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Electrospun microcrystalline cellulose/chitosan porous composite nanofibrous membranes modified by non-thermal plasma for gaseous formaldehyde adsorption

Xiong J, Luo R, Jia Z, Ge S, Lam SS, Xie L, et al.

Int J Biol Macromol, 2024 Jan;256(Pt 2):128399.
PMID: 38007014 DOI: 10.1016/j.ijbiomac.2023.128399

To develop a green and facile adsorbent for removing indoor polluted formaldehyde (HCHO) gas, the biomass porous nanofibrous membranes (BPNMs) derived from microcrystalline cellulose/chitosan were fabricated by electrospinning. The enhanced chemical adsorption sites with diverse oxygen (O) and nitrogen (N)-containing functional groups were introduced on the surface of BPNMs by non-thermal plasma modification under carbon dioxide (CO2) and nitrogen (N2) atmospheres. The average nanofiber diameters of nanofibrous membranes and their nanomechanical elastic modulus and hardness values decreased from 341 nm to 175-317 nm and from 2.00 GPa and 0.25 GPa to 1.70 GPa and 0.21 GPa, respectively, after plasma activation. The plasma-activated nanofibers showed superior hydrophilicity (WCA = 0°) and higher crystallinity than that of the control. The optimal HCHO adsorption capacity (134.16 mg g-1) of BPNMs was achieved under a N2 atmosphere at a plasma power of 30 W and for 3 min, which was 62.42 % higher compared with the control. Pyrrolic N, pyridinic N, CO and O-C=O were the most significant O and N-containing functional groups for the improved chemical adsorption of the BPNMs. The adsorption mechanism involved a synergistic combination of physical and chemical adsorption. This study provides a novel strategy that combines clean plasma activation with electrospinning to efficiently remove gaseous HCHO.

Matched MeSH terms: Formaldehyde/chemistry
Fulltext Detection of epidermal growth factor receptor mutations in formalin fixed paraffin embedded biopsies in Malaysian non-small cell lung cancer patients

Shi Yeen TN, Pathmanathan R, Shiran MS, Ahmad Zaid FA, Cheah YK

J Biomed Sci, 2013 Apr 16;20:22.
PMID: 23590575 DOI: 10.1186/1423-0127-20-22

BACKGROUND: Somatic mutations of the epidermal growth factor receptor (EGFR) are reportedly associated with various responses in non-small cell lung cancer (NSCLC) patients receiving the anti-EGFR agents. Detection of the mutation therefore plays an important role in therapeutic decision making. The aim of this study was to detect EGFR mutations in formalin fixed paraffin embedded (FFPE) samples using both Scorpion ARMS and high resolution melt (HRM) assay, and to compare the sensitivity of these methods.
RESULTS: All of the mutations were found in adenocarcinoma, except one that was in squamous cell carcinoma. The mutation rate was 45.7% (221/484). Complex mutations were also observed, wherein 8 tumours carried 2 mutations and 1 tumour carried 3 mutations.
CONCLUSIONS: Both methods detected EGFR mutations in FFPE samples. HRM assays gave more EGFR positive results compared to Scorpion ARMS.

Matched MeSH terms: Formaldehyde/chemistry*
Fulltext Detection of formaldehyde in water: a shape-effect on the plasmonic sensing properties of the gold nanoparticles

Nengsih S, Umar AA, Salleh MM, Oyama M

Sensors (Basel), 2012;12(8):10309-25.
PMID: 23112601 DOI: 10.3390/s120810309

The effect of morphology on the plasmonic sensing of the presence of formaldehyde in water by gold nanostructures has been investigated. The gold nanostructures with two different morphologies, namely spherical and rod, were prepared using a seed-mediated method. In typical results, it was found that the plasmonic properties of gold nanostructures were very sensitive to the presence of formaldehyde in their surrounding medium by showing the change in both the plasmonic peaks position and the intensity. Spherical nanoparticles (GNS), for example, indicated an increase in the sensitivity when the size was increased from 25 to 35 nm and dramatically decreased when the size was further increased. An m value, the ratio between plasmonic peak shift and refractive index change, as high as 36.5 nm/RIU (refractive index unit) was obtained so far. An expanded sensing mode to FD was obtained when gold nanostructures with nanorods morphology (GNR) were used because of the presence of two plasmonic modes for response probing. However, in the present study, effective plasmonic peak shift was not observed due to the intense plasmonic coupling of closely packed nanorod structures on the surface. Nevertheless, the present results at least provide a potential strategy for response enhancement via shape-effects. High performance plasmonic sensors could be obtained if controlled arrays of nanorods can be prepared on the surface.

Matched MeSH terms: Formaldehyde/chemistry
In situ hybridization: detecting viral nucleic acid in formalin-fixed, paraffin-embedded tissue samples

Mabruk MJ

Expert Rev Mol Diagn, 2004 Sep;4(5):653-61.
PMID: 15347259

In situ hybridization is a method for detecting specific nucleic acid sequences within individual cells. This technique permits visualization of viral nucleic acid or gene expression in individual cells within their histologic context. In situ hybridization is based on the complementary binding of a labeled nucleic acid probe to complementary sequences in cells or tissue sections, followed by visualization of target sequences within the cells. It has been used widely for the detection of viral nucleic acid sequences within individual cells. This review will define the technical approaches of in situ hybridization and its current application to detect viral nucleic acids within formalin-fixed, paraffin-embedded tissue samples, with special reference to the Epstein-Barr virus.

