Mesothelial injury is the pivot in the development of adhesions. An increase in the proliferation of mesothelial cells was verified by in vitro studies with the use of keratinocyte growth factor ...(KGF). This study investigated the influence of KGF associated with thermo-sterilized carboxymethyl chitosan (NOCCts) in the reduction of pericardial adhesions.
An induction model of pericardial adhesion was carried out in 24 pigs. Animals were randomly allocated to receive topical application of KGF, KGF + NOCCts, NOCCts, or saline (control). At 8 weeks, intrapericardial adhesions were evaluated and a severity score was established. The time spent to dissect the adhesions and the amount of sharp dissection used, were recorded. Histologic sections were stained with sirius red for a morphometric evaluation using a computer-assisted image analysis system. Cytokeratin AE1/AE3 immunostaining were employed to identify mesothelial cells.
The severity score expressed in median (minimum to maximum), in relation to the control group (17 15 to 18), was lower in the KGF + NOCCts group (7 6 to 9, p < 0.01) followed by the KGF group (11.5 9 to 12, 0.01 < p < 0.05) and the NOCCts group (12 9 to 14, p > 0.05). The dissection time was significantly lower in the KGF + NOCCts group (7.1 + or - 0.6 vs 33.9 + or - 9.2 minutes, p < 0.001). A significantly less sharp dissection was also required in the KGF + NOCCts group. In the adhesion segment, a decreased collagen proportion was found in the KGF + NOCCts group (p < 0.05). Mesothelial cells were present more extensively in groups in which KGF was delivered (p = 0.01).
The use of KGF associated with NOCCts resulted in a synergic action that decreases postoperative pericardial adhesions in a highly significant way.
•Battery sizing and rule-based operation are achieved concurrently.•Hybrid operation strategy that combines different strategies is proposed.•Three operation strategies are compared through ...multi-objective optimization.•High Net Present Value and Self Sufficiency Ratio are achieved at the same time.
The optimal components design for grid-connected photovoltaic-battery systems should be determined with consideration of system operation. This study proposes a method to simultaneously optimize the battery capacity and rule-based operation strategy. The investigated photovoltaic-battery system is modeled using single diode photovoltaic model and Improved Shepherd battery model. Three rule-based operation strategies—including the conventional operation strategy, the dynamic price load shifting strategy, and the hybrid operation strategy—are designed and evaluated. The rule-based operation strategies introduce different operation parameters to run the system operation. multi-objective Genetic Algorithm is employed to optimize the decisional variables, including battery capacity and operation parameters, towards maximizing the system’s Self Sufficiency Ratio and Net Present Value. The results indicate that employing battery with the conventional operation strategy is not profitable, although it increases Self Sufficiency Ratio. The dynamic price load shifting strategy has similar performance with the conventional operation strategy because the electricity price variation is not large enough. The proposed hybrid operation strategy outperforms other investigated strategies. When the battery capacity is lower than 72kWh, Self Sufficiency Ratio and Net Present Value increase simultaneously with the battery capacity.
The knowledge of dimensional changes during the electrochemical intercalation of Li
+ ions in a secondary Li
+ ion battery is of fundamental importance for a comprehensive understanding of the ...degradation mechanism of the negative electrode. In this work in situ electrochemical atomic force microscopy was used to measure the step height change during the intercalation/de-intercalation of Li
+ into the graphene layers of highly oriented pyrolytic graphite (HOPG). During the first intercalation/de-intercalation cycle an irreversible increase of graphene layer spacing of about 24
±
7% was evidenced. During consecutive repetitive scanning between 3 and 0.005 V vs. Li/Li
+, a reversible change of the step height of the HOPG of about ±17% could be observed in 1 M LiClO
4 in ethylene carbonate and dimethyl carbonate in a 1:1 (w/w) ratio. The statistical procedure to determine the height changes introduced in the present study is superior to the evaluation of single line scans.
