bluuebunny/crossref_metadata_2025_split huggingface dataset:
Addendum to Tetrachloroethylene [BAT value documentation, 2018]
Authors: Bolt H.M. , Drexler H. , Hartwig A. ,   MAK Commission
Published: November 2019

Abstract

In 2017, the German Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area has re‐evaluated tetrachloroethylene [
127‐18‐4
], considering tetrachloroethylene in blood to characterize the internal exposure at the workplace. Available publications are described in detail.

The exposure equivalents for carcinogenic substances (EKA) of inhaled tetrachloroethylene and tetrachloroethylene in blood were confirmed and extended by recent data. The evaluation of the BAT value was based on the relationship between tetrachloroethylene uptake by inhalation at the MAK value and the corresponding concentration of tetrachloroethylene in blood. An eight‐hour exposure at the present MAK value of 10 ml tetrachloroethylene/m
3
correlates, 16 hours after exposure, with a mean tetrachloroethylene concentration in blood of approximately 200 µg/l. Hence, a BAT value of 200 µg tetrachloroethylene/l blood was evaluated. Sampling time is 16 hours after exposure.
Addendum zu Molybdän und seine Verbindungen [BAT value documentation in German language, 2019]
Authors: Michalke B. , Drexler H. , Hartwig A. ,   MAK Commission
Published: November 2019

Abstract
In 2018, the German Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area has re‐evaluated Molybdenum and its compounds. Available publications are described in detail.
In recent publications since the last evaluation in 2005 some authors investigated Molybdenum concentrations in blood or urine with respect to occupational Molybdenum exposure, however, without a conclusive outcome: The results of the different studies were either contradictory or missed respective exposure data and/or quality control measures. Therefore, no BAT value (biological tolerance value) was derived. However, some studies reported background concentrations in men, women or children, most of them with sufficiently applied quality control. In these studies, it was found that nutrition is the most important contribution to Molybdenum in urine. Several studies with quality control means and with sufficient statistical power revealed similar concentration ranges between 34–50 µg/L urine and/or 95% percentiles around 150 µg/L urine. In conclusion, a BAR of 150 µg Molybdenum/L urine was derived.
Tobacco‐specific nitrosamines – Determination of
N
‐nitrosoanabasine,
N
‐nitrosoanatabine,
N
‐nitrosonornicotine and 4‐(methylnitrosamino)‐1‐(3‐pyridyl)‐1‐butanol in urine by LC‐MS/MS [Biomonitoring methods, 2019]
Authors: Scherer G. , Gilch G. , Köhler D. , Völkel W. , Göen T. , Hartwig A. ,   MAK Commission
Published: November 2019

Abstract
The working group “Analyses in Biological Materials” of the Permanent Senate Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area developed and validated the presented biomonitoring method.

This analytical method permits the determination of tobacco‐specific nitrosamines (TSNA) in urine using liquid chromatography‐tandem mass spectrometry (LC‐MS/MS). The parameters in question are
N
‐nitrosoanabasine (NAB),
N
‐nitrosoanatabine (NAT),
N
‐nitrosonornicotine (NNN) and 4‐(methylnitrosamino)‐1‐(3‐pyridyl)‐1‐butanol (NNAL). NNAL is a metabolite of 4‐(methylnitrosamino)‐1‐(3‐pyridyl)‐1‐butanone (NNK). Due to its sensitivity, this method is suitable for the detection of the aforementioned analytes in the urine of smokers. NNAL can also be quantified in the urine of passive smokers.

The analytes NAB, NAT, NNN and NNAL are present in urine in both free and glucuronidated forms. For the determination of the total TSNA level in urine, the glucuronides are cleaved by enzymatic hydrolysis and then the analytes are isolated and concentrated using solid phase extraction (SPE). Two sorbent materials are used for sample preparation via SPE, first a material based on molecularly imprinted polymers and then a mixed‐mode cation exchange polymer. Analysis is performed by LC‐MS/MS. Deuterated internal standards are used for calibration. Calibration standards are prepared in pooled urine obtained from non‐smokers and are processed in the same way as the samples to be analysed.
1,4‐Dichlorobenzene [MAK Value Documentation, 2018]
Authors: Hartwig A. ,   MAK Commission
Published: November 2019

Abstract

The German Commission for the investigation of Health Hazards of Chemical Compounds in the Work Area has re‐evaluated 1,4‐dichlorobenzene [
106‐46‐7
] considering all toxicological endpoints. Available publications and unpublished study reports are described in detail.

