Enhanced Hydrogen Production from Sawdust Decomposition Using Hybrid-Functional Ni-CaO-Ca₂SiO₄ Materials

A hybrid-functional material consisting of Ni as catalyst, CaO as CO₂ sorbent, and Ca₂SiO₄ as polymorphic “active” spacer was synthesized by freeze-drying a mixed solution containing Ni, Ca and Si precursors, respectively, to be deployed during sawdust decomposition that generated gases mainly containing H₂, CO, CO₂ and CH₄. The catalytic activity showed a positive correlation to the Ni loading, but at the expense of lower porosity and surface area with Ni loading beyond 20 wt %, indicating an optimal Ni loading of 20 wt % for Ni-CaO-Ca₂SiO₄ hybrid-functional materials, which enables ∼626 mL H₂ (room temperature, 1 atm) produced from each gram of sawdust, with H₂ purity in the product gas up to 68 vol %. This performance was superior over a conventional supported catalyst Ni–Ca₂SiO₄ that produced 443 mL H₂ g-sawdust^–1 under the same operating condition with a purity of ∼61 vol %. Although the Ni-CaO bifunctional material in its fresh form generated a bit more H₂ (∼689 mL H₂ g-sawdust^–1), its cyclic performance decayed dramatically, resulting in H₂ yield reduced by 62% and purity dropped from 73 to 49 vol % after 15 cycles. The “active” Ca₂SiO₄ spacer offers porosity and mechanical strength to the Ni-CaO-Ca₂SiO₄ hybrid-functional material, corresponding to its minor loss in reactivity over cycles (H₂ yield reduced by only 7% and H₂ purity dropped from 68 to 64 vol % after 15 cycles)

Clinical Implications of iNOS Levels in Triple-Negative Breast Cancer Responding to Neoadjuvant Chemotherapy

<div><p>Triple-negative breast cancer is a high-risk breast cancer with poor survival rate. To date, there is a lack of targeted therapy for this type of cancer. One unique phenomenon is that inflammatory breast cancer is frequently triple negative. However, it is still ambiguous how inflammation influences triple-negative breast cancer growth and responding to chemotherapy. Herein, we investigated the levels of inflammation-associated enzyme, iNOS, in 20 triple-negative breast cancer patients’ tumors, and examined its correlation with patients’ responses to platinum-based neoadjuvant chemotherapy. Our studies showed that triple-negative breast cancer patients with attenuated iNOS levels in tumor cells after treatment showed better responses to platinum-based neoadjuvant chemotherapy than other triple-negative breast cancer patients. Our further <i>in vitro</i> studies confirmed that induction of proper levels of NO increased the resistance to cisplatin in triple-negative MDA-MB-231 cells. Our data suggest that aberrant high level of iNOS/NO are associated with less effectiveness of platinum-based neoadjuvant chemotherapy in triple-negative breast cancer. Therefore, we propose to monitor iNOS levels as a new predictor for triple-negative breast cancer patient’s response to platinum-based neoadjuvant chemotherapy. Moreover, iNOS/NO is considered as a potential target for combination therapy with platinum drugs for triple-negative breast cancer.</p></div

Detection of iNOS protein levels in TNBC tissues by immunohistochemistry.

<p>Top panel: demonstration of iNOS levels in patient’s tumor changing from positive to negative after treatment in IDC. Bottom panel: demonstration of iNOS levels in patient’s tumor changing from negative to positive after treatment in ILC.</p

Western blot demonstration of increase nitrotyrosine levels in MDA-MB-231 cells after treatmented with NO donor.

<p>Western blot demonstration of increase nitrotyrosine levels in MDA-MB-231 cells after treatmented with NO donor.</p

Comparison of tumor volume reduction in TNBC patients between iNOS expression decreased group and iNOS expression increased and positively remained unchanged group after neoadjuvant chemotherapy.

<p>Asterisk indicates p<0.01.</p

Comparison of tumor volume reduction in TNBC patients between positive expression of iNOS and negative expression of iNOS after neoadjuvant chemotherapy.

<p>Comparison of tumor volume reduction in TNBC patients between positive expression of iNOS and negative expression of iNOS after neoadjuvant chemotherapy.</p

Analysis of iNOS protein levels in TNBC patients by immunoblotting.

<p>Analysis of iNOS protein levels in TNBC patients by immunoblotting.</p

The presence of DETA NONOate reverse the inhibitory effect of cisplatin on MDA-MB-231 cells.

<p>Asterisk indicates p<0.01.</p