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Biomedical subjects

H Yang

Publications and source records attributed to H Yang.

At least 217 records · Page 12Linked to original sources
PubMed2001

[Degradation of trichloroethylene by discharge plasma process].

Two types of discharge and two kinds of discharge reactors was employed to decompose trichloroethylene (TCE) in air. The results showed that both pulsed discharge and AC discharge were efficient to the degradation of TCE. Under the pulsed discharge with peak voltage of 42 kV, gas resident time of 15 s and TCE initial concentration of 1350 mg/m3, the degradation efficiency of TCE was close to 100% in the hallow reactor and the higher voltage results in a higher degradation efficiency. For the AC discharge, the degradation efficiency of TCE reached 90% with applied voltage of 30 kV. Meanwhile, increasing the applied frequency of AC voltage can enhance the degradation of TCE. The energy consumption for TCE degradation by AC discharge was higher than that by pulsed discharge. The energy consumption for TCE degradation efficiency of 80% by pulsed and AC discharge were 4.9 W.h/m3 and 116 W.h/m3, respectively. In addition, the energy consumption in the packed reactor was higher comparing with that in the hallow one.

Trichloroethylene↗
PubMed2001

Ability of Agrogyron elongatum to accumulate the single metal of cadmium, copper, nickel and lead and root exudation of organic acids.

Agrogyron elongatum were grown in nutrient solution containing moderate to high amounts of separate heavy metal of Cd, Cu, Ni and Pb in a greenhouse for a 9-day. Cd, Cu, Ni and Pb generally led to decrease in the elongation of roots although the length of seedlings exposed to Cd and Pb at 0.05 and 0.5 mg/L showed to be slightly greater than that of controls. Of the four metals in the experiment, Pb was absorbed and accumulated to the highest level, with the concentrations of 92,754 mg/kg dry weight (DW) in roots and 11,683 mg/kg DW in shoots. Cd was moderately accumulated in Agrogyron elongatum, but the maximum bioaccumulation coefficients (BCs) for roots and shoots were observed. The patterns for Cu and Ni uptake and distribution in plants differed from those of Pb and Cd, as it was showed that the shoot accumulation of Cu and Ni was significantly higher than in roots. A. elongatum had the highest Ni concentration in shoots (30,261 mg/kg DW) at the external concentration of 250 mg/L. Cu ranked second, with a shoot concentration of 12,230 mg/kg DW when 50 mg/L Cu in solution was applied. For the four trace elements tested, the highest concentrations in shoots decreased by the order of Ni > Cu > Pb > Cd (mg/kg DW), and those in roots were Pb > Cd > Ni > Cu (mg/kg DW). Malic, oxalic and citric acids exuded by roots exposed to 1 and 50 mg/L of the metals were detected. Release of organic acids from plants significantly differed among the metal treatments. Cu was most effectively in inducing root exudation of the three types of organic acids. Cd, and Ni were also the inducers of secretion of malic and oxalic acids. With reference of Pb, a small amounts of malic and oxalic acids were detected in the root exudates, but few quantities of citric acid were found. However, no correlation between alternations in root exudation of organic acids and metal accumulation could be established.

Cadmium↗
PubMed2001

[The research of mathematical model for inositol-1,4,5-triphosphate-induced Ca2+ oscillations].

This article mainly illustrates the model for agonist-stimulated Ca2+ oscillations that involves two roles for cytosolic Ca2+: (a) inositol-1.4.5-triphosphate(IP3) inhibits Ca2+ release from the endoplasmic reticulum (ER); (b) IP3 acts on phosphate C, via a Gq protein related mechanism and hence stimulates Ca2+ release from ER. The model assumes that the ER IP3 receptor is a tetramer of independent subunit that can bind both Ca2+ and IP3. The reason for inhibition of Ca2+ oscillations is that IP3-receptor/Ca(2+)-channel slowly comes back to the beginning stable state. The key parameter for Ca2+ oscillations is the ratio of Maximum Ca2+ dependent IP3 input rate (v6) to IP3 decay rate constant (v7): I when v6/v7 < 0.28, no oscillation could be found; II when 0.28 < v6/v7 < 0.572, oscillation starts; III when v6/v7 > 0.572, Ca2+ ceases and arrives at a stable state quickly.

