Cellulose Acetate Filter Research Articles

Nitrosamine and nicotine exposure after switching from filtered to unfiltered cigarette smoking: a cross-over clinical trial

BackgroundThe cellulose acetate filter is a plastic attachment on nearly all commercial cigarettes sold worldwide. It is the main component of discarded cigarette butts, and the most prevalent waste item...

Supercapacitive Multimode Sensing with Tunable Graphene Sheet Film Electrodes

AbstractSupercapacitive multimode sensing is gaining significant attention across diverse domains, particularly within burgeoning fields of intelligent wearables and human‐computer interaction. Typically, these sensors are constructed using a matrix of conductive nanowires and soft materials such as polydimethylsiloxane (PDMS), which serve as electrodes in thin film supercapacitors (TFSs). To facilitate multimode sensing, ability to modulate response curves is crucial for practical application. In this study, we introduce porous conducting graphene sheet (GS) films with customizable thickness as TFS electrodes. We first develop a wafer‐scale fabrication method using vacuum filtration, to yield GS films with adjustable sheet resistance that can approach the percolation threshold. The use of a hydrophilic cellulose acetate (CA) filter membrane facilitates spontaneuous and nondestructive detachment of the GS film from the membrane post‐dehydration. The spontaneous separation mechanism is elucidated through time‐dependent contact angle measurements on porous films. The GS film, once separated, can be seamlessly and consistently incorporated into TFS devices as electrodes. This integration allows for multimode sensing capability with simultaneous capacitive strain sensing and ionotropic temperature sensing. The tunable nature of these porous GS films by adjusting the electrode thickness, enables fine‐tuning of the response curves for multimode sensing.

A preliminary study on 3D printing feedstock derived from cellulose recovered from cigarette butts

AbstractIn this work, we describe the recovery of cellulose acetate (r-CA) polymer from waste cigarette butts (CBs) and their subsequent conversion into feedstock for 3D printing technology. The extraction process for CBs includes two stages: initial washes in water, followed by additional washes in ethanol. A final step involves a dissolution and reprecipitation process, resulting in the creation of a fine powder. The recovery polymer has been analysed and compared to commercial cellulose acetate (p-CA) and unsmoked cigarette filter (u-CA) to assess its purity and examine alterations in its physicochemical properties. The CA powder has also been plasticized with different biocompatible plasticizers to improve the mechanical properties of the CA. We analyze the rheological properties to identify the suitable composition as feedstock for 3D printing.

Cellulose acetate filter rods tuned by surface engineering modification for typical smoke components adsorption

Abstract A series of filter rods (FRs) with sodium alginate (SA) modification were prepared by a simple one-pot pre-treatment surface modification method for the retention of typical smoke components. The influences of SA on the physico-chemical properties and adsorption behaviors (or retention characteristics) toward FRs were investigated in detail. Based on the results of XRD, BET, and SEM, it can be inferred that SA modification has no influences on compositions and textural properties of FRs. However, surface modification of FR by SA can greatly improve the hydrophilicity of FR, which is crucial for water retention. In situ diffuse Fourier-transform infrared spectroscopy results demonstrate that FR modified by 2 g·L−1 SA presents superior adsorption character for acetone. The differences in the adsorption or retention of water and acetone are ascribed to surface enriched functional groups tuned by surface engineering modification. By contrast, the modification of SA had no obvious effect on the adsorption of CO at room temperature. By contrast, at high temperature, low modification concentration is conducive to the CO2 and CO adsorption. It presents a good perspective for the rational design of new filter materials to reduce the release of harmful components in cigarette smoke.

