Exploring consistent ratios in morphometry of the proximal tibia: insights for knee arthroplasty.

INTRODUCTION: The current study, which delves into proximal tibia morphometric parameters in a Greek sample, not only analyzes whether specific linear distance ratios are consistent but also paves the way for a potential novel metric system for knee arthroplasty imaging studies using constant ratios. These findings could have significant implications for future enlarged research and clinical practice. METHODS: A total of 38 dried tibiae were evaluated by two independent investigators. The following distances were measured with a digital Vernier sliding caliper: (1) the mediolateral distance of the proximal surface (A), (2) the anteroposterior distance of the proximal surface (B), (3) The longitudinal length of the bone (C), (4) the line connecting the anterior margin of the proximal surface with the highest peak of the tibia tuberosity (D), (5) the depth of the proximal margin of the medial articular facet (AF) (medial plateau) (E) and (6) the depth of the proximal margin of the lateral AF (lateral plateau) (F). RESULTS: The A, B, C, D, E, and F mean distances were 71.3 mm, 47.4 mm, 340.2 mm, 37.1 mm, 42 mm, and 35.9 mm. Reliability analysis for each observer on all measurements revealed an interclass correlation (ICC) score of 0.975 (observer 1) and 0.971 (observer 2). The ratio A/B was 1.5, A/C was a constant 0.2, and D/C was 0.1. The ratio E/F was 1.2. The six measurements (A-F) showed excellent inter-observer reliability (all ICC values > 0.990). CONCLUSIONS: The study established constant ratios of the studied linear distances around the proximal tibia. Considering these ratios, asymmetrical tibial components in knee arthroplasty seem to replicate the native anatomy more closely. Furthermore, the distance from the anterior margin of the proximal surface to the tibial tuberosity peak, constituting one-tenth of the longitudinal length of the tibia, shows promise as a metric system for imaging studies, especially in assessing lesions around tibial components.

Suggestion of a Novel Classification Based on the Anatomical Region and Type of Bilateral Fatigue Femoral Fractures.

Purpose: Bilateral fatigue femoral fractures (BFFF) represent an extremely rare clinical entity. The present study introduces a novel classification, in order to categorize the BFFFs and provide a thorough review of all these, so far in the literature, reported cases. Methods: The BFFF were classified taking into account the anatomical region of the femoral fracture; (fh): femoral head, (sc): sub-capital, (pt): peri-trochanteric, (st): sub-trochanteric, (s): shaft, (d): distal femur and the fracture type (complete or incomplete); type I: bilateral incomplete fractures, type II: unilateral incomplete fracture, and type III: bilateral complete fractures. Type III was further subdivided into type IIIA: bilateral non-displaced fractures, type IIIB: unilateral displaced fracture, and type IIIC: bilateral displaced fractures. Furthermore, a meticulous review of the PubMed and MEDLINE databases was conducted to locate all articles reporting these injuries. Results: A total of 38 patients (86.8% males), with a mean age of 25.3 years, suffering BFFFs were identified from the literature search. The mean time interval from symptoms' onset to diagnosis was 54 days. According to the proposed classification, 2.6% of the fractures were categorized as type I (h), 36.8% as type I (sc), 2.6% as type I(st/s), 7.9% as type I (s), 2.6% as type I (d), 5.4% as type II (fh), 26.3% as type II (sc), 2.6% as type IIIA (st), 2.6% as type IIIA (d), 5.4% as type IIIB (sc), 2.6% as type IIIB (d) and 2.6% as type IIIC (sc). Surgery was performed in 52.6%, while non-operative treatment was followed in 47.4% of the population. Regarding the fracture type, 75% of type I fractures were conservatively treated, while 91.7% and 66.6% of type II and III fractures were surgically treated. For patients treated conservatively, the mean time from diagnosis to return to previous status was 260 days, while for patients treated surgically, 343 days. Conclusions: BFFFs, although rare, may pose a diagnostic and therapeutic challenge. The present classification offers valuable information and may act as a guide for the management of these patients.

Press-fit vs threaded acetabulum components for total hip arthroplasty - A systematic review with metanalysis.

