bluuebunny/crossref_metadata_2025_split huggingface dataset:
Deciduous Dentition of Fossil Hominins
Authors: Bailey Shara E 
Published: January 2017

Abstract

The deciduous dentition is the first of two successive sets of teeth in humans. It consists of 20 teeth that are shed and replaced by the permanent teeth, of which there are 32. The most significant differences in the teeth of fossil hominins and great apes are the reduction of canine size, the change in canine shape and the increased complexity of the deciduous lower first molar. At about 2.5 million years ago, one hominin lineage –
Paranthropus
– continued to increase size and complexity of molars, and reduce canine and incisor size, while the lineage leading to our species
Homo sapiens
underwent dental reduction and simplification. Compared to earlier hominins, the deciduous teeth of recent humans are greatly reduced in size and complexity. However, the range of size and morphological variation among geographic populations is very wide, especially for deciduous first molars.

Key Concepts

Hominin deciduous teeth differ from those of great apes primarily in the size and shape of the upper and lower canines and shape of lower first molar.

Hominin deciduous incisors are smaller than those of great apes and early hominin upper incisors are more heteromorphic (greater differences in size between lateral and central incisors).

Hominin deciduous canines are shorter, smaller and less pointed than those of great apes.

Hominin deciduous canines are more diamond shaped and less conical than those of great apes.

Hominin deciduous lower first molars are nonsectorial and have more cusps than those of great apes.

Hominin deciduous molars are larger and may be morphologically more complex than those of great apes.

The genus
Homo
is characterised by incisor expansion, further canine diminution and molar reduction.

Neanderthals can be statistically distinguished from
Homo sapiens
in the shape and cusp size of deciduous molars.

Recent humans are highly variable compared to their fossil relatives, but tend to have even smaller and more simplified canines and postcanine teeth.
Cranial Vault Thickness in the Genus

H
omo
Authors: Copes Lynn E 
Published: January 2017

Abstract

Cranial vault thickness (CVT) has been noted to vary across members of the genus
Homo
, peaking in
Homo erectus
and declining more recently.
Homo sapiens
, for example, have been noted to have particularly thin vaulted crania. However, the variation within and between species has less frequently been investigated. Cranial vaults are also made up of component layers: two cortical and one trabecular (diploë), and the thickness of these layers may vary independently or in predictable ways. The data on variation in CVT in modern
H. sapiens
and extinct members of the genus
Homo
are reviewed along with the hypotheses for the purported hypertrophic vaults in
H. erectus
. The hypotheses include interpersonal violence providing selective pressure for increased CVT, biomechanical pressures from elongated vault shape, allometric scaling, mechanical forces from increased mastication and systemic increases in growth hormones from exercise.

Key Concepts

Cranial vaults are made up of three layers: inner and outer layers are cortical or compact bone, which sandwich a middle trabecular layer called diploë.

Total cranial vault thickness in modern
Homo sapiens
may vary with age, sex, bone type or genetic ancestry.

Some fossil human ancestors had thicker or thinner cranial vaults than modern humans.

There are no clear reasons for why one species or one individual has a thicker vault than another.
Hydroquinone‐Based Biarylic Polyphenols as Redox Organocatalysts for Dioxygen Reduction: Dramatic Effect of Orcinol Substituent on the Catalytic Activity
Authors: Lebeuf Raphaël , Nardello‐Rataj Véronique , Aubry Jean‐Marie 
Published: January 2017

AbstractA series of 18 new biaryls has been synthesized and investigated with regard to their organocatalytic efficiency. They consist of a hydroquinone core linked to a phenol or a resorcinol moiety. It is shown that the resorcinol moiety substituted on its meta position has a strong impact on the catalytic activities of these compounds towards the reduction of dioxygen by diethylhydroxylamine (DEHA) in aqueous medium. While the derivative consisting of the two cores spaced by three methylene units is completely inactive, substitution on the hydroquinone part leads to tremendously active catalysts, especially the biaryl consisting of methoxyhydroquinone‐orcinol. Two mechanisms are proposed to explain the dramatic efficiency of the novel hydroquinone‐based biarylic polyphenols for the catalytic reduction of dioxygen, both considering the influence of the orcinol moiety on the semiquinone anion intermediate. As a first hypothesis, this substituent could promote its direct reduction by DEHA to regenerate the hydroquinone, which will react again to regenerate the semiquinone. On the other hand, an intramolecular hydrogen bond could enhance the reactivity of the semiquinone anion toward dioxygen by an addition–elimination mechanism. In this case, the elimination would provide the corresponding quinone but, since the reduction of the quinones by DEHA is much slower than the observed kinetics, a reduction by DEHA prior to the elimination has to be considered to generate the semiquinone anion instead of the quinone.magnified image
Antibacterial PVA membranes containing TiO2/N‐halamine nanoparticles
Authors: Ma Wei , Li Lin , Li Jing , Ren Xuehong , Gu Zhi‐Guo , Huang Tung‐Shi 
Published: January 2017

