Ice core evidence for atmospheric oxygen decline since the Mid-Pleistocene transition.

The history of atmospheric oxygen (PO2) and the processes that act to regulate it remain enigmatic because of difficulties in quantitative reconstructions using indirect proxies. Here, we extend the ice-core record of PO2 using 1.5-million-year-old (Ma) discontinuous ice samples drilled from Allan Hills Blue Ice Area, East Antarctica. No statistically significant difference exists in PO2 between samples at 1.5 Ma and 810 thousand years (ka), suggesting that the Late-Pleistocene imbalance in O2 sources and sinks began around the time of the transition from 40- to 100-ka glacial cycles in the Mid-Pleistocene between ~1.2 Ma and 700 ka. The absence of a coeval secular increase in atmospheric CO2 over the past ~1 Ma requires negative feedback mechanisms such as Pco2-dependent silicate weathering. Fast processes must also act to suppress the immediate Pco2 increase because of the imbalance in O2 sinks over sources beginning in the Mid-Pleistocene.

Two-million-year-old snapshots of atmospheric gases from Antarctic ice.

Over the past eight hundred thousand years, glacial-interglacial cycles oscillated with a period of one hundred thousand years ('100k world'1). Ice core and ocean sediment data have shown that atmospheric carbon dioxide, Antarctic temperature, deep ocean temperature, and global ice volume correlated strongly with each other in the 100k world2-6. Between about 2.8 and 1.2 million years ago, glacial cycles were smaller in magnitude and shorter in duration ('40k world'7). Proxy data from deep-sea sediments suggest that the variability of atmospheric carbon dioxide in the 40k world was also lower than in the 100k world8-10, but we do not have direct observations of atmospheric greenhouse gases from this period. Here we report the recovery of stratigraphically discontinuous ice more than two million years old from the Allan Hills Blue Ice Area, East Antarctica. Concentrations of carbon dioxide and methane in ice core samples older than two million years have been altered by respiration, but some younger samples are pristine. The recovered ice cores extend direct observations of atmospheric carbon dioxide, methane, and Antarctic temperature (based on the deuterium/hydrogen isotope ratio δDice, a proxy for regional temperature) into the 40k world. All climate properties before eight hundred thousand years ago fall within the envelope of observations from continuous deep Antarctic ice cores that characterize the 100k world. However, the lowest measured carbon dioxide and methane concentrations and Antarctic temperature in the 40k world are well above glacial values from the past eight hundred thousand years. Our results confirm that the amplitudes of glacial-interglacial variations in atmospheric greenhouse gases and Antarctic climate were reduced in the 40k world, and that the transition from the 40k to the 100k world was accompanied by a decline in minimum carbon dioxide concentrations during glacial maxima.

Treatments of tilapia (Oreochromis niloticus) using nitric oxide for quality improvement: Establishing a potential method for large-scale processing of farmed fish.

BACKGROUND: To find a succedaneum of present methods for slaughtering tilapia, we have demonstrated the influence of nitric oxide (NO) (saturated NO solution) through euthanasia before slaughter on the animal welfare and muscle color of tilapia. The results suggested that NO euthanasia significantly improved the animal welfare and muscle color. Besides, the investigation of NO postmortem treatment on the muscle color and color stability of tilapia fillets suggested that NO postmortem treatment not only improved the muscle color and color stability but also prolonged the shelf-life of tilapia fillets during the refrigerated storage. OBJECTIVE: To further investigate the effect of NO euthanasia on the quality of tilapia fillets and to estimate the safety of NO treatments (NO euthanasia and NO postmortem treatment) for the application of NO treatments in industrial manufacturing of tilapia and possibly of other fish species. METHODS: NO euthanasia was adopted in this study following a simulated fish processing line. HbNO and MbNO values were measured to clarify the mechanism and process of NO euthanasia. The blood parameters, muscle pH, rigor index, drip loss and total volatile basic nitrogen (TVB-N) values were measured to evaluate the quality of the fillets obtained from NO euthanized tilapia. Besides, the nitrate (NO3-) levels in the muscles after the refrigerated storage were detected to estimate the food safety of both NO euthanasia and NO postmortem treatment. RESULTS: Fillets obtained from the tilapia euthanized by NO showed a later reduction of muscle pH, a later onset of rigor mortis postmortem and less drip loss during the refrigerated storage than control. NO euthanasia caused less TVB-N than control and prolonged the shelf life of tilapia fillets. Moreover, the NO3- levels in the muscles of both NO euthanasia and NO postmortem treatment after the refrigerated storage were below the maximum permitted limit. CONCLUSION: Both the NO euthanasia and NO postmortem treatment are suitable for improving the quality of tilapia fillets and reducing the food safety threats, which may be valuable for industrial manufacturing of tilapia and may be applicable for other fish species.

