleus complex contracture.Methods In a retrospective study 938 patients with BSCP were studied.Patients underwent gait analysis and clinical examination.248 patients (496 limbs) met the inclusion criteria.Data from motion analysis and clinical examination were used to calculate the prevalence and to further classify fixed equinus foot.Results The prevalence of equinus was 83.3%.During clinical exam 246 (59.6%) limbs showed combined gastrosoleus complex contracture and 167 (40.4%) isolated gastrocnemius contracture.Max.DF at stance and mean DF at initial contact were significantly reduced in combined contracture,while max.ROM was increased (P < 0.05).Conclusions Corroborating the results of previous studies,in this study there was a high prevalence of fixed equinus in patients with BSCP.The prevalence of equinus correlated with increasing age.As half of the patients with fixed equinus show a different involvement of gastrocnemius and soleus muscle,we recommend to apply Silfverski(o)ld's test to discriminate between those two types to choose the appropriate surgical therapy.展开更多
Neurons synthesizing the neurotransmitter dopamine exert crucial functions in the mammalian brain. The biggest and most important population of dopamine-synthesizing neurons is located in the mammalian ventral midbra...Neurons synthesizing the neurotransmitter dopamine exert crucial functions in the mammalian brain. The biggest and most important population of dopamine-synthesizing neurons is located in the mammalian ventral midbrain （VM）, and controls and modulates the exe- cution of motor, cognitive, affective, motivational, and rewarding behaviours. Degeneration of these neurons leads to motor deficits that are characteristic of Parkinson＇s disease, while their dysfunction is involved in the pathogenesis of psychiatric disorders including schizophrenia and addiction. Because the aetiology and therapeutic prospects for these diseases include neurodevelopmental aspects, substantial scientific interest has been focused on deciphering the mechanistic pathways that control the generation and sur- vival of these neurons during embryonic development. Researches during the last decade revealed the pivotal role of the secreted Wntl ligand and its signaUing cascade in the generation of the dopamine-synthesizing neurons in the mammalian VM. Here, we summarize the initial and more recent findings that have unravelled several Wntl-controUed genetic networks required for the proliferation and commitment of VM progenitors to the dopaminergic cell fate during midgestational embryonic stages, and for the correct differentiation of these progenitors into postmitotic dopamine-synthesizing neurons at late midgestational embryonic and foetal stages.展开更多
Organochlorine pesticides (OCP) were monitored at the Weissfluhjoch site (Switzerland) and the top of Mt. Sonnblick (Austria) with a low volume active air sampler and semipermeable membrane devices (SPMD). The air sam...Organochlorine pesticides (OCP) were monitored at the Weissfluhjoch site (Switzerland) and the top of Mt. Sonnblick (Austria) with a low volume active air sampler and semipermeable membrane devices (SPMD). The air sampling rates (Rair) of the SPMD for OCP were calculated. Statistical tests showed that there was no significant difference between Rair at the two different sampling sites. Quantitative structure-property relationship (QSPR) models of the Rair of the SPMD were developed for OCP using partial least square (PLS) regression. Quantum chemical descriptors computed by the semi-empirical PM6 method were used as predictor variables. The cumulative variance of the dependent variable explained by the PLS components and determined by cross-validation (Q2cum) was >0.818 for each optimal model. This indicates that the model has good predictive ability and robustness. The Rair of the SPMD for OCP is related to the total energy, the van der Waals area and the total dipole moment of the OCP molecules. The main factors governing Rair values of OCP are intermolecular interactions and the energy required for cavity-formation in dissolution of OCP into triolein of the SPMD. The linear correlation coefficient between predicted and experimental values were all >0.921.展开更多
