C, N, and P stoichiometry for leaf litter of 62 woody species in a subtropical evergreen broadleaved forest

To understand leaf litter stoichiometry in a subtropical evergreen broadleaved forest, we measured the contents of carbon (C), nitrogen (N) and phosphorus (P) in leaf litters of 62 main woody species in a natural forest of C. kawakamii Nature Reserve in Sanming, Fujian Province. Differences in leaf litter stoichiometry were analyzed across leaf forms (evergreen, deciduous), life forms (tree, semi-tree or shrub), and main families. Additionally, the phylogenetic signal was measured by Blomberg's K to explore the correlation between family level differentiation time and litter stoichiometry. Our results showed that the contents of C, N and P in the litter of 62 woody species were 405.97-512.16, 4.45-27.11, and 0.21-2.53 g·kg^-1, respectively. C/N, C/P and N/P were 18.6-106.2, 195.9-2146.8, and 3.5-68.9, respectively. Leaf litter P content of evergreen tree species was significantly lower than that of deciduous tree species, and C/P and N/P of evergreen tree species were significantly higher than those of deciduous tree species. There was no significant difference in C, N content and C/N between the two leaf forms. There was no significant difference in litter stoichiometry among trees, semi-trees and shrubs. Effects of phylogeny on C, N content and C/N in leaf litter was significant, but not on P content, C/P and N/P. Family differentiation time was negatively correlated with leaf litter N content, and positively correlated with C/N. Leaf litter of Fagaceae had high C and N contents, C/P and N/P, and low P content and C/N, with an opposite trend for Sapidaceae. Our findings indicated that litter in subtropical forest had high C, N content and N/P, but low P content, C/N, and C/P, compared with the global scale average value. Litter of tree species in older sequence of evolutionary development had lower N content but higher C/N. There was no difference of leaf litter stoichiometry among life forms. There were significant differences in P content, C/P, and N/P between different leaf forms, with a characteristic of convergence.

[Effects of warming on physicochemical property of Cunninghamia lanceolata branch and leaf litter in subtropical plantation]

At the regional scale, substrate properties are the key factors driving litter decomposition rate. In this study, soil temperature was increased by buried heating cables to explore the impacts of climate warming on the physical and chemical properties in branch and leaf of Cunninghamia lanceolata litter. The results showed that after 5 years of soil warming (4 ℃), the contents of nitrogen (N), phosphorus (P) and water-soluble substance in branch litter increased by 35.2%, 40.8% and 7.6%, while that in leaf litter increased by 41.2%, 45.9% and 5.9%, respectively. The contents of carbon (C), cellulose and C/N in branch litter decreased by 5.1%, 11.6% and 28.8%, and in leaf litter decreased by 5.3%, 11.3% and 33.3%, respectively. Soil warming led to 29.8% increase in specific leaf area (SLA) and 40.7% decrease in tensile strength (LTS) of leaf litter. However, warming did not affect lignin content and pH value in both branch and leaf litter. ¹³C NMR and infrared spectrum analysis showed that the contents of amino acids, polysaccharides, polyphenols and aliphatic compounds in litter changed significantly after warming. Warming effect differed between litter organs, in that polysaccharides increased significantly only in leaf litter and the increase of amino acids in branch litter was greater than that in leaf litter. Overall, soil warming significantly changed the physical and chemical properties in C. lanceolata branch and leaf litter, which might accelerate the decomposition rate at the initial stage due to the increase of N, P contents and the decrease of LTS, but might decelerate the decomposition rate at the later stage due to an increase of complex polymers content in the litter.

ACETAMINOPHEN ADMINISTERING IN ORDER TO OBLITERATE HEMODYNAMICALLY SIGNIFICANT PATENT DUCTUS ARTERIOSUS IN NEONATES WITH EXTREMELY LOW BIRTH WEIGHT

BACKGROUND

Patent ductus arteriosus (PDA) is one of the most common pathological conditions within the neonatal period Functioning of hemodynamically significant patent ductus arteriosus can cause a development ofvarious complications. This is why the earliest possible drug therapy or surgery is required in order to eliminate this fetal communication.

THE AIM

to study the efficacy and safety of acetaminophen administering to infants with low birth weight for medical obliteration of hemodynamically significant ductus arteriosus.

MATERIALS AND METHODS

The study included 16 infants with gestational age up to 29 weeks and birth weight less than 1200 g, the average birth weight was 980±230 g and gestation was 26,4±1,4 weeks. The average age of the observable patients at the moment of the beginning of the acetaminophen therapy was 56±6 h. Ductus arteriosus diameter was 3,75±1,25 mm. All the children underwent drug obliteration of the PDA through the intravenous acetaminophen administering. 15 mg / kg of the drug was given every 6 hours for three days. The full treatment course included 12 injections.