AbstractInorganic–organic composites have received considerable attention due to their combined properties. In this study, a N‐halamine precursor poly[5,5‐dimethyl‐3‐(3′‐triethoxysilylpropyl)‐hydantoin] (PSPH) was synthesized and used for the production of inorganic–organic hybrid particles after reacting with nano‐TiO2 by a sol–gel process. The hybrid particles were characterized by FT‐IR, XRD, and TGA‐DTG. After chlorinated in the dilute sodium hypochlorite solution, antibacterial Cl‐PSPH‐TiO2 nanoparticles (NPS) could be obtained and used for production of polyvinyl alcohol (PVA) composite membranes. The synthesized PSPH‐TiO2/PVA composite membranes were characterized by SEM, FT‐IR, XRD, and TGA‐DTG. Meanwhile, antibacterial property, UV light stability, mechanical properties, and storage stability of the composite membranes were tested. The antibacterial composite membranes with Cl‐PSPH‐TiO2 could inactivate 99.97% of Staphylococcus aureus (3.03 logs) and 100% of Escherichia coli O157:H7 (6.12 logs) within 30 min. The antibacterial composite membranes also showed good UV light stability, regeneration ability, and excellent storage stability.
Copper(I)‐Catalyzed Cascade Dearomatization of Tryptophols with 3‐Indolylphenyliodonium Salts
Authors: Liu Chuan , Yi Ji‐Cheng , Dai Li‐Xin , You Shu‐Li 
Published: January 2017

AbstractA copper(I)‐catalyzed intermolecular cascade dearomatization reaction of 2‐substituted tryptophols with 3‐indolylphenyliodonium salts has been developed. This approach provided a direct and general access to versatile furoindolines with two quaternary stereogenic centers in good to excellent yields under mild reaction conditions.
A systematic review of sinonasal oncocytomas and oncocytic carcinomas: Diagnosis, management, and technical considerations
Authors: Hodzic Zerina , Rowan Nicholas R. , Kashiwazaki Ryota , Willson Thomas J. , Wang Eric W. , Lee Stella E. 
Published: January 2017

BackgroundOncocytomas and oncocytic carcinomas are rare tumors of the sinonasal cavity with the propensity for local invasion. This report and systematic review details a case of a nasal oncocytoma involving the lacrimal sac and provides an update of the current literature.MethodsA systematic literature review was performed using PubMed and Ovid databases. The data obtained from published articles with sinonasal oncocytoma/oncocytic carcinoma as the primary diagnosis included patient demographics, presentation, radiographic and histologic findings, management, and recurrence rates.ResultsTwenty cases were identified. The most common symptoms were epistaxis (n = 11) and nasal obstruction (n = 11). Involvement of the nasal cavity was most common (n = 17), followed by the paranasal sinuses (n = 13) and nasolacrimal apparatus (n = 4). Recurrence occurred in 55% of cases. Recurrence was associated with invasion or infiltration found on histology or the presence of both invasion/infiltration and mitotic figures/pleomorphism (p < 0.05), with no significant relationship between recurrence and age at diagnosis (p = 0.42), sex (p = 0.65), and location of tumor (p = 0.14). The authors present the case of a 73‐year‐old woman with a 5‐month history of worsening epistaxis and biopsy‐proven oncocytoma. Complete surgical resection of the tumor using combined endonasal endoscopic and anterior orbitotomy approach is described.ConclusionOncocytomas and oncocytic carcinomas are rare tumors of the sinonasal cavity with a high rate of local recurrence and orbital involvement. Surgical resection is the treatment of choice and complete resection can be achieved with an endoscopic endonasal approach.
Computational fluid dynamic modeling of nose‐to‐ceiling head positioning for sphenoid sinus irrigation
Authors: Craig John R. , Palmer James N. , Zhao Kai 
Published: January 2017