Retention of per- and polyfluoroalkyl substances by syringe filters

Per- and polyfluoroalkyl substances (PFAS) are being increasingly measured in water and wastewater due to emerging toxicity concerns and strict regulatory limits. Previous studies have filtered water samples to remove suspended solids before PFAS analysis. However, filtration may introduce negative bias to measured PFAS concentrations. Using a well-controlled syringe pump assembly, we evaluated retention of six perfluoroalkyl carboxylates, three perfluoroalkyl sulfonates, one fluorotelomer sulfonate, and two perfluorooctane sulfonamides by glass-fiber, glass-fiber cellulose acetate, nylon, polyethersulfone, polypropylene, polyvinylidene fluoride/ difluoride, and surfactant-free cellulose acetate filters. The impacts of water quality and operational parameters were also investigated for select filter types. We found that PFAS were retained on all filters, with the glass-fiber cellulose acetate filters demonstrating the lowest retention. For all filters, PFAS retention was linearly related to chain length and hydrophobicity above certain thresholds (i.e., log D higher than 1.5). Importantly, more PFAS were retained at low filtrate volumes, and ~ 30 mL filtrate was required before the retention efficiencies stabilized. Solution pH only affected the retention of perfluorooctane sulfonamides. Pore size (i.e., 0.20, 0.45, 0.70 µm), filtration rate (i.e., 0.5, 1.0 mL min−1), and PFAS concentration (i.e., 10, 100 µg L−1), did not exert major influences on PFAS retention. The presence of dissolved organic matter improved PFAS permeation. Based on the reported results, filtration introduces bias and is not recommended for sample pretreatment.

Smart win–win waste management: superhydrophobic filter using valorized cellulose acetate from discarded cigarette butts for cleaning up marine oil spill at Hurghada Red Sea shore in Egypt

The essential target of academics and the industrial sector is the innovation of an industrial ecology approach. Worldwide, cigarette butts (CBs) comprise the most predominant form of litter that spreads into the ecosystem and inland. In the meantime, oil is spilled into marine life from various activities and transportation. The result is a complex oil–water composition in a high concentration that causes severe hazards to the environment and to aquatic life. In this regard, the current investigation focuses on obtaining hydrophobic cellulose acetate from CBs for use as a filter media. The filter is applied in marine oil spill separation as a win–win industrial ecology technique. Initially, the separated CB residuals were prepared by successive washing. Subsequently, the obtained cellulose acetate fibers were characterized by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). Furthermore, the new CB-based filters were used in the separation/adsorption of marine oil wastewater spill. Subsequently, a group of experiments were conducted. The results showed that the cleanup efficiency could be up to 99% in terms of chemical oxygen demand (COD). Moreover, the products were recovered by washing with hot water for further use, which showed high removal activity that reached 95% after successive uses. In comparison to commercial oil sorption materials, the results were promising as the RP-C18 cartridge revealed a maximum oil removal of 90%. Such preliminary data on a cellulose acetate filter scheme are a good indicator in the development of an oil spill facility, being a suitable candidate for controlling oil wastewater effluent streams.

Test of two membrane filter types for biomass collectionin community profiling by metabarcoding

With the rapid development of microorganism biodiversity estimation and community profiling via DNA metabarcoding, there is a growing need to identify key stages affecting the results of experiment. In order to ensure high-quality reproducible results, all potential sources of bias should be explored. While bioinformatic pipelines can be often corrected and optimized to recalculate results, the initial steps of sample collection procedure, potentially influencing the downstream results of bacterial community profiling, are much harder to correct easily, without repeating the whole experiment. We examined the differences of the amplicon bacterial community profiles generated from aquatic microbial communities captured by polycarbonate (PC) and cellulose acetate (CA) filters. The microbial community profiles were shown to be significantly different by biodiversity. When using a PC-filters, alpha- and beta-diversity of communities were significantly higher. Differential abundance analysis showed enrichment of major cyanobacterial OTUs in CA-treated communities. Based on these results, the use of PC-filters is the most optimal for bacterial community profiling by metabarcoding of the 16S rRNA gene fragments.

Surface plasma modification of cellulose acetate fiber filter for the adsorption of typical components in smoke components.

Surface modification of cellulose acetate filter rods with low temperature plasma was performed to explore the retention and adsorption effect of modified filter rods on typical components (CO, H2O, benzene, and formaldehyde) in cigarette smoke. The surface structure and composition of the cellulose acetate filter rods were modified by changing the plasma treatment time. The modified filter rods were characterized by N2 physical adsorption (BET), scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), contact angle of H2O, Fourier transform infrared spectroscopy (FTIR) and in situ DRIFTS. Various functional groups were found on the surface of filter rods with the introduction of plasma modification, which exhibited strong retention performance for water vapor in cigarette smoke at room temperature and significantly enhanced adsorption for harmful substances (CO, benzene, and formaldehyde) in cigarette smoke.

