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91.
Proof-of-concept has been demonstrated for a process that will utilize nutrients from sludge liquor, natural light, and CO2 from biogas to grow microalgae at wastewater treatment plants. This process will reduce the impact of returning side-streams to the head of the plant. The produced algae will be fed to anaerobic digesters for increased biogas production. Dewatering of anaerobically digested sludge in centrifuges produces reject water with extremely low transmittance of light. A pretreatment procedure was developed that improved light transmittance for reject water from the FREVAR, Norway, wastewater treatment plant from 0.1% T to 77% T (670 nm, 1 cm path). Chlorella sp. microalgae were found to be suitable for growth in this pre-treated reject water. Typical nitrogen removal was 80-90 g N/kg TSS of produced microalgae. The microalgae were successfully harvested by chemically assisted flocculation followed by straining through a 33 microm sieve cloth, achieving up to 99% recovery. Harvested algae were anaerobically co-digested with wastewater sludge. The specific methane gas production (mL CH4/g VS fed) for the algae varied from less than 65% to 90% of the specific methane gas production for the wastewater sludge, depending on digester temperature, retention time and pre-treatment of the algae biomass.  相似文献   
92.
Journal of Computational Electronics - The strain- and electric field-dependent electronic and optical properties of monolayer GaInS2 have been calculated using density functional...  相似文献   
93.
For efficient charge separations, multimaterial hetero‐nanostructures are being extensively studied as photocatalysts. While materials with one heterojunction are widely established, the chemistry of formation of multijunction heterostructures is not explored. This needs a more sophisticated approach and modulations. To achieve these, a generic multistep seed mediated growth following controlled ion diffusion and ion exchange is reported which successfully leads to triple‐material hetero‐nanostructures with bimetallic‐binary alloy‐binary/ternary semiconductors arrangements. Ag2S nanocrystals are used as primary seeds for obtaining AuAg‐AuAgS bimetallic‐binary alloyed metal–semiconductor heterostructures via partial reduction of Ag(I) using Au(III) ions. These are again explored as secondary seeds for obtaining a series of triple‐materials heterostructures, AuAg‐AuAgS‐CdS (or ZnS or AgInS2), with introduction of different divalent and trivalent ions. Chemistry of each step of the gold ion–induced changes in the rate of diffusion and/or ion exchanges are investigated and the formation mechanism for these nearly monodisperse triple material heterostructures are proposed. Reactions without gold are also performed, and the change in the reaction chemistry and growth mechanism in presence of Au is also discussed.  相似文献   
94.
CONTEXT: Human immunodeficiency virus (HIV) infection has been associated with an increasing incidence of malignancy, and HIV-infected persons have an increased incidence of primary lung carcinoma compared with the general population. OBJECTIVE: To investigate the molecular changes present in HIV-associated lung tumors and compare them with those present in lung carcinomas arising in HIV-indeterminate subjects ("sporadic tumors"). DESIGN: Convenience sample. SUBJECTS: Archival tissues from 11 HIV-positive persons and from 35 persons of indeterminate HIV status. SETTING: University-based medical centers and affiliated hospitals. MAIN OUTCOME MEASURES: Analysis of frequency of loss of heterozygosity (LOH) and microsatellite alteration (MA) using polymerase chain reaction and 16 polymorphic microsatellite markers at 8 chromosomal regions frequently deleted in lung cancer. Presence of HIV and human papillomavirus (HPV) sequences. RESULTS: The overall frequency of LOH at all chromosomal regions tested and the frequencies at most of the individual regions were similar in the 2 groups. Frequency of MA present in the HIV-associated tumors (0.18) was 6-fold higher than in sporadic tumors (0.03) (P<.001). At least 1 MA was present in 10 (91%) of 11 HIV-associated tumors vs 17 (48%) of 35 sporadic tumors (P=.02). Molecular changes were independent of tumor stage and gender. HIV and HPV sequences were not detected in the HIV-associated lung carcinomas. CONCLUSIONS: Microsatellite alterations, which reflect widespread genomic instability, occur at greatly increased frequency in HIV-associated lung carcinomas. Although the mechanism underlying the development of increased MAs is unknown, it may play a crucial role in the development of many HIV-associated tumors.  相似文献   
95.