In mouse liver, 1,4‐dichlorobenzene causes carcinoma after oral and inhalation exposure and is mitogenic and cytotoxic. In reliable studies it is not genotoxic. As a non‐genotoxic mechanism is of prime importance and genotoxic effects play at most a minor part, provided the maximum concentration at the workplace (MAK value) is observed, 1,4‐dichlororbenzene is now classified in Category 4 for carcinogenic substances.

The chronic local NOAEC of 20 ml/m
3
for changes in the olfactory epithelium of the rat nose would correspond to a MAK value of 10 ml/m
3
. However, the most sensitive toxicological effect is hepatocellular hypertrophy with a LOAEL of 10 mg/kg body weight and day in an oral 52‐week study with dogs. Because of the low severity and incidence of the effect, a NAEL (no adverse effect level) of 5 mg/kg body weight and day is assumed. This NAEL is scaled to a MAK value of 2 ml/m
3
.

Since a systemic effect is critical, Peak Limitation Category II is assigned. As it is not known if the effects are due to the metabolites or 1,4‐dichlorobenzene itself, the default excursion factor of 2 is assigned.

The NOAECs for developmental toxicity in rats and rabbits are 500 and 100 ml/m
3
, respectively, and the differences to the MAK value are sufficient. Therefore, damage to the embryo or foetus is unlikely when the MAK value is observed and 1,4‐dichlorobenzene is assigned to Pregnancy Risk Group C. Skin contact may contribute significantly to systemic toxicity and 1,4‐dichlorobenzene remains designated with an “H” notation. Sensitization is not expected from the limited data.
Di‐
tert
‐dodecyl pentasulfide /Di‐
tert
‐dodecyl polysulfide [MAK value documentation, 2018]
Authors: Hartwig A. ,   MAK Commission
Published: November 2019

Abstract

The German Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area has re‐evaluated the maximum concentration at the work place (MAK value), the Pregnancy Risk Group and the absorption through the skin of di‐
tert
‐dodecyl pentasulfide [
31565‐23‐8
] and di‐
tert
‐dodecyl polysulfide [
68583‐56‐2
;
68425‐15‐0
].

The systemic toxicity is low and the substances are at most minimally irritating to skin and eye. Acidophilic globuli are present in the kidney of male rats in an oral 28‐day study at 50 mg/kg body weight and day, presumably resulting from an α2u‐globulin mediated kidney toxicity which, however, has not actually been proven. Based on this LOAEC the MAK value would be 10 mg/m
3
. However, the substances are poorly water‐soluble liquids and an accumulation in the lung is expected. Most of the di‐
tert
‐dodecyl pentasulfide and di‐
tert
‐dodecyl polysulfide molecule consists of hydrocarbon chains resulting in characteristics similar to severely refined mineral oil, for which a MAK value of 5 mg/m
3
had been set as the respirable fraction (R) based on inhalation studies. Therefore, the MAK‐value for di‐
tert
‐dodecyl pentasulfide and di‐
tert
‐dodecyl polysulfide is also set at 5 mg/m
3
R. Peak Limitation is designated as well by analogy with severely refined mineral oil with Category II and excursion factor of 4.

New data on developmental toxicity are not available. As the MAK value is lowered, Pregnancy Risk Group C is retained. Skin contact is not expected to contribute significantly to systemic toxicity.
Di‐
n
‐butyl phthalate [MAK value documentation, 2017]
Authors: Hartwig A. ,   MAK Commission
Published: November 2019

Abstract

The German Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area has re‐evaluated the developmental toxicity of di‐
n
‐butyl phthalate. Available publications are described in detail. In prenatal developmental toxicity studies in rats, the most sensitive endpoint was altered morphometry (size and organization) of the seminiferous cords, the precursor of the seminiferous tubules, at 50 mg/kg body weight and day and above; the NOAEL was 30 mg/kg body weight and day. In rats, teratogenic effects like hypospadia and underdeveloped or absent epididymides were observed at 250 mg/kg KG body weight and day and above; the NOAEL was 100 mg/kg body weight and day.

