Variations of forage yield and forage-livestock balance in grasslands over the Tibetan Pla-teau, China.

An in-depth understanding of variations in grassland productivity and forage-livestock balance is the basis of ecological barrier construction and ecosystem conservation in the Qinghai-Tibetan Plateau. Using an ecohydrological process-based model VIP with remotely sensed vegetation index and leaf area index, we simulated the spatial and temporal variations of grassland productivity in the Tibetan Plateau in 2000-2018. The variations in the status of forage-livestock balance at the county level were analyzed, combining with agriculture and animal husbandry statistics in the same period. The results showed that the mean annual net primary productivity (NPP) of grassland in the Tibetan Plateau was 158.4 g C·m-2·a-1, which had increased significantly in the past 20 years, with a significant increase in 44.7% of the total area. Climate warming, increased precipitation, prolonged growing season, and elevated carbon dioxide concentration were main driving forces for grassland productivity. The mean theoretical livestock carrying capacity estimated based on pasture yield was 1.17 SU·hm-2, with a growth rate of 0.011 SU·hm-2. The situation of overgrazing in the Tibetan Plateau had generally improved since 2000. The proportion of counties with severe overgrazing had dropped to less than 20%. In areas with more severe overgrazing, animal husbandry's maintenance and development mainly relied on supplementation of crop straw. The results could provide a scientific basis for regional agricultural and animal husbandry structural adjustment and environmental protection.

[Evaluating the response of yield and evapotranspiration of winter wheat and the adaptation by adjusting crop variety to climate change in Huang-Huai-Hai Plain].

Based on the multi-model datasets of three representative concentration pathway (RCP) emission scenarios from IPCC5, the response of yield and accumulative evapotranspiration (ET) of winter wheat to climate change in the future were assessed by VIP model. The results showed that if effects of CO2 enrichment were excluded, temperature rise would lead to a reduction in the length of the growing period for wheat under the three climate change scenarios, and the wheat yield and ET presented a decrease tendency. The positive effect of atmospheric CO2 enrichment could offset most negative effect introduced by temperature rising, indicating that atmospheric CO2 enrichment would be the prime reason of the wheat yield rising in future. In 2050s, wheat yield would increase 14.8% (decrease 2.5% without CO2 fertilization) , and ET would decrease 2.1% under RCP4.5. By adoption of new crop variety with enhanced requirement on accumulative temperature, the wheat yield would increase more significantly with CO2 fertilization, but the water consumption would also increase. Therefore, cultivar breeding new irrigation techniques and agronomical management should be explored under the challenges of climate change in the future.

Marine natural product des-O-methyllasiodiplodin effectively lowers the blood glucose level in db/db mice via ameliorating inflammation.

AIM: des-O-methyllasiodiplodin (DML) from Cerbera manghas has shown antagonistic activity against mineralocorticoid receptor (MR). Considering the involvement of MR in the insulin tolerance, we attempted to investigate the potential of DML in the treatment of type 2 diabetes mellitus (T2DM). METHODS: Surface plasmon resonance (SPR) technology and reporter gene-based assays were used to study protein-small molecule interactions. HepG2 and 3T3-L1 cells were treated with H2O2 (0.2 mmol/L) or aldosterone (10 nmol/L) for 24 h. The expression of MR in the cells was downregulated with siRNA. The anti-inflammatory effect of the compound was evaluated, respectively. db/db mice were administered DML (30 mg·kg(-1)·d(-1)) for 4 weeks. Serum biochemical parameters and insulin sensitivity were examined. The expression levels of pro-inflammatory cytokines (MCP-1, TNF-α and IL-6) and ROS-related genes (NADPH p47 subunit and transcriptional factor PU.1) in adipose tissues and livers were analyzed using real-time RT-PCR. RESULTS: In HepG2 and 3T3-L1 cells, both H2O2 and aldosterone markedly stimulates the expression of MCP-1, TNFα, IL-6, p47 and PU.1 genes. Co-treatment with DML (10 µmol/L) significantly reduced the H2O2- or aldosterone-induced expression of these genes. SPR-based assay confirmed the antagonistic activity of DML against the interaction between SRC-1 and MR-LBD. Furthermore, DML decreased aldosterone-induced MR transcriptional activity in a dose-dependent manner. Downregulation of MR with siRNA in the cells prevented or significantly attenuated aldosterone-stimulated expression of these genes, whereas DML did no longer affect the expression of these genes except that of IL-6. Oral administration of DML effectively reduced the levels of blood glucose and glycosylated hemoglobin (HbA1c) in db/db mice. The treatment also rectified the expression of pro-inflammatory factor and ROS-related genes in db/db mice. CONCLUSION: DML effectively lowers the blood glucose level in db/db mice possibly via ameliorating the expression of obesity-related pro-inflammatory cytokines, highlighting the potential of the marine natural product as a drug lead for the treatment of metabolic disorders.

DNA repair gene XRCC4 codon 247 polymorphism modified diffusely infiltrating astrocytoma risk and prognosis.

