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1.
In the present studies, no porphyrins were found in the lunar surface fines collected from the Sea of Tranquillity by the Apollo 11 mission, from the Ocean of Storms by the Apollo 12 mission, and from the nonmare Fra Mauro Formation by the Apollo 14 expedition under the conditions in which porphyrins would have been detected had they been present in amounts as small as 10–14 mole.  相似文献   

2.
Microbiological profiles were determined for surfaces of the command module, lunar module (ascent and descent stages), instrument unit, Saturn S-4B stage, and the spacecraft lunar module adapter of the Apollo 10 and 11 spacecraft. Average levels of contamination of the command module were 2.1 x 10(4) and 2.7 x 10(4) microorganisms per ft(2) for Apollo 10 and 11, respectively. With the exception of the exterior surfaces of the ascent stage of the lunar module and the interior surfaces of the command module, average levels of microbial contamination on all components of the Apollo 11 were found to be lower than those observed on Apollo 10. For each Apollo mission, approximately 2,000 colonies were picked from a variety of media and identified. The results showed that approximately 95% of all isolates were those considered indigenous to humans; the remaining were associated with soil and dust in the environment. However, the ratio of these two general groups varied depending on the degrees of personnel density and environmental control associated with each module.  相似文献   

3.
A review of the work on searches for biogenic structures and viable life forms in Apollo 11 and 12 samples shows no evidence for biology in these samples. The total amount of samples examined and the negative results from the variety of systems conducive to growth and metabolic activity make it highly improbable that life will be found in surface samples yet to be tested.  相似文献   

4.
Lunar material collected during the Apollo 11, 12, 14, and 15 missions has been used to treat 12 species of higher plant tissue cultures. Biochemical and morphological studies have been conducted on several of these species. Tobacco tissue cultures treated with 0.22 g of lunar material exhibited increased greening more complex chloroplasts, less cytoplasmic vacuolation and greater vesiculation. Pine tissue cultures reacted to treatment by an increased deposition of tannin-like materials. The percentage of dry weight and soluble protein was increased in cultures treated with either lunar or terrestrial rock materials. Lunar Science Institute Contribution.  相似文献   

5.
The data concerning the indigenous organic compounds in the lunar samples has been consistent. The Apollo 11 sample appeared to be moderately contaminated, and most investigators found known terrestrial artifacts in these samples. The Apollo 12 data indicated that perhaps benzene and toluene were indigenous to the Moon at concentrations below 100 parts per billion. Other, more complex organic molecules (in particular of aromatic structure) might also be present, but in concentrations below 1 ppb. In general, the structural types reported have been relatively simple; perhaps indicating that what little organic chemistry occurs on the lunar surface can best be described as reactions between individual atoms of carbon, hydrogen, oxygen and nitrogen.  相似文献   

6.
Water extracts of lunar fines were analyzed for amino acids by a gas-liquid chromatographic technique whereby amino acids were converted to the N-trifluoroacetyln-butyl, esters prior to analysis. The lunar material studied included both Apollo 14 (14240 SESC and 14298) and Apollo 12 (12023) samples. The water extract of the special Apollo 14 sample (14240 SESC) was analyzed both for free and bound amino acids (hydrolysis with 6 N hydrochloric acid). In both the hydrolyzed and unhydrolyzed extracts, the amino acids were not observed above background levels.The analysis of Apollo 12 and 14 samples (12023 14298) yielded similar results. Detection limits were established at 300 pg to 1 ng for different amino acids. A large chromatographic peak with a retention temperature of 126°C was observed on analysis of sample, (12023); it was identified as oxalic acid by GC-MS. The concentration of amino acids in the Apollo 14 SESC samples processed and analyzed in the joint experiments at Ames by GLC and IEC were found to be extremely low (glycine at 3 to 4 ng g–1). As the quantities were so minute, these identifications could not be confirmed by GLC-MS and therefore should still be considered as tentative. Other studies included the analysis of performance standards at the 2 to 6 ng level of each of 17 amino acids, and the analysis of 5 ml of H2O containing 2 ppb of each amino acid. Recovery of amino acids added to lunar fines were conducted at the 10, 50, and 70 ng level of each amino acid with 50 to 70 mg of lunar material. The recoveries varied from as high as 80% for some of the aliphatics to complete loss of the amino acids ornithine and lysine.Contributed from Missouri Agricultural Experiment Station Journal Series No. 6255. Approved by the Director. Supported in part by grants from the National Aeronautics and Space Administration (NGR 26-004-011) and the Experiment Station Chemical Laboratories.  相似文献   