Background: Several methods have been utilized to prevent pericardial and retrosternal adhesions, but none of them evaluated the mesothelial regenerative hypothesis. There are evidences that the ...mesothelial trauma reduces pericardial fibrinolytic capability and induces an adhesion process. Keratinocyte growth factor (KGF) has proven to improve mesothelial cells proliferation. This study investigated the influence of keratinocyte growth factor in reducing post-surgical adhesions. Methods: Twelve pigs were operated and an adhesion protocol was employed. Following a stratified randomization, the animals received a topical application of KGF or saline. At 8 weeks, intrapericardial adhesions were evaluated and a severity score was established. The time spent to dissect the adhesions and the amount of sharp dissection used, were recorded. Histological sections were stained with sirius red and morphometric analyses were assessed with a computer-assisted image analysis system. Results: The severity score was lower in the KGF group than in the control group (11.5 vs 17, p = 0.005). The dissection time was lower in the KGF group (9.2 ± 1.4 min vs 33.9 ± 9.2 min, p = 0.004) and presented a significant correlation with the severity score (r = 0.83, p = 0.001). A significantly less sharp dissection was also required in the KGF group. Also, adhesion area and adhesion collagen were significantly lower in the KGF group than in the control group. Conclusion: The stimulation of pericardial cells with KGF reduced the intensity of postoperative adhesions and facilitated the re-operation. This study suggests that the mesothelial regeneration is the new horizon in anti-adhesion therapies.
Using a multi-disciplinary approach, this paper integrated spatial analysis with agricultural and energy system modelling to assess the impacts of drought on crop water demand, water availability, ...crop yield, and electricity requirements for irrigation. This was done by a novel spatially-explicit and integrated water-food-energy nexus model, using the spatial climatic data generated by the mesoscale MESAN and STRÅNG models. In this study, the model was applied to quantify the effects of drought on the Swedish irrigation sector in 2013, a typical drought year, for a specific crop. The results show that drought can severely affect the crop yield if irrigation is not applied, with a peak yield reduction of 18 t/ha, about 50 % loss as compared to the potential yield in irrigated conditions. Accordingly, the water and energy requirements for irrigation to halt the negative drought effects and maintain high yields are significant, with the peaks up to 350 mm and 700 kWh per hectare. The developed model can be used to provide near real-time guidelines for a comprehensive drought management system. The model also has significant potentials for applications in precision agriculture, especially using high-resolution satellite data.
Purpose
Recently, treatment of Hinchey III diverticulitis by laparoscopic peritoneal lavage has been questioned. Moreover, long-term outcomes have been scarcely reported. Primary outcome was to ...determine the recurrence rate of diverticulitis after a successful laparoscopic peritoneal lavage in Hinchey III diverticulitis. Secondary outcomes were identification of associated risk factors for recurrence and elective sigmoidectomy rate.
Methods
A retrospective cohort study in a tertiary referral center was performed. Patients with Hinchey III diverticulitis who underwent a successful laparoscopic peritoneal lavage between June 2006 and December 2019 were eligible. Diverticulitis recurrence was analyzed according to the Kaplan–Meier and log-rank test, censoring for death, loss of follow-up, or elective sigmoid resection in the absence of recurrence. Risk factors for recurrence were identified using Cox regression analysis.
Results
Sixty-nine patients had a successful laparoscopic peritoneal lavage (mean age: 63 years; 53.6% women). Four patients had an elective sigmoid resection without recurrences. Recurrence rate was 42% (
n
= 29) after a median follow-up of 63 months. The cumulative global recurrence at 1, 3, and 5 years was 30% (95% CI, 20–43%), 37.5% (95% CI, 27–51%), and 48.9% (95% CI, 36–64%), respectively. Smoking (HR, 2.87; 95% CI, 1.22–6.5;
p
= 0.016) and episodes of diverticulitis prior to laparoscopic peritoneal lavage (HR, 5.2; 95% CI, 2.11–12.81;
p
< 0.001) were independently associated with an increased risk of recurrence.
Conclusions
Diverticulitis recurrence after a successful laparoscopic peritoneal lavage is high, decreasing after the first year of follow-up. Smoking and previous episodes of acute diverticulitis independently increase the risk of new episodes of diverticulitis.