Changes of the bulbar conjunctiva as the result of glaucoma medication treatment

Aims/Purpose: To determine changes of the bulbar conjunctiva as the result of glaucoma medication treatment.Methods: We used an impression cytology method which implies the application of a cellulose acetate filter to the ocular surface, twice in the same place, to remove superficial layers of the nasal quadrant conjunctiva epithelium. The strips were removed after a few seconds of exposure, transferred into a fixative solution, followed by histological staining and light microscopy examination. The presence of squamous metaplasia was assessed using Nelson's scale, based on cells' morphology, staining behaviour, integrity and nucleoplasmic ratio. The case study included the first group of patients suffering from POAG and DED (80) (mean age = 63.8 ± 6.7 years) which was divided into 4 subgroups: 1 ‐ patients (40), who suffer from glaucoma for less than 5 years; 2 (40) ‐ more than 5 years; subgroup a (40) ‐ with one drug instilled, b (40) ‐ 2 or more drugs instilled. The second group consisted of almost healthy patients (mean age = 67.9 ± 8.9 years) All of them underwent general ophthalmological examination.Results: According to OSDI all glaucoma patients had dry eye symptoms (15 or more points). In subgroup 1 40% were diagnosed with Nelson I, 60% with Nelson II. In subgroup 2 15% had Nelson I, 55% had Nelson II and 30% had Nelson III. In subgroup a 20% of patients had Nelson I, 60% had Nelson II, and 20% were diagnosed with Nelson III. In subgroup b 30% had Nelson I, 60% had Nelson II, 10% of patients had Nelson III.Conclusions: 80% of cases show changes that correspond to II‐III Nelson degrees according to Nelson classification. The severity of metaplasia correlated with the duration of eye drops therapy, but not with the amount of them. According to the results that we received, and the international data, it is recommended to choose drugs without preservatives and other potentially toxic components for the long‐term treatment of glaucoma.

Protecting public health and the environment: towards a general ban on cellulose acetate cigarette filters in the European Union.

After the establishment of a causal relationship between tobacco use and cancer in the 1950s, cellulose acetate filters were introduced with the claim to reduce the adverse health impact of unfiltered cigarettes. Often perceived to be more pleasant and healthy, filters encouraged smoking. However, filtered cigarettes are more deeply inhaled to obtain the same nicotine demand while altered combustion releases more tobacco-specific nitrosamines. The increasing use of cigarette filter ventilation is associated with a sharp rise in lung adenocarcinomas in recent decades. While not preventing adverse health effects, a global environmental problem has been created due to the non-biodegradable filter litter, causing ecotoxicological effects and the spread of microplastics. Recently, the Belgian Superior Health Council advised policymakers to ban cigarette filters as single-use plastics at both national and European levels. This article outlines the arguments used to justify this plea (human health and environment), the expected effects of a filter ban, as well as the public reception and reactions of the tobacco industry. The specific context of the European Union is discussed including the revision of the Single-Use Plastics Directive, affording a new opportunity to ban plastic filters. This perspective article aims to fuel the momentum and cooperation among member states for this purpose.

From cave to spring: Understanding transport of suspended sediment particles in a fully phreatic karst conduit using particle analysis and geochemical methods

