CO2 Adsorption on N-Doped Porous Biocarbon Synthesized from Biomass Corncobs in Simulated Flue Gas.

This study was to develop a low-cost N-doped porous biocarbon adsorbent that can directly adsorb CO2 in high-temperature flue gas from fossil fuel combustion. The porous biocarbon was prepared by nitrogen doping and nitrogen-oxygen codoping through K2CO3 activation. Results showed that these samples exhibited a high specific surface area of 1209-2307 m2/g with a pore volume of 0.492-0.868 cm3/g and a nitrogen content of 0.41-3.3 wt %. The optimized sample CNNK-1 exhibited a high adsorption capacity of 1.30 and 0.27 mmol/g in the simulated flue gas (14.4 vol % CO2 + 85.6 vol % N2) and a high CO2/N2 selectivity of 80 and 20 at 25 and 100 °C and 1 bar, respectively. Studies revealed that too many microporous pores could hinder CO2 diffusion and adsorption due to the decrease of CO2 partial pressure and thermodynamic driving force in the simulated flue gas. The CO2 adsorption of the samples was mainly chemical adsorption at 100 °C, which depended on the surface nitrogen functional groups. Nitrogen functional groups (pyridinic-N and primary and secondary amines) reacted chemically with CO2 to produce graphitic-N, pyrrolic-like structures, and carboxyl functional groups (-N-COOH). Nitrogen and oxygen codoping increased the amount of nitrogen doping content in the sample, but acidic oxygen functional groups (carboxyl groups, lactones, and phenols) were introduced, which weakened the acid-base interactions between the sample and CO2 molecules. It was demonstrated that SO2 and water vapor had inhibition effects on CO2 adsorption, while NO nearly has no effect on the complex flue gas. Cyclic regenerative adsorption showed that CNNK-1 possessed excellent regeneration and stabilization ability in complex flue gases, indicating that corncob-derived biocarbon had excellent CO2 adsorption in high-temperature flue gas.

A sustainable nanocellulose-based superabsorbent from kapok fiber with advanced oil absorption and recyclability.

Creating a low-cost, highly efficient, and recyclable superabsorbent for spilled-oil cleanup is of great significance but remains a big challenge. Herein, we report a facile strategy to produce economic, environmentally friendly, and reusable foam from agricultural waste kapok fibers. These kapok-derived cellulose nanofibrils foams (KNFs) demonstrate a hierarchically porous structure at micro-level with ultra-low density (2.7 mg·cm-3). The superhydrophobic KNFs (150.5°) show outstanding oil absorption (126.8-320.4 g·g-1) and oil-water separation performance. Notably, a facile approach is designed to reuse KNFs easily by a homemade oil release system. The release behavior of the KNFs is quantitatively analyzed and confirmed by the Rigter-Peppas model, indicating that the oil release followed the Fickian diffusion. The KNFs exhibit desirable reusability, and can be recycled for at least 50 times while keeping excellent oil absorption, and release performance. These advantages prove that the KNF is a desirable substitute for spilled-oil treatment.

Superhydrophobic-superoleophilic biochar-based foam for high-efficiency and repeatable oil-water separation.

Leakage accidents occurring during oil production and transportation are currently one of the most serious environmental problems worldwide. Developing efficient and environmentally friendly oil-water separation methods is the key to solve this problem. In this work, a facile method to fabricate a high-performance oil absorbent through the loading of ball-milled biochar (BMBC) and octadecylamine on the skeleton of melamine foam (MF) is reported. The resulting ball-milled biochar-based MF (BMBC@MF) displayed a complex three-dimensional porous structure. The BM biochar on the surface of BMBC@MF forms nano/µm-scale folds, which reduced the surface energy of BMBC@MF after grafted octadecylamine. These structures resulted in the conversion of the hydrophilic surface of MF to hydrophobic surface. These characteristics made the modified foam an excellent oil absorbent with a high oil absorption capacity (43-155 times its own weight) and extraordinary recyclability. Furthermore, the BMBC@MF could maintain high hydrophobicity and adsorption stability in a wide pH range (from 1 to 11). More importantly, BM biochar is a cheap and readily available material to make BMBC@MF possible for large-scale production. Therefore, this work provides an effective way for low-cost, environmentally friendly, and large-scale production of superhydrophobic adsorbents for oil-water separation.

Ultralight, hydrophobic, sustainable, cost-effective and floating kapok/microfibrillated cellulose aerogels as speedy and recyclable oil superabsorbents.