In a two‐generation reproduction toxicity study in rats, a LOAEL of 80 mg/kg body weight and day, the lowest dose, could be derived for foetotoxicity and decreased live pup weight at birth. In rats, the NOAEL for behavioural toxicity is 291 mg/kg body weight and day in male pups. From a one‐generation reproduction toxicity study in mice, a NOAEL of 420 mg/kg body weight and day could be derived for foetotoxicity and decreased number of live pups. The NOAELs and the LOAEL for developmental toxicity and foetotoxicity can be scaled to concentrations of 32, 107, 84 (LOAEL) and 252 mg/m
3
, respectively, at the workplace. Thus, damage to the embryo or foetus is unlikely when the MAK value of 0.58 mg/m
3
is not exceeded, and the classification in Pregnancy Risk Group C is confirmed.
Remotely Triggered Assembly of 3D Mesostructures Through Shape‐Memory Effects
Authors: Park Jun Kyu , Nan Kewang , Luan Haiwen , Zheng Ning , Zhao Shiwei , Zhang Hang , Cheng Xu , Wang Heling , Li Kan , Xie Tao , Huang Yonggang , Zhang Yihui , Kim Seok , Rogers John A. 
Published: November 2019

Abstract3D structures that incorporate high‐performance electronic materials and allow for remote, on‐demand 3D shape reconfiguration are of interest for applications that range from ingestible medical devices and microrobotics to tunable optoelectronics. Here, materials and design approaches are introduced for assembly of such systems via controlled mechanical buckling of 2D precursors built on shape‐memory polymer (SMP) substrates. The temporary shape fixing and recovery of SMPs, governed by thermomechanical loading, provide deterministic control over the assembly and reconfiguration processes, including a range of mechanical manipulations facilitated by the elastic and highly stretchable properties of the materials. Experimental demonstrations include 3D mesostructures of various geometries and length scales, as well as 3D aquatic platforms that can change trajectories and release small objects on demand. The results create many opportunities for advanced, programmable 3D microsystem technologies.
Versatile Homoleptic Naphthyl‐Acetylide Heteronuclear [Pt2M4(CC‐Np)8] (M = Ag, Cu) Phosphors for Highly Efficient White and NIR Hybrid Light‐Emitting Diodes
Authors: Fresta Elisa , Fernández‐Cestau Julio , Gil Belén , Montaño Patricia , Berenguer Jesús R. , Moreno María Teresa , Coto Pedro B. , Lalinde Elena , Costa Rubén D. 
Published: November 2019

AbstractA new family of low‐energy emitting organic phosphors (OPs) based on [Pt2M4(CC‐1‐Np)8] clusters, in which M is either Ag(I) (1) or Cu(I) (2) and CC‐1‐Np is the strongly delocalized 1‐naphthylacetylide ligand, are presented. The inclusion of the 1‐naphthylacetylide moiety is crucial to achieve very emissive and stable OPs that do not experience photoinduced heat generation and oxidation in both white and NIR hybrid light‐emitting diodes (HLEDs) operating under ambient conditions. In short, the first use of these novel OPs leads to i) HLEDs with NIR emission centered at 730 nm, color purity close to 0.99, and remarkable luminous efficacies of ≈1.5 lm W−1 that is comparable to commercial NIR‐LEDs and ii) daylight white LEDs with luminous efficacies of 75 lm W−1 and stabilities of >500 h. Thus, this work provides relevant information for the synthesis, design, and application of a new family of low‐energy emitting OPs toward efficient and stable white and NIR hybrid LEDs.
Identification of Bond‐Weakening Spirosilane Catalyst for Photoredox α‐C−H Alkylation of Alcohols
Authors: Sakai Kentaro , Oisaki Kounosuke , Kanai Motomu 
Published: November 2019

AbstractThe development of catalyst‐controlled site‐selective C(sp3)−H functionalization is a current major challenge in organic synthesis. This paper describes DFT‐guided identification of pentavalent silicate species as a novel bond‐weakening catalyst for the α‐C−H bonds of alcohols together with a photoredox catalyst and a hydrogen atom transfer catalyst. Specifically, Martin's spirosilane accelerated α‐C−H alkylation of alcohols.magnified image
A Large Anisotropic Enhancement of the Charge Carrier Mobility of Flexible Organic Transistors with Strain: A Hall Effect and Raman Study
Authors: Choi Hyun Ho , Yi Hee Taek , Tsurumi Junto , Kim Jae Joon , Briseno Alejandro L. , Watanabe Shun , Takeya Jun , Cho Kilwon , Podzorov Vitaly 
Published: November 2019

