[Characteristics of main layer and regeneration layer of Haloxylon ammodendron plantations at different ages on the southern edge of the Gurbantunggut Desert, Northwest China]. / å¤å°”ç­é€šå¤ç‰¹æ²™æ¼ å—ç¼˜ä¸åŒæž—é¾„äººå·¥æ¢­æ¢­æž—ä¸»æž—å±‚å’Œæ›´æ–°å±‚ç‰¹å¾.

The population structure characteristics, natural regeneration, and the influential factors of Haloxylon ammodendron plantations at six different stand ages on the southern edge of the Gurbantunggut Desert were studied. The results showed that H. ammodendron plantation at the stand age of 7 could naturally regenerate. At the stand age of 17, the densities of the seedlings (＜30 cm height), saplings (30≤H＜50 height), and small trees (≥50 cm height) reached optimal class, and the mean height and base diameter of the small tress reached 1.10 m and 1.91 cm, respectively. The parent trees in H. ammodendron plantation at the stand age of 20 grew best. The height of 35% individuals grew up to 2.50-3.00 m, and the basal stem diameter of 23.1% individuals grew up to 8.00-10.00 cm. The height and diameter growth of the parent trees in H. ammodendron plantation at the stand age of 33 apparently declined, but the regeneration ability by natural seed dispersal was still strong. The regeneration density of natural seed dispersal showed the greatest correlation with the available nitrogen content in 0-100 cm soil layer (0.87), followed by the soil rapidly available phosphorus content (0.84) and the soil water content (0.79). The soils with pH 8.1-8.6 did not limit the nutrient growth of the regeneration layer. In the main stand layer, the individual density of whole regeneration layer showed the greatest correlation with the biomass of the parent trees (0.77), while the density of regeneration layer of the small trees showed the greatest correlation with the planting density (0.71) and the age of the parent trees (0.70).

Characterization of Chondrogenic Gene Expression and Cartilage Phenotype Differentiation in Human Breast Adipose-Derived Stem Cells Promoted by Ginsenoside Rg1 In Vitro.

BACKGROUND/AIMS: Investigating and understanding chondrogenic gene expression during the differentiation of human breast adipose-derived stem cells (HBASCs) into chondrogenic cells is a prerequisite for the application of this approach for cartilage repair and regeneration. In this study, we aim to characterize HBASCs and to examine chondrogenic gene expression in chondrogenic inductive culture medium containing ginsenoside Rg1. METHODS: Human breast adipose-derived stem cells at passage 3 were evaluated based on specific cell markers and their multilineage differentiation capacity. Cultured HBASCs were treated either with basic chondrogenic inductive conditioned medium alone (group A, control) or with basic chondrogenic inductive medium plus 10 µg/ml (group B), 50 µg/ml (group C), or 100µg/ml ginsenoside Rg1 (group D). Cell proliferation was assessed using the CCK-8 assay for a period of 9 days. Two weeks after induction, the expression of chondrogenic genes (collagen type II, collagen type XI, ACP, COMP and ELASTIN) was determined using real-time PCR in all groups. RESULTS: The different concentrations of ginsenoside Rg1 that were added to the basic chondrogenic inductive culture medium promoted the proliferation of HBASCs at earlier stages (groups B, C, and D) but resulted in chondrogenic phenotype differentiation and higher mRNA expression of collagen type II (CO-II), collagen type XI (CO-XI), acid phosphatase (ACP), cartilage oligomeric matrix protein (COMP) and ELASTIN compared with the control (group A) at later stages. The results reveal an obvious positive dose-effect relationship between ginsenoside Rg1 and the proliferation and chondrogenic phenotype differentiation of HBASCs in vitro. CONCLUSIONS: Human breast adipose-derived stem cells retain stem cell characteristics after expansion in culture through passage 3 and serve as a feasible source of cells for cartilage regeneration in vitro. Chondrogenesis in HBASCs was found to be prominent after chondrogenic induction in conditions containing ginsenoside Rg1.

[Effects of plastic film mulching on soil CO2 efflux and CO2 concentration in an oasis cotton field].

A field study was conducted to compare soil CO2 efflux and CO2 concentration between mulched and non-mulched cotton fields by using closed chamber method and diffusion chamber technique. Soil CO2 efflux and CO2 concentration exhibited a similar seasonal pattern, decreasing from July to October. Mulched field had a lower soil CO2 efflux but a higher CO2 concentration, compared to those of non-mulched fields. Over the measurement period, cumulative CO2 efflux was 1871.95 kg C . hm-2 for mulched field and 2032.81 kg C . hm-2 for non-mulched field. Soil CO2 concentration was higher in mulched field (ranging from 5137 to 25945 µL . L-1) than in non- mulched field (ranging from 2165 to 23986 µL . L-1). The correlation coefficients between soil CO2 concentrations at different depths and soil CO2 effluxes were 0.60 to 0.73 and 0.57 to 0.75 for the mulched and non-mulched fields, indicating that soil CO2 concentration played a crucial role in soil CO2 emission. The Q10 values were 2.77 and 2.48 for the mulched and non-mulched fields, respectively, suggesting that CO2 efflux in mulched field was more sensitive to the temperature.