RESULTS

The expected effect (closing of the ductus arteriosus) was achieved in 14 (87.5%) children undergoing the drug therapy. Two children with the birth weight of 1000 g and 1200 g remained with the ductus arteriosus open, but the signs of the left heart volume overload decreased significantly. To achieve a clinical benefit, it took 11 injections of the drug, on average. The children with the ongoing therapy were receiving enteral nutrition with the standard dosages corresponding to their age. No complications of the urinary tract, gastrointestinal tract or haemostatic system were registered.

CONCLUSION

Using acetaminophenfor medical obliteration of the ductus arteriosus is a highly effective and safe method of treatment that has to be used in routine clinical practice. Dosing of the drug is easy to control and change, hence it is possible to cancel the drug administering as soon as the required result is achieved so as to minimize any complications.

Arsenate reduction and methylation in the cells of Trichoderma asperellum SM-12F1, Penicillium janthinellum SM-12F4, and Fusarium oxysporum CZ-8F1 investigated with X-ray absorption near edge structure

Synchrotron radiation-based X-ray absorption near edge structure (XANES) was introduced to directly analysis chemical species of arsenic (As) in the cells of Trichoderma asperellum SM-12F1, Penicillium janthinellum SM-12F4, and Fusarium oxysporum CZ-8F1 capable of As accumulation and volatilisation. After exposure to As(V) of 500 mg L(-1) for 15 days, a total of 60.5% and 65.3% of the accumulated As in the cells of T. asperellum SM-12F1 and P. janthinellum SM-12F4, respectively, was As(III), followed by 31.3% and 32.4% DMA (dimethylarsinic acid), 8.3% and 2.3% MMA (monomethylarsonic acid), respectively. However, for F. oxysporum CZ-8F1, 54.5% of the accumulated As was As(III), followed by 37.8% MMA and 7.7% As(V). The reduction and methylation of As(V) formed As(III), MMA, and DMA as the primacy products, and the reduction of As(V) might be more easily processed than the methylation. These results will help to understanding the mechanisms of As detoxification and its future application in bioremediation.

Low-density to high-density transition in Ce75Al23Si2 metallic glass

Using in situ high-pressure x-ray diffraction (XRD), we observed a pressure-induced polyamorphic transition from the low-density amorphous (LDA) state to the high-density amorphous (HDA) state in Ce(75)Al(23)Si(2) metallic glass at about 2 GPa and 300 K. The thermal stabilities of both LDA and HDA metallic glasses were further investigated using in situ high-temperature and high-pressure XRD, which revealed different pressure dependences of the onset crystallization temperature (T(x)) between them with a turning point at about 2 GPa. Compared with Ce(75)Al(25) metallic glass, minor Si doping shifts the onset polyamorphic transition pressure from 1.5 to 2 GPa and obviously stabilizes both LDA and HDA metallic glasses with higher T(x) and changes their slopes dT(x)/dP. The results obtained in this work reveal another polyamorphous metallic glass system by minor alloying (e.g. Si), which could modify the transition pressure and also properties of LDA and HDA metallic glasses. The minor alloying effect reported here is valuable for the development of more polyamorphous metallic glasses, even multicomponent bulk metallic glasses with modified properties, which will trigger more investigations in this field and improve our understanding of polyamorphism and metallic glasses.

Comprehensive study of lead pollution in Shanghai by multiple techniques

Aerosol samples of PM10 particulates were examined with particle-induced X-ray emission (PIXE and micro-PIXE ), inductively coupled plasma-mass spectrometry, and X-ray absorption fine structures (XAFS) to investigate atmospheric Pb concentrations and its chemical species and to decide the source assignment. From the elemental analyses, lead concentrations were averaged at 369 and 237 ng.m-3 in aerosol samples of PM10 collected from 19 monitor sites in Shanghai in the winter of 2002 and 2003, respectively. The XAFS results show that major chemical forms of the lead particulates are probably PbCl2, PbSO4, and PbO. A calculation of isotope ratio and chemical mass balance of the PM10 samples revealed that the atmospheric lead particulates in Shanghai in the two periods were mainly from coal combustors, iron and steel plants, and automobile exhausts, with coal combustion dominating the lead pollution after the phasing out of leaded gasoline in 1997 in Shanghai.