AbstractUtilizing the intrinsic mobility–strain relationship in semiconductors is critical for enabling strain engineering applications in high‐performance flexible electronics. Here, measurements of Hall effect and Raman spectra of an organic semiconductor as a function of uniaxial mechanical strain are reported. This study reveals a very strong, anisotropic, and reversible modulation of the intrinsic (trap‐free) charge carrier mobility of single‐crystal rubrene transistors with strain, showing that the effective mobility of organic circuits can be enhanced by up to 100% with only 1% of compressive strain. Consistently, Raman spectroscopy reveals a systematic shift of the low‐frequency Raman modes of rubrene to higher (lower) frequencies with compressive (tensile) strain, which is indicative of a reduction (enhancement) of thermal molecular disorder in the crystal with strain. This study lays the foundation of the strain engineering in organic electronics and advances the knowledge of the relationship between the carrier mobility, low‐frequency vibrational modes, strain, and molecular disorder in organic semiconductors.
Multifunctional Ultrastretchable Printed Soft Electronic Devices for Wearable Applications
Authors: Tian Bin , Liu Qun , Luo Chengsheng , Feng Yu , Wu Wei 
Published: November 2019

AbstractMultifunctionality is a major development trend in flexible stretchable wearable electronics, requiring integration of electrical conductivity, sensing performance, and heating management on a portable electronic device. Herein, the silver fractal dendrites (Ag FDs) conductive ink is formulated and deposited into the polystyrene–block–polyisoprene–block–polystyrene (SIS) thin films by a simple and cost‐effective transfer‐printing method for preparing the patterned multifunctional wearable electronics (MWEs). The MWEs based on Ag FDs ink‐38 wt% exhibit high electrical conductivity (4.86 × 105 S m−1), excellent sensing property (highly stretchability of 500% with a maximum gauge factor (GF) of 659.5), low‐voltage driving Joule heating performance (heated to 52.3 °C at 1 V), and good mechanical stability. As strain sensors, the MWEs have been successfully used to monitor the bending motion of the six major joints in the human body. As Joule heaters, the MWEs have been successfully used for thermochromism and hyperthermia. The developed MWEs prepared by a simple and low‐cost transfer‐printing possess highly promising application for next‐generation multifunctional and smart wearable electronics.
High‐Voltage Photogeneration Exclusively via Aggregation‐Induced Triplet States in a Heavy‐Atom‐Free Nonplanar Organic Semiconductor
Authors: Davy Nicholas C. , Koch Marius , Ngongang Ndjawa Guy Olivier , Lin Xin , Man Gabriel J. , Lin YunHui L. , Sorli Jeni C. , Rand Barry P. , Kahn Antoine , Scholes Gregory D. , Loo Yueh‐Lin 
Published: November 2019

AbstractThe electron–hole recombination kinetics of organic photovoltaics (OPVs) are known to be sensitive to the relative energies of triplet and charge‐transfer (CT) states. Yet, the role of exciton spin in systems having CT states above 1.7 eV—like those in near‐ultraviolet‐harvesting OPVs—has largely not been investigated. Here, aggregation‐induced room‐temperature intersystem crossing (ISC) to facilitate exciton harvesting in OPVs having CT states as high as 2.3 eV and open‐circuit voltages exceeding 1.6 V is reported. Triplet excimers from energy‐band splitting result in ultrafast CT and charge separation with nonradiative energy losses of <250 meV, suggesting that a 0.1 eV driving force is sufficient for charge separation, with entropic gain via CT state delocalization being the main driver for exciton dissociation and generation of free charges. This finding can inform engineering of next‐generation active materials and films for near‐ultraviolet OPVs with open‐circuit voltages exceeding 2 V. Contrary to general belief, this work reveals that exclusive and efficient ISC need not require heavy‐atom‐containing active materials. Molecular aggregation through thin‐film processing provides an alternative route to accessing 100% triplet states on photoexcitation.
Positional behavior and substrate use in wild adult bearded capuchin monkeys (Sapajus libidinosus)
Authors: Wright Kristin A. , Biondi Luiz , Visalberghi Elisabetta , Ma Ziyang , Izar Patricia , Fragaszy Dorothy 
Published: November 2019