Background: Threaded acetabular components (TACs) have been shown to offer greater initial stability compared to press-fit acetabular components (PFACs). Despite these biomechanical advantages, the use of threaded cups remains. This study compares the outcomes of TACs to PFACs in total hip arthroplasty (THA), providing evidence-based data regarding their failure rates and radiological evaluation. Methods: A meticulous research of PubMed and MEDLINE databases, following the PRISMA guidelines, was conducted, to identify all articles regarding the outcome of the use of TCAs compared to PFACs in THA. Subsequently, statistical analysis with metanalysis concerning: 1) the instances of revision due to aseptic loosening and 2) the radiological evaluations of TACs compared to PFACs and sensitivity analysis were performed. Results: This metanalysis encompassed seven studies, enrolling 7878 cases of THA utilizing PFAC, and 6684 cases using TAC. The overall odds ratio (OR) for revision due to aseptic loosening in THA using PFAC compared to TAC was 3.10 (95 % CI 0.37-25.72). Additionally, when assessing radiolucency findings across the same categories, the pooled OR was 0.53 (95 % CI 0.26-1.08). An examination of studies with larger sample sizes revealed no statistically significant variance. After adjusting for age, no substantial difference was detected. However, upon gender adjustment, it was observed that females undergoing THA with PFAC had a 5-fold risk of revision (OR = 5.26, 95 % CI 0.25-111.91, p-value = 0.29) compared to females with TAC, although without reaching statistical significance. Moreover, females exhibited a slightly elevated risk for revision due to aseptic loosening post-PFAC THA compared to males [(OR = 5.26, 95 % CI 0.25-111.91) (OR = 2.51, 95 % CI 0.01-1051.68) respectively], and for radiolucency findings [(OR 0.74, 95 % CI 0.20-1.11) (OR 0.29, 95 % CI 0.03-3.36) respectively]. Conclusions: The PFACs remain the main option for total hip reconstruction, while TACs might be a viable alternative, especially in cases of osteoporosis.

Clinical Considerations of First Extensor Wrist Compartment (FEWC) Variants and De Quervain's Disease: A Review Study.

The first extensor wrist compartment (FEWC) displays significant variants. This review highlights all possible variants that may be associated with the occurrence and pathophysiology of de Quervain's tenosynovitis. A thorough search of PubMed and MEDLINE databases, following the PRISMA guidelines, was conducted from 2002 to 2022 to evaluate all FEWC variants, including the following: 1) the presence of an inter-tendinous septum, 2) the number of tendinous slips of the abductor pollicis longus (APL) and the extensor pollicis brevis (EPB) muscles, 3) their distal insertions and 4) the presence of a bony ridge within the FEWC. A total of 3878 wrists (1277 cadaveric and 1296 de Quervain patients) were included. Of the 1234 cadavers, a total of 701 (56.8%) were males and 533 (43.2%) were females. Regarding the 883 patients, 178 (20.2%) of them were males and 705 (79.8%) were females. An inter-tendinous septum was identified in 42.9% (47% of the patients' wrists compared to 39.3% of the cadaveric wrists, p<0.0001). Cadaveric wrists presented two or more slips for the APL in a significantly higher percentage (92.5%, p < 0.0001) compared to de Quervain patients' wrists (74.5%). Regarding the EPB muscle, de Quervain patients' wrists had a single slip in 93% (p=0.0007) and two or more slips in 3.6%, compared to cadaveric wrists (a single slip in 87%, and two or more slips in 11%, p< 0.0001). A bony ridge over the radial styloid process was recorded in 58.9% of the cadaveric wrists compared to 17.8% of the patients' wrists (p < 0.0001). Remarkable diversity concerning the structures within the FEWC was reported. The presence of an inter-tendinous septum dividing the FEWC and a single EPB muscle slip is more likely to be found in patients with de Quervain's disease.

Smart Surfaces: Photocatalytic Degradation of Priority Pollutants on TiO2-Based Coatings in Indoor and Outdoor Environments-Principles and Mechanisms.