Comparison and multivariate statistical analysis of anthocyanin composition in Lycium ruthenicum Murray from different regions to trace geographical origins: The case of China.

Anthocyanin composition in forty-five Lycium ruthenicum Murray (LRM) samples grown in China was identified by high-performance liquid chromatography-electrospray ionisation-mass spectrometry (HPLC-ESI-MS) and quantified by HPLC with a diode array detector (HPLC-DAD). The results showed that the overall pattern of anthocyanin composition of LRM from different provinces was the same, while the individual and total anthocyanin concentrations, were significantly different, indicating an important impact of geographical origin on anthocyanin composition, which can be considered as credible indices for LRM classification. Principal component analysis (PCA) and linear discriminant analysis (LDA) were applied to develop discrimination models for the anthocyanin concentrations. PCA clearly separated the LRM based on its geographical origins. LDA satisfactorily categorized the samples by providing a 100% success rate based on geographical origins. The results obtained could be used to trace the geographical origin of LRM.

Influence of postmortem treatment with nitric oxide on the muscle color and color stability of tilapia (Oreochromis niloticus) fillets.

BACKGROUND: Nitric oxide (NO) has been recognized as pivotal for color and color stability of meat products and has an evident effect on inhibiting microbial growth in processed meat. The use of indirect NO (nitrate/nitrite) in industrial meat curing has potential deleterious effects and great concerns have been expressed over residual nitrite in meat after curing. To find a succedaneum, we have demonstrated the influence of direct NO (saturated NO solution) through euthanasia before slaughter on the fillets color of tilapia and the results suggested that direct NO treatment prior to slaughter is a good procedure to improve the color of tilapia fillets. OBJECTIVE: To further investigate the effect of direct NO on the muscle color and shelf-life of fillets from tilapia, this study was conducted to investigate the muscle color and color stability of tilapia fillets postmortem treated with saturated NO solution and their shelf-life during refrigerated storage. METHODS: Tilapia fillets were immersed in a saturated NO solution for 13 min, vacuum-packed and stored at refrigerated temperature for 15 days. Visual observations, color values and absorption maxima were used to evaluate the muscle color and color stability of tilapia fillets. Total volatile basic nitrogen (TVB-N) values were used to evaluate the shelf-life of tilapia fillets during refrigerated storage. RESULTS: By visual observation, NO treated tilapia fillets showed a brighter red color as compered to control samples after NO-treatment and during the whole storage. The redness (a*) values of NO treated tilapia fillets were significantly increased (P < 0.05) after NO-treatment, continuously increased (P < 0.05) during the earlier 9 days of the storage and remained roughly unchanged during the rest days of the storage. While the a* values of control samples decreased progressively during the storage. NO-treatment effectively improved the muscle color and color stability of tilapia fillets. The peak wavelengths of extract from the muscles of NO treated tilapia fillets increased from 418 nm to 421 nm at 15 d of the storage, while that of control decreased from 418 nm to 410 nm, indicated that color improvement in NO-treated tilapia fillets is mainly due to the formation of MbNO. Moreover, NO-treatment resulted in less TVB-N values than control (16.06 and 21.93 mg of N/100 g at the end of the storage, respectively), prolonging the shelf-life of tilapia fillets. CONCLUSION: The results suggested that postmortem treatment with NO is a good procedure not only for improving the muscle color and color stability but also for prolonging the shelf-life of tilapia fillets during the storage, which is valuable for industrial manufacturing of tilapia and possibly for other fish species.

Atmospheric composition 1 million years ago from blue ice in the Allan Hills, Antarctica.

Here, we present direct measurements of atmospheric composition and Antarctic climate from the mid-Pleistocene (∼1 Ma) from ice cores drilled in the Allan Hills blue ice area, Antarctica. The 1-Ma ice is dated from the deficit in (40)Ar relative to the modern atmosphere and is present as a stratigraphically disturbed 12-m section at the base of a 126-m ice core. The 1-Ma ice appears to represent most of the amplitude of contemporaneous climate cycles and CO2 and CH4 concentrations in the ice range from 221 to 277 ppm and 411 to 569 parts per billion (ppb), respectively. These concentrations, together with measured δD of the ice, are at the warm end of the field for glacial-interglacial cycles of the last 800 ky and span only about one-half of the range. The highest CO2 values in the 1-Ma ice fall within the range of interglacial values of the last 400 ka but are up to 7 ppm higher than any interglacial values between 450 and 800 ka. The lowest CO2 values are 30 ppm higher than during any glacial period between 450 and 800 ka. This study shows that the coupling of Antarctic temperature and atmospheric CO2 extended into the mid-Pleistocene and demonstrates the feasibility of discontinuously extending the current ice core record beyond 800 ka by shallow coring in Antarctic blue ice areas.