In photosynthetic organisms, tetrapyrrole-mediated retrograde signals are proposed to contribute to a bal- anced nuclear gene expression （NGE） in response to metabolic activity in chloroplasts. We followed an experi...In photosynthetic organisms, tetrapyrrole-mediated retrograde signals are proposed to contribute to a bal- anced nuclear gene expression （NGE） in response to metabolic activity in chloroplasts. We followed an experimental short- term approach that allowed the assessment of modified NGE during the first hours of specifically modified enzymatic steps of the Mg branch of tetrapyrrole biosynthesis, when pleiotropic effects of other signals can be avoided. In response to 24-h-induced silencing of CHLH, CHLM, and CHL27 encoding the CHLH subunit of Mg chelatase, the Mg protoporphyrin methyltransferase and Mg protoporphyrin monomethylester cyclase, respectively, deactivated gene expression rapidly led to reduced activity of the corresponding enzymes and altered Mg porphyrin levels. But NGE was not substantially altered. When these three genes were continuously inactivated for up to 4 d, changes of transcript levels of nuclear genes were determined. CHL27 silencing for more than 24h results in necrotic leaf lesions and modulated transcript levels of oxidative stress-responsive and photosynthesis-associated nuclear genes （PhANGs）. The prolonged deactivation of CHLH and CHLM results in slightly elevated transcript levels of PhANGs and tetrapyrrole-associated genes. These time-resolved studies indicate a complex scenario for the contribution of tetrapyrrole biosynthesis on NGE mediated by IO2-induced signaling and feedback-regulated ALA synthesis.展开更多
基金supported by GSI Helmholtzzentrum für Schwerionenforschung GmbH, Darmstadt, as part of the R & D Project No. SI-URDK2224 with the University of Rostocksupport by the Federal Ministry of Education and Research (BMBF) under Grant No. 05P21RFFA2supported by the Helmholtz Association under Grant No. ERC-RA-0041。
文摘We report on commissioning experiments at the high-energy,high-temperature(HHT)target area at the GSI Helmholtzzentrum für Schwerionenforschung GmbH,Darmstadt,Germany,combining for the first time intense pulses of heavy ions from the SIS18 synchrotron with high-energy laser pulses from the PHELIX laser facility.We demonstrate the use of X-ray diagnostic techniques based on intense laserdriven X-ray sources,which will allow probing of large samples volumetrically heated by the intense heavy-ion beams.A new target chamber as well as optical diagnostics for ion-beam characterization and fast pyrometric temperature measurements complement the experimental capabilities.This platform is designed for experiments at the future Facility for Antiproton and Ion Research in Europe GmbH(FAIR),where unprecedented ion-beam intensities will enable the generation of millimeter-sized samples under high-energy-density conditions.
基金We thank the Mexican Consejo Nacional de Humanidades,Ciencias y Tecnologías(CONAHCYT)for the financial support provided to the first author to carry out his training in the Institutional Doctoral Program in Agricultural and Forestry Sciences(PIDCAFUJED)with Scholarship No.334852financial support with agreement number CONACYT-FRQ-2016:279459 for the project“Genome-wide scans for detecting adaptation to climate and soil in Populus tremuloides as the most widely distributed tree species in North America”Dr.Jesús M.Olivas-García assisted in the sampling in the state of Chihuahua,Mexico,and Katrin Groppe,Thünen Institute of Forest Genetics,Germany,provided excellent lab work.The Emerging Leaders of the Americas Program(ELAP)of the Government of Canada awarded a scholarship and the Institute of Integrative and Systems Biology(IBIS)of Laval University allowed the use of its campus and contributed to the training of the first author.
文摘The presence of heterozygous individuals in a population is crucial for maintaining genetic diversity,which can positively affect fitness and adaptability to environmental changes.While inbreeding generally reduces the proportion of heterozygous individuals in a population,polyploidy tends to increase the proportion.North American Populus tremuloides is one of the most widely distributed and ecologically important tree species in the Northern Hemisphere.However,genetic variation in Mexican populations of P.tremuloides,including the genetic signatures of their adaptation to a variety of environments,remains largely uncharacterized.The aim of this study was to analyze how inbreeding coefficient(FIS)and ploidy are associated with clonal richness,population cover,climate and soil traits in 91 marginal to small,isolated populations of this tree species throughout its entire distribution in Mexico.Genetic variables were determined using 36,810 filtered SNPs derived from genome re-sequencing.We found that FIS was approximately between 0 and e1,indicating an extreme heterozygosity excess.One key contributor to the observed extreme heterozygosity excess was asexual reproduction,although ploidy levels cannot explain this excess.Analysis of all neutral SNPs showed that asexual reproduction was positively correlated with observed heterozygosity(Ho)but negatively correlated with expected heterozygosity(He).Analysis of outlier SNPs also showed that asexual reproductionwas positively correlated with Ho and negatively correlated with He,although this latter correlation was not significant.These findings support the presence of a Meselson effect.