Heterogeneous photocatalysis using semiconductor oxides such as TiO2, provides an up-and-coming solution for the degradation of environmental pollutants compared with other technologies. TiO2-containing construction materials and paints activated by UV/solar light destroy the ozone precursors NO and NO2 up to 80% and 30%, respectively. The majority of TiO2 materials developed so far are primarily for outdoor use. In recent years, substantial efforts have been made to investigate further the photocatalytic activity of materials containing TiO2 toward priority air pollutants such as NO, NO2, and volatile organic compounds (VOCs) frequently accumulated at high concentration levels, particularly in indoor spaces. The intention of the investigations was to modify the titanium dioxide (TiO2), so that it may be activated by visible light and subsequently used as additive in building envelop materials and indoor paints. This has been achieved, to a high extent, through doping of TiO2 with transition metals such as V, Cr, Fe, Mn, Ni, Co, Cu, and Zn, which reduce the energy gap of TiO2, facilitating the generation of free electrons and holes, thus, extending the absorption spectral range of modified TiO2 to the area of visible light (bathochromic shift-redshift). A substantial problem using TiO2-containing paints and other building materials in indoor environments is the formation of byproducts, e.g., formaldehyde, through the heterogeneous photocatalytic reaction of TiO2 with organic matrices. This affects the air quality in confined spaces and, thus, becomes a possible risk for human health and wellbeing. This work describes the principles and mechanisms of the photocatalytic reactions at the air/catalyst interface of priority pollutants such as NO, benzene, and toluene as individual compounds or mixtures. Emphasis is placed on the reaction and recombination processes of the charge carriers, valence band positive holes (h+) and free electrons (e-), on the surface of TiO2, and on key factors affecting the photocatalytic processes, such as humidity. A hypothesis on the role of aromatic compounds in suppressing the recombination process (h+ and e-) is formulated and discussed. Furthermore, the results of the photocatalytic degradation of NO under visible light conditions using different admixtures of TiO2 and manganese doped (Mn-TiO2) are presented and discussed.

Knee Septic Arthritis Caused by Pantoea agglomerans.

Introduction: Septic arthritis usually affects native joints and represents an invasion of the joint space by a wide variety of microorganisms, most commonly bacteria, such as Staphylococci, Streptococci, and Gram-negative rods. An extremely rare case of septic knee arthritis caused by Pantoea agglomerans in a 67-year-old male is presented. Case Report: The patient was initially treated with arthroscopic debridement, but due to persistent symptomatology open surgical debridement 3 days after initial surgery was also performed. Cultures yielded P. agglomerans and Streptococcus agalactiae. He was commenced on causative antimicrobial treatment including intravenous linezolid, ciprofloxacin, and clindamycin. He was discharged 10 days later, on oral linezolid and ciprofloxacin for 3 months. Conclusion: Delayed diagnosis in septic arthritis cases and inadequate control of the infection may lead to insufficient treatment and devastating consequences for the patient. The treatment includes surgical debridement and proper antimicrobial agents. Cultures dictate the proper treatment; hence, microbiological examination is of utmost importance, since it may reveal unusual organisms for which empirical treatment may prove insufficient.

Partial Superficial Parotidectomy Versus Extracapsular Anatomical Dissection for the Treatment of Benign Parotid Tumors.

OBJECTIVES: Superficial benign parotid tumors are a common neoplasm of the salivary glands. Different surgical procedures have been applied for partial superficial parotidectomy (PSP) and extracapsular dissection (ECD), which are the two predominant surgical techniques. Our study aimed to evaluate PSP versus ECD for benign parotid tumors, in relation to post-operative complications and recurrence rates. MATERIALS AND METHODS: 266 patients who underwent parotidectomies of benign superficial parotid tumors were evaluated retrospectively. The first group (PSP group) was composed of 143 patients who underwent PSP, and the second group (ECD group) was composed of 123 patients who underwent ECD. RESULTS: In the ECD group the rate of patients presenting with total postoperative permanent facial nerve paralysis, House-Brackmann grade III, was 0.8%, whereas in the PSP group it was 1.4%. Frey's syndrome was only reported in the PSP group. Salivary fistula occurred in both groups at similar rates. Sensation dysfunction due to greater auricular nerve division occurred in 72% patients in the PSP group and 10.6% in the ECD group. No statistical difference regarding recurrence rates was found between the two groups. CONCLUSIONS: Both ECD and PSP procedures are safe surgical options for superficial parotidectomy in the treatment of benign tumors, with similar recurrence rates and post-surgical complications, apart from sensation abnormalities due to more extensive auricular nerve division.

Evaluation of the fate of the active ingredients of insecticide sprays used indoors.