Cellulose aerogels achieve excellent absorption of waste oil and organic pollutant, which has received lots of attention recently. It is still a big challenge to obtain aerogels with both high cost-effectiveness and advanced oil absorption performance, since it is a time-consuming, and environmentally unfriendly process to obtain cellulose, compared with direct usage of natural fibers. In this manuscript, we develop highly porous and hydrophobic kapok/microfibrillated cellulose (MFC) aerogels with a dual-scale hierarchically porous structure at micro-level as cost-effective, sustainable, and floating superabsorbents via simple vacuum freeze-drying and surface modification. Kapok, a natural hollow fiber, has been recently considered as a new sustainable resource for oil cleanup. By partially replacing MFC with chopped kapok fibers in MFC aerogels (MMAs), the resultant kapok/MFC aerogels (KCAs) exhibit ultralow density (5.1 mg/cm-3), ultrahigh porosity (99.58%) and hydrophobicity (140.1°) leading to advanced oil sorption (130.1 g/g) that is 25.3% higher than that of MMAs. In addition, these KCAs can rapidly and selectively absorb waste oil from oil-water mixture with ultrahigh absorption ability of 104-190.1 g/g, which is comparable to other environmentally unfriendly and high-cost aerogels. Furthermore, the KCAs own excellent reusability and sustainability. These benefits enable the KCAs a suitable alternative to clean oil spills.

Effect of Intravenous Dexmedetomidine During General Anesthesia on Acute Postoperative Pain in Adults: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.

BACKGROUND: Dexmedetomidine has been shown to have an analgesic effect. However, no consensus was reached in previous studies. METHODS: Electronic databases such as PubMed, Embase, and Cochrane Central were searched for relevant randomized controlled trials. The relative risk and weighted mean difference (WMD) were used to analyze the outcomes. Random-effects model was used for meta-analysis. RESULTS: Compared with the normal saline group, patients using DEX showed a significantly decreased pain intensity within 6 hours [WMD=-0.93; 95% confidence interval (CI), -1.34 to -0.53) and at 24 hours after surgery (WMD=-0.47; 95% CI, -0.83 to -0.11). DEX usage significantly reduced the cumulative opioids consumption at 24 hours after surgery (WMD=-6.76; 95% CI, -10.16 to -3.35), decreased the rescue opioids consumption in postanesthesia care unit (WMD=-3.11; 95% CI, -5.20 to -1.03), reduced the risk of rescue analgesics (relative risk=0.49; 95% CI, 0.33-0.71), and the interval to first rescue analgesia was prolonged (WMD=34.93; 95% CI, 20.27-49.59). CONCLUSIONS: Intravenous DEX effectively relieved the pain intensity, extended the pain-free period, and decreased the consumption of opioids during postoperative recovery of adults in general anesthesia.

Effect of Oxycodone Combined With Dexmedetomidine for Intravenous Patient-Controlled Analgesia After Video-Assisted Thoracoscopic Lobectomy.

OBJECTIVE: To investigate the effect of the combination of oxycodone and dexmedetomidine for patient-controlled analgesia (PCA) after video-assisted thoracoscopic (VATS) lobectomy. DESIGN: A prospective, randomized, double-blind, controlled trial. SETTING: Shandong Cancer Hospital and Institute in Jinan, China. PARTICIPANTS: Eighty-four patients with lung cancer undergoing VATS lobectomies were recruited. INTERVENTIONS: Patients were randomly assigned to one of the following two groups: oxycodone and dexmedetomidine (group OD) or oxycodone alone (group O). Before induction of anesthesia, patients in group OD received 0.5 µg/kg, dexmedetomidine diluted to 20 mL with physiologic saline and infused for 10 minutes intravenously. The PCA protocol was 50 mg of oxycodone and 0.05 µg/kg/h dexmedetomidine diluted to 100 mL. Patients in group O received 20 mL of physiologic saline infused for 10 minutes. Their PCA protocol consisted of 50 mg of oxycodone diluted to 100 mL. Intravenous PCA was used for postoperative analgesia (lasting for 48 h). MEASUREMENTS AND MAIN RESULTS: Pain at rest and during movement was assessed by a blinded observer using the Visual Analog Scale pain score (VAS) at 4, 6, 24, and 48 hours after surgery, and the level of sedation simultaneously was assessed using the Ramsay Sedation Scale. Total oxycodone consumption, requirements for rescue analgesia, side effects, and satisfaction with pain management were recorded within 48 hours after surgery. Eighty patients' data were analyzed at the end of the study (40 in each group). Visual Analog Scale scores decreased at 4, 6, and 24 hours at rest and during movement in group OD compared with group O (p<0.05). The level of patient satisfaction in group OD was significantly higher than that in group O (p<0.05). Oxycodone consumption in group OD was significantly lower than that in group O (p<0.001). Group O experienced more nausea and vomiting 6 hours after surgery than did group OD (p< 0.05). CONCLUSION: The combination of oxycodone and dexmedetomidine for PCA after VATS lobectomy can reduce oxycodone consumption, improve patient satisfaction, and provide better analgesia with fewer side effects (nausea and vomiting) compared with PCA with oxycodone alone.