AbstractKarst aquifers are vulnerable to contamination, especially in the context of heavy rainfall events. Contamination is often associated with turbidity that can originate from the soil zone, infiltrating surface waters or resuspension of previously deposited sediments within the aquifer. While turbidity events can be well monitored at karst springs, related information about the sediment origin and the spatiotemporal input function usually remain unknown. Thus, the mobility and attenuation of the particulate matter and associated pollutants can hardly be determined quantitatively. A tracer test with suspended cave sediments and solute tracers for comparison has hence been performed in a karst aquifer at the Blue Spring (Blautopf) in Southern Germany. The tracers were injected in the cave system, at the beginning of a fully phreatic karst conduit, and monitored at the spring after a travel distance of 1250 m. The particle‐size distribution was monitored using a particle counter and sediment samples were filtered with 0.45‐μm cellulose acetate filters. Particles on the filter were analysed for major and trace elements as well as rare earth elements (REE) by ICP‐MS after acid digestion. Results show that (1) sediment particles were transported faster than solutes, which was interpreted as a transport in the main flow path of the conduit, whereas conservative tracers tend to diffuse into smaller fissures as well. (2) All measured particles sizes were transported at similar flow velocities. (3) A transport associated to sediment particles could be shown for all measured elements. This study presents a methodological improvement of comparative sediment tracer tests as well as deeper insights into particle and element transport processes in karst aquifers, originating from previously deposited cave sediment. Results provide deeper knowledge into transport processes of sediment‐associated contaminants, such as heavy metals which may strongly be affected by the particle size. This knowledge contributes to a better management of karst water resources in the context of turbidity events.

Preparation of a High-Performance Asymmetric Supercapacitor by Recycling Aluminum Paper and Filter Components of Heated Tobacco.

In this study, Al paper and cellulose acetate (CA) filters derived from heated tobacco waste were successfully converted into current collectors and active materials for a supercapacitor device. Typically, heated tobacco contains electrically discontinuous Al paper. First, Al was extracted from the tobacco waste using HCl to produce Lewis acid (AlCl3). This acid was then used in an Al electrodeposition process utilizing the chloroaluminate ionic liquid reaction between the acid and the base (RCl) at room temperature. To enhance the conductivity, a supplementary coating of Al metal was applied to the Al paper through electrodeposition, thus re-establishing the electrical continuity of the discontinuous parts and forming an Al-coated current collector. Moreover, the CA filters were carbonized under a nitrogen atmosphere, yielding carbon precursors (C-CA) for the supercapacitor electrodes. To further enhance the electrochemical performance, nickel oxide (NiO) was incorporated into C-CA, resulting in C-CA@NiO with pseudocapacitance. The specific surface area of CA increased with carbonization and the subsequent incorporation of NiO. The as-synthesized C-CA and C-CA@NiO materials were applied to an Al-coated current collector to obtain C-CA- and C-CA@NiO-based electrodes, exhibiting stable electrochemical behavior in the voltage range of -1.0 to 0 V and 0 to 1.0 V, respectively. An asymmetric supercapacitor (ASC) device was assembled with C-CA@NiO and C-CA as the positive and negative electrodes, respectively. This ASC device demonstrated a high specific capacitance of 40.8 F g-1, while widening the operating voltage window to 2.0 V. The high electrochemical performance of the device is attributed to the successful Al electrodeposition, which facilitates the electrical conductivity and increased porosity of the C-CA@NiO and C-CA materials. To the best of our knowledge, this is a pioneering study in regards to the conversion of biomass waste into current collectors and active materials to fabricate a practical ASC device. Our findings highlight the potential of reusing Al paper and CA filters from heated tobacco waste as essential components of energy storage devices.

Cytologic features of the bulbar conjunctiva in patients with primary open-angle glaucoma-associated dry eye disease

