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In this paper, the N,N′-dicyclohexylterephthalamide (DCHT) with various morphologies and sizes was prepared by antisolvent precipitation at room temperature, and DCHT single crystals were also grown. Among them, DCHT crystals precipitated from deionized water (H2O), alcohol (C2H5OH) and N′N-dimethylformamide (DMF) are particle-like crystallites (DCHT-H2O), cuboid (DCHT-C2H5OH) and large rectangular crystals (DCHT-DMF), respectively. The powder XRD results show that the (002) plane is the dominant growth plane of the DCHT crystals, and the diffraction peak intensity of (100) plane is negatively correlated with the size of the DCHT crystals. The single-crystal XRD results show that the minimum distance between the two nearest DCHT molecules is the hydrogen bond distance (2.21 Å), and the (100) crystal plane is the plane of hydrogen bonding between DCHT molecules. Thus, it is speculated that the hydrogen bonding interaction is the main driving force for the growth of DCHT crystals. Further, the effect of different morphologies and sizes of DCHT on isotactic polypropylene (iPP) crystallization was investigated. Non-isothermal crystallization studies revealed that the DCHT size plays a decisive role in increasing the crystallization temperature of iPP. Through isothermal crystallization, it was found that the upper critical temperature of β-α growth "transition" of iPP could be related to the morphology of DCHT. Finally, the iPP film was attached to the surface of DCHT single crystal, and its crystallization behavior was studied. It is confirmed that the (001) plane is the epitaxial plane of DCHT to the β-iPP molecular chain, while the epitaxial plane of β-iPP is the (110) plane. [ABSTRACT FROM AUTHOR]

Ce-, Nd-, and Er-containing glasses based on the PbO–SiO2 binary system are synthesized. The process of mass crystallization for the production of glass-crystalline (ceramic glass) materials as a result of their heat treatment at different temperatures is studied. Compositions of glass ceramics with the indicated crystallization nucleators are developed. It is established that a glass-crystalline material with improved physicochemical properties has been synthesized at relatively low crystallization temperatures (750°C). [ABSTRACT FROM AUTHOR]

Due to children and adolescents' widespread use of electronic devices, researchers have focused on pre-and early postnatal electromagnetic field (EMF) exposure. However, little is known about the effects of EMF exposure on the optic nerve. The aim of study was to investigate the changes occurring in the optic nerve and the protective effects of melatonin (mel) and omega 3 (ω-3) in rats. Thirty-five pregnant rats were divided into seven groups, Cont, Sham, EMF, EMF + melatonin (EMF + Mel), EMF + ω3, Mel, and ω3. The EMF groups were exposed to 900 megahertz (MHz) EMF daily for two hours during pregnancy. After the experiment, the right optic nerve of each offspring rat was removed and fixed in glutaraldehyde. Thin and semi-thin sections were taken for electron microscopic and stereological analyses. Myelinated axon numbers, myelin sheath thicknesses, and axonal areas were estimated using stereological methods. The groups had no significant differences regarding mean numbers of axons, mean axonal areas, or mean myelin sheath thicknesses (p > 0.05). Histological observations revealed impaired lamellae in the myelin sheath of most axons, and vacuolization was frequently observed between the myelin sheath and axon in the EMF-exposed group. The Mel and ω-3-treated EMF groups exhibited well-preserved myelinated nerve fibers and intact astrocytes and oligodendrocytes. At the ultrastructural level, Mel and ω3 exhibits a neuroprotective effect on the optic nerve exposed to prenatal EMF. The protective effects of these antioxidants on oligodendrocytes, which play an essential role in myelin formation in the central nervous system, now require detailed investigation. [ABSTRACT FROM AUTHOR]

Monomer casting nylon‐6 (MC PA6), as a high‐performance engineering plastic, replaces metals to be widely applied, while further improving the mechanical properties of MC PA6 is significant for its withstanding heavy loads and increasing its range of applications. In this work, amide nucleating agent (NUDA) with good compatibility and crystal matching relationship with PA6 was firstly dissolved in ε‐caprolactam monomer, and MC PA6‐NUDA was synthesized in situ. NUDA self‐assembled into special frameworks and induced epiphytic crystallization of PA6 to form an enhanced sheaf‐like crystal on its surface with microfibrillar structure during the parallel polymerization–crystallization process. Incorporation of appropriate content of NUDA improved the melting/crystallization point and crystallinity with decreasing grain size obviously, and advanced the crystallization process of MC PA6 mainly via reducing the nucleation potential energy and inducing the formation of crystal nuclei. As a result, the glass transition temperature increased, the tensile strength exhibited a significant 22% increase and the fracture toughness was nearly three times that of neat MC PA6. Meanwhile, deformation with many yield folds as well as stress‐whitening phenomena were observed on the impact‐fractured surfaces, presenting a ductile fracture feature, indicating reinforcing and toughening effect of NUDA on the PA6 matrix. © 2023 Society of Industrial Chemistry. [ABSTRACT FROM AUTHOR]