Growth/differentiation factor-5 induces osteogenic differentiation of human ligamentum flavum cells through activation of ERK1/2 and p38 MAPK.

Ossification of ligamentum flavum (OLF) is a pathological ectopic ossification in the spinal ligament, leading to spinal canal stenosis, but little was known about its pathogenesis. A previous study has found growth/differentiation factor (GDF)-5 expression at ossified sites of the ligaments from OLF patients. This study aimed to investigate the osteogenic effects of GDF-5 on cultured human ligamentum flavum cells (LFCs). LFCs were isolated from human spinal ligamentum flavum, and treated with or without recombinant human (rh) GDF-5. Alkaline phosphatase (ALP) activity was measured. Expression of osteocalcin was assessed by reverse transcriptase-PCR, Western blotting and immunofluorescence. Matrix mineralization was assessed by alizarin red staining. Activation of mitogen-activated protein kinases (MAPK) ERK1/2, p38 and JNK were detected by Western blotting. We found that rhGDF-5 treatment increased ALP activity and osteocalcin expression in a time- and dose-dependent manner, and induced mineralized nodule form. In addition, rhGDF-5 challenge mediated the ERK1/2 and p38 activation but not JNK. Inhibiting this activation pharmacologically, using U0126, a ERK1/2 inhibitor, or SB203580, a p38 inhibitor, resulted in significantly lower ALP activity and osteocalcin protein expression. The present study shows that rhGDF-5 induces osteogenic differentiation of human LFCs through activation of ERK1/2 and p38 MAPK. These findings give some new insight into the pathogenesis of OLF.

An alternative approach in the treatment of thumb web contracture skin defects: lateral tarsal artery flap.

BACKGROUND: Thumb web contracture is a common complication after hand injury, and can markedly affect whole hand function. Therefore, surgery involving thumb web reconstruction is often necessary to restore normal function of the involved hand. In this study, we present the application of the lateral tarsal artery (LTA) flap in first web reconstruction. METHODS: From November 1, 2005 to October 31, 2007, seven patients with severe post trauma or burn contractures around the first web space were treated with a LTA flap. All the patients were followed up. RESULTS: All flaps survived, with an average size of 6.7 cm x 4.8 cm. There were no complications or recurrent contractures during follow-up. All patients were satisfied with the esthetic appearance and functional outcome of the reconstruction. CONCLUSION: The LTA flap could be an excellent option for covering various defects in the thumb web space, serving as an excellent alternative for the thumb web space reconstruction.

[Effects of drip irrigation under mulching on cotton root and shoot biomass and yield].

By using bidirectional sampling method with soil drill, the effects of different amounts of drip irrigation (2618, 2947, 3600 and 4265 m3 x hm(-2)) under mulching on the root distribution, aboveground growth, and yield of cotton was studied in field. The results indicated that irrigation amount affected the root and shoot growth significantly. In all irrigation treatments, cotton root was mainly distributed in mulched area, occupying 60.65%-73.45% of total root biomass, while only 39.35%-26.55% was distributed in bare area. Water stress increased rooting depth, root biomass, and the extent of lateral rooting. Significant differences were observed in the biological characteristics and the biomass accumulation and allocation of cotton plant among different irrigation treatments. Over-irrigation (4265 m3 x hm(-2)) increased plant height, width of inverse fourth leaf, and amounts of branch and bud, and thus, accelerated biomass accumulation rate. Over-irrigation also increased the root/shoot ratio and the proportion of biomass allocated to vegetative organs, but increased the fruit abscission rate and therefore reduced the economic yield. It was suggested that both excessive soil moisture content and water stress could affect the biomass accumulation and allocation in different cotton organs and at various life stages. Under the conditions of our experiment, 3600 m3 x hm(-2) was the optimal irrigation amount.

Reconstruction of soft tissue defect of the extremity with the perforator flap from inguinal region.

BACKGROUND: The perforator flap has become a very useful reconstructive means of soft tissue defect of extremities. The perforator flap from the inguinal region has advantages that include the ability to cover a large area with little donor site morbidity and provision of suitable thickness for reconstruction. METHODS: From July 1, 2005 to June 30, 2007, 10 patients with various types of soft tissue defect underwent reconstruction with 10 perforator flaps from the inguinal region. Six flaps were applied to the upper extremities and four flaps to the lower extremities. The dimensions of the transferred flaps ranged from 7-30 cm in length and 4-10 cm in width. RESULTS: The postoperative course of all 10 flaps was uneventful and all flaps survived. Distal small partial necrosis was observed in one case due to arterial insufficiency of the distal part of the flap. All patients were satisfied with the functional and esthetic resurfacing outcome. CONCLUSION: Use of perforator flap from the inguinal region could overcome the disadvantages of the traditional free groin flap, and represents a safe and useful tool for coverage of soft tissue defects.