Purpose: To examine the features of the bulbar conjunctiva in patients who developed dry-eye disease (DED) after drug treatment for primary open-angle glaucoma (POAG). Methods: Impression cytology was performed by applying twice a strip of cellulose acetate filter to the ocular surface to remove the superficial epithelial layers of the temporal bulbar conjunctiva. The strips were removed with a peeling motion in a few seconds, and the samples were immediately fixed in 95% ethyl alcohol, stained with hematoxylin and eosin, mounted on glass slides and coverslipped for light microscopy. Squamous metaplasia was graded according to Nelson’s grading system on the basis of cell morphology, staining and integrity as well as the nucleus-to-cytoplasm ratio. This study included a case group of 80 patients (mean age, 63.8 +- 6.7 years) with POAG-associated DED, with the group being divided into four subgroups. Subgroups 1 and 2 were composed of 40 patients each, with glaucoma duration of less or more than 5 years, respectively. Subgroups a and b were composed of 40 patients each, with a number of topical ocular hypotensive drugs used equal to one or at least two, respectively. The control group was composed of 20 apparently healthy volunteers (mean age, 67.9 +- 8.9 years). All patients underwent a routine eye examination. Results: All patients with glaucoma had symptoms of DED with Ocular Surface Disease Index (OSDI) scores of at least 15. In subgroup 1, 60% had Nelson’s grade 1 and 40%, Nelson’s grade 2 squamous metaplasia. In subgroup 2, 10% had Nelson’s grade 1; 60%, Nelson’s grade 2 and 30%, Nelson’s grade 3 squamous metaplasia. In subgroup a, 20% had Nelson’s grade 1; 60%, Nelson’s grade 2 and 30%, Nelson’s grade 3 squamous metaplasia. In subgroup b, 10% had Nelson’s grade 1; 60%, Nelson’s grade 2 and 30%, Nelson’s grade 3 squamous metaplasia. Conclusion: Changes in the bulbar conjunctival epithelium corresponded to Nelson’s grade 2 or 3 squamous metaplasia in 80% of patients who developed DED after drug treatment for POAG. The severity of squamous metaplasia correlated with the duration of glaucoma and, consequently, longer use of hypotensive eye drops (r1 = 0.15, p1 = 0.02, p2 = 0.01). Findings of the current study and international guidelines argue for the use of the medications containing no preservatives or potentially toxic components in long-term therapy against glaucoma.

Evaluation of laboratory and environmental exposure systems for protein modification upon gas pollutants and environmental factors

Chemical modifications of proteins induced by ambient ozone (O3) and nitrogen oxides (NOx) are of public health concerns due to their potential to trigger respiratory diseases. The laboratory and environmental exposure systems have been widely used to investigate their relevant mechanism in the atmosphere. Using bovine serum albumin (BSA) as a model protein, we evaluated the two systems and aimed to reduce the uncertainties of both the reactants and products in the corresponding kinetic study. In the laboratory simulation system, the generated gaseous pollutants showed negligible losses. Ten layers of BSA were coated on the flow tube with protein extraction recovery of 87.4%. For environmental exposure experiment, quartz fiber filter was selected as the upper filter with low gaseous O3 (8.0%) and NO2 (1.7%) losses, and cellulose acetate filter was appropriate for the lower filter with protein extraction efficiency of 95.2%. The protein degradation process was observed without the exposure to atmospheric oxidants and contributed to the loss of protein monomer mass fractions, while environmental factors (e.g., molecular oxygen and ultraviolet) may cause greater protein monomer losses. Based on the evaluation, the study exemplarily applied the two systems to protein modification and both showed that O3 promotes the protein oligomerization and nitration, while increased temperature can accelerate the oligomerization and increased relative humidity can inhibit the nitration in the environmental exposure samples. The developed laboratory and environmental systems are suitable for studying protein modifications formed under different atmospheric conditions. A combination of the two will further reveal the actual mechanism of protein modifications.

Upcycling of the Used Cigarette Butt Filters through Pyrolysis Process: Detailed Kinetic Mechanism with Bio-Char Characterization.

Thermo-chemical conversion via the pyrolysis of cigarette butt (CB) filters was successfully valorized and upcycled in the pre-carbonization and carbonization stages. The pre-carbonization stage (devolatilization) of the precursor material (cellulose acetate filter, r-CAcF) was analyzed by micro-scale experiments under non-isothermal conditions using TG-DTG-DTA and DSC techniques. The results of a detailed kinetic study showed that the decomposition of r-CAcF takes place via complex mechanisms, including consecutive reaction steps and two single-step reactions. Consecutive stages include the α-transition referred to as a cellulose polymorphic transformation (cellulose I → II) through crystallization mechanism changes, where a more thermodynamically ordered system was obtained. It was found that the transformation rate of cellulose I → II ('cellulose regeneration') is strongly affected by the presence of alkali metals and the deacetylation process. Two single-step reactions showed significant overlapping behavior, which involves a nucleation-controlled scission mechanism (producing levoglucosan, gaseous products, and abundant radicals) and hydrolytic decomposition of cellulose by catalytic cleavage of glycosidic bonds with the presence of an acidic catalyst. A macro-scale experiment showed that the operating temperature and heating rate had the most notable effects on the total surface area of the manufactured carbon. A substantial degree of mesoporosity with a median pore radius of 3.1695 nm was identified. The presence of macroporosity on the carbon surface and acidic surface functional groups was observed.

