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Improvement of wheat straw anaerobic digestion through alkali pre-treatment: Carbohydrates bioavailability evaluation and economic feasibility

Romero-Güiza MS, Wahid R, Hernández V, Møller H, Fernández B

Sci Total Environ, 2017 Oct 01;595:651-659.
PMID: 28402918 DOI: 10.1016/j.scitotenv.2017.04.006

Lignocellulosic biomasses such as wheat straw are widely used as a feedstock for biogas production. However, these biomasses are mainly composed of a compact fibre structure and therefore, it is recommended to treat them prior to its usage for biogas production in order to improve their bioavailability. The aim of this work is to evaluate, in terms of performance stability, methane yield and economic feasibility, two different scenarios: a mesophilic codigestion of wheat straw and animal manure with or without a low-energy demand alkaline pre-treatment (0.08gKOHgTS-1of wheat straw, for 24h and at 25°C). Besides this, said pre-treatment was also analysed based on the improvement of the bioavailable carbohydrate content in the untreated versus the pre-treated wheat straw. The results pointed out that pre-treated wheat straw prompted a more stable performance (in terms of pH and alkalinity) and an improved methane yield (128% increment) of the mesophilic codigestion process, in comparison to the "untreated" scenario. The pre-treatment increased the content of cellulose, hemicellulose and other compounds (waxes, pectin, oil, etc.) in the liquid fraction, from 5% to 60%, from 11.5% to 39.1% TS and from 57% to 79% of the TS in the liquid fraction for the untreated and pre-treated wheat straws, respectively. Finally, the pre-treated scenario gained an energy surplus of a factor 13.5 and achieved a positive net benefit of 90.4€tVS-WS-1d-1, being a favourable case for an eventual scale-up of the combined process.

Matched MeSH terms: Waxes
Fulltext Oily fish, liquid wax esters and keriorrhoea – a review

Barling, Peter Micheal, YI, Huan Foong

International e-Journal of Science, Medicine & Education, 2015;9(1):21-25.
MyJurnal

Keriorrhoea is the involuntarily passing of orange oil per rectum. One of us (PMB) had the misfortune to experience this symptom, together with considerable gastrointestinal disturbances for a prolonged period of time after consumption of a deep sea fish, orange roughy, which is rich in liquid wax esters (LWEs). This paper presents a summary of available evidence concerned with the physiology and pathology of ingestion of LWEs, which can enter the human diet in substantial amounts from consumption of several species of deep-sea fish. LWEs are poorly digested and absorbed by the human body. They generally cause keriorrhoea when ingested deliberately or accidentally. Jojoba oil, which is a plant LWE, together with certain nutritional products (e.g. olestra) and medical (e.g. Orlistat) which are not LWEs may mimic the effects of LWEs, and cause similar gastrointestinal disturbances. This paper discusses the potential effects of LWEs as components of gastrointestinal micelles, and predicts that the orange oil which is leaked from a bout of keriorrhoea may contain considerable volumes of triacylglycerols (TAGs).

Matched MeSH terms: Waxes
Fulltext A review of the mechanism and role of wax inhibitors in the wax deposition and precipitation

Hao, Lim Zhen, Hikmat Said Al-Salim, Norida Ridzuan

Pertanika Journal of Science & Technology, 2019;27(1):499-526.
MyJurnal

The continuous depletion of global oil reserves with the propensity for light distillates
propels the oil and gas industry to explore heavier fractions of crude oils with significant
amount of paraffin waxes. However, the precipitation and deposition of waxes during the
transportation of these waxy crude oils in the pipelines contribute to several issues, such as
the flowability reduction, excessive pumping cost, and wax gel formation, that adversely
affect the supposedly steady offshore oil production. As a result, substantial resources are
expended to resolve these flow assurance problems. The wax inhibitors and pour point
depressants are developed and modified to meet the wax remediation criteria. Essentially,
the wax crystals are formed through the nucleation, growth, and agglomeration processes,
while the deposition of these waxes occurs via molecular diffusion and shear dispersion.
The wax inhibitors are able to control the growth of wax crystals through nucleation, cocrystallization,
adsorption, and dispersion interactions. This paper particularly assessed
the following compounds: (1) polymeric wax inhibitors, (2) nano-hybrid pour point
depressants, (3) organic solvents, and
(4) surfactants. Given the significance of
these compounds in the deposition and
precipitation of waxes, it is imperative to
comprehensively explore the types and
nature of these compounds and their recent
applications as well as to critically assess
their strengths and drawbacks, which were
addressed in this paper. Furthermore, the
challenges of using these compounds and the factors that govern their efficiencies were also discussed. Accordingly, the carbon
length and the molecular weight of both paraffin waxes and wax inhibitors are among the
most influential factors.