SummaryThe procedures for the purification of commercial chitosan samples as hydrochlorides and in the neutralized form are described. Thermal analysis reveals that, independently of the purification ...method, all samples are highly pure. The agreement between values of degrees of acetylation determined by conductimetric titrations and by 1H nmr spectroscopy is very good. The aqueous solutions of both forms of purified chitosan were free of aggregation as evaluated by their Huggins constants. The potential use of solutions of chitosan hydrochloride in acid-free aqueous NaCl for the studies aiming to characterize the solution behavior of chitosan is demonstrated.
•O-acyl chitosans have stronger effects than parent chitosan on membrane models.•Hydrogen bonding with phospholipids appears not to be crucial for activity.•Results confirm the importance of ...hydrophobic interactions.•Hydrophobic derivatives should be more effective if activity depends on the membrane.
One of the major challenges in establishing the mechanisms responsible for the chitosan action in biomedical applications lies in the determination of the molecular-level interactions with the cell membrane. In this study, we probed hydrophobic interactions and H-bonding in experiments with O,O′-diacetylchitosan (DACT) and O,O′-dipropionylchitosan (DPPCT) incorporated into monolayers of distinct phospholipids, the zwitterionic dipalmitoyl phosphatidyl choline (DPPC), and the negatively charged dipalmitoyl phosphatidyl glycerol (DPPG) and dimyristoyl phosphatidic acid (DMPA). The importance of hydrophobic interactions was confirmed with the larger effects observed for DACT and DPPCT than for parent chitosan (Chi), particularly for the more hydrophobic DPPCT. Such larger effects were noted in surface pressure isotherms and elasticity of the monolayers. Since H-bonding is hampered for the chitosan derivatives, which have part of their hydroxyl groups shielded by O-acylation, these effects indicate that H-bonding does not play an important role in the chitosan–membrane interactions. Using polarization-modulated infrared reflection absorption (PM-IRRAS) spectroscopy, we found that the chitosan derivatives were incorporated into the hydrophobic chain of the phospholipids, even at high surface pressures comparable to those in a real cell membrane. Taken together, these results indicate that the chitosan derivatives containing hydrophobic moieties would probably be more efficient than parent chitosan as antimicrobial agents, where interaction with the cell membrane is crucial.
Purpose
To compare the intraoperative and postoperative outcomes between right laparoscopic colectomy (RLC) and left laparoscopic colectomy (LLC) for colon cancer.
Method
Patients who underwent ...elective RLC or LLC for colon cancer between January 2004 and December 2014 were identified and elected for a retrospective analysis. Primary outcomes were technical difficulty (including operative time, intraoperative complications, and conversion rate) and postoperative outcome (including postoperative complications, length of hospital stay, reinterventions, readmissions, and mortality).
Results
A total of 547 patients (mean age: 68.5 years old; 48.4% males) were analyzed. The RLC group had a higher mean age (71 vs 65;
p
< 0.001), ASA 3/4 grade (36 vs 26%;
p
= 0.02), and comorbidity rate (61 vs 48%,
p
= 0.003). Regarding technical difficulty, no difference was found between the groups in intraoperative complications (4.1 vs 5.9%;
p
= 0.34) or conversion rate (6.2 vs 3.9%,
p
= 0.24). Mean operative time was significantly shorter for RLC (162 vs 185 min,
p
< 0.001). Regarding postoperative outcome, the RLC group had a higher overall morbidity (20.5 vs 13.3%,
p
= 0.03), ileus (10.6 vs 2.4%,
p
< 0.001), and a longer hospital stay (4.7 vs 3.9 days,
p
= 0.003), with no differences regarding reoperations, readmissions, or mortality. The multivariate analysis showed that RLC were independently associated with a longer operative time and postoperative ileus.
Conclusions
RLC for colon cancer was independently associated with a shorter operative time, an increased risk of ileus, and a longer hospital stay than left laparoscopic colectomy in high-volume centers.
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