BackgroundAfter sinus surgery, patients are commonly instructed to irrigate with saline irrigations with their heads over a sink and noses directed inferiorly (nose‐to‐floor). Although irrigations can penetrate the sinuses in this head position, no study has assessed whether sphenoid sinus penetration can be improved by irrigating with the nose directed superiorly (nose‐to‐ceiling). The purpose of this study was to use a validated computational fluid dynamics (CFD) model of sinus irrigations to assess the difference in sphenoid sinus delivery of irrigations after irrigating in a nose‐to‐floor vs nose‐to‐ceiling head position.MethodsBilateral maxillary antrostomies, total ethmoidectomies, wide sphenoidotomies, and a Draf III frontal sinusotomy were performed on a single fresh cadaver head. CFD models were created from postoperative computed tomography maxillofacial scans. CFD modeling software was used to simulate a 120‐mL irrigation to the left nasal cavity with the following parameters: flow rate 30 mL/second, angle of irrigation 20 degrees to the nasal floor, and either nose‐to‐floor or nose‐to‐ceiling head positioning.ResultsIn the postoperative CFD models, the sphenoid sinuses were completely penetrated by the irrigation while in a nose‐to‐ceiling head position. However, no sphenoid sinus penetration occurred in the nose‐to‐floor position. Other sinuses were similarly penetrated in both head positions, although the ipsilateral maxillary sinus was less penetrated in the nose‐to‐ceiling position.ConclusionCFD modeling demonstrated that the nose‐to‐ceiling head position was superior to the nose‐to‐floor position in delivering a 120‐mL irrigation to the sphenoid sinuses.
An Ultrastable and Easily Regenerated Hydrogen‐Bonded Organic Molecular Framework with Permanent Porosity
Authors: Hu Falu , Liu Caiping , Wu Mingyan , Pang Jiandong , Jiang Feilong , Yuan Daqiang , Hong Maochun 
Published: January 2017

AbstractA robust hydrogen‐bonded organic framework HOF‐TCBP (H4TCBP=3,3′,5,5′‐tetrakis‐(4‐carboxyphenyl)‐1,1′‐biphenyl) has been successfully constructed and structurally characterized. It possesses a permanent 3D porous structure with a 5‐fold interpenetrated dia topological network. This activated HOF‐TCBP has a high BET surface area of 2066 m2 g−1 and is capable of highly selective adsorption and separation of light hydrocarbons under ambient conditions. It shows excellent thermal stability, as demonstrated by PXRD experiments and N2 adsorption tests. Practical use of HOF‐TCBP is facilitated by the ease of its preparation and renewal through rotary evaporation.
Nucleotide‐Independent Copper(II)‐Based Distance Measurements in DNA by Pulsed ESR Spectroscopy
Authors: Lawless Matthew J. , Sarver Jessica L. , Saxena Sunil 
Published: January 2017

AbstractA site‐specific Cu2+ binding motif within a DNA duplex for distance measurements by ESR spectroscopy is reported. This motif utilizes a commercially available 2,2′‐dipicolylamine (DPA) phosphormadite easily incorporated into any DNA oligonucleotide during initial DNA synthesis. The method only requires the simple post‐synthetic addition of Cu2+ without the need for further chemical modification. Notably, the label is positioned within the DNA duplex, as opposed to outside the helical perimeter, for an accurate measurement of duplex distance. A distance of 2.7 nm was measured on a doubly Cu2+‐labeled DNA sequence, which is in exact agreement with the expected distance from both DNA modeling and molecular dynamic simulations. This result suggests that with this labeling strategy the ESR measured distance directly reports on backbone DNA distance, without the need for further modeling. Furthermore, the labeling strategy is structure‐ and nucleotide‐independent.
Copper‐Catalyzed Three‐Component Annulations of Alkenes, Nitrosoarenes, and N‐Hydroxyallylamines To Form Fused Oxazinane/Isoxazolidine Heterocycles
Authors: Kawade Rahul Kisan , Liu Rai‐Shung 
Published: January 2017

AbstractOne‐pot cascade annulations among nitrosoarenes, alkenes, and N‐hydroxyallylamines have been achieved with CuCl/O2 catalysts, forming fused oxazinane/isoxazolidine heterocycles with excellent diastereoselectivity (d.r. >20:1). To enhance the synthetic utility, we developed a successive cleavage of the two N−O bonds of the resulting heterocycles. A mechanism involving dipolar [3+2] cycloadditions of nitrone intermediates with their tethered alkenes is postulated for formation of these heterocycles.
Stereodivergent‐at‐Metal Synthesis of [60]Fullerene Hybrids
Authors: Marco‐Martínez Juan , Vidal Sara , Fernández Israel , Filippone Salvatore , Martín Nazario 
Published: January 2017