基金supported by the National Natural Science Foundation of China (No.20877011)the DAAD (German Academic Exchange Service) Scientific Research Visiting Scholarship+3 种基金the Chinese National Programs for High Technology Research and Development (No.2011AA060604)the State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences (No.KF2009-17)the Key Laboratory of Industrial Ecology and Environmental Engineering,Ministry of Education of China (No.0802)the Scientific Research Foundation for Returned Overseas Chinese Scholars,Ministry of Education of China
文摘The concentration of polychlorinated biphenyls （PCBs） in the urban air of Dalian, China was monitored from November 2009 to October 2010 with active high-volume sampler and semipermeable membrane device （SPMD） passive sampler. The concentration of PCBs （particle ＋ gas） （∑PCBs） ranged from 18.6 to 91.0 pg/m3, with an average of 50.9 pg/m3, and the most abundant dioxin-like PCB （DL-PCBs） was PCB118. The WHO-TEQ values of DL-PCBs were 3.6--22.1 fg/m3, with an average of 8.5 fg/m3, and PCB126 was the maximum contributor to ZTEQ. There was a much larger amount of PCBs in the gas phase than in the particulate phase. The dominant PCB components were lower and middle molecular weight PCBs. With increasing chlorination level, the concentration of the PCB congeners in the air decreased. The gas-particulate partitioning of PCBs was different for the four seasons. The gas- particulate partitioning coefficients （logKp） vs. subcooled liquid vapor pressures （logPL~） of PCBs had reasonable correlations for different sampling sites and seasons. The absorption mechanism contributed more to the gas-particulate partitioning process than adsorption. Correlation analysis of meteorological parameters with the concentration of PCBs was conducted using SPSS packages. The ambient temperature and atmospheric pressure were important factors influencing the concentration of PCBs in the air. The distribution pattern of the congeners of PCBs and the dominant contributors to DL-PCBs and TEQ in active samples and SPMDs passive samples were similar. SPMD mainly sequestrated gas phase PCBs.
文摘In this paper,we consider the use of blind deconvolution for optoacoustic(photoacoustic)imaging and investigate the performance of the method as means for increasing the resolution of the reconstructed image beyond the physical restrictions of the system.The method is demonstrated with optoacoustic measurement obtained from six-day-old mice,imaged in the near-infrared using a broadband hydrophone in a circular scanning configuration.Wefind that estimates of the unknown point spread function,achieved by blind deconvolution,improve the resolution and contrast in the images and show promise for enhancing optoacoustic images.
基金financially supported by the research unit of Group Sadoway Laboratory,Department of Materials Science and Engineering,Massachusetts Institute of Technology,77 Massachusetts Avenue,Cambridge,MA,02139-4307,United Statesthe Portuguese Foundation for Science and Technology(FCT)for his Ph.D.scholarship(PD/BD/128041/2016)+2 种基金financially supported by the Base Funding(UIDB/00511/2020)of the Laboratory for Process Engineering,Environment,Biotechnology and Energy–LEPABEfunded by national funds through the FCT/MCTES(PIDDAC)continuous support from MIT Portugal Program。
文摘Recently,a disruptive idea was reported about the discovery of a new type of battery named Liquid Displacement Battery(LDB)comprising liquid metal electrodes and molten salt electrolyte.This cell featured a novel concept of a porous electronically conductive faradaic membrane instead of the traditional ion-selective ceramic membrane.LDBs are attractive for stationary storage applications but need mitigation against self-discharge.In the instant battery chemistry,Li|LiCl-PbCl_(2)|Pb,reducing the diffusion coefficient of lead ions can be a way forward and a solution can be the addition of Pb O to the electrolyte.The latter acts as a supplementary barrier and complements the function of the faradaic membrane.The remedial actions improved the cell’s coulombic efficiency from 92%to 97%without affecting the voltage efficiency.In addition,the limiting current density of a 500 m Ah cell increased from 575 to 831 m A cm;and the limiting power from 2.53 to 3.66 W.Finally,the effect of Pb O on the impedance and polarization of the cell was also studied.