Matched MeSH terms: Formaldehyde/chemistry*
Kinetics based reaction optimization of enzyme catalyzed reduction of formaldehyde to methanol with synchronous cofactor regeneration

Marpani F, Sárossy Z, Pinelo M, Meyer AS

Biotechnol Bioeng, 2017 12;114(12):2762-2770.
PMID: 28832942 DOI: 10.1002/bit.26405

Enzymatic reduction of carbon dioxide (CO2 ) to methanol (CH3 OH) can be accomplished using a designed set-up of three oxidoreductases utilizing reduced pyridine nucleotide (NADH) as cofactor for the reducing equivalents electron supply. For this enzyme system to function efficiently a balanced regeneration of the reducing equivalents during reaction is required. Herein, we report the optimization of the enzymatic conversion of formaldehyde (CHOH) to CH3 OH by alcohol dehydrogenase, the final step of the enzymatic redox reaction of CO2 to CH3 OH, with kinetically synchronous enzymatic cofactor regeneration using either glucose dehydrogenase (System I) or xylose dehydrogenase (System II). A mathematical model of the enzyme kinetics was employed to identify the best reaction set-up for attaining optimal cofactor recycling rate and enzyme utilization efficiency. Targeted process optimization experiments were conducted to verify the kinetically modeled results. Repetitive reaction cycles were shown to enhance the yield of CH3 OH, increase the total turnover number (TTN) and the biocatalytic productivity rate (BPR) value for both system I and II whilst minimizing the exposure of the enzymes to high concentrations of CHOH. System II was found to be superior to System I with a yield of 8 mM CH3 OH, a TTN of 160 and BPR of 24 μmol CH3 OH/U · h during 6 hr of reaction. The study demonstrates that an optimal reaction set-up could be designed from rational kinetics modeling to maximize the yield of CH3 OH, whilst simultaneously optimizing cofactor recycling and enzyme utilization efficiency.

Matched MeSH terms: Formaldehyde/chemistry*
Fulltext The impact of local surface changes in Borneo on atmospheric composition at wider spatial scales: coastal processes, land-use change and air quality

Pyle JA, Warwick NJ, Harris NR, Abas MR, Archibald AT, Ashfold MJ, et al.

Philos Trans R Soc Lond B Biol Sci, 2011 Nov 27;366(1582):3210-24.
PMID: 22006963 DOI: 10.1098/rstb.2011.0060

We present results from the OP3 campaign in Sabah during 2008 that allow us to study the impact of local emission changes over Borneo on atmospheric composition at the regional and wider scale. OP3 constituent data provide an important constraint on model performance. Treatment of boundary layer processes is highlighted as an important area of model uncertainty. Model studies of land-use change confirm earlier work, indicating that further changes to intensive oil palm agriculture in South East Asia, and the tropics in general, could have important impacts on air quality, with the biggest factor being the concomitant changes in NO(x) emissions. With the model scenarios used here, local increases in ozone of around 50 per cent could occur. We also report measurements of short-lived brominated compounds around Sabah suggesting that oceanic (and, especially, coastal) emission sources dominate locally. The concentration of bromine in short-lived halocarbons measured at the surface during OP3 amounted to about 7 ppt, setting an upper limit on the amount of these species that can reach the lower stratosphere.

Matched MeSH terms: Formaldehyde/chemistry
Cellular and humoral responses in the respiratory tract of goats following intranasal stimulation using formalin-killed Pasteurella haemolytica A2

Zamri-Saad M, Effendy AW, Israf DA, Azmi ML

Vet Microbiol, 1999 Mar 12;65(3):233-40.
PMID: 10189198

A study to determine the immunoglobulin and cellular responses in the respiratory tract of goats following intranasal exposures to formalin-killed Pasteurella haemolytica A2 was carried out. Forty-two goats were divided into two groups. Goats in Group 1 were subjected to double intranasal exposures to formalin-killed P. haemolytica A2 while goats in Group 2 were the unexposed control. Prior to and at weekly intervals post-exposure, three goats from each group were killed, serum samples were collected while the lungs were flushed with 50 ml normal saline before the right apical lobes were fixed in 10% buffered formalin. Both serum and lung lavage fluid were subjected to enzyme-linked immunosorbent assay (ELISA) to determine the levels of IgA, IgM and IgG while the formalin-fixed tissues were examined histologically. IgA levels in the lung lavage fluid increased rapidly to reach a significantly (p < 0.05) high level as early as Week 2 post-exposure and remained significantly (p < 0.05) high throughout the study period. The IgM levels increased at an intermediate rate to reach a significantly (p < 0.05) high level at Week 3 post-exposure before they decreased to an insignificant (p > 0.05) level the following week and the weeks thereafter. IgG levels increased gradually and only reached a significantly (p < 0.01) high level at Weeks 5 and 6 of the study. The size of the bronchus-associated lymphoid tissue (BALT) and the number of lymphocytes in BALT increased significantly from Week 2 and remained high thereafter. However, differences in the numbers of BALT were insignificant (p > 0.05) initially before becoming significantly (p < 0.05) high at Weeks 5 and 6. The BALT responses were parallel to those of imunoglobulins in the lung lavage fluid.

Matched MeSH terms: Formaldehyde/chemistry
Sealing ability of various restorative materials as coronal barriers between endodontic appointments

Tapsir Z, Aly Ahmed HM, Luddin N, Husein A

J Contemp Dent Pract, 2013 Jan 1;14(1):47-50.
PMID: 23579892

To evaluate and compare the microleakage of various restorative materials used as coronal barriers between endodontic appointments.

Matched MeSH terms: Formaldehyde/chemistry