7.
The National Aeronautics and Space Administration (NASA) requires that microorganisms which could contaminate the surface of the moon as the result of lunar missions be enumerated and identified so that life forms in lunar materials returned to earth may be more easily recognized as being of native or terrestrial origin.Assessment of microbial contamination in the intramural environments used for the assembly and test of the manned lunar spacecraft (Apollo) was made using fallout strips and air samplers. Microbial contamination on the surfaces of Apollo Command and Lunar Modules was determined by use of the swab-rinse method.Preliminary results indicate that the levels of microbial contamination which accumulated on exposed stainless steel surfaces, as well as airborne microbial contamination in the high bay assembly areas, were similar to those encountered in the unmanned spacecraft assembly areas. However, higher levels of microbial contamination were detected on the Apollo spacecraft than on the unmanned lunar spacecraft.  相似文献   

8.
The lunar samples from Apollo flights 11 through 17 provided the students of chemical evolution with an opportunity of examining extraterrestrial materials for evidence of early prebiological chemistry in the solar system. Our search was directed to water-extractable compounds with emphasis on amino acids. Gas chromatography, ion-exchange chromatography and gas chromatography combined with mass spectrometry were used for the analysis. It is our conclusion that amino acids are not present in the lunar regolith above the background levels of our investigations.  相似文献   

9.
The lunar samples from Apollo flights 11 through 17 provided the students of chemical evolution with an opportunity of examining extraterrestrial materials for evidence of early prebiological chemistry in the solar system. Our search was directed to water-extractable compounds with emphasis on amino acids. Gas chromatography, ion-exchange chromatography and gas chromatography combined with mass spectrometry were used for the analysis. It is our conclusion that amino acids are not present in the lunar regolith above the background levels of our investigations.  相似文献   

10.
Sanger, or dideoxynucleotide sequencing, is an important tool for biomolecular research. An important trend in DNA sequencing is to find new and innovative ways to provide high-quality, reliable sequences in a more efficient manner, using automated capillary electrophoresis. The Apollo100 combines Sanger cycle sequencing and solid-phase reversible immobilization for product purification in a single instrument with robotic liquid handling and microfluidic (Microscale On-chip Valve) chips that have onboard thermal cycling and pneumatic mixing. Experiments were performed to determine how the DNA sequencing results from the Apollo100 compared with conventional, manual methods used in a core facility setting. Through rigorous experimentation of multiple baseline runs and a dilution series of template concentration, the Apollo100 generated sequencing that exceeded 900 bases with a quality score of 20 or above. When comparing actual client samples of amplicons, plasmids, and cosmids, Apollo100 sequencing results did not differ significantly from those reactions prepared manually. In addition, bacterial genomic DNA was sequenced successfully, directly with the Apollo100, although results were of lower quality than the standard manual method. As a result of the microscale capabilities, the Apollo100 offers valuable savings with respect to the quantity of reagents consumed compared with current manual sequencing methods, thereby continuing the demand for smaller template and reagent requirements. In conclusion, the Apollo100 can generate high-quality DNA sequences for common templates equivalent to those produced using manual sequencing methods and increases efficiency through reduced labor and reagents.  相似文献   

11.
An organic solvent extract of billion year old Nonesuch Shale was examined for porphyrins by means of fluorometry and high resolution mass spectrometry. It appears to contain at least three or more classes of porphyrins, one similar to tetraphenyl porphin and the others more complex. Many are apparently chelated with copper, nickel, zinc, iron and vanadyl and are highly aromatic. We have also examined the extracts of Apollo 11, 12 and 14 surface fines for pophyrins by spectrophotofluorometry but we found none even though our method was capable of detecting 10−13 moles per gm of sample. Lunar Science Institute Contribution.  相似文献   

12.
Extraction, hydrolysis and crushing procedures have proven useful in analyzing for some of the carbon-containing compounds which are present in Apollo 11 and 12 lunar samples. Three main extraction methods employed with aqueous and nonaqueous solvents were refluxing in open and closed systems, Soxhlet extraction, and sonication. With water and acids, refluxing was the method of choice. Of the various nonaqueous solvent systems used, benzene: methanol mixtures were most often selected, and sonication was favored over Soxhlet extraction. Extraction of lunar samples with water followed by acid hydrolysis of the water extract was found to be superior to direct acid hydrolysis of lunar material in the search for amino acids or their precursors. Direct acid hydrolysis of lunar materials did demonstrate however, that carbides or carbide-like compounds are present on the moon. Hydrolysis with deuterated acids and bases showed that lunar samples contain indigenous methane and ethane and confirmed the presence of carbide-like materials. Crushing experiments also showed that gaseous hydrocarbons can be released from lunar samples.  相似文献   