Calcium Channels↗
PubMed2001

[Further correction for the original plant of baiying and shuyangquan].

Textual researches show that Baiyang and Shuyangquan in Shen Nong's Herbal Classic are not the herb medicine Baimaoteng. However, Kuqie in the Grand Dictionary of Chinese Medicine and Baiying can be substitutes of Baimaoteng for medicine. Shuyangquan has not been used for many years. From Ming and Qing dynasties, Shuyangquan's original plant should be Solanum septemlobtum Bunge. In the period of Tang and Song dynasties, its original plant should be S. japonense Nakai. Shuyangquan in Shen Nong's Herbal Classic should be S. dulcamara L. In The Grand Dictionary of Chinese Medicine, Kuqie and Qiannianbulanxin renamed as S. dulcamara was really a mistake.

Plants, Medicinal↗
PubMed2001

Effect and mechanism of electronic magnetic pulse on peripheral lymphocytes in dogs.

OBJECTIVE: To study the effects of electronic magnetic pulse (EMP) on peripheral lymphocytes in dogs and to explore the mechanisms of the biological effects of EMP. METHODS: T, TH and TS lymphocytes were estimated by acid phosphatase cytochemistry. Apoptotic lymphocytes and Bax and Bcl-2 proteins related to apoptosis were observed with in situ terminal labeling and immunocytochemistry. RESULTS: Peripheral T lymphocyte subpopulations decreased obviously after EMP irradiation with (2-12) x 10(4) V/m. Apoptotic percentages of lymphocytes increased with the elevation of EMP doses. Ten days after different intensity radiation, the Bax protein was found to be elevated in accord with the peak value of lymphocyte apoptosis. However, Bcl-2 protein decreased obviously. CONCLUSION: A definite field intensity EMP could induce injury to lymphocytes. Apoptosis induced by EMP is one of the main causes of peripheral lymphocyte death and leads to immunosuppression of the body. These results suggest that people should pay more attention to the injury caused by EMP, especially to the immunological functions of the body.

Animals↗
PubMed2001

[Structure and function of mouse p16INK4a locus].

Inactivation of p16INK4a is highly related with tumors. We obtained a 14.5 kb mouse genomic DNA fragment through screening the 129/SvJ mouse genomic library. Bioinformatics study suggests that the fragment contain three exons, which encode a 17,941 dolton polypeptide consisted of 168aa. The polypeptide has 7 potential phosphorylation sites, which indicates that the function of p16INK4a itself may be under the control of phosphorylation. Many interspersed elements and simple repeats were found in the noncoding region. These elements and repeats may cause retroposition and recombination and thus be responsible for some of the p16INK4a locus deletion. We also compared our sequence of exon 1 alpha with those published elsewhere and found that polymorphism may exist.

Amino Acid Sequence↗
PubMed2001

E2F-1 up-regulates c-Myc and p14(ARF) and induces apoptosis in colon cancer cells.

Although overexpression of E2F-1 can induce apoptosis in a variety of tumor cell lines, the mechanisms by which E2F-1 induces apoptosis remain ambiguous. In this study, we examine the ability of E2F-1 to induce apoptosis in colon cancer and the molecular mechanisms underlying E2F-1-mediated apoptosis. HT-29 and SW-620 colon adenocarcinoma cells (both mutant p53) were treated by mock infection or adenoviral vectors Ad5CMV (empty vector), Ad5CMVLacZ (beta-galactosidase), and Ad5CMVE2F-1 (E2F-1) at multiplicity of infection of 100. Western blot analysis confirmed marked overexpression of E2F-1 in both cell lines. By 5 days after infection, E2F-1 overexpression resulted in >25-fold reduction in cell growth and >90% loss of cell viability in both cell lines. Cell cycle analysis of Ad-E2F-1-infected cells revealed an increase in G(2)/M and sub-G(1) populations. By in situ terminal deoxynucleotidyl transferase (Tdt)-mediated nick end labeling analysis, evidence of apoptosis was observed including internucleosomal DNA fragmentation and the formation of apoptotic bodies. In addition, caspase-3 and poly(ADP-ribose) polymerase apoptotic fragments were detected by 48 h after treatment with Ad-E2F-1. Of mechanistic importance, overexpression of E2F-1 caused a G(2)/M arrest followed by increased levels of c-Myc and p14(ARF) proteins. Additionally, expression of the antiapoptotic Bcl-2 family member Mcl-1 was down-regulated in E2F-1-overexpressing cells. In conclusion, E2F-1 overexpression initiates apoptosis and suppresses growth in HT-29 and SW620 colon adenocarcinoma cells. Overexpression of E2F-1 triggers apoptosis and is associated with up-regulation of c-Myc and p14(ARF) proteins and down-regulation of Mcl-1. Therefore, E2F-1 is a potentially active gene therapy agent for the treatment of colon cancer.

