Storages and leaching losses of soil water dissolved CO2 and N2O on typical land use hillslopes in southeastern hilly area of China.

The dynamics of soil water dissolved CO2 and N2O are important in determining the fates of soil CO2 and N2O. However, related mechanisms and processes have been rarely revealed. In this study, storages and leaching losses of soil water dissolved CO2 and N2O were investigated on the tea garden (TG) and bamboo forest (BF) hillslopes. Soil water storage and leaching flux were simulated by the HYDRUS-3D model and the soil water dissolved CO2 and N2O concentrations were acquired by field monitoring. Results showed that the storages of soil water dissolved CO2 and N2O ranged from 1.30 to 14.86 kg C ha-1 and 0.24 to 388.99 g N ha-1 on the TG hillslope, respectively, while they ranged from 0.49 to 52.29 kg C ha-1 and 0.50 to 14.22 g N ha-1 on the BF hillslope, respectively. The annual leaching loss of soil water dissolved CO2 and N2O were 26.17 kg C ha-1 and 29.46 g N ha-1, respectively, on the TG hillslope, while they were 49.51 kg C ha-1 and 4.35 g N ha-1 on the BF hillslope, respectively. The dissolved CO2 leaching loss mainly occurred in summer, especially in July on both hillslopes. Peaks of dissolved N2O leaching loss on the TG hillslope were observed after the application of basal fertilizer, accompanying with precipitation events. Instead, peaks of dissolved N2O leaching loss on the BF hillslope were observed in summer. The main influencing factors of dissolved CO2 and N2O storages were temperature, precipitation, and fertilization, with total effects generally >0.30. However, that of the dissolved CO2 and N2O leaching losses was the precipitation, with total effects >0.57. Dissolved CO2/N2O concentration was more important than soil water storage in determining the dissolved CO2/N2O storage, while the leaching flow rate was more crucial than dissolved CO2/N2O concentration in determining the dissolved CO2/N2O leaching loss. These findings expanded our knowledge of sources and sinks of greenhouse gases on the terrestrial ecosystem.

Association Between Dexamethasone and Delirium in Critically Ill Patients: A Retrospective Cohort Study of a Large Clinical Database.

BACKGROUND: Delirium is a common complication in intensive care unit (ICU) patients, and it can significantly increase the length of hospital stay and cost. Dexamethasone is widely used in various inflammatory diseases and must be used with caution in critically ill patients. Previous studies have shown that the effect of corticosteroid use on the development of delirium in critically ill patients is still controversial, and there is inconclusive conclusion about the effect of dexamethasone on delirium in such patients. Therefore, this study aimed to confirm the effect of dexamethasone use and the dose on the incidence of delirium and patient prognosis in critically ill patients through a large cohort study. METHODS: A retrospective cohort study was conducted using data extracted from the Medical Information Mart for Intensive Care III database, which is a large and freely available database of all 46,476 patients who visited Beth Israel Deaconess Medical Center in Boston, Massachusetts, USA and were admitted to the ICU between 2001 and 2012. The primary outcome was the development of delirium, using multivariate logistic regression analysis to reveal the relationship between dexamethasone and delirium. Secondary endpoints were in-hospital mortality, ICU mortality, total length of stay, and length of ICU stay, and the relationship between dexamethasone and prognosis was assessed with Cox proportional hazards models. Propensity score matching with 1:1 grouping was used to eliminate the effect of confounders on both cohorts. The locally weighted scatter plot smoothing technique was used to investigate the dose correlation between dexamethasone and outcomes, subgroup analysis was used to account for heterogeneity, and different correction models and propensity matching analysis were used to eliminate potential confounders. RESULTS: Finally, 38,509 patients were included, and 2204 (5.7%) used dexamethasone. No significant statistical difference was observed in basic demographic information after propensity score matching between the two study groups. A significantly higher incidence of delirium (5.0% versus 3.4%, P < 0.001), increased in-hospital mortality (14.9% versus 10.3%, P < 0.001), ICU mortality (9.0% versus 7.5%, P = 0.008), and longer length of stay and ICU stay were observed in patients taking dexamethasone compared with those not taking dexamethasone. Multivariate logistic and Cox regression analyses confirmed that dexamethasone was significantly associated with delirium (adjusted odds ratio = 1.48, 95% confidence interval [CI] = 1.09-2.00, P = 0.012), in-hospital mortality (adjusted hazard ratio = 1.19, 95% CI = 1.02-1.40, P = 0.032), and ICU mortality (adjusted hazard ratio = 1.62, 95% CI = 1.22-2.15, P = 0.001). Compared with critically ill patients using high-dose dexamethasone, the risk of delirium was lower in the dose less than the 10 mg group, and patients using 10-14 mg may be associated with a lower risk of in-hospital death and the least ICU mortality, length of hospital stay, and ICU stay. CONCLUSIONS: This study demonstrated that the use of dexamethasone in critically ill patients exacerbated the occurrence of delirium while increasing the risk of in-hospital death, ICU death, and length of hospital stay, with a lower risk of delirium and a shorter total length of hospital stay with low-dose dexamethasone than with larger doses.

Persistent proliferation of keratinocytes and prolonged expression of pronociceptive inflammatory mediators might be associated with the postoperative pain in KK mice.

Epidermal keratinocytes play a vital role in restoration of the intact skin barrier during wound healing. The negative effect of hyperglycemia may prolong the wound healing process. Epidermal keratinocytes have been demonstrated to modulate and directly initiate nociceptive responses in rat models of fractures and chemotherapy-induced neuropathic pain. However, it is unclear whether epidermal keratinocytes are involved in the development and maintenance of incisional pain in nondiabetic or diabetic animals. In the current study, using behavioral tests and immunohistochemistry, we investigated the differential keratinocytes proliferation and expression of pronociceptive inflammatory mediators in keratinocytes in C57BL/6J mice and diabetic KK mice. Our data showed that plantar incision induced postoperative pain hypersensitivity in both C57BL/6J mice and KK mice, while the duration of postoperative pain hypersensitivity in KK mice was longer than that in C57BL/6J mice. Moreover, plantar incision induced the keratinocytes proliferation and expression of IL-1ß and TNF-α in keratinocytes in both C57BL/6J mice and KK mice. Interestingly, compared to C57BL/6J mice, the slower and more persistent proliferation of keratinocytes and expression of IL-1ß and TNF-α in keratinocytes were observed in KK mice. Together, our study suggested that plantar incision may induce the differential keratinocytes proliferation and expression of IL-1ß and TNF-α in kertinocytes in diabetic and nondiabetic animals, which might be associated with the development and maintenance differences in diabetic and nondiabetic postoperative pain.