Preparation of Antibacterial Softwood via Chemical Attachment of Quaternary Ammonium Compounds Using Supercritical CO₂

Conversion of inexpensive and abundant softwood into useful construction materials is of significant economic and environmental importance. The currently available methods for wood treatment are not sufficiently effective to overcome the drawbacks of softwood including warping and biodeterioration. In the present research, a novel process was developed to address these challenges by chemically attaching antibacterial quaternary ammonium compounds (QACs) to hemlock using supercritical carbon dioxide (scCO₂). Nine QACs containing at least one hydroxyl group were synthesized and characterized by 1D and 2D nuclear magnetic resonance spectroscopy (NMR), attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), and high resolution mass spectroscopy (HRMS). The antibacterial activity of these QACs were screened against the representative bacteria Escherichia coli, revealing that the antibacterial activity is dependent on the QAC molecular structure. Two QACs that demonstrated strong antibacterial activity were selected and chemically attached to hemlock by using hexamethylene diisocyanate (HDI) as a linker via a carbamate/urethane linkage in scCO₂. The chemically modified hemlock demonstrated exceptional antibacterial activity and improved dimensional stability, suggesting potential application of this route in the conversion of softwood into advanced durable decking and fencing materials

Neoadjuvant chemotherapy versus primary debulking surgery in advanced epithelial ovarian cancer: A meta-analysis of peri-operative outcome

<div><p>Objective</p><p>To assess whether neoadjuvant chemotherapy (NACT) is superior to primary debulking surgery (PDS) with regard to optimal cytoreduction, peri-operative morbidity, mortality, and quality of life (QOL) in advanced epithelial ovarian cancer (EOC).</p><p>Methods</p><p>We searched the PubMed, Embase, Cochrane Central Register of Controlled Trials, Web of Science, Registers of Clinical Trials for randomized controlled trials (RCTs) comparing NACT to PDS in women with Federation of International Gynaecologists and Obstetricians stage Ⅲ-Ⅳ EOC. RevMan 5.3 software was utilized for statistical analysis.</p><p>Results</p><p>Four RCTs involving 1,607 women with advanced EOC were included. Compared with PDS, NACT provided a higher rate of complete cytoreduction (risk ratio [RR], 1.95; 95% confidence interval [CI], 1.33 to 2.87), optimal cytoreduction (RR: 1.61 [95%CI: 1.05 to 2.47]), but there was no significant difference in residual disease 0–1 cm (p = 0.49). NACT was associated with lower peri-operative morbidity with respect to infection (RR: 0.30 [95% CI: 0.16 to 0.56]), gastrointestinal fistula (RR: 0.24 [95% CI: 0.06 to 0.95]), any grade 3 or 4 adverse event (RR: 0.29 [95% CI: 0.11 to 0.78]), and less post-surgical death within 28 days (RR: 0.14 [95% CI: 0.04 to 0.49]). NACT provided better QOL in terms of fatigue (weight mean difference [WMD], -3.28; [95% CI: -3.99 to -2.57]), role functioning (WMD: 5.29 [95% CI: 4.44 to 6.14]), emotional functioning (WMD: 6.19 [95% CI: 5.57 to 6.82]), and cognitive functioning (WMD: 1.02 [95% CI: 0.43 to 1.61]) at 6-month follow-up compared with PDS.</p><p>Conclusions</p><p>NACT is associated with superior optimal cytoreduction, lower peri-operative morbidity as well as post-surgical mortality, and better QOL compared to initial surgery in patients with advanced EOC. Future research should focus on improving the efficacy of NACT.</p></div

The quality assessment for selected randomized controlled trials.

<p>Low risk of bias (green circles), unclear risk of bias (yellow circles) and high risk of bias (red circles).</p

Details of included studies.

<p>Details of included studies.</p

Additional file 1 of A theoretical study on toluene oxidization by OH radical

Additional file 1: Figure S1. Flow chart of experimental reaction of toluene degradation. Figure S2. Results of Geometric Optimization Employing the B3LYP/6-311++G(d,p) Computational Scheme under Solvation Model based on Density (SMD) Conditions. Figure S3. Intrinsic Reaction Coordinate (IRC) Analysis of Each Transition State at the B3LYP/6-311++G(d,p) Level of Theory. Figure S4. (a): Comprehensive Reaction Rate Constant Fitting at a Reaction Temperature of 25 °C. (b): Comprehensive Reaction Rate Constant Fitting at a Reaction Temperature of 40 °C. (c): Comprehensive Reaction Rate Constant Fitting at a Reaction Temperature of 50 °C. (d): Comprehensive Reaction Rate Constant Fitting at a Reaction Temperature of 60 °C. (e): Comprehensive Reaction Rate Constant Fitting at a Reaction Temperature of 70 °C. Figure S5. Fitting of the Experimental Comprehensive Reaction Arrhenius Equation. Figure S6. (a) Arrhenius Equation Fitting for the Reaction IS+·OH → IM1 + H2O. (c) Arrhenius Equation Fitting for the Reaction IS+·OH → IM6. (e) Arrhenius Equation Fitting for the Reaction IS+·OH → IM8 + H2O. (f) Arrhenius Equation Fitting for the Reaction FS8+·OH → IM14. (g) Arrhenius Equation Fitting for the Reaction FS8+·OH → IM15. Table S1. T1 Diagnostic Values for All Species in the Reaction under CCSD/cc-pVDZ. Table S2. (a) Experimental instrument for degradation of toluene and model thereof. (b) Experimental Reagent specifications and supplier for degradation of toluene. Table S3. (a): Absolute Energy Data for All Species Calculated Using the B3LYP/6-311++G(d,p) Computational Scheme. (b): Absolute Energy Data for All Species Calculated at the G4MP2 Level of Theory. Table S4. Cartesian Coordinates of Each Species Calculated Using the B3LYP/6-311++G(d,p) Computational Scheme. Table S5. Imaginary Frequency Data of Each Transition State Calculated at the B3LYP/6-311++G(d,p) Level of Theory. Table S6. Free Energy Data of Various Reaction Species at 303 K–340 K (in atomic units, a.u.)

Search strategy.

<p>Search strategy.</p

Flowchart of literature search.

<p>RCT, randomized controlled trial. NACT, neoadjuvant chemotherapy followed by interval debulking surgery. PDS, primary cytoreductive surgery.</p

Extent of residual disease.

<p>NACT: neoadjuvant chemotherapy followed by interval debulking surgery. PDS: primary debulking surgery.</p

Emotional functioning and cognitive functioning at cycle 6 and 6-month follow-up.

<p>NACT, neoadjuvant chemotherapy followed by interval debulking surgery; PDS, primary debulking surgery.</p

Post-operative complications and mortality.

<p>NACT: neoadjuvant chemotherapy followed by interval debulking surgery. PDS: primary cytoreductive surgery.</p