Adenoviridae↗
PubMed2001

Diversity of Arabidopsis genes encoding precursors for phytosulfokine, a peptide growth factor.

Phytosulfokine-alpha (PSK-alpha), a unique plant peptide growth factor, was originally isolated from conditioned medium of asparagus (Asparagus officinalis) mesophyll cell cultures. PSK-alpha has several biological activities including promoting plant cell proliferation. Four genes that encode precursors of PSK-alpha have been identified from Arabidopsis. Analysis of cDNAs for two of these, AtPSK2 and AtPSK3, shows that both of these genes consist of two exons and one intron. The predicted precursors have N-terminal signal peptides and only a single PSK-alpha sequence located close to their carboxyl termini. Both precursors contain dibasic processing sites flanking PSK, analogous to animal and yeast prohormones. Although the PSK domain including the sequence of PSK-alpha and three amino acids preceding it are perfectly conserved, the precursors bear very limited similarity among Arabidopsis and rice (Oryza sativa), suggesting a new level of diversity among polypeptides that are processed into the same signaling molecule in plants, a scenario not found in animals and yeast. Unnatural [serine-4]PSK-beta was found to be secreted by transgenic Arabidopsis cells expressing a mutant of either AtPSK2 or AtPSK3 cDNAs, suggesting that both AtPSK2 and AtPSK3 encode PSK-alpha precursors. AtPSK2 and AtPSK3 were expressed demonstrably not only in cultured cells but also in intact plants, suggesting that PSK-alpha may be essential for plant cell proliferation in vivo as well as in vitro. Overexpression of either precursor gene allowed the transgenic calli to grow twice as large as the controls. However, the transgenic cells expressing either antisense cDNA did not dramatically decrease mitogenic activity, suggesting that these two genes may act redundantly.

Amino Acid Sequence↗
PubMed2001

[Relationship between soil water content and water use efficiency of apple leaves].

The relationship between soil water content and water use efficiency (WUE) of apple tree leaf was examined, and the mechanism of WUE variation was also studied by using pot-culture. The results showed that the WUE was upmost when soil water relative content (SWC) reached 52.0%. The increase of WUE when SWC decreased from 77.2% to 52.0% was mainly caused by the change of stomatal conductance. The decline of carboxylation efficiency resulted in the decrease of WUE when SWC decreased from 52.0% to 20.1%. The WUE returned up after being rewatered, but could not reach the control level within a week. The WUE decreased when the soil was waterlogged, but reached the control level in three days after being waterlogged. After the third day, the WUE decreased gradually with the extending of the time being waterlogged. On the sixth day being waterlogged, the carboxylation efficiency decreased.

Malus↗
PubMed2001

[Autotrophic ammonium-removal of sludge liquor].

The autotrophic ammonium-removal process was realized in floating bed reactors with sludge liquor as substrate. Biofilm of autotrophic bacteria were formed on the surface of carriers in reactors. The main operation conditions of the reactors were as the following: T = 28 degrees C, pH = 8.0 and DO = 0.8-1.0 mg/L. The average surface load of two reactors in series was NH4(+)-N 3-4 g/(m2.d), and the general autotrophic ammonium-removal efficiency was about 70%. The Autotrophic ammonium-removal technology promises considerable savings in regard to the oxygen consumption and external organic carbon addition compared with the conventional nitrification-denitrification technology when it was used to treat ammonium-rich and unfavourable C/N ratio wastewater.

Biofilms↗
PubMed2001

[The application of air-lift loop column filling with porous carrier in wastewater treatment].