The fate of the active ingredients of insecticide sprays after use in indoor environments was investigated. Indoor air sampling was performed through two types of adsorbents, namely, TENAX TA and XAD-2 (10 L). After sampling, both adsorbents were ultrasonically extracted and analyzed by Gas Chromatography coupled to Mass Spectroscopy. The separation and analysis of the selected compounds were satisfactory and fast (duration of the chromatographic run: 40 min). The method was linear for all examined chemicals over the tested range (2 to 50 ng of absolute compound); limits of detection ranged from 0.42 to 1.32 ng of absolute compound. The method was then applied in the determination of the active ingredients of three commercially available insecticide sprays that were separately used in a full-scale environmental chamber (30 m(3)). After spraying, the fate of the active ingredients [propoxur, piperonyl butoxide (PBO) and pyrethrin insecticides] was monitored over 40 minutes, with and without ventilation. Both adsorbent materials were proven to be efficient and the differences in the concentrations deriving from sampling with both materials were in almost all cases less than 10%. All chemicals were removed in rates that exceeded 80%, after the 40 minutes of monitoring, exhibiting different decay rates. The removal of insecticides was not significantly affected by the ventilation of the chamber. The correlation analysis of propoxur, PBO and pyrethrins with the aerosols of various sizes (15 fractions, from 0.3 to > 20 microm) showed that propoxur and PBO mainly associated with the medium size aerosols (3-7.5 microm) while pyrethrins seem to link more with heavier particles (> 10 microm).

Detecting conversation topics in primary care office visits from transcripts of patient-provider interactions.

OBJECTIVE: Amid electronic health records, laboratory tests, and other technology, office-based patient and provider communication is still the heart of primary medical care. Patients typically present multiple complaints, requiring physicians to decide how to balance competing demands. How this time is allocated has implications for patient satisfaction, payments, and quality of care. We investigate the effectiveness of machine learning methods for automated annotation of medical topics in patient-provider dialog transcripts. MATERIALS AND METHODS: We used dialog transcripts from 279 primary care visits to predict talk-turn topic labels. Different machine learning models were trained to operate on single or multiple local talk-turns (logistic classifiers, support vector machines, gated recurrent units) as well as sequential models that integrate information across talk-turn sequences (conditional random fields, hidden Markov models, and hierarchical gated recurrent units). RESULTS: Evaluation was performed using cross-validation to measure 1) classification accuracy for talk-turns and 2) precision, recall, and F1 scores at the visit level. Experimental results showed that sequential models had higher classification accuracy at the talk-turn level and higher precision at the visit level. Independent models had higher recall scores at the visit level compared with sequential models. CONCLUSIONS: Incorporating sequential information across talk-turns improves the accuracy of topic prediction in patient-provider dialog by smoothing out noisy information from talk-turns. Although the results are promising, more advanced prediction techniques and larger labeled datasets will likely be required to achieve prediction performance appropriate for real-world clinical applications.

VOC and carbonyl emissions from carpets: a comparative study using four types of environmental chambers.

Emissions of Volatile Organic Compounds (VOCs) and carbonyls from carpets of different type (wool, synthetic) over a time period of three days at 23 degrees C, at 45% relative humidity, 0.5 air change rate and a loading factor of 0.4 m(2) m(-3) were measured. The experiments were carried out at four different environmental chambers (volumes of 0.02/0.28/0.45/30 m(3)). For TVOCs, maximum concentrations up to 2300 microg m(-3) (for carpet with synthetic backing) were found. Aromatic compounds e.g. benzene, toluene, the xylenes and styrene are emitted in relatively low concentrations, while for 4-phenylcyclohexene and 2, 2-butoxyethoxy-ethanol concentrations up to 170 and 320 microg m(-3), respectively, were measured. In all experiments, emission rates reached the maximum value within few hours from the beginning of the experiment. The emission rates of TVOCs from the same type of carpet measured with various types of chambers (0.02/0.28/0.45/30 m(3)), exhibited differences of up to 75%. Chamber concentrations of carbonyls (formaldehyde, acetaldehyde, acetone and propanale) are of a few microg m(-3). Acetone and formaldehyde reach concentrations up to 15 and 10 microg m(-3), respectively.

Characterisation of urban inhalation exposures to benzene, formaldehyde and acetaldehyde in the European Union: comparison of measured and modelled exposure data.

