Prospects of ZnS and ZnO as smart semiconductor materials in light-activated antimicrobial coatings for mitigation of severe acute respiratory syndrome coronavirus-2 infection.

We carried out theoretical and experimental analyses of ZnO and ZnS nanoparticles as smart semiconductor materials in light-activated antimicrobial coating for application in masks. We used low-cost hydrothermally processable precursors to direct the growth of the coatings on cotton fabric. Both ZnO and ZnS coatings had high reactivities as disinfection agents in photocatalysis reactions for the degradation of a methylene blue dye solution. Also, these coatings showed excellent UV protection properties. For understanding at the molecular level, the broad-spectrum biological activities of the ZnO and ZnS coatings against Fusarium Oxysporum fungi, Escherichia coli bacteria, and severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) virus and their variants, were investigated computationally. Hexagonal Zn6O6 and Zn6S6 clusters were used as models for the simulations through excited- and ground-state calculations. The theoretical findings show that changes in the local chemical environment in these excited systems have a profound impact on their physical and chemical properties and thus, can provide a better understanding to engineer new functional materials in light-activated antimicrobial coatings for the mitigation of SARS-CoV-2 infection.

The circumferential resection margins status: A comparison of robotic, laparoscopic and open total mesorectal excision for mid and low rectal cancer.

INTRODUCTION: Minimally invasive surgery for rectal cancer (RC) is now widely performed via the laparoscopic approach, but robotic-assisted surgery may overcome some limitations of laparoscopy in RC treatment. We compared the rate of positive circumferential margins between robotic, laparoscopic and open total mesorectal excision (TME) for RC in our institution. METHODS: Mid and low rectal adenocarcinoma patients consecutively submitted to robotic surgery were compared to laparoscopic and open approach. From our prospective database, 59 patients underwent robotic-assisted rectal surgery from 2012 to 2015 (RTME group) were compared to our historical control group comprising 200 open TME (OTME group) and 41 laparoscopic TME (LTME group) approaches from July 2008 to February 2012. Primary endpoint was to compare the rate of involved circumferential resection margins (CRM) and the mean CRM between the three groups. Secondary endpoint was to compare the mean number of resected lymph nodes between the three groups. RESULTS: CRM involvement was demonstrated in 20 patients (15.5%) in OTME, 4 (16%) in LTME and 9 (16.4%) in the RTME (p = 0.988). The mean CRM in OTME, LTME and RTME were respectively 0.6 cm (0-2.7), 0.7 cm (0-2.0) and 0.6 cm (0-2.0) (p = 0.960). Overall mean LN harvest was 14 (0-56); 16 (0-52) in OTME, 13 (1-56) in LTME and 10 (0-45) in RTME (p = 0.156). CONCLUSION: Our results suggest that robotic TME has the same oncological short-term results when compared to the open and laparoscopic technique, and it could be safely offered for the treatment of mid and low rectal cancer.

Nonoperative management of rectal cancer after chemoradiation opposed to resection after complete clinical response. A comparative study.

INTRODUCTION: Surgery is the standard treatment of rectal cancer after neoadjuvant therapy. Some authors advocate a nonoperative management (NOM) after complete clinical response (cCR) following chemoradiotherapy (CRT). We compare our results with NOM to standard resection in a retrospective analysis. METHODS: Rectal adenocarcinomas submitted to NOM after CRT between September 2002 and December 2013 were compared to surgical patients that had pathological complete response (pCR) during the same period. Endpoints were Overall Survival (OS), Disease Free Survival (DFS), Local Relapse (LR) and Distant Relapse (DR). RESULTS: Forty-two NOM patients compared to 69 pCR patients operated after a median interval of 35 weeks after CRT. NOM tumors were distal (83.3% vs 59.4%, p = 0.011), less obstructive (26.2% vs 54.4%, p = 0.005) and had a lower digital rectal score (p = 0.024). Twelve (28.0%) recurrences in NOM group and eight (11.5%) in the surgical group occurred after a follow-up of 47.7 and 46.7 months respectively. Isolated LR occurred in five (11%) NOM patients and one (1.4%) in the surgical group. Four (80%) LR were surgically salvaged in NOM group. No difference in OS was found (71.6% vs 89.9%, p = 0.316) but there was a higher DFS favoring surgical group (60.9% vs 82.8%, p = 0.011). Distal tumors had worse OS compared to proximal tumors in surgical group (5-year OS of 85.5% vs 96.2%, p = 0.038). CONCLUSION: The NOM achieved OS comparable to surgical treatment and spared patients from surgical morbidity but it resulted in more recurrences. This approach cannot be advocated routinely and controlled trials are warranted.

Chromium(VI) induced alterations in mouse spleen cells: a short-term assay.

Cr(VI), the highest oxidation state for chromium, is a carcinogenic and mutagenic agent. In vivo and in vitro Cr(VI) toxic effects are related to its intracellular fate. Once inside the cell it is reduced to stable Cr(III) by cysteine, glutathione and ascorbic acid. Additionally, as Cr(V) and/or Cr(IV) intermediates have been reported in Cr(VI) reactions with biological reductants, chromium damage is thought to originate from these chemical species. This work investigated the morphology of splenic cells after short-term exposure to Cr(VI). A dose of 30 mg of K2CrO4/kg body weight was administered to mice and the effects were studied 24 and 48 h after the injections. Histological results revealed a time-dependency effect of Cr(VI) on splenic cells. Changes included enlargement of the capsule and depletion of the red pulp cells, accompanied by an increase in macrophages, 24 h after injection. Partial restoration of red pulp was noted after 48 h.

Interaction of Ruthenium(II)-dipyridophenazine Complexes with CT-DNA: Effects of the Polythioether Ancillary Ligands.

The complexes [Ru([9]aneS(3))(dppz)Cl]Cl 1 and [Ru([12]aneS(4))(dppz)]Cl(2)2 ([9]aneS(3) = 1,4,7- trithiaciclononane and [12]aneS(4) = 1,4,7,10-tetrathiaciclododecane) were synthesised and fully characterised. These complexes belong to a small family of dipyridophenazine complexes with non-polypyridyl ancillary ligands . Interaction studies of these complexes with CT-DNA (UV/Vis titrations, steady-state emission and thermal denaturation) revealed their high affinity for DNA . Intercalation constants determined by UV/Vis titrations are of the same order of magnitude (10(6)) as other dppz metallointercalators, namely [Ru(II)(bpy)(2)dppz]S(2+). Differences between l and2 were identified by steady-state emission and thermal denaturation studies . Emission results are in accordance with structural data, which indicate how geometric distortions and different donor and/or acceptor ligand abilities affect luminescence. The possibility of noncovalent interactions between ancillary ligands and nucleobases by van der Waals contacts and H-bridges is discussed . Furthermore, complex l undergoes aquation under intra-cellular conditions and an equilibrium with the aquated form l' is attained . This behaviour may increase the diversity of available interaction modes.