An air lift loop reactor filling with porous carrier particles was utilized as aeration column. Experiments were carried out in wide operating conditions. The experimental results showed that in the range of gas flow rate from 0.117 to 0.156 m3/(min.m3), a higher efficiency of removal of ammonium-N was achieved, and when the gas flow rate was above 0.039 m3/(min.m3), the COD was completely degraded in about 1 h. The filling ratio of the porous carriers in the column was an important factor for the removal of C and N compounds, and a filling ratio of 15% was proved to be most suitable in the operation ranges. The experimental results also indicated that the effect of aeration temperature on the removal efficiency was significant and the highest efficiency was obtained at around 25 degrees C.

Nitrogen↗
PubMed2001

[Influence of heart position change on body surface potential distribution].

Based on a 3-D emulational body torso model, the influence of changes of heart position caused by deep inspiration etc. on body surface potential maps(BSPMs) was studied in forward electrocardiography. In this report, BSPMs and ECGs during QRS were provided while the heart was in the normal position, or rotated clockwise to the vertical or counterclockwise to the transverse.

Algorithms↗
PubMed2001

[PCR amplification of anaerobic fungal 18S rDNA from landfill sites].

Nucleic acid based techniques are widely used to characterize microbial communities in environmental samples. In this study, seven landfill leachates were tested for the presence of 18S rRNA genes from anaerobic fungi from the family Chytridiomycetes. A nested Polymerase Chain Reaction (PCR) strategy was employed to amplify the 18S rRNA gene region of Chytridiomycetous fungi from landfill sites samples. All of the PCR products from landfill leachates amplified with the first primer pair NS1/NS8 and the second primer pair Chyt-719/Chyt-1553 were subjected to agarose gel electrophoresis to show seven samples containing fungi from the family Chytridiomycetes. One of the positive results was then selected for cloning and sequencing of the PCR product to confirm the identity of the amplified DNA. The molecular data presented here reveals for the first time that Chytridiomycetous fungi associated with the anaerobic rumen environment are also present in landfill sites.

Anaerobiosis↗
PubMed2001

[Pharmacokinetics of adriamycin by bronchial artery infusion for non-small cell bronchogenic carcinoma].

OBJECTIVE: This pharmacokinetic study was conducted to determine the plasma concentration of adriamycin after bronchial artery infusion (BAI), and to compare it with the conventional chemotherapy. METHODS: Twenty-four healthy rabbits were divided into 4 groups with 6 animals in each. Comparison of the parameters was investigated in pharmacokinetics after ear-lobe venous injection of ADM (Group 1) and in combination with DDP or/and MMC (Groups 2, 3, 4). Intracardial blood samples were obtained according to the fixed time and quantity. Dose for each drug was: ADM 2 mg/kg, DDP 4 mg/kg, and MMC 2 mg/kg. Seventeen patients suffering from primary non-small cell bronchogenic carcinoma, the central type, confirmed by pathology and cytology comprised the clinical group, all of whom showing single blood supply by angiography, was given bronchial artery infusion. According to the scheduled time and quantity, we sampled blood species via indwelling catheter in the right median cubital vein after the bronchial artery infusion. Dose of the each drug was: ADM 40 mg/m2, DDP 80 mg/m2, and MMC 14 mg/m2. Plasma concentration of ADM was determined by fluorophotometry. Since the cessation of chemotherapy, blood samples were taken from the thoracic aorta via indwelling catheter at 0, 1, 3, 5, 10, 15 and 20 minutes; venous blood samples were taken from the right cubital vein through the indwelling catheter at 0, 5, 10, 15, 20 minutes, and also at 0.5, 1, 2, 4, 8, 12, 24 and 48 hours altogether at 20 time-spots with 2 ml per sample. RESULTS: The calibration curve was linear from 10 ng/ml to 1,000 ng/ml with r = 0.9983. The relationship standard difference (RSD) within a day was lowered to 2%, and the RSD between days was lowered to 3%. The formula of concentration-time curve for ADM was C microgram/ml = 129.44e(-13.36t) + 0.25e(-0.072t) in animal Group 1, and C microgram/ml = 370.93e(-23.43t) + 0.04e(-0.09t) in Group 4 animal. The formula in the clinical group was C microgram/ml(artery) = 448.61e(-66.62t) + 16.35e(-8.13t)(artery) and C microgram/ml(vein) = 15.69e(-21.66t) + 0.07e(-0.038t)(vein). CONCLUSION: Compared with the conventional chemotherapy in pharmacokinetics, bronchial artery infusion can be used as a treatment for non-small cell bronchogenic carcinoma with more effectiveness and less side effects.