BACKGROUND, AIM AND SCOPE: All across Europe, people live and work in indoor environments. On average, people spend around 90% of their time indoors (homes, workplaces, cars and public transport means, etc.) and are exposed to a complex mixture of pollutants at concentration levels that are often several times higher than outdoors. These pollutants are emitted by different sources indoors and outdoors and include volatile organic compounds (VOCs), carbonyls (aldehydes and ketones) and other chemical substances often adsorbed on particles. Moreover, legal obligations opposed by legislations, such as the European Union's General Product Safety Directive (GPSD) and Registration, Evaluation, Authorisation and Restriction of Chemicals (REACH), increasingly require detailed understanding of where and how chemical substances are used throughout their life-cycle and require better characterisation of their emissions and exposure. This information is essential to be able to control emissions from sources aiming at a reduction of adverse health effects. Scientifically sound human risk assessment procedures based on qualitative and quantitative human exposure information allows a better characterisation of population exposures to chemical substances. In this context, the current paper compares inhalation exposures to three health-based EU priority substances, i.e. benzene, formaldehyde and acetaldehyde. MATERIALS AND METHODS: Distributions of urban population inhalation exposures, indoor and outdoor concentrations were created on the basis of measured AIRMEX data in 12 European cities and compared to results from existing European population exposure studies published within the scientific literature. By pooling all EU city personal exposure, indoor and outdoor concentration means, representative EU city cumulative frequency distributions were created. Population exposures were modelled with a microenvironment model using the time spent and concentrations in four microenvironments, i.e. indoors at home and at work, outdoors at work and in transit, as input parameters. Pooled EU city inhalation exposures were compared to modelled population exposures. The contributions of these microenvironments to the total daily inhalation exposure of formaldehyde, benzene and acetaldehyde were estimated. Inhalation exposures were compared to the EU annual ambient benzene air quality guideline (5 microg/m3-to be met by 2010) and the recommended (based on the INDEX project) 30-min average formaldehyde limit value (30 microg/m3). RESULTS: Indoor inhalation exposure contributions are much higher compared to the outdoor or in-transit microenvironment contributions, accounting for almost 99% in the case of formaldehyde. The highest in-transit exposure contribution was found for benzene; 29.4% of the total inhalation exposure contribution. Comparing the pooled AIRMEX EU city inhalation exposures with the modelled exposures, benzene, formaldehyde and acetaldehyde exposures are 5.1, 17.3 and 11.8 microg/m3 vs. 5.1, 20.1 and 10.2 microg/m3, respectively. Together with the fact that a dominating fraction of time is spent indoors (>90%), the total inhalation exposure is mostly driven by the time spent indoors. DISCUSSION: The approach used in this paper faced three challenges concerning exposure and time-activity data, comparability and scarce or missing in-transit data inducing careful interpretation of the results. The results obtained by AIRMEX underline that many European urban populations are still exposed to elevated levels of benzene and formaldehyde in the inhaled air. It is still likely that the annual ambient benzene air quality guideline of 5 microg/m3 in the EU and recommended formaldehyde 30-min average limit value of 30 microg/m3 are exceeded by a substantial part of populations living in urban areas. Considering multimedia and multi-pathway exposure to acetaldehyde, the biggest exposure contribution was found to be related to dietary behaviour rather than to inhalation. CONCLUSIONS: In the present study, inhalation exposures of urban populations were assessed on the basis of novel and existing exposure data. The indoor residential microenvironment contributed most to the total daily urban population inhalation exposure. The results presented in this paper suggest that a significant part of the populations living in European cities exceed the annual ambient benzene air quality guideline of 5 microg/m3 in the EU and recommended (INDEX project) formaldehyde 30-min average limit value of 30 microg/m3. RECOMMENDATIONS AND PERSPECTIVES: To reduce exposures and consequent health effects, adequate measures must be taken to diminish emissions from sources such as materials and products that especially emit benzene and formaldehyde in indoor air. In parallel, measures can be taken aiming at reducing the outdoor pollution contribution indoors. Besides emission reduction, mechanisms to effectively monitor and manage the indoor air quality should be established. These mechanisms could be developed by setting up appropriate EU indoor air guidelines.

[Evaluation of total exposure to benzene and formaldehyde in the European countries]. / Valutazione dell'esposizione totale a benzene e formaldeide nei paesi europei.