Study on structure and wetting characteristic of cattail fibers as natural materials for oil sorption.

Cattail fiber is considered as one of the biomasses for oil sorption purposes. In this work, the unique structure and wetting characteristic, as well as the basic mechanisms governing oil uptake of cattail fibers were investigated. Cattail fibers grow in tufts with down-like structure consisting of root, stem, seed and several fibers. A single cattail fiber was bamboo-shaped exhibiting 4-dimensional open spaces with fineness varying between 10 and 17.5 µm, average length at 7.9 ± 1.2 mm. The skeleton of the fiber consists of lignocellulose coated by a hydrophobic wax coating with 45.41% of crystallinity. The exceptional chemical, physical and microstructural properties enable the cattail fiber to be highly hydrophobic and oleophilic. The water droplets could stand on the fibers' surfaces with the contact angles more than 130°, while oil droplets disappear quickly from the fibers' surfaces within several seconds. When used as the sorbent for oil, cattail fibers were found to absorb about 12 g of oil per gram of fibers and retained over 88% of absorbed oil even after 24 h dripping. The unique structure of cattail fibers played an important role in oil sorption. The result proposed that cattail fibers are a promising natural source for the production of oil absorbents.

Effect of Dexmedetomidine Alone for Intravenous Patient-Controlled Analgesia After Gynecological Laparoscopic Surgery: A Consort-Prospective, Randomized, Controlled Trial.

Gynecological laparoscopic surgery is minimally invasive compared with open surgical approaches, but postoperative pain is generally undermanaged. Pain management strategies related to the procedure-specific efficacy are needed. Many studies have shown that dexmedetomidine (DEX) has opioid-sparing properties. It is not clear whether DEX used alone for intravenous patient-controlled analgesia (PCA) could reduce postoperative pain after an invasive procedure. We hypothesized that DEX alone would reduce postoperative pain in women patients undergoing an elective gynecological laparoscopic procedure.This CONSORT-prospective randomized controlled clinical study aimed to investigate the effects of DEX alone for intravenous PCA after gynecological laparoscopic operation. Forty women patients scheduled for elective gynecological laparoscopy were enrolled into the study at Shandong Cancer Hospital and Institute and randomly allocated into two groups (n = 20 each). In the DEX group (group D), the intravenous PCA protocol was DEX 0.25 µg/kg/h diluted to 100 mL in 0.9% saline. In the fentanyl group (group F), the PCA protocol was fentanyl 20 µg/kg diluted to 100 mL in 0.9% saline. The primary outcome was the mean pain score on a visual analogue scale (VAS) at 6 hours after the operation. The secondary outcomes included the Ramsay sedation score, the incidence of postoperative nausea and vomiting (PONV), satisfaction with pain control, and time to recovery of gastrointestinal function.There were no significant differences in the patients' characteristics and intraoperative measurements (P > 0.05). No patients received rescue analgesic. The mean VAS scores at 6 hours post-operatively were not significantly different between the groups (P > 0.05). The incidence of PONV was less in group D than in group F (P < 0.05). The Ramsay sedation scores were not significantly between the groups (P > 0.05). Satisfaction with pain control was higher and time to recovery of gastrointestinal function was lower in group D (P < 0.05).DEX alone is effective for intravenous patient-controlled analgesia after gynecological laparoscopic surgery without a change in sedation and with fewer side effects, and this effect was associated with better satisfaction with postoperative pain control and earlier recovery of gastrointestinal function.

Effects of epidural analgesia with different concentrations of bupivacaine plus fentanyl on pain in patients undergoing thoracic surgery.

OBJECTIVE: To investigate and compared the efficacy and safety of epidural analgesia with different concentrations of bupivacaine plus fentanyl on pain in patients undergoing thoracic surgery. METHODS: 120 cases undergoing elective thoracic surgery were randomly divided into A, B, C and D four groups each with 30 cases, and they were treated with 0.25% (A group), 0.375% (B group), 0.50% (C group) and 0.75% (D group) bupivacaine plus fentanyl 0.4 mg. The pain conditions postoperative 4 h, 8 h, 12 h, 24 h and 48 h were evaluated by visual analogue scale (VAS). The PCA pressing numbers and incidence of adverse reactions were compared between the four groups. RESULTS: By postoperative 4 h, the VAS in D group were obviously lower than those in the other three groups (P all <0.05), and the other three groups showed no significances (P>0.05). However, the four groups showed no significant differences in VAS by postoperative 8 h, 12 h, 24 h and 48 h (P all >0.05). The incidences of respiratory depression in C and D groups were markedly higher than those in A and B groups (P all <0.05). CONCLUSIONS: 0.25%~0.375% bupivacaine plus fentanyl 0.4 mg using in epidural analgesia in patients undergoing thoracic surgery can lead to safe and effective analgesic effect.