The DNA repair gene X-ray cross-complementary group 4 (XRCC4), an important caretaker of the overall genome stability, is thought to play a major role in human tumorigenesis. We investigated the association between an important polymorphic variant of this gene at codon 247 (rs373409) and diffusely infiltrating astrocytoma (DIA) risk and prognosis. This hospital-based case-control study investigated this association in the Guangxi population. In total, 242 cases with DIA and 358 age-, sex-, and race-matched healthy controls were genotyped using TaqMan-PCR technique. We found a significant difference in the frequency of XRCC4 genotypes between cases and controls. Compared with the homozygote of XRCC4 codon 247 Ala alleles (XRCC4-AA), the genotypes of XRCC4 codon 247 Ser alleles (namely XRCC4-AS or -SS) increased DIA risk (odds ratios [OR], 1.82 and 2.89, respectively). Furthermore, XRCC4 polymorphism was correlated with tumor dedifferentiation of DIA (r = 0.261, p < 0.01). Additionally, this polymorphism modified the overall survival of DIA patients (the median survival times were 26, 14, and 8 months for patients with XRCC4-AA, -AS, and -SS, respectively). Like tumor grade, XRCC4 codon 247 polymorphism was an independent prognostic factor influencing the survival of DIA. These results suggest that XRCC4 codon 247 polymorphism may be associated with DIA risk and prognosis among the Guangxi population.

The polymorphism of XRCC3 codon 241 and AFB1-related hepatocellular carcinoma in Guangxi population, China.

PURPOSE: The relationship between aflatoxin B1 (AFB1) exposure and hepatocellular carcinoma (HCC) has been previously demonstrated and supported with strong epidemiological evidence. However, the role of genetic polymorphism of X-ray cross-complementing group 3 (XRCC3) codon 241 (namely: Thr241Met), which may be involved in the repair of DNA double-strand breaks caused by carcinogens such as AFB1, been less well elaborated. METHODS: We conducted a case-control study including 491 cases and 862 controls to evaluate the associations between this polymorphism and HCC risk for Guangxi population by means of polymerase chain reaction-restriction fragment length polymorphism analysis. RESULTS: We found that individuals with the XRCC3 genotypes with codon 241 Met (namely XRCC3-TM or XRCC3-MM) had an increased risk of HCC than those with the homozygote of XRCC3 codon 241 Thr alleles (namely XRCC3-TT, adjusted odds ratios 2.22 and 7.19; 95% confidence intervals 1.72-2.88 and 4.52-11.42, respectively). The risk of HCC, moreover, did appear to differ more significantly among individuals featuring high-level AFB1-DNA adducts, whose adjusted odds ratios (95% confidence intervals) were 11.59 (5.73-23.47) and 37.54 (16.32-86.32), respectively. CONCLUSIONS: These findings support the hypothesis that the XRCC3 Thr241Met polymorphism may be associated with the risk of AFB1-related HCC among the Guangxi population.

[Perioperative continuous positive airway pressure therapy for severe obstructive sleep apnea hypopnea syndrome patients].

OBJECTIVE: (1) To investigate the severe obstructive sleep apnea hypopnea syndrome (OSAHS) patients' perioperative variations of their polysomnographic indices, to discuss the necessity for their perioperative treatment; (2) To investigate the effects of continuous positive airway pressure (CPAP) on severe OSAHS patients during their perioperative period. METHODS: (1) 21 cases severe OSAHS patients were selected for at least 7 days preoperative CPAP therapy, and this group of patients were also given 3 continuous nights autotitrated CPAP (AutoSet) therapy postoperatively, i.e., the first 3 nights after operation. The 21 cases were remonitored with PSG during the second night after operation with their AutoSet ON. And all the 21 cases had revised uvulopalatopharygoplasty, in which the uvula is reserved completely. All patients apnea hypopnea index(AHI), lowest SaO2 (LSaO2), and sleep structure indices were calculated. (2) Another 24 cases of severe OSAHS patients without preoperative CPAP therapy or tracheotomy were selected as the control group, all patients received polysomnography (PSG) on the second night postoperatively. RESULTS: (1) 6 cases' condition of the control group got worse during the second night after operation, their LSaO2 are lower and their AHI got higher than pre-operation. For the another 18 cases, their condition got better than before operation. (2) 21 cases' AHI and LSaO2 are 61.1 +/- 9.9, 65.0% +/- 9.6% respectively before CPAP treatment, and the AHI and LSaO2 are 2.2 +/- 1.4, 94.5% +/- 2.9% during CPAP therapy. P < 0.001 (TTEST). All the 21 cases main symptoms disappeared after 1 week CPAP therapy. All 21 cases could tolerate AutoSet treatment well for the first 3 nights after operation. During the 2nd night with AutoSet therapy, the AHI and LSaO2 are 3.6 +/- 1.8 and 93.7% +/- 3.4% respectively. (3) For the 2nd night after operation, the CPAP and AutoSet treating group's AHI is lower than that of the control group, also the LSaO2 is higher, the deep and REM sleep stages are longer, and the S1, S2 sleep stages are shorter than that of the latter. CONCLUSION: For severe OSAHS patients, the postoperative condition has the possibility of getting worse. Perioperative CPAP therapy can have OSAHS patients severe condition alleviated, so the perioperative risks could be lowered; During the first 3 postoperative nights, AutoSet can be well tolerated by severe OSAHS patients.

[Application of CO2 laser and T tube in the treatment of the laryngeal stenosis].

OBJECTIVE: To introduce a new method for treating laryngeal stenosis of both children and adults using silicon T tube and CO2 laser. METHODS: Twenty-two cases stenosis of adults and children were treated with silicon T tube and CO2 laser. The tracheotomy were enlarged upward, the laryngeal cavity scar was removed by using CO2 laser and the laryngeal cavity was exposed by distending laryngoscope under general anesthesia. The follow up time is between 1 to 3 years. RESULTS: The 22 cases were successfully decanulated postoperatively in 12 to 24 months. Silicon 4 cases's T tube were either too high or too low and had second operation. CONCLUSION: The method for treating laryngeal stenosis of both children and adults using silicon T tube and CO2 laser are effective, easy to operate, less invasive and have a short recovery interval.