AbstractChiral fullerene–metal hybrids with complete control over the four stereogenic centers, including the absolute configuration of the metal atom, have been synthesized for the first time. The stereochemistry of the four chiral centers formed during [60]fullerene functionalization is the result of both the chiral catalysts employed and the diastereoselective addition of the metal complexes used (iridium, rhodium, or ruthenium). DFT calculations underpin the observed configurational stability at the metal center, which does not undergo an epimerization process.
Diversity‐Oriented Synthesis of Cyclic Azapeptides by A3‐Macrocyclization Provides High‐Affinity CD36‐Modulating Peptidomimetics
Authors: Zhang Jinqiang , Mulumba Mukandila , Ong Huy , Lubell William D. 
Published: January 2017

AbstractMacrocyclization has enabled the use of peptides in drug discovery creating a need for methods to synthesize diverse peptide macrocycles. Azapeptides have advanced to clinically used drugs, however, few cyclic azapeptides have been studied. A multiple component “A3‐macrocyclization” strategy is described for the preparation of diverse cyclic azapeptides and is demonstrated by the synthesis of 15 growth hormone releasing hormone‐6 (GHRP‐6) analogs. Certain cyclic aza‐GHRP‐6 analogs exhibited unprecedented affinity for the CD36 receptor, and capacity to modulate Toll‐like receptor agonist‐induced overproduction of nitric oxide, and reduce pro‐inflammatory cytokine and chemokine production in macrophages.
Gold(I) Carbenoids: On‐Demand Access to Gold(I) Carbenes in Solution
Authors: Sarria Toro Juan M. , García‐Morales Cristina , Raducan Mihai , Smirnova Ekaterina S. , Echavarren Antonio M. 
Published: January 2017

AbstractChloromethylgold(I) complexes of phosphine, phosphite, and N‐heterocyclic carbene ligands are easily synthesized by reaction of trimethylsilyldiazomethane with the corresponding gold chloride precursors. Activation of these gold(I) carbenoids with a variety of chloride scavengers promotes reactivity typical of metallocarbenes in solution, namely homocoupling to ethylene, olefin cyclopropanation, and Buchner ring expansion of benzene.
A Columnar Liquid‐Crystal Phase Formed by Hydrogen‐Bonded Perylene Bisimide J‐Aggregates
Authors: Herbst Stefanie , Soberats Bartolome , Leowanawat Pawaret , Lehmann Matthias , Würthner Frank 
Published: January 2017

AbstractA new perylene bisimide (PBI) dye self‐assembles through hydrogen bonds and π–π interactions into J‐aggregates that in turn self‐organize into liquid‐crystalline (LC) columnar hexagonal domains. The PBI cores are organized with the transition dipole moments parallel to the columnar axis, which is an unprecedented structural organization in π‐conjugated columnar liquid crystals. Middle and wide‐angle X‐ray analyses reveal a helical structure consisting of three self‐assembled hydrogen‐bonded PBI strands that constitute a single column of the columnar hexagonal phase. This remarkable assembly mode for columnar liquid crystals may afford new anisotropic LC materials for applications in photonics.
Light‐Activated Sensitive Probes for Amine Detection
Authors: Valderrey Virginia , Bonasera Aurelio , Fredrich Sebastian , Hecht Stefan 
Published: January 2017

AbstractOur new, simple, and accurate colorimetric method is based on diarylethenes (DAEs) for the rapid detection of a wide range of primary and secondary amines. The probes consist of aldehyde‐ or ketone‐substituted diarylethenes, which undergo an amine‐induced decoloration reaction, selectively to give the ring‐closed isomer. Thus, these probes can be activated at the desired moment by light irradiation, with a sensitivity that allows the detection of amines at concentrations as low as 10−6 m in solution. In addition, the practical immobilization of DAEs on paper makes it possible to detect biogenic amines, such as cadaverine, in the gas phase above a threshold of 12 ppbv within 30 seconds.
Nucleating agent‐containing P(LLA‐mb‐BSA) multi‐block copolymers with balanced mechanical properties
Authors: Wu Binshuang , Zeng Xiaoqing , Wu Linbo , Li Bo‐Geng 
Published: January 2017