Quality analysis of commercial samples of Ziziphi spinosae semen (suanzaoren) by means of chromatographic fingerprinting assisted by principal component analysis.

Due to the scarcity of resources of Ziziphi spinosae semen (ZSS), many inferior goods and even adulterants are generally found in medicine markets. To strengthen the quality control, HPLC fingerprint common pattern established in this paper showed three main bioactive compounds in one chromatogram simultaneously. Principal component analysis based on DAD signals could discriminate adulterants and inferiorities. Principal component analysis indicated that all samples could be mainly regrouped into two main clusters according to the first principal component (PC1, redefined as Vicenin II) and the second principal component (PC2, redefined as zizyphusine). PC1 and PC2 could explain 91.42% of the variance. Content of zizyphusine fluctuated more greatly than that of spinosin, and this result was also confirmed by the HPTLC result. Samples with low content of jujubosides and two common adulterants could not be used equivalently with authenticated ones in clinic, while one reference standard extract could substitute the crude drug in pharmaceutical production. Giving special consideration to the well-known bioactive saponins but with low response by end absorption, a fast and cheap HPTLC method for quality control of ZSS was developed and the result obtained was commensurate well with that of HPLC analysis. Samples having similar fingerprints to HPTLC common pattern targeting at saponins could be regarded as authenticated ones. This work provided a faster and cheaper way for quality control of ZSS and laid foundation for establishing a more effective quality control method for ZSS.

Quality assessment of Fructus xanthii based on fingerprinting using high-performance liquid chromatography.

Because almost every traditional Chinese medicine (TCM) is a multicomponent system, QC of TCMs always involves various difficulties. As a current popular quality assessment approach, focusing on qualitative and quantitative analysis of certain compounds contained in herbal medicine has been widely used for the sake of expediency rather than being a practical and realistic way. However, this method does not take the existence of other constituents into account. Comparatively, the chromatographic fingerprint of the components is a more suitable approach to holistically assess the quality of herbal drugs. Fructus xanthii is a well-known herbal drug listed in all editions of the Chinese Pharmacopoeia. However, there is no quality evaluation method given in its monograph, even for the above-mentioned expediency. This paper reports an HPLC fingerprinting method for quality evaluation of F. xanthii. The HPLC profiles of 27 batches of commercial samples were further analyzed using chemometric methods, including similarity evaluation and principal component analysis. As a result, the established HPLC fingerprint contained 23 characteristic peaks; therein, 13 peaks were unambiguously assigned by comparing their retention times and UV spectra with those of reference compounds, and five peaks were tentatively identified on the basis of their MS/MS fragmentation patterns and UV spectra. Moreover, it could be clearly observed that caffeoylquinic acid and its analogs predominate in F. xanthii. Except for three samples identified as outliers, 24 other commercial samples displayed similar HPLC profiles, indicating that the quality of the herbs from different markets is stable and consistent.

Study on triterpenoic acids distribution in Ganoderma mushrooms by automatic multiple development high performance thin layer chromatographic fingerprint analysis.

Ganoderma--"Lingzhi" in Chinese--is one of the superior Chinese tonic materia medicas in China, Japan, and Korea. Two species, Ganoderma lucidum (Red Lingzhi) and G. sinense (Purple Lingzhi), have been included in the Chinese Pharmacopoeia since its 2000 Edition. However, some other species of Ganoderma are also available in the market. For example, there are five species divided by color called "Penta-colors Lingzhi" that have been advocated as being the most invigorating among the Lingzhi species; but there is no scientific evidence for such a claim. Morphological identification can serve as an effective practice for differentiating the various species, but the inherent quality has to be delineated by chemical analysis. Among the diverse constituents in Lingzhi, triterpenoids are commonly recognized as the major active ingredients. An automatic triple development HPTLC fingerprint analysis was carried out for detecting the distribution consistency of the triterpenoic acids in various Lingzhi samples. The chromatographic conditions were optimized as follows: stationary phase, precoated HPTLC silica gel 60 plate; mobile phase, toluene-ethyl acetate-methanol-formic acid (15 + 15 + 1 + 0.1); and triple-development using automatic multiple development equipment. The chromatograms showed good resolution, and the color images provided more specific HPTLC fingerprints than have been previously published. It was observed that the abundance of triterpenoic acids and consistent fingerprint pattern in Red Lingzhi (fruiting body of G. lucidum) outweighs the other species of Lingzhi.

Chemical pattern-aided classification to simplify the intricacy of morphological taxonomy of Epimedium species using chromatographic fingerprinting.