文摘Neoplastic cells are formed as a result of reprogramming the gene expression. It is only when these cells are classified as non-local by the normal cells that confrontation occurs, and thus cancer begins as a disease. The tumorogenic degradation of the skeletal muscle plays a highly important role in the pathomechanism of the disease. It transforms a diminishing differentiation into an increasing homeostatic disorder, and is forced to provide energy to the malignant cells. This characterizes the completed form of the pathomechanism. Blocking the pathomechanism is the goal of a therapy that can be realized on two levels: At the level of reprogramming of the gene expression, which initiates the formation of neoplastic cells, a “reprogramming” of the reprogramming of gene expression could be achieved by altering the genomic flow of information. Increased anabolism (corresponding to the nutrient surplus) as well as increased catabolism (corresponding to nutrient) could lead to respective changes of the flows of genomic information. These opposing flows in a patient could be expected to result in interference or a shearing effect. Patients with acromegaly exhibit a 9.25% increased neoplasia prevalence, whilst patients with hyperthyroidism have 8.41% increased neoplasia prevalence. Patients with acromegaly and hyperthyroidism have a lower prevalence of neoplasia of 3.30%, i.e. the chance of these patients not contracting cancer is three times greater than patients with either only acromegaly or only hyperthyroidism. At the level of tumorogenic degradation of skeletal muscle, inhibition of muscle degradation by means of hypertriglyceridemia results in a significant prolongation of the life of carcinoma patients. This is based on the fact that inhibition of muscle degradation occurs after infusion of triglyceride emulsion. In the case of S. sanguinis bacteremia, there may be an interaction between enzymes from S. sanguinis, from the digestive tract and from the tumor. The source of infection determines the inactivation of the tumor enzyme and thus suppresses tumor development.
基金support by the Federal Ministry of Education and Research(BMBF)under Grant No.05P21RFFA2supported by the Helmholtz Association under Grant No.ERC-RA-0041.
文摘We present in situ measurements of spectrally resolved X-ray scattering and X-ray diffraction from monocrystalline diamond samples heatedwith an intense pulse of heavy ions.In this way,we determine the samples’heating dynamics and their microscopic and macroscopic structuralintegrity over a timespan of several microseconds.Connecting the ratio of elastic to inelastic scattering with state-of-the-art density functionaltheory molecular dynamics simulations allows the inference of average temperatures around 1300 K,in agreement with predictions fromstopping power calculations.The simultaneous diffraction measurements show no hints of any volumetric graphitization of the material,butdo indicate the onset of fracture in the diamond sample.Our experiments pave the way for future studies at the Facility for Antiproton andIon Research,where a substantially increased intensity of the heavy ion beam will be available.