STUDY OF PATHOLOGICAL CHANGES IN THE CONJUNCTIVA AND CORNEA USING IMPRESSION CYTOLOGY IN CASES OF PTERYGIUM: A CROSSSECTIONAL STUDY CONDUCTED AT ONE OF THE TERTIARY CARE CENTERS OF NORTHERN INDIA

Background: Pterygium is a benign, proliferative, degenerative condition of conjunctiva and sub conjunctival tissue that has the potential to impair vision. Impression cytology is the process of removing the outermost layers of ocular surface epithelium using cellulose acetate filter paper. There are various methods to investigate Pterygium, we carried out this study through impression cytology. This was a cross-sectional study carried out in Materials and Methodology: Career Institute of Medical Sciences, Lucknow including 100 patients with pterygium. From each eye, 4 impressions were collected through impression cytology, which included 2 conjunctival and 2 corneal impressions to study thecytological changes occurring throughout inter-palpebral ocular surface in the eye with pterygium. The cytology Results: of the surface cells overlying the pterygium exhibits squamous metaplasia, goblet cell hyperplasia, and keratinization of the epithelial cells. These cytological changes are not only seen over pterygium conjunctiva and cornea around the pterygium but they are also seen over the unaffected sites of the interpalpebral conjunctiva and cornea in the same eye. Conclusion: Pterygium is a graded series of the ocular surface variations occurring through out the inter-palpebral bulbar conjunctiva and cornea, with most advanced variation shappening directly over pterygium surface, confirming that pterygium is certainly anocular surface disorder. This study suggests that impression cytology represents a fast,cost-effective,and non-invasive tool for understanding the pathology of pterygium.

Investigating electrospun oil sorbents derived from cigarette filters

A highly effective oil sorbent, made from cigarette filters, was produced using a low complexity, single-step process. This was done to address the dual issues of oil pollution and cigarette filter litter. The oil sorption capacity was found for electrospun cellulose acetate sorbents, made from both virgin cellulose acetate and cigarette filters. Not only did the cigarette filter derived sorbent have a higher oil sorption capacity than sorbents found in other studies (with a capacity of 93.7 g/g), but the sorbent was also produced using a less complex and less energy-intensive method. Additionally, the oil sorption capacity for the cigarette filter sorbent was found to be higher than that of a virgin cellulose acetate sorbent. This was thought to be due to the additive, glycerol triacetate (GA), found within the cigarette filters. This means that not only does sourcing the cellulose acetate from cigarette filters tackle cigarette filter pollution, but it also produces a more effective sorbent. Therefore, the cigarette filter derived oil sorbent produced in this study has the potential to be a highly effective, and more sustainable, solution for the remediation of oil pollution.

Rapid and sensitive detection of Pectobacterium carotovorum subsp. carotovorum in fresh produce using silica-coated magnetic nanoparticles combined with filtration-based real-time PCR