Benzene and formaldehyde are among the principal components in the air of various indoor occupational and non-occupational environments. Both compounds are toxicologically relevant for humans as recognized carcinogens. In order to evaluate the total exposure and to assess the possible health risk caused by benzene and formaldehyde for different population groups at European level, the JRC Institute for Health and Consumer Protection in Ispra launched the AIRMEX (IndoorAir Monitoring and ExposureAssessment Study) project in October 2003. It aims at identifying and quantifying the main indoor pollutants particularly in kindergartens, schools and public buildings. It also intends to evaluate the overall exposure of people working and occupying these areas. Measuring campaigns were carried out in pre-selected indoor environments in various European cities (Catania, Athens, Arnhem, Nijmegen, Brussels, Thessaloniki). Preliminary results clearly indicate that indoor air concentrations for volatile compounds (VOC) including benzene are higher than/or similar to those found outdoors, ranging from a few micrograms (about 8 microg/m3) to 281 microg/m3. Outdoor concentrations vary from 7 to 153 microg/m3. Personal exposure concentrations are generally higher than the indoor/outdoor concentrations. In most cases they are twice as high as indoor concentrations (or even higher) and significantly higher than outdoor concentrations. Air concentrations of aldehydes inside buildings/kindergartens were up to 7-8 times higher than outside. This mostly concerns formaldehyde, and it seems that strong indoor sources exist which clearly determine the indoor air concentrations. Formaldehyde concentrations in public buildings and offices vary from 3 to 30 microg/m3, and those in kindergartens vary from 6 to 11 microg/m3 (Arnhem/Nijmegen). The highest values for formaldehyde, up to 29,9 microg/m3, were found in Catania, Athens and Thessaloniki.

Building materials. VOC emissions, diffusion behaviour and implications from their use.

Five cement- and five lime-based building materials were examined in an environmental chamber for their emissions of Volatile Organic Compounds (VOCs). Typical VOCs were below detection limits, whereas not routinely analysed VOCs, like neopentyl glycol (NPG), dominated the cement-based products emissions, where, after 72 h, it was found to occur, in levels as high as 1400 µg m(-3), accounting for up to 93% of total VOCs. The concentrations of NPG were not considerably changed between the 24 and 72 h of sampling. The permeability of building materials was assessed through experiments with a dual environmental chamber; it was shown that building materials facilitate the diffusion of chemicals through their pores, reaching equilibrium relatively fast (6 h).

Investigation of volatile organic compounds and phthalates present in the cabin air of used private cars.

The presence of selected volatile organic compounds (VOCs) including aromatic, aliphatic compounds and low molecular weight carbonyls, and a target set of phthalates were investigated in the interior of 23 used private cars during the summer and winter. VOC concentrations often exceeded levels typically found in residential indoor air, e.g. benzene concentrations reached values of up to 149.1 microg m(-3). Overall concentrations were 40% higher in summer, with temperatures inside the cars reaching up to 70 degrees C. The most frequently detected phthalates were di-n-butyl-phthalate and bis-(2-ethylhexyl) phthalate in concentrations ranging from 196 to 3656 ng m(-3).

Identification of 2,3-dimethyl-2,3-diisobutyl succinonitrile in laser printer emissions.

2,3-Dimethyl-2,3-diisobutyl succinonitrile was identified as the main volatile organic compound (>90%) emitted from laser printers during the printing process. Experiments were carried out in a large environmental chamber of 30 m3, where the printers were placed and working simulating 'real office setting' conditions. Air samples were taken on Tenax TA adsorbent cartridges in the vicinity of the printers and further analyzed by thermal desorption gas chromatography/mass spectrometry (TDGC/MS). The structure of the compound has been determined and is presented in this study. Additional data obtained by nuclear magnetic resonance (NMR), Fourier transform infrared (FTIR) spectroscopy, and liquid chromatography/tandem mass spectrometry (LC/MS/MS) support the proposed structure, with no reported CAS number, as 2,3-dimethyl-2,3-diisobutyl succinonitrile. It is a byproduct of the thermal decomposition of 2,2'-azobis(2,4-dimethyl valeronitrile), a commercially available free radical polymerization initiator used in polymerization processes during the manufacture of the toners. By means of head-space GC/MS, 15 toners used in black & white and colour printers have been investigated. Six of them contained 2,3-dimethyl-2,3-diisobutyl succinonitrile, which has also been detected in the respective processed paper.