文摘PURPOSE. To study some functional candidate genes in cataract families of Indi an descent. METHODS. Nine Indian families, clinically documented to have congeni tal/childhood cataracts, were screened for mutations in candidate genes such as CRYG (A→D), CRYBB2, and GJA8 by PCR analyses and sequencing. Genomic DNA sample s of either probands or any representative affected member of each family were P CR amplified and sequenced commercially. Documentation of single nucleotide poly morphisms (SNPs) and candidate mutations was done through BLAST SEARCH(http://ww w.ncbi.nlm.nih.gov/ blast/Blast.- cgi?). RESULTS. Several single nucleotide polymorphisms in CRYG, CRYBB2, and G JA8 genes were observed. Because they do not co-segregate with the phenotype, t hey were excluded as candidates for the cataract formation in these patients. However, a substitution (W151C in exon 6 of CRYBB2) was identi fied as the most likely causative mutation underlying the phenotype of central n uclear cataract in all affected members of family C176. Protein structural inter pretations demonstrated that no major structural alterations could be predicted and that even the hydrogen bonds to the neighboring Leu166 were unchanged. Surpr isingly, hydropathy analysis of the mutant βB2-crystallin featuring the amino acids at position 147 to 155, further increased the hydrophobicity, which might impair the solubility of the mutant protein. Finally, the Cys residue at positio n 151 might possibly be involved in intramolecular disulphide bridges with other cysteines during translation, possibly leading to dramatic structural changes. CONCLUSIONS. Exon 6 of CRYBB2 appears to be a critical region susceptible for mu tations leading to lens opacity.
文摘BACKGROUND: An association between exposure to vehicular traffic in urban areas and the exacerbation of cardiovascular disease has been suggested in previous studies. This study was designed to assess whether exposure to traffic can trigger myocardial infarction. METHODS: We conducted a case-crossover study in which cases of myocardial infarction were identified with the use of data from the Cooperative Health Research in the Region of Augsburg Myocardial Infarction Registry in Augsburg, in southern Germany, for the period from February 1999 to July 2001. There were 691 subjects for whom the date and time of the myocardial infarction were known who had survived for at least 24 hours after the event, completed the registry’s standardized interview, and provided information on factors that may have triggered the myocardial infarction. Data on subjects’activities during the four days preceding the onset of Symptoms were collected with the use of patient diaries. RESULTS: An association was found between exposure to traffic and the onset of a myocardial infarction within one hour afterward(odds ratio, 2.92; 95 percent confidence interval, 2.22 to 3.83; P< 0.001). The time the subjects spent in cars, on public transportation, or on motorcycles or bicycles was consistently linked with an increase in the risk of myocardial infarction. Adjusting for the level of exercise on a bicycle or for getting up in the morning changed the estimated effect of exposure to traffic only slightly(odds ratio for myocardial infarction, 2.73; 95 percent confidence interval, 2.06 to 3.61; P< 0.001). The subject’s use of a car was the most common source of exposure to traffic; nevertheless, there was also an association between time spent on public transportation and the onset of a myocardial infarction one hour later. CONCLUSIONS: Transient exposure to traffic may increase the risk of myocardial infarction in susceptible persons.
基金supported bv the National Natural Science Foundation of China(20877011)State Key Laboratory of Environmental Chemistry and Ecotoxicology,Research Center for Eco-Environmental Sciences,Chinese Academy of Science(KF2009-17)+1 种基金the Key Laboratory of Industrial Ecology and Environmental Engineering,China Ministry of Education(0802)Scientific Research Foundation for Returned Overseas Chinese Scholars~~
基金supported by the National Natural Science Foundation of China(20877011)the DAAD(German Academic Exchange Service) Scientific Research Visiting Scholarship,the National High Technology Research and Development Program of China(2011AA060604)+2 种基金the State Key Laboratory of Environmental Chemistry and Ecotoxicology,Research Center for Eco-Environmental Sciences,Chinese Academy of Sciences (KF2009-17)the Key Laboratory of Industrial Ecology and Environmental Engineering,Ministry of Education of China(0802)the Scientific Research Foundation for the Returned Overseas Chinese Scholars,Ministry of Education of China
文摘PCDD/Fs in the urban air of Dalian,China were monitored with high-volume active sampler from November 2009 to October 2010.The concentration of Cl 4-8 DD/Fs ranged from 3065 to 49538 fg m-3,with an average of 10249 fg m-3.The international toxic equivalents(I-TEQ) value of that was 61.8 1182 fg m-3,with an average of 235 fg m-3,which was comparable to those in the other urban locations around the world.It was found that the Cl 4 8 DD/Fs appeared to be present mainly in the particle phase during winter,spring and autumn,while during summer which were dominantly in gas phase.The ratio of Cl 4-8 DD/Fs present in particle phase increased with the increasing level of chlorination.The concentrations of PCDFs and PCDDs decreased with the increase of chlorinated level,while the concentrations of 2,3,7,8-PCDDs congeners increased with the increase of chlorination level.The homolog profiles of the concentrations of PCDFs presented were higher than those of the PCDDs,which indicated the PCDD/Fs pollution source of the air in Dalian was characteristic for thermal source pollution.The correlation analysis of meteorological parameters with the concentrations of Cl 4-8 CDD/Fs was conducted using SPSS packages,and it was found that the ambient temperature and atmospheric pressure were important factors influence the concentration of PCDD/Fs in the air.The respiratory risk and intake dioxins of the residents around the sampling sites were studied in the paper.It was found that Junge-Pankow model was much more accurate in predicting the gas-particle partitioning behavior of PCDD/Fs homologues during winter,while the Harner-Bidleman model shows better agreement with the measured data during winter and summer.
