Formaldehyde and VOC emissions from plywood panels bonded with bio-oil phenolic resins.

Pyrolysis bio-oil was used to partially substitute for phenol in reacting with formaldehyde for the production of bio-oil phenol formaldehyde plywood (BPFP) panels, with the phenol substitution ratio being 20%, 40%, or 60%. Emissions of formaldehyde and volatile organic compounds (VOCs) from the BPFP panels were studied using solid-phase micro-extraction (SPME) followed by headspace gas chromatography/mass spectrometry (GC/MS), and were compared to those from the phenol formaldehyde plywood (PFP) panels. The sources for VOCs were analyzed, and the health risks associated with the BPFP were examined. Results showed that at 80 °C: (1) Formaldehyde emissions from the BPFP panels were increased to about 4 times that of PFP; (2) VOCs emissions were significantly reduced by up to 84.9% mainly due to the greatly reduced phenol emissions, although the total number of VOCs was increased from 20 to 35; (3) BPFP presents greatly increased carcinogenic and non-carcinogenic health risks because of its much stronger emissions of formaldehyde, N,N-dimethylformamide, benzofuran, furfural, and many chemicals from the bio-oil. It is highly advisable that the health risks are properly taken care of before the wide application of BPFP, or similar bio-oil based engineered wood products.

Antioxidant Activity of the Lignins Derived from Fluidized-Bed Fast Pyrolysis.

A challenge in recent years has been the rational use of forest and agriculture residues for the production of bio-fuel, biochemical, and other bioproducts. In this study, potentially useful compounds from pyrolytic lignins were identified by HPLC-MS/MS and untargeted metabolomics. The metabolites identified were 2-(4-allyl-2-methoxyphenoxy)-1-(4-hydroxy-3-methoxyphenyl)-1-propanol, benzyl benzoate, fisetinidol, phenyllactic acid, 2-phenylpropionic acid, 6,3'-dimethoxyflavone, and vanillin. The 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity (DPPH), trolox equivalent antioxidant capacity (TEAC), and total phenolics content (TPC) per gram of pyrolytic lignin ranged from 14 to 503 mg ascorbic acid equivalents, 35 to 277 mg trolox equivalents, and 0.42 to 50 mg gallic acid equivalents, respectively. A very significant correlation was observed between the DPPH and TPC (r = 0.8663, p ≤ 0.0001), TEAC and TPC (r = 0.8044, p ≤ 0.0001), and DPPH and TEAC (r = 0.8851, p ≤ 0.0001). The polyphenolic compounds in the pyrolytic lignins which are responsible for radical scavenging activity and antioxidant properties can be readily profiled with HPLC-MS/MS combined with untargeted metabolomics. The results also suggest that DPPH, TEAC, and TPC assays are suitable methods for the measurement of antioxidant activity in a variety of pyrolytic lignins. These data show that the pyrolytic lignins can be considered as promising sources of natural antioxidants and value-added chemicals.

[Treatment of constipation by intensive acupoints thread embedding combined with local anal operation].

OBJECTIVE: To search for the best therapy for slow transmission constipation (STC) or mixed constipation (MC) by intensive acupoints thread embedding (IATE). METHODS: A total of 310 patients with constipation were assigned to 5 groups using a stratification control method. The 62 patients of STC in the observation group I were treated by IATE at Dachangshu (BL 25), Tianshu (ST 25), Zhongji (CV 3) and Zusanli (ST 36) acupoints; the 62 of MC in the observation group II by IATE at the same acupoints and local anal operation; both the 62 of STC in the control group I and the 62 of MC in the control group 1I were treated by oral administration of Simo Decoction, while the 62 of MC in the control group III were treated by local anal operation alone. Conditions of defecation were recorded every day in the 6-month follow-up period. Gastrointestinal transit test (GITT) was carried out before and after treatment. One follow-up was conducted at the 1st, 3rd and 6th month. RESULTS: In the 124 patients of the two observation groups, 52 (41.9%) were cured after treatment, they could normally discharge stool, 5 (4.0%) showed markedly effective with their constipation alleviated, but having occasional bowel slackened sensation. In the control group I and II, none was cured or effectively treated, while in the control group III, the efficacy in 8 patients were judged as marked effective, but none was cured. CONCLUSION: IATE is a convenient and effective composite therapy. It shows favorable clinical efficacy for STC, and also for MC in case of combined with local anal operation.