Animals↗
PubMed2001

[Palliative irradiation combined with chemotherapy for lung cancer with brain metastasis].

OBJECTIVE: To evaluate to effects and complications of palliative irradiation combined with chemotherapy for lung cancer with brain metastasis. METHODS: Eighty-two non-small cell lung cancer with brain metastasis were treated, of whom 48 had extracranial metastasis simultaneously. All patients received chemotherapy (Teniposide and cis-platin) prior to and also after radiotherapy. The multiple-intracranial metastasis patients received whole brain radiation therapy to a dose of 33-39 Gy/11-13 fx. The others who had single intracranial lesion received whole brain irradiation of 30 Gy/10 fx and a boost of 15 Gy/5 fx. RESULTS: The overall 1- and 2-year actuarial survival rates were 46.7% and 6.7%. For patients with brain metastasis and extracranial lesions, the 1- and 2-year survival rates were 32.4% and 4.4%. For patients with intracranial metastasis only, they were 61.2% and 8.8%, respectively (P = 0.003). The median survival of these two groups were 8 and 12 months. There was no significant correlation between the survivals rate and the histological type or the number of intracranial metastasis. No severe complications were observed during the treatment and follow-up. CONCLUSION: The regimen of combined chemotherapy with radiotherapy is effective for lung cancer with brain metastasis. The survival rate of patients with intracranial metastasis only is obviously higher than those with multiple extracranial lesions in addition to brain metastasis.

Adult↗
PubMed2001

[Studies on epidemic feature of enteric adenoviruses infection in feces of infants with diarrhea in Shenzhen].

OBJECTIVE: To estimate the enteric adenoviruses infection in feces of infants with diarrhea in Shenzhen. METHODS: All 195 fecal samples of infants were tested by PCR. Amplimers were analysed by Rsa I endonucleases and the type of enteric adenovirus identified. RESULTS: The positive rate of adenovirus DNA in fecal samples was 13.33% (26/195) while the prevalence rates of enteric adenovirus type 40, adenovirus type 41 and the other type of adenovirus were 2.56% (5/195), 8.21% (16/195) and 2.56% (5/195) respectively. Fever was the characteristic symptom of adenovirus infection. CONCLUSION: Enteric adenovirus type 40 and 41 were important pathogens which caused infant diarrhea in Shenzhen, with latter the majorty.

Adenoviridae Infections↗
PubMed2001

[A pilot study on rapid glaucoma screening].

OBJECTIVE: To screen glaucoma effectively and rapidly and evaluate the specificity and sensitivity of the method. METHODS: 734 subjects were screened in 4 weekend days. All subjects underwent intraocular pressure (IOP) examination with Tonopen, anterior chamber depth measurement with Van Herick method, fundus photography without pupil dilatation and supra-threshold perimetry with Frequency Doubling Perimeter (FDP), Octopus and Humphery automatic perimeter. The cases with positive results in the above examinations should undertake threshold perimetry and fundus stereo photography for the evaluation of the retinal nerve fiber layer (RNFL). RESULTS: Of the 734 subjects with complete data, there were 55 cases with open angle glaucoma (7.5%), 59 angle-closure glaucoma (8.4%) and 98 glaucoma suspects (13.4%). The IOP of 34 patients was > 21 mm Hg in all the glaucomatous patients (29.8%). The abnormal rates of optic nerve and visual field were 94.5% and 67.3% respectively in the patients with open-angle glaucoma. The abnormal rates of anterior chamber, visual field and optic nerve were 89.8%, 72.9% and 45.8% respectively. CONCLUSIONS: The most efficient method for screening open-angle glaucoma is fundus stereo photography with evaluation by an expert. Anterior chamber evaluation is necessary in screening glaucoma. Supra-threshold perimetry has limited specificity, and FDP might be a promising method in screening glaucoma with relatively good specificity.

Adolescent↗