文摘Background Most orthopedic surgeons prefer spica cast immobilization in children for 4 to 12 weeks after surgical hip reconstruction in children with developmental hip dysplasia.This challenging treatment may be associated with complica-tions.Studies are lacking that focus on early mobilization without casting for postoperative care after hip reconstruction.Methods Twenty-seven children(3.4±2.0 years),including 33 hips with developmental hip dysplasia(DDH)and dislocation of the hip(Tonnis grade 1 to 4),who underwent hip reconstruction(Dega acetabuloplasty,varisation-derotation osteotomy and facultative open reduction)were retrospectively included in this study.Postoperatively the patients were placed in an individual foam shell with 30 degrees of hip abduction,hip extension,and neutral rotation.Early mobilization physiotherapy was performed within the first few days after the surgery under epidural anaesthesia.Full weight bearing was allowed after 3-4 weeks.All children received a clinical examination and radiographic evaluation before and after surgical intervention.The follow-up period was 12.3±2.9 months.Results On average,the postoperative acetabular index decreased significantly from 36.9 to 21.7 degrees and the center-edge angle increased from 9.9 to 28.6 degrees.All hips had reached Tonnis grade 1 at the time of the last follow-up.No complications such as dislocation of the bone wedge,avascular necrosis of the acetabulum or femur,lack of non-union,or nerve injury,were reported.Conclusions In this cohort study,hip reconstruction was successful according to clinical and radiographic outcome param-eters after early mobilization without cast therapy.Early mobilization may be used as an alternative treatment option after hip reconstruction in DDH.
文摘Background Equinus is a common deformity in children with bilateral spastic cerebral palsy (BSCP).While dynamic equinus usually is treated by conservative therapy,fixed contractures need surgical correction.To choose the appropriate surgical method,it is important to discriminate between isolated gastrocnemius shortening and combined gastrosoleus complex contracture.Methods In a retrospective study 938 patients with BSCP were studied.Patients underwent gait analysis and clinical examination.248 patients (496 limbs) met the inclusion criteria.Data from motion analysis and clinical examination were used to calculate the prevalence and to further classify fixed equinus foot.Results The prevalence of equinus was 83.3%.During clinical exam 246 (59.6%) limbs showed combined gastrosoleus complex contracture and 167 (40.4%) isolated gastrocnemius contracture.Max.DF at stance and mean DF at initial contact were significantly reduced in combined contracture,while max.ROM was increased (P < 0.05).Conclusions Corroborating the results of previous studies,in this study there was a high prevalence of fixed equinus in patients with BSCP.The prevalence of equinus correlated with increasing age.As half of the patients with fixed equinus show a different involvement of gastrocnemius and soleus muscle,we recommend to apply Silfverski(o)ld's test to discriminate between those two types to choose the appropriate surgical therapy.