Simultaneous Removal of NO and Hg(0) from Flue Gas over Mn-Ce/Ti-PILCs.

A series of Mn-Ce/Ti-PILCs (PILCs, pillared interlayered clays) catalysts were prepared via impregnation method in simultaneous removal of NO and elemental mercury in simulated flue gas. The physicochemical properties of these catalysts have been examined by some characterization methods, such as H2-TPR, nitrogen adsorption, XRD and XPS. Mn(6%)-Ce(6%)/Ti-PILCs exhibited superior NO conversion (>95%) and Hg(0) removal efficiency (>90%) at low temperature (250 °C). The results indicated that the elemental mercury had little impact on NO removal efficiency, while the presence of NH3 and NO in SCR system inhibited the Hg(0) removal. NO and Hg(0) removal activity was strongly affected by the transform between surface adsorbed oxygen and lattice oxygen. The species ratio of Mn(4+)/Mn(3+) and Ce(4+)/Ce(3+) on the catalyst surface contributed to the NO conversions and Hg(0) removal. Mn-Ce/Ti-PILCs displayed a broad prospect for controlling the emission of NO and mercury. On the basis of the results obtained, a mechanism for the simultaneous removal of NO and Hg(0) was proposed for the Mn-Ce/Ti-PILCs catalysts: -NH2 + NO → N2 + H2O, -OH + 1/2 Hg(ad) →1/2 HgO + 1/2 H2O.

Removal of element mercury by medicine residue derived biochars in presence of various gas compositions.

Pyrolyzed biochars from an industrial medicinal residue waste were modified by microwave activation and NH4Cl impregnation. Mercury adsorption of different modified biochars was investigated in a quartz fixed-bed reactor. The results indicated that both physisorption and chemisorption of Hg(0) occurred on the surface of M6WN5 which was modified both microwave and 5wt.% NH4Cl loading, and exothermic chemisorption process was a dominant route for Hg(0) removal. Microwave activation improved pore properties and NH4Cl impregnation introduced good active sites for biochars. The presence of NO and O2 increased Hg(0) adsorption whereas H2O inhibited Hg(0) adsorption greatly. A converse effect of SO2 was observed on Hg(0) removal, namely, low concentration of SO2 promoted Hg(0) removal obviously whereas high concentration of SO2 suppressed Hg(0) removal. The Hg(0) removal by M6WN5 was mainly due to the reaction of the C−Cl with Hg(0) to form HgCl2, and the active state of C−Cl(*) groups might be an intermediate group in this process. Thermodynamic analysis showed that mercury adsorption by the biochars was exothermic process and apparent adsorption energy was 43.3 kJ/mol in the range of chemisorption. In spite of low specific surface area, M6WN5 proved to be a promising Hg(0) sorbent in flue gas when compared with other sorbents.

Human malignant melanoma-derived progestagen-associated endometrial protein immunosuppresses T lymphocytes in vitro.

Progestagen-associated endometrial protein (PAEP) is a glycoprotein of the lipocalin family that acts as a negative regulator of T cell receptor-mediated activation. However, the function of tumor-derived PAEP on the human immune system in the tumor microenvironment is unknown. PAEP is highly expressed in intermediate and thick primary melanomas (Breslow's 2.5mm or greater) and metastatic melanomas, correlating with its expression in daughter cell lines established in vitro. The current study investigates the role of melanoma cell-secreted PAEP protein in regulating T cell function. Upon the enrichment of CD3+, CD4+ and CD8+ T cells from human peripheral blood mononuclear cells, each subset was then mixed with either melanoma-derived PAEP protein or PAEP-poor supernatant of gene-silenced tumor cells. IL-2 and IFN-γ secretion of CD4+ T cells significantly decreased with the addition of PAEP-rich supernatant. And the addition of PAEP-positive cell supernatant to activated lymphocytes significantly inhibited lymphocyte proliferation and cytotoxic T cell activity, while increasing lymphocyte apoptosis. Our result suggests that melanoma cell-secreted PAEP protein immunosuppresses the activation, proliferation and cytotoxicity of T lymphocytes, which might partially explain the mechanism of immune tolerance induced by melanoma cells within the tumor microenvironment.