[Determination of trace germanium by HG-ICP and study on the medium influence].

A method to determine the content of trace germanium by hydride generation inductively coupled plasma atomic emission spectrometry was established. The influences of different acidic medium, concentration of NaBH4 and other concomitant elements are examined systemically. The optimal analytical conditions were discussed and examined. The detection limit is 0.2 ng x mL(-1) and the precision is 0.9%. The value of germanium content detected in environmental reference material agrees with the certified value. The medium influence on determining trace germanium was studied in detail.

[Fluorescence spectroscopy study of human serum albumin quenched by rifampicin capsules].

It is obvious that the albumin is a kind of important large biophysical molecular. The albumin is the main component of plasma within cell. It is also the matter basis of life phenomenon. The fluorescence spectroscopy of human serum albumin (HSA) and the interaction of HSA and the rifampicin capsules (lfp) were studied. When the rifampicin capsules (lfp) was added into HSA solution gradually, an interesting new phenomenon emerged in emission spectrum. The combination constant of rifampicin capsules (lfp) is about Ks = 5.149 x 10(4) L x mol(-1), and the dissociation constant is about Kd = 19.42 x 10(-6) mol x L(-1). The quenching process of rifampicin capsules (lfp)-HSA is not dynamic quenching, which resulted from the molecular diffusion and collision. That is the static quenching process resulting from the chemical component between molecules. The energy transfer efficiency between rifampicin capsules (lfp) and HSA is E=0.42. According to these calculation results, the combination position between the binding site of rifampicin capsules (lfp) and the tryptophane of HSA is about R=2.567 nm. The critical distance, when transfer efficiency equals 50%, is about R0 = 2.433 nm.

[Fluorescence spectroscopy study of humen serum albumin quenched by levofloxacin].

The fluorescence spectroscopy of humen serum albumin (HSA) and the interaction of HSA and the Levofloxacin were studied. When the Levofloxacin was added into HSA solution gradually, an interesting new phenomenon emerged in emission spectrum peak. The intensity of 343.70 nm emission peak of HSA decreased obviously and moved towards long-wavelength, which is atypical quenching phenomenon. It was found that the excitation peak of HSA was positioned at 286.70 nm also. A new emission peak emerged at 503.96 nm, which resulted from the Levofloxacin. The excitation peaks of 503.96 nm fluorescence of Levofloxacin were positioned at 300.16 nm and 336.16 nm. When Levoflaxasin was added into HSA gradually, the 300.16 nm and 336.16 nm excitation peaks moved towards long wavelength. The dissociation constant of Levofloxacin from HSA is about Kd = 3.65 x 10(-5) (mol x L(-1)). The combination constant of Levofloxacin is about Ks = 2.742 x 10(4) (L x mol(-1)). The quenching process of Levofloxacin-HSA is not dynamic quenching, which resulted from the molecular diffusion and collision. It is caused by the static quenching process resulting from the chemical component between molecules. The energy transfer efficiency between Levofloxacin and HSA is E = 0.372. According to these calculation results, the combination position between the binding site of Levofloxacin and the tryptophane of HSA is about R = 1.933 nm.

[Study of reference material for excitation spectrum wavelength calibration of fluorescence spectrophotometer].

A reference material used for wavelength calibration of fluorescence spectrophotometer was found. The holmium doped oxide reference material GBW(E) 130112 is a kind of standard reference material for absorption spectrophotometer. It can emit 547.7 nm fluorescence when excited by xenon lamp light. The excitation spectrum of 547.7 nm fluorescence was measured. It was found that the measured peaks of excitation spectrum are positioned at 333.56, 360.43 and 418.39 nm, respectively, which are coincident with the true values 333.8, 360.9 and 418.5 nm of reference material certification. It was illustrated that the holmium doped oxide reference material GBW(E)130112 could be used as reference material for the excitation wavelength calibration of the fluorescence spectrophotometer. Its property could be enhanced very much if high luminescent efficiency material is selected as rare earth ion doped matrix, and the purity is enhanced to reduce the cross relaxation.

Application of ion chromatography to the determination of water-soluble inorganic and organic ions in atmospheric aerosols.

A simple, sensitive and convenient ion chromatography(IC) method was established for the simultaneous determination of twelve water-soluble inorganic anions(F- , Cl- , NO2(-), NO3(-), SO3(2-), SO4(2-) , PO4(3-)), and fifteen water-soluble organic ions(formate, acetate, MSA, oxalate, malonate, succinate, phthalates, etc.) in atmospheric aerosols. The linear concentrations ranged from 0.005 microg/m3 to 500 microg/m3 ( r = 0.999-0.9999). The relative standard deviation (RSD) were 0.43%-2.00% and the detection limits were from 2.7 ng/m3 to 88 ng/m3. The proposed method was successfully applied to the simultaneous determination of those inorganic ions and organic ions in PM2.5 of Beijing.