The "disease-specific" (dsp) region next to the hrp gene cluster of Erwinia amylovora is required for pathogenicity but not for elicitation of the hypersensitive reaction. A 6.6-kb apparent operon, dspEF, was found responsible for this phenotype. The operon contains genes dspE and dspF and is positively regulated by hrpL. A BLAST search revealed similarity in the dspE gene to a partial sequence of the avrE locus of Pseudomonas syringae pathovar tomato. The entire avrE locus was sequenced. Homologs of dspE and dspF were found in juxtaposed operons and were designated avrE and avrF. Introduced on a plasmid, the dspEF locus rendered P. syringae pv. glycinea race 4 avirulent on soybean. An E. amylovora dspE mutant, however, elicited a hypersensitive reaction in soybean. The avrE locus in trans restored pathogenicity to dspE strains of E. amylovora, although restored strains were low in virulence. DspE and AvrE are large (198 kDa and 195 kDa) and hydrophilic. DspF and AvrF are small (16 kDa and 14 kDa) and acidic with predicted amphipathic alpha helices in their C termini; they resemble chaperones for virulence factors secreted by type III secretion systems of animal pathogens.  相似文献   
96.
The most prevalent menace since the end of the cold war is the occurrence of civil wars and local and regional conflicts. The term "low intensity conflict" describes the new threat environment and covers a multitude of phenomena, such as civil wars, guerrilla warfare, terrorism and counterinsurgency operations occurring between routine, peaceful inter- or intrastate competition, and a sustained conventional conflict. There is a great challenge to alert the physicians in general, and the surgical community of the world in particular, to the new threat environment and the medical challenges involved in treating casualties of low intensity conflicts. Specifically, a new international body of surgeons might be required to coordinate the recruitment, training, and creditation for surgeons with special expertise in the management of victims of such conflicts and to facilitate research and general knowledge of the medical challenges of modern conflicts.  相似文献   
97.
The goal of our research is to develop an experimental and analytical framework for spatiotemporal imaging of human brain function. Preliminary studies suggest that noninvasive spatiotemporal maps of cerebral activity can be produced by combining the high spatial resolution (millimeters) of functional MRI (fMRI) with the high temporal resolution (milliseconds) of electroencephalography (EEG) and magnetoencephalography (MEG). Although MEG and EEG are sensitive to millisecond changes in mental activity, the ability to resolve source localization and timing is limited by the ill-posed "inverse" problem. We conducted Monte Carlo simulations to evaluate the use of MRI constraints in a linear estimation inverse procedure, where fMRI weighting, cortical location and orientation, and sensor noise statistics were realistically incorporated. An error metric was computed to quantify the effects of fMRI invisible ("missing") sources, "extra" fMRI sources, and cortical orientation errors. Our simulation results demonstrate that prior anatomical and functional information from MRI can be used to regularize the EEG/MEG inverse problem, giving an improved solution with high spatial and temporal resolution. An fMRI weighting of approximately 90% was determined to provide the best compromise between separation of activity from correctly localized sources and minimization of error caused by missing sources. The accuracy of the estimate was relatively independent of the number and extent of the sources, allowing for incorporation of physiologically realistic multiple distributed sources. This linear estimation method provides an operator-independent approach for combining information from fMRI, MEG, and EEG and represents a significant advance over traditional dipole modeling.  相似文献   
98.
During a six-month period 2,221 haemocultures obtained from patients hospitalized in the Faculty Hospital Olomouc were examined. In all 304 isolated bacteria the sensitivity was assessed by the standard dilution micromethod and moreover all positive haemocultures were examined the "direct" disc method. Agreement between the results of the two methods was proved in 84% of pairs of tests and within a range from 67 to 100%, depending on the type of antimicrobial preparation. Based on these findings it may be stated that assessment of the sensitivity by the "direct" method agrees significantly with assessment of the sensitivity according to minimal inhibitory concentrations (MIC). In patients with septicaemia this procedure makes it possible to change empirical antibiotherapy by 24 hours sooner to aimed therapy.  相似文献   
99.
Coarse frequency offset estimate and tracking of residual frequency offset are two crucial stages for frequency synchronization in OFDM based WLAN systems. An improved frequency offset estimation scheme is proposed for tracking residual offset. The estimation scheme is dependent on the position of an OFDM symbol in a frame.  相似文献   
100.
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