13.
A major issue in telomere research is to understand how the integrity of chromosome ends is preserved . The human telomeric protein TRF2 coordinates several pathways that prevent checkpoint activation and chromosome fusions. In this work, we identified hSNM1B, here named Apollo, as a novel TRF2-interacting factor. Interestingly, the N-terminal domain of Apollo is closely related to that of Artemis, a factor involved in V(D)J recombination and DNA repair. Both proteins belong to the beta-CASP metallo-beta-lactamase family of DNA caretaker proteins. Apollo appears preferentially localized at telomeres in a TRF2-dependent manner. Reduced levels of Apollo exacerbate the sensitivity of cells to TRF2 inhibition, resulting in severe growth defects and an increased number of telomere-induced DNA-damage foci and telomere fusions. Purified Apollo protein exhibits a 5'-to-3' DNA exonuclease activity. We conclude that Apollo is a novel component of the human telomeric complex and works together with TRF2 to protect chromosome termini from being recognized and processed as DNA damage. These findings unveil a previously undescribed telomere-protection mechanism involving a DNA 5'-to-3' exonuclease.  相似文献   

14.
Uterine flushings from ewes on days 0, 3, 6, 9, 12 and 15 of the estrous cycle were analyzed for total protein content. Flushings from days 9, 12 and 15 had greater (P<.01) amounts of protein than those from 0, 3 and 6. Antisera to uterine fluids from ewes at day 10 to 12 or day 14 to 15 of pregnancy detected two uterine-specific antigens in uterine flushings at day 7, 11 and 15 but not at days 0 and 3 of the cycle. A third uterine antigen was also detected in kidney tissue extracts. All three antigens were present in endometrial extracts at each stage examined. Progesterone, or estrogen plus progesterone, administration to ovariectomized ewes induced the appearance of the two uterine-specific antigens. The third antigen was detectable even in ovariectomized ewes. No pregnancy-specific antigens were detected in flushings from days 7, 11 or 15 of gestation. The effect of pregnancy on endometrial protein synthesis was examined in vitro . No differences were seen in the incorporation of (3)H-leucine in day 11 pregnant or nonpregnant or in day 14 pregnant or nonpregnant endometrium. No differences in total uterine lumenal protein were observed. Endometrial secretions, obtained by conditioning media with endometrial explant cultures, were evaluated to assess their effect on protein synthesis in day 11 embryos cultured in vitro . No significant effects of endometrial secretions or serum were observed.  相似文献   

15.

Background

Apollo, a genome annotation viewer and editor, has become a widely used genome annotation and visualization tool for distributed genome annotation projects. When using Apollo for annotation, database updates are carried out by uploading intermediate annotation files into the respective database. This non-direct database upload is laborious and evokes problems of data synchronicity.

Results

To overcome these limitations we extended the Apollo data adapter with a generic, configurable web service client that is able to retrieve annotation data in a GAME-XML-formatted string and pass it on to Apollo's internal input routine.

Conclusion

This Apollo web service adapter, Apollo2Go, simplifies the data exchange in distributed projects and aims to render the annotation process more comfortable. The Apollo2Go software is freely available from ftp://ftpmips.gsf.de/plants/apollo_webservice.  相似文献   

16.
17.
Human chromosome ends are protected by shelterin, an abundant six-subunit protein complex that binds specifically to the telomeric-repeat sequences, regulates telomere length, and ensures that chromosome ends do not elicit a DNA-damage response (reviewed in). Using mass spectrometry of proteins associated with the shelterin component Rap1, we identified an SMN1/PSO2 nuclease family member that is closely related to Artemis. We refer to this protein as Apollo and report that Apollo has the ability to localize to telomeres through an interaction with the shelterin component TRF2. Although its low abundance at telomeres indicates that Apollo is not a core component of shelterin, Apollo knockdown with RNAi resulted in senescence and the activation of a DNA-damage signal at telomeres as evidenced by telomere-dysfunction-induced foci (TIFs). The TIFs occurred primarily in S phase, suggesting that Apollo contributes to a processing step associated with the replication of chromosome ends. Furthermore, some of the metaphase chromosomes showed two telomeric signals at single-chromatid ends, suggesting an aberrant telomere structure. We propose that the Artemis-like nuclease Apollo is a shelterin accessory factor required for the protection of telomeres during or after their replication.  相似文献   