文摘Neurons synthesizing the neurotransmitter dopamine exert crucial functions in the mammalian brain. The biggest and most important population of dopamine-synthesizing neurons is located in the mammalian ventral midbrain （VM）, and controls and modulates the exe- cution of motor, cognitive, affective, motivational, and rewarding behaviours. Degeneration of these neurons leads to motor deficits that are characteristic of Parkinson＇s disease, while their dysfunction is involved in the pathogenesis of psychiatric disorders including schizophrenia and addiction. Because the aetiology and therapeutic prospects for these diseases include neurodevelopmental aspects, substantial scientific interest has been focused on deciphering the mechanistic pathways that control the generation and sur- vival of these neurons during embryonic development. Researches during the last decade revealed the pivotal role of the secreted Wntl ligand and its signaUing cascade in the generation of the dopamine-synthesizing neurons in the mammalian VM. Here, we summarize the initial and more recent findings that have unravelled several Wntl-controUed genetic networks required for the proliferation and commitment of VM progenitors to the dopaminergic cell fate during midgestational embryonic stages, and for the correct differentiation of these progenitors into postmitotic dopamine-synthesizing neurons at late midgestational embryonic and foetal stages.
基金supported by the National Natural Science Foundation of China (20877011)the State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences (KF2009-17)+2 种基金the Key Laboratory of Industrial Ecology and Environmental Engineering, China Ministry of Education (0802)Scientific Research Foundation for Returned Overseas Chinese ScholarsThe Monitoring Network in the Alpine Region for Persistent and other Organic Pollutants, MONARPOP, was funded by the EU Interreg III B Alpine Space Programme (Alpine Space) and by the participating partners
文摘Organochlorine pesticides (OCP) were monitored at the Weissfluhjoch site (Switzerland) and the top of Mt. Sonnblick (Austria) with a low volume active air sampler and semipermeable membrane devices (SPMD). The air sampling rates (Rair) of the SPMD for OCP were calculated. Statistical tests showed that there was no significant difference between Rair at the two different sampling sites. Quantitative structure-property relationship (QSPR) models of the Rair of the SPMD were developed for OCP using partial least square (PLS) regression. Quantum chemical descriptors computed by the semi-empirical PM6 method were used as predictor variables. The cumulative variance of the dependent variable explained by the PLS components and determined by cross-validation (Q2cum) was >0.818 for each optimal model. This indicates that the model has good predictive ability and robustness. The Rair of the SPMD for OCP is related to the total energy, the van der Waals area and the total dipole moment of the OCP molecules. The main factors governing Rair values of OCP are intermolecular interactions and the energy required for cavity-formation in dissolution of OCP into triolein of the SPMD. The linear correlation coefficient between predicted and experimental values were all >0.921.
文摘In photosynthetic organisms, tetrapyrrole-mediated retrograde signals are proposed to contribute to a bal- anced nuclear gene expression （NGE） in response to metabolic activity in chloroplasts. We followed an experimental short- term approach that allowed the assessment of modified NGE during the first hours of specifically modified enzymatic steps of the Mg branch of tetrapyrrole biosynthesis, when pleiotropic effects of other signals can be avoided. In response to 24-h-induced silencing of CHLH, CHLM, and CHL27 encoding the CHLH subunit of Mg chelatase, the Mg protoporphyrin methyltransferase and Mg protoporphyrin monomethylester cyclase, respectively, deactivated gene expression rapidly led to reduced activity of the corresponding enzymes and altered Mg porphyrin levels. But NGE was not substantially altered. When these three genes were continuously inactivated for up to 4 d, changes of transcript levels of nuclear genes were determined. CHL27 silencing for more than 24h results in necrotic leaf lesions and modulated transcript levels of oxidative stress-responsive and photosynthesis-associated nuclear genes （PhANGs）. The prolonged deactivation of CHLH and CHLM results in slightly elevated transcript levels of PhANGs and tetrapyrrole-associated genes. These time-resolved studies indicate a complex scenario for the contribution of tetrapyrrole biosynthesis on NGE mediated by IO2-induced signaling and feedback-regulated ALA synthesis.