ABSTRACTIn order to obtain high performance bioplastics and thermoplastic elastomers, P(LLA‐mb‐BSA) multi‐block copolymers containing 30 wt % and 70 wt % soft segment (PLBSA30 and PLBSA70 for short) were synthesized via chain extension and coupling of poly(L‐lactic acid) (PLLA) and poly(butylene succinate‐co‐adipate) (PBSA) prepolymers in the presence of 1% nucleating agent (NA). They were characterized with proton nuclear magnetic resonance (1H NMR), gel permeation chromatography (GPC), differential scanning calorimetry (DSC), polarizing optical microscopy (POM), thermal gravimetric analysis (TGA), transmission electron microscope (TEM), and tensile and impact test. The relatively high molecular weights of (Mn 8200 g/mol and 3100 g/mol for PLLA and PBSA, respectively) the polyester sequences are helpful to improve the PLLA crystallization and the flexibility of the PBSA soft segment. Nucleation effect further accelerates the crystallization of PLLA segment. The synergistic effect of these factors results in good balance between stiffness and toughness. PLBSA30s containing 1% zinc citrate (ZnCC) or talc behave as ultra‐tough bioplastics with ultrahigh impact strength over 50 kJ/m2 and excellent tensile properties. PLBSA70 containing 1% ZnCC possesses elongation at break of 600% and retains high modulus (56 MPa) and strength (16 MPa) and therefore behaves as an excellent thermoplastic elastomer. The excellent and balanced properties would extend the end applications of these PLLA‐based materials. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44777.
Investigation of nanoyarn preparation by modified electrospinning setup
Authors: Levitt Ariana S. , Knittel Chelsea E. , Vallett Richard , Koerner Michael , Dion Genevieve , Schauer Caroline L. 
Published: January 2017

ABSTRACTHigher ordered structures of nanofibers, including nanofiber‐based yarns and cables, have a variety of potential applications, including wearable health monitoring systems, artificial tendons, and medical sutures. In this study, twisted assemblies of polyacrylonitrile (PAN), polyvinylidene fluoride trifluoroethylene (PVDF‐TrFe), and polycaprolactone (PCL) nanofibers were fabricated via a modified electrospinning setup, consisting of a rotating cone‐shaped copper collector, two syringe pumps, and two high voltage power supplies. The fiber diameters and twist angles varied as a function of the rotary speed of the collector. Mechanical testing of the yarns revealed that PVDF‐TrFe and PCL yarns have a higher strain‐to‐failure than PAN yarns, reaching 307% for PCL nanoyarns. For the first time, the porosity of nanofiber yarns was studied as a function of twist angle, showing that PAN nanoyarns are more porous than PCL yarns. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44813.
Effect of layer thickness on the electrical parameters and conduction mechanisms of conjugated polymer‐based heterojunction diode
Authors: Yıldız D. E. , Apaydın D. H. , Toppare L. , Cirpan A. 
Published: January 2017

ABSTRACTIn this study, thickness‐dependent current density–voltage (J–V) characteristics obtained for poly{(9,9‐dioctylfluorene)−2,7‐diyl‐(4,7‐bis(thien‐2‐yl) 2‐dodecyl‐benzo[1,2,3] triazole)} (PFTBT) conjugated copolymer based heterojunction diode fabricated on ITO were investigated in terms of electrical characteristics. In order to analyze J–V plots with ITO/PEDOT:PSS/PFTBT:PC61BM/LiF/Al configuration, the thickness‐dependent J–V measurements were applied in the thickness range between 90 and 200 nm. The effect of PFTBT:PC61BM layer thickness on the forward J–V characteristics were investigated by evaluating electrical parameters such as zero bias barrier height (ΦBo), ideality factor (n), shunt resistance (Rsh), series resistance (Rs), the interface states density (Nss), and space‐charge limited mobility. The results show that at PFTBT:PC61BM layer thickness of 90 and 200 nm, ideality factor for ITO/PEDOT:PSS/PFTBT:PC61BM/LiF/Al heterojunction diodes ranged from 2.726 to 3.121 and the thermionic emission over the heterojunction diodes is crucial at low current densities and the intrinsic thermally generated charge carriers controlled the forward current this region of the heterojunction diode. At relatively higher voltage, the current mechanism of ITO/PFTBT:PC61BM/PEDOT:PSS/LiF/Al heterojunction diodes were found to obey a space charge limited (SCLC) conduction mechanism. The values of Nss and Rs in heterojunction diodes increase with increasing PFTBT:PC61BM layer thickness and effect the main electrical parameters of diodes. In addition, the leakage current of heterojunction diodes are taken and interpreted via Poole‐Frenkel emission and Schottky emission. The leakage current was controlled in ITO/PEDOT:PSS/PFTBT:PC61BM/LiF/Al heterojunction diodes by Poole‐Frenkel emission above 140 nm and by Schottky emission under 140 nm. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44817.