18.
Autoflora in the upper respiratory tract of Apollo astronauts.   总被引:1,自引:1,他引:0       下载免费PDF全文
The typical microbial inhabitants of the oral and nasal cavities of Apollo astronauts were identified before space flight and generally found to be similar to those previously reported for healthy male adults. Additional analyses of samples collected immediately after return of the Apollo 13, 14, 15, and 16 crew members to earth were performed to evaluate the effects of space travel on the microbial bioburden of the upper respiratory tract. In-flight cross-contamination and buildup of pathogens such as Staphylococcus aureus were noted, although significant increases in nonpathogenic species were absent. Other proposed alterations, such as dysbacteriosis (flooding of the mouth with a single species) and simplification of the autoflora, did not occur. Generally, the incidence and quantitation of each species after flight was within the preflight range, although the number of viable Haemophilus cells recovered from the mouth decreased significantly after space flight. Except for those minor alterations listed above, the aerobic and anaerobic bacterial components of the upper respiratory autoflora of Apollo astronauts was found to be stable after space flight of up to 295 h.  相似文献   

19.
ATP binding cassette (ABC) transporters play diverse roles, including lipid transport, in all kingdoms. ABCG subfamily transporters that are encoded as half-transporters require dimerization to form a functional ABC transporter. Different dimer combinations that may transport diverse substrates have been predicted from mutant phenotypes. In Arabidopsis thaliana, mutant analyses have shown that ABCG11/WBC11 and ABCG12/CER5 are required for lipid export from the epidermis to the protective cuticle. The objective of this study was to determine whether ABCG11 and ABCG12 interact with themselves or each other using bimolecular fluorescence complementation (BiFC) and protein traffic assays in vivo. With BiFC, ABCG11/ABCG12 heterodimers and ABCG11 homodimers were detected, while ABCG12 homodimers were not. Fluorescently tagged ABCG11 or ABCG12 was localized in the stem epidermal cells of abcg11 abcg12 double mutants. ABCG11 could traffic to the plasma membrane in the absence of ABCG12, suggesting that ABCG11 is capable of forming flexible dimer partnerships. By contrast, ABCG12 was retained in the endoplasmic reticulum in the absence of ABCG11, indicating that ABCG12 is only capable of forming a dimer with ABCG11 in epidermal cells. Emerging themes in ABCG transporter biology are that some ABCG proteins are promiscuous, having multiple partnerships, while other ABCG transporters form obligate heterodimers for specialized functions.  相似文献   

20.
水稻低温发芽力QTL定位和遗传分析   总被引:5,自引:0,他引:5  
以Kinmaze(粳稻)/DV85(籼稻)的重组自交系F10世代群体检测了影响水稻低温发芽力性状的数量性状基因座(QTL)。通过测定不同时期的低温发芽率,确定了15℃低温、第10d为检测低温发芽率的最适处理温度和时间,该条件下能够充分检测到品种的差异和分离群体的变异。通过设置对照,证明所检测的低温发芽率不受休眠及二次休眠的影响。15℃低温、第10d时,Kinmaze的发芽率达35%,DV85的发芽率只有7%,两亲本之间存在明显差异,该群体81个家系的低温发芽率变幅在0%~99%之间。QTL分析结果检测到5个与低温发芽力相关的基因座,分别位于第2、6、7、11和12染色体上。位于第2、6和11染色体上的qLTG-2、qLTG-6和qLTG-11贡献率分别为27.1%、17.1%和15.0%,对低温发芽力性状的增效基因来自DV85;位于第7、12染色体上qLTG-7和qLTG-12的贡献率分别为22.9%和8.8%,增效基因来自Kinmaze。其中,qLTG-6和qLTG-11在染色体上的位置与已报道的有关低温发芽力QTL位置相似,而qLTG-2、qLTG-7和qLTG-12为新检测的低温发芽力基因座。上位性分析结果显示,第3与第5染色体上存在影响低温发芽力的互作位点,其互作可以提高低温发芽力,而第7染色体上的两位点之间的互作降低了低温发芽力。  相似文献   

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