Hair follicle defects and squamous cell carcinoma formation in Smad4 conditional knockout mouse skin

Smad4 is the common mediator for TGFbeta signals, which play important functions in many biological processes. To study the role of Smad4 in skin development and epidermal tumorigenesis, we disrupted this gene in skin using the Cre-loxP approach. We showed that absence of Smad4 blocked hair follicle differentiation and cycling, leading to a progressive hair loss of mutant (MT) mice. MT hair follicles exhibited diminished expression of Lef1, and increased proliferative cells in the outer root sheath. Additionally, the skin of MT mice exhibited increased proliferation of basal keratinocytes and epidermal hyperplasia. Furthermore, we provide evidence that the absence of Smad4 resulted in a block of both TGFbeta and bone morphogenetic protein (BMP) signaling pathways, including p21, a well-known cyclin-dependent kinase inhibitor. Consequently, all MT mice developed spontaneous malignant skin tumors from 3 months to 13 months of age. The majority of tumors are malignant squamous cell carcinomas. A most notable finding is that tumorigenesis is accompanied by inactivation of phosphatase and tensin homolog deleted on chromosome 10 (Pten), activation of AKT, fast proliferation and nuclear accumulation of cyclin D1. These observations revealed the essential functions of Smad4-mediated signals in repressing skin tumor formation through the TGFbeta/BMP pathway, which interacts with the Pten signaling pathway.

Compared with parenteral nutrition, enteral feeding attenuates the acute phase response and improves disease severity in acute pancreatitis

BACKGROUND

In patients with major trauma and burns, total enteral nutrition (TEN) significantly decreases the acute phase response and incidence of septic complications when compared with total parenteral nutrition (TPN). Poor outcome in acute pancreatitis is associated with a high incidence of systemic inflammatory response syndrome (SIRS) and sepsis.

AIMS

To determine whether TEN can attenuate the acute phase response and improve clinical disease severity in patients with acute pancreatitis.

METHODS

Glasgow score, Apache II, computed tomography (CT) scan score, C reactive protein (CRP), serum IgM antiendotoxin antibodies (EndoCAb), and total antioxidant capacity (TAC) were determined on admission in 34 patients with acute pancreatitis. Patients were stratified according to disease severity and randomised to receive either TPN or TEN for seven days and then re-evaluated.

RESULTS

SIRS, sepsis, organ failure, and ITU stay, were globally improved in the enterally fed patients. The acute phase response and disease severity scores were significantly improved following enteral nutrition (CRP: 156 (117-222) to 84 (50-141), p < 0.005; APACHE II scores 8 (6-10) to 6 (4-8), p < 0.0001) without change in the CT scan scores. In parenterally fed patients these parameters did not change but there was an increase in EndoCAb antibody levels and a fall in TAC. Enterally fed patients showed no change in the level of EndoCAb antibodies and an increase in TAC.

CONCLUSION

TEN moderates the acute phase response, and improves disease severity and clinical outcome despite unchanged pancreatic injury on CT scan. Reduced systemic exposure to endotoxin and reduced oxidant stress also occurred in the TEN group. Enteral feeding modulates the inflammatory and sepsis response in acute pancreatitis and is clinically beneficial.

[Comparative study of methods of active effects on human brain to reveal abilities of low level perception]

Active methods of the influence upon the person with the aim of forming special states of the brain in order to obtain reproducible and strong perception of low level signals are compared. If the human brain is immediately exposed to the force by penetrating physical fields (i.e. magnetic, electromagnetic, acoustic) than best results can be obtained while using electromagnetic and acoustic fields; in this case the effectiveness of the tests on perception grows from (50 +/- 6) to (79 +/- 9)%. If the brain is forced through the peripheral sensory systems (visual and acoustic analyzers and skin receptors) than perception grows from (50 +/- 6) to (85 +/- 10)%. Special device for influence upon the brain through visual analyzer with the help of bylatheral photo-stimulation is described. The outlook of the control upon special states of brain with the aim to reveal abilities to the low level perception is discussed.

[A statistic approach to interpretation, results processing and hypo thesis testing in experiments on exposuring the human brain to perception of low level signals]

There are shown the limitations of using the generally accepted approaches to statistic data processing at the perception of low level signals on Bernully scheme when specific nature on the phenomenon (the human ability to perception is not constant, uncontrolled and manifests itself for a short time) isn't taken into account. A new approach to the statistic processing of measurement results is also proposed. It is based on the sequence analysis of correct answers in a series, the use of sequential statistic procedures (criteria), maximally taking into account the perception specificity and the measurement features. The estimate of first kind error in proposed method has been carried out.

[Effect of buyang huanwu decoction on the antithrombotic functions of the vessel wall]

The effects of Buyang Huanwu Decoction (BYHWD) on the antithrombotic functions of vessel wall were studied with human umbilical vein perfusion. It was observed that the both of Von Willebrand factor release stimulated by thrombin from the vessel walls and conversion of fibrinogen to fibrin catalyzed by thrombin were inhibited by BYHWD. There were no obvious effects of BYHWD on the thrombin adsorption to the vessel walls and the thrombin induced release of PGI2 as well as fibrinolysis inhibiting activity from the vessel walls.