Epimedium herb (Yinyanghuo), one of the popular Chinese materia medica, is a multiple species colony of Epimedium genus belonging to Berberidaceae. There are five species of Epimedium that have been officially adopted in Chinese Pharmacopoeia under the same crude drug name 'Yinyanghuo' comprising Epimedium brevicornu, E. koreanum, E. sagittatum, E. pubescens, and E. wushanense. In addition, non-official species like E. acuminatum, E. miryanthum and E. leptorrhizum are also mix-used. Frequently, the morphological taxonomical identification is very difficult during on-site inspection for species authentication in the market. Researchers are often bewildered by the multiple species ambiguity when putting this crude drug in use. Referring to the bioactive constituents that are vital for therapeutic efficacy, the key to clarifying the multiple species confusion should rely on analysis of the bioactive composition. It is well known that medicinal Epimedium herbs contain special C-8 prenylated flavonol glycosides which contribute to various bioactivities and the major four, epimedin A (A), epimedin B (B), epimedin C (C) and icariin (I), are unanimously used as bioactive markers for quality control. In this study, HPLC-DAD fingerprinting was performed for investigating the molecular spectrum of various Epimedium species. It was found that the four major flavonoids constitute the middle part of the chromatographic profiles to form a specific region (named as 'ABCI fingerprint region') being dominant in the HPLC profiles of all medicinal Epimedium species, and the five official species express five different 'ABCI' patterns (different peak: peak ratios). Our study found that the convergent tendency of the 'ABCI region' among multiple species of Epimedium could facilitate differentiation of complex commercial samples based on similar bioactive composition should confer similar bioactivities. Merging the different species that possess the same 'ABCI region' pattern into the same group can create a simpler bioactive-fraction-aided classification array by clustering the commercial samples into three bioactive ingredients-based fingerprint patterns - 'E.b. pattern', 'E.k. pattern' and 'extensive E.w. pattern'. This approach offers the feasibility of characterizing and quality-controlling complex samples in the same genus designated under a single herbal drug entity on the premise of possessing the same bioactive ingredients pattern and supported by long-term traditional usage.

Study of the destructive effect to inherent quality of Angelicae dahuricae radix (Baizhi) by sulfur-fumigated process using chromatographic fingerprinting analysis.

The after-harvesting sun-dried process of Angelicae dahuricae radix (Chinese name: Baizhi) was previously the traditional treatment for commodity. Over recent decades the natural drying process for some fleshy roots or rhizomes of Chinese materia medica has been replaced by sulfur-fumigation for curtailing the drying duration and pest control. We used high performance liquid chromatography (HPLC) and high performance thin-layer chromatography (HPTLC) fingerprinting analysis to investigate the potential damaging effect of the sulfur-fumigating process. The experimental conditions were as follows. HPTLC analysis was carried out on pre-coated silica-gel 60 plate, twice development was performed with two solvent systems (mobile phase) A, chloroform-ethyl acetate (10:1) and B, hexane-chloroform-ether (4:1:2); the fluorescent images were observed under UV 365 nm. HPLC was preceeded on Zorbax SB-C(18) column; the linear gradient elution was conducted with mobile phase prepared from methanol-0.5% acetic acid; column temperature was at 25 degrees C; the detection wavelength was 250 nm. We found serious degradation of the majority of coumarins in sulfur-fumigated Baizhi. The destructive effect was manifested by the defaced chromatographic profile and verified by imitating the sulfur dioxide reaction with the constituents in Baizhi in the laboratory. It is suggested that sulfur-fumigation process is an unacceptable approach for processing herbal drugs.

Effect of Xuesaitong soft capsule on hemorrheology and in auxiliarily treating patients with acute cerebral infarction.

OBJECTIVE: To observe the therapeutic effect of Xuesaitong soft capsule (XST) and its effect on platelet counts, coagulation factor 1 (CF1) as well as hemorrheologic indexes in treating patients with acute cerebral infarction (ACI). METHODS: Two hundred and four patients with ACI were assigned into two groups, the control group (n = 96) and the treated group (n = 108). They were all treated with conventional Western medicines, including mannitol, troxerutin, citicoline, piracetam and aspirin, while to the treated group, XST was given additionally through oral intake, twice a day, 2 capsules each time for 8 successive weeks. The clinical efficacy was evaluated according to the nerve function deficits scoring and the changes of platelet count. CF1 and hemorrheological indexes were measured before and after treatment. RESULTS: The total effective rate was 87.0% in the treated group, and 87.5% in the control group, respectively, showing insignificant difference between them. But the markedly effective rate in the treated group (66.7%) was significantly higher than that in the control group (27.1%, P < 0.01). The count of platelet was not changed significantly in both groups after treatment, while CF1 in them evidently lowered at the end of the 4th and 8th weeks of treatment, but showed insignificant difference between the two groups. The hematocrit, whole blood viscosity and plasma viscosity in both groups were all improved significantly after treatment, but also showed insignificant difference in comparison of the two groups. CONCLUSION: XST has good efficacy in auxiliary treatment of patients with ACI, though its mechanism remains to be further explored.