Matched MeSH terms: Waxes
Fulltext Accelerated Thermal Cycling Test of Microencapsulated Paraffin Wax/Polyaniline Made by Simple Preparation Method for Solar Thermal Energy Storage

Silakhori M, Naghavi MS, Metselaar HSC, Mahlia TMI, Fauzi H, Mehrali M

Materials (Basel), 2013 Apr 29;6(5):1608-1620.
PMID: 28809232 DOI: 10.3390/ma6051608

Microencapsulated paraffin wax/polyaniline was prepared using a simple in situ polymerization technique, and its performance characteristics were investigated. Weight losses of samples were determined by Thermal Gravimetry Analysis (TGA). The microencapsulated samples with 23% and 49% paraffin showed less decomposition after 330 °C than with higher percentage of paraffin. These samples were then subjected to a thermal cycling test. Thermal properties of microencapsulated paraffin wax were evaluated by Differential Scanning Calorimeter (DSC). Structure stability and compatibility of core and coating materials were also tested by Fourier transform infrared spectrophotometer (FTIR), and the surface morphology of the samples are shown by Field Emission Scanning Electron Microscopy (FESEM). It has been found that the microencapsulated paraffin waxes show little change in the latent heat of fusion and melting temperature after one thousand thermal recycles. Besides, the chemical characteristics and structural profile remained constant after one thousand thermal cycling tests. Therefore, microencapsulated paraffin wax/polyaniline is a stable material that can be used for thermal energy storage systems.

Matched MeSH terms: Waxes
Flexible microfluidic cloth-based analytical devices using a low-cost wax patterning technique

Nilghaz A, Wicaksono DH, Gustiono D, Abdul Majid FA, Supriyanto E, Abdul Kadir MR

Lab Chip, 2012 Jan 7;12(1):209-18.
PMID: 22089026 DOI: 10.1039/c1lc20764d

This paper describes the fabrication of microfluidic cloth-based analytical devices (μCADs) using a simple wax patterning method on cotton cloth for performing colorimetric bioassays. Commercial cotton cloth fabric is proposed as a new inexpensive, lightweight, and flexible platform for fabricating two- (2D) and three-dimensional (3D) microfluidic systems. We demonstrated that the wicking property of the cotton microfluidic channel can be improved by scouring in soda ash (Na(2)CO(3)) solution which will remove the natural surface wax and expose the underlying texture of the cellulose fiber. After this treatment, we fabricated narrow hydrophilic channels with hydrophobic barriers made from patterned wax to define the 2D microfluidic devices. The designed pattern is carved on wax-impregnated paper, and subsequently transferred to attached cotton cloth by heat treatment. To further obtain 3D microfluidic devices having multiple layers of pattern, a single layer of wax patterned cloth can be folded along a predefined folding line and subsequently pressed using mechanical force. All the fabrication steps are simple and low cost since no special equipment is required. Diagnostic application of cloth-based devices is shown by the development of simple devices that wick and distribute microvolumes of simulated body fluids along the hydrophilic channels into reaction zones to react with analytical reagents. Colorimetric detection of bovine serum albumin (BSA) in artificial urine is carried out by direct visual observation of bromophenol blue (BPB) colour change in the reaction zones. Finally, we show the flexibility of the novel microfluidic platform by conducting a similar reaction in a bent pinned μCAD.

Matched MeSH terms: Waxes/chemistry*
A practical three visit complete denture system

Ling BC

Ann R Australas Coll Dent Surg, 2000 Oct;15:66-8.
PMID: 11709981

Standard prosthodontic procedures require five visits to construct a set of complete maxillary and mandibular dentures. Various attempts have been made to reduce these procedures to four or three appointments. However, most of these techniques require the use of visible light polymerized resin as the final denture base materials. Visible light-cured resin materials have inferior physical properties and biocompatibility problems as compared with heat cured polymethylmethacrylate. This paper describes a system of complete denture construction which requires three clinical appointments instead of the usual five visits. This system is made possible by using the VLC base/tray material as the preliminary impression material as well as the application of a new biometric wax occlusion rim. It retains the use of polymethylmethacrylate as the denture base material. This system also utilizes all the procedures used in the conventional five appointment system of complete denture construction.

Matched MeSH terms: Waxes/chemistry
A three-visit, complete-denture technique utilizing visible light-cured resin for tray and base plate construction

Ling BC

Quintessence Int, 2004 Apr;35(4):294-8.
PMID: 15119715

This article describes a technique of constructing a set of maxillary and mandibular complete dentures in three visits instead of the usual five clinical appointments. This system of complete-denture construction is made possible because of the combined use of visible light-cured material as an impression tray and record base material, as well as the use of new biometric wax occlusion rims. Unlike some earlier techniques that use light-cured resin composites as the denture base materials, this method retains the use of heat-cured polymethylmethacrylate as the denture base material.