Pectobacterium carotovorum subsp. carotovorum (Pcc) possesses a powerful enzymatic mechanism that destroys plant-cell walls. Therefore, Pcc is the etiology of soft-rot disease in several crops and is recognized as one of the most important pathogens in agriculture. Soft-rot is difficult to control at the source when infection occurs. Thus, it is essential to develop sensitivity monitoring and diagnostic methods for timely control measures. Molecular detection methods, such as real-time polymerase chain reaction (PCR), are widely used for detecting Pcc. However, because Pcc is present at low levels in initial soft-rot infection, enrichment and efficient pathogen-separation methods are needed for sensitive monitoring. In this study, filtration was used as a pretreatment method for pathogen concentration, and silica-coated magnetic nanoparticles (SMN)- based real-time PCR was employed to detect low levels of Pcc in fresh produce. As a result, 102 CFU/10 mL was detected by various DNA-extraction methods in pure culture, whereas SMN detected up to 101 CFU/10 mL. In addition, when DNA was extracted using SMN after filtration using a cellulose acetate filter, the sensitivity of real-time PCR was improved to 10° CFU/10 mL. In conclusion, the pretreatment method including SMN, and concentration procedures increased the detection sensitivity by 100-fold; in potato and chicory, 101 CFU/g was detected at a frequency of 90% of the samples, and 10° CFU/g was detected at 70%; and in Kimchi Cabbage, 101 CFU/g was detected at 100% and 10° CFU/g was detected at 80%.

A groundbreaking biorefinery loop for the valorization of cigarette butts into fermentable sugars and bioethanol

Cigarette Butts are one of the most diffused and toxic waste in urban contexts. They are composed by a cellulose acetate filter, used to retain toxic compounds during the smoking of cigarette, and eventual tobacco's residues. This work had the ambitious to exploit cigarette butts in a biorefinery scheme to produce fermentable sugars and bioethanol. Cigarette butts followed different sequential operations. Deacetylation of cellulose acetate was optimized by a lipase treatment, which played an important role in the biological degradation and deacetylation of cellulose acetate. The following cellulase addition allowed the conversion of the deacetylated cellulose into fermentable sugars. In particular, the best performances were obtained with a cellulase addition of 10% of the cigarette butts, which led to a final fermentable sugars' concentration of about 12 g/L, corresponding to a cigarette butts' conversion of about 70% w/w. Then, the fermentable sugars were used as substrates for bioethanol production by three different yeasts: Metschnikowia pulcherrima MALV5, Lachancea fermentati LS16 and Saccharomyces cerevisiae EC1118. Metschnikowia pulcherrima MALV5, Lachancea fermentati LS16 achieved similar results with a bioethanol production of 2.14 and 2.44 g/L, respectively, corresponding to a fermentable sugars conversion of about 20% w/w.

Effect of hormonal contraceptives on the ocular surface and the tear film

Dry eye syndrome (DES) is a common multifactorial disease of the tears andocular surface associated with sex hormones. Hormonal contraception is arisk factor for DES, but its relationship with DES exacerbations in womenof childbearing age is still unclear. This study aimed to evaluate changesof the tear film and ocular surface of young women using the hormonalcontraceptive agent. It was a case-control study involving 56 healthywomen aged 20 to 45 y.o. Subjects was divided into two groups i.e. thehormonal contraceptives group and the control group without hormonalcontraceptive. Subjects were interviewed with the ocular surface diseaseindex (OSDI) questionnaire. Tear secretion and tear stability were measuredusing Schirmer’s I test and fluorescein tear break-up time test (TBUT).Ocular surface impression cytology with cellulose acetate filter paper wastaken from inferonasal bulbar conjunctiva and was stained with periodicacid- Schiff (PAS) and counterstained with hematoxylin and eosin (HE). Nosignificantly decrease in tear secretion and tear stability in the hormonalcontraceptives group compared with the control groups was observed (p >0.05). However, a statistically significant decrease in goblet cell density andconjunctival epithelium metaplasia was observed, where 25% of the hormonalcontraceptives group had an abnormal impression cytology result comparedwith the control group (p<0.05). The hormonal contraceptives group also hada higher OSDI score than the control group, although it was not statisticallysignificant (p> 0.05). The hormonal contraceptives group had a signifificanteffect on the ocular surface in which it induced squamous metaplasia andinflflammation of conjunctival cells and the reduced number of goblet cellsp<0.05). The slightly decreased tear film volume and stability accompaniedby an increase in OSDI score found in the hormonal contraceptives groupsupport the possibility of hormonal contraceptive use as one of the riskfactors in the occurrence of dry eye syndrome.