AbstractNatural selection for positional behavior (posture and locomotion) has at least partially driven the evolution of anatomical form and function in the order Primates. Examination of bipedal behaviors associated with daily activity patterns, foraging, and terrestrial habitat use in nonhuman primates, particularly those that adopt bipedal postures and use bipedal locomotion, allows us to refine hypotheses concerning the evolution of bipedalism in humans. This study describes the positional behavior of wild bearded capuchins (Sapajus libidinosus), a species that is known for its use of terrestrial substrates and its habitual use of stones as tools. Here, we test the association of terrestrial substrate use with bipedal posture and locomotion, and the influence of sex (which co‐varies with body mass in adults of this species) on positional behavior and substrate use. Behavior and location of 16 wild adult bearded capuchins from two groups were sampled systematically at 15 s intervals for 2 min periods for 1 year (10,244 samples). Despite their different body masses, adult males (average 3.5 kg) and females (average 2.1 kg) in this study did not differ substantially in their positional behaviors, postures, or use of substrates for particular activities. The monkeys used terrestrial substrates in 27% of samples. Bipedal postures and behaviors, while not a prominent feature of their behavior, occurred in different forms on the two substrates. The monkeys crouched bipedally in trees, but did not use other bipedal postures in trees. While on terrestrial substrates, they also crouched bipedally but occasionally stood upright and moved bipedally with orthograde posture. Bearded capuchin monkeys' behavior supports the suggestion from anatomical analysis thatS. libidinosusis morphologically better adapted than its congeners to adopt orthograde postures.
Influence of food availability and climate on behavior patterns of western black crested gibbons (Nomascus concolor) at Mt. Wuliang, Yunnan, China
Authors: Ning Wen‐He , Guan Zhen‐Hua , Huang Bei , Fan Peng‐Fei , Jiang Xue‐Long 
Published: November 2019

AbstractFood abundance and climatic factors can significantly affect the behavior of animals and constrain their activity budgets. The population of western black crested gibbons (Nomascus concolor) in Mt. Wuliang lives in montane forest and is close to the northern extreme of the distribution for gibbons (Hylobatidae). Their habitats show remarkable seasonal variation in terms of food availability, temperature, and rainfall. To understand behavioral adaptations of western black crested gibbons to different sets of ecological conditions, we examined relationships among food availability, mean temperature, rainfall, and behavior patterns by observing two groups for 1 year each. Our results revealed that activity budget was affected by food availability and mean temperature. The gibbons spent more time eating flowers when that resource was more available and spent less time moving when fruit was more available. The gibbons spent less time feeding and more time resting, and spent less feeding time on fruit and leaves when the mean temperature was lower. These results suggest that the gibbons displayed a pronounced preference for flowers as a food resource and adopted a time minimizer strategy when high‐nutrient food items (i.e., fruit) were more available. In addition, the gibbons adopted an energy‐conserving strategy during periods of low temperature. The flexibility of behavioral patterns in responding to food availability and temperature may potentially improve the gibbons’ prospects of surviving and reproducing in a northern montane forest.
New landmarks in endonasal surgery: from nasal bone to anterior cribriform plate including branches of anterior ethmoidal artery and nerve and terminal nerve
Authors: Roussel Lise‐Marie , Patron Vincent , Maubert Eric , Escalard Clément , Goux Didier , Beaudouin Vincent , Lechapt Emmanuèle , Moreau Sylvain , Hitier Martin 
Published: November 2019

BackgroundDespite the development of anterior skull base surgery, the anatomy of the nasal bone and anterior cribriform plate remains unclear. A recent study confirmed 2 distinct foramina in the anterior part of cribriform plate: the ethmoidal slit (ES) and the cribroethmoidal foramen (CF). The aim of this study was to specify their content, their anatomic relationship to the frontal sinus and skull base, and their potential value in skull base surgery.MethodsDissections were performed on 36 cadaver heads. Macro‐ and microscopic examinations were carried out. Microcomputed tomography scans contrasted with osmium were performed to identify vessels and nerves. Histology with neural, meningeal, or luteinizing hormone‒releasing hormone immunomarkers was performed on the content of the foramina. Finally, endonasal surgical dissections were carried out.ResultsThe ES and the CF were observed in all cases. They measured a mean of 4.2 and 1.6 mm, respectively. The ES contained dura mater, arachnoid tissues, lymphatics, and the terminal nerve. The CF contained the anterior ethmoidal nerve and artery. This foramen continued forward with the cribroethmoidal groove, which measured a mean of 2.5 mm. This groove was under the frontal sinus and in front of the skull base. We also described a “cribroethmoidal canal” and a “nasal bone foramen.”ConclusionThe clinical applications of this new anatomic description concern both cribriform plate and frontal sinus surgeries. Identifying the terminal nerve passing through the ES is a step forward in understanding pheromone recognition in humans.