Matched MeSH terms: Waxes/chemistry
Development and in-vitro characterization of fish oil oleogels containing benzoyl peroxide and salicylic acid as keratolytic agents

Rehman K, Tan CM, Zulfakar MH

Drug Res (Stuttg), 2014 Mar;64(3):159-65.
PMID: 24026957 DOI: 10.1055/s-0033-1355351

Topical keratolytic agents such as benzoyl peroxide (BP) and salicylic acid (SA) are one of the common treatments for inflammatory skin diseases. However, the amount of drug delivery through the skin is limited due to the stratum corneum. The purposes of this study were to investigate the ability of fish oil to act as penetration enhancer for topical keratolytic agents and to determine the suitable gelator for formulating stable fish oil oleogels. 2 types of gelling agents, beeswax and sorbitan monostearate (Span 60), were used to formulate oleogels. To investigate the efficacy of fish oil oleogel permeation, commercial hydrogels of benzoyl peroxide (BP) and salicylic acid (SA) were used as control, and comparative analysis was performed using Franz diffusion cell. Stability of oleogels was determined by physical assessments at 20°C and 40°C storage. Benzoyl peroxide (BP) fish oil oleogels containing beeswax were considered as better formulations in terms of drug permeation and cumulative drug release. All the results were found to be statistically significant (p<0.05, ANOVA) and it was concluded that the beeswax-fish oil combination in oleogel can prove to be beneficial in terms of permeation across the skin and stability.

Matched MeSH terms: Waxes/chemistry
Fulltext Can bone wax cause cholesterol granuloma in the petrous apex? A case report

Wong EHC, Lim CC, Ong CA, Narayanan P

Int J Surg Case Rep, 2020;72:587-589.
PMID: 32698294 DOI: 10.1016/j.ijscr.2020.06.086

BACKGROUND: Cholesterol granuloma (CG) is a rare entity but is the commonest lesion in the petrous apex. They are associated with chronic ear disease and previous temporal bone surgery. While bone wax has been known to cause foreign body reaction due to its non-resorbable property in the mastoid, it has not been documented to cause CG formation.
CASE PRESENTATION: We described a 43 years old male who presented with a right mastoid swelling, nine years after a right retro-sigmoid craniotomy and excision for a cerebellopontine angle meningioma. He also had multiple cranial neuropathies involving trigeminal, facial and vestibulocochlear nerves. Temporal bone CT and MRI showed features suggestive of cholesterol granuloma with extensive bony erosions. He was treated with surgical excision and drainage where bone wax residues were found intraoperatively. Histopathological analysis of the lesion confirmed the diagnosis of cholesterol granuloma. Post-operatively, the mastoid swelling resolved and his recovery was uneventful.
CONCLUSION: Our case showed that CG could manifest as a complication of bone wax usage in a neurosurgical procedure. Even though further study is needed to draw a definitive conclusion on this theory, we believe this paper will contribute to the current literature as it is the only reported case of cholesterol granuloma with bone wax as the possible causative agent. This is important so that surgeons are aware of this potential complication and use this haemostatic agent more judiciously.

Matched MeSH terms: Waxes
Fulltext Nanoemulsification of Rice Bran Wax Policosanol Enhances Its Cardio-protective Effects via Modulation of Hepatic Peroxisome Proliferator-activated Receptor gamma in Hyperlipidemic Rats

Ishaka A, Imam MU, Ismail M

J Oleo Sci, 2020;69(10):1287-1295.
PMID: 33028753 DOI: 10.5650/jos.ess20098

Policosanol, a mixture of long-chain alcohols found in animal and plant waxes, has several biological effects including lipid-lowering that have been extensively studied. However, its bioavailability is low. To investigate the effect of nanoemulsified rice bran wax policosanol (NPOL) on plasma homocysteine, heart and liver histology in hyperlipidemic rats, high-fat diet containing 2.5% cholesterol was used to induce hyperlipidemia in Sprague Dawley rats. The hyperlipidemic rats were treated with NPOL and rice bran wax policosanol (POL) in comparison with normal diet (ND), high-cholesterol diet (HCD) and simvastatin-treated rats. Plasma homocysteine, heart and liver histology, and hepatic mRNA expression of peroxisome proliferator-activated receptor gamma (PPARG) were evaluated. The NPOL group, similar to the simvastatin group, showed reduced plasma homocysteine, preserved heart and liver histology, and down-regulated hepatic PPARG mRNA in comparison to the control group, and was better than the POL group. The results suggest that the modest effect of NPOL on homocysteine and preservation of heart and liver histology could be through the regulation of PPARG expression on a background of increased assimilation of rice bran wax policosanol.

Matched MeSH terms: Waxes/chemistry*
Gaining access through a calcified pulp chamber: a clinical challenge

Ngeow WC, Thong YL

Int Endod J, 1998 Sep;31(5):367-71.
PMID: 9823142

Dental pulp is prone to dystrophic mineralization; this mineralization can be so extensive that the entire root canal system is obliterated. As a result, root canal treatment can become a difficult if not impossible task. This article presents the endodontic management of a tooth with an obliterated pulp chamber and associated with a discharging sinus in a teenage patient. The role of a calcium hydroxide lining to induce mineralization and cause the obliteration of the pulpal space is also discussed.

Matched MeSH terms: Waxes

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