The primary challenge of salt hydrates as phase change materials (PCMs) is their high degree of supercooling (∆TSup). Past studies have attempted to alleviate ∆TSup by incorporating nucleators possessing similar lattice structure, without a thorough analysis of the nucleator/PCM interactions. This work presents a novel in‐operando study to visually observe the crystallization process of zinc nitrate hexahydrate (ZNH) in real‐time using suitable nucleators and a thickener. We have introduced a new dataset where zinc acetate dihydrate (ZnAc.2H) has been employed as an additive to ZNH for thermal energy storage (TES). According to our in‐operando study, ZnAc.2H underwent hydrolysis in molten ZNH to precipitate needle‐like ZnO particles, which acted as nucleators for the PCM. In the absence of a thickener, the crystal propagation of ZNH exhibited a preferential directional tendency, whereas incorporation of thickener made the phase change process uniform along all directions. Self‐hydrolysis of ZnAc.2H generated excess water which caused the undesirable effect of broadening the endothermic peak. The addition of carboxymethyl cellulose (CMC) thickener could restrict the activity of excess water and reduce the broadening of the endothermic peak. Differential scanning calorimetry (DSC) revealed that 5 wt% ZnAc.2H additive and 2 wt% CMC thickener added to ZNH can considerably improve the TES properties of ZNH PCM (∆HFusion 125.9 J·g−1, ∆TSup 3.0°C, melting point [M.P.] 29.0°C). Our in‐operando studies can unveil real‐time phase change behaviors to better design PCM systems with desired characteristics. [ABSTRACT FROM AUTHOR]

Supercooling (∆TSup) is one of the crucial problems in utilizing a phase change material (PCM), which has been attempted to overcome using nucleators possessing small lattice disregistry without comprehensive understanding of the nucleation phenomenon. Here, this work studies the interactions between nucleators and PCM via in‐operando direct visualization for the first time, to the best of our knowledge, to better understand the crystallization process during freezing of a PCM using zinc nitrate hexahydrate (ZNH) and a zinc oxide (ZnO) nucleator. According to our in‐operando study, freezing was randomly initiated by only a fraction of the nucleator particles during each thermal cycling. However, previously unresponsive nucleators also suddenly crystalized PCM when the propagating crystal encountered them, improving the crystal initiation and thereby ∆TSup. Consequently, for equal wt% of ZnO, better nucleation behavior was obtained using uniformly distributed small nucleator particles throughout the PCM, as compared to either large or poorly distributed aggregated nucleators. DSC results using ZnO‐needle as nucleator confirmed a 38% and 33.3% lower ∆TSup upon employing 5 wt% small (individual) particles (~4 μm on average), as compared to using equal wt% of small (aggregated) particle clusters (~200 μm) and large particles (~46 μm), respectively. Crystallization of ZNH caused additional hair‐like ZnO growth preferentially decorated along lateral faces of the original nucleator particles. The in‐operando studies are valuable tools to correlate inherent crystallization phenomena to the practical thermal energy storage properties of the system. [ABSTRACT FROM AUTHOR]

The nucleator is a method to estimate the volume of a particle, i.e. a compact subset of ℝ3, which is widely used in Stereology. It is based on geometric sampling and known to be unbiased. However, the prediction of the variance of this estimator is non-trivial and depends on the underlying sampling scheme. We propose well established tools from quasi-Monte Carlo integration to address this problem. In particular, we show how the theory of reproducing kernel Hilbert spaces can be used for variance prediction and how the variance of estimators based on the nucleator idea can be reduced using lattice (or lattice-like) points. We illustrate and test our results on various examples.

The thermal properties of a sorbitol‐type nucleating agent (viz. 1,2,3‐trideoxy‐4,6:5,7‐bis‐O‐[(4‐propylphenyl)methylene]‐nonitol (TBPMN)) were examined in this study, and the influence of common processing additives assessed. In addition, we describe a novel approach to monitor in situ the self‐assembly of the nucleator in presence of additives by optical microscopy. The performance of sorbitol compounds is closely associated to their chemical structure and ability to self‐assemble. TBPMN formed elongated fibrils from the melt under inert atmosphere, in molted polypropylene, or in presence of antioxidants. However, calcium stearate (CaSt) and glycerol monostearate hampered growth, and yielded thinner fibrils. In presence of the additives, melting point depression of the nucleator occurred, and resulted in a lower degree of crystallinity upon cooling. Performance evaluation of the nucleator in polypropylene blends revealed an increased crystallization temperature when antioxidants were present, while CaSt inhibited nucleator activity. The effect of mono‐glycerides was found highly dependent on the processing conditions. Noteworthy, blends containing all the additives displayed the highest performance. This study highlights the importance of the preparation method of polymer additive blends to achieving the best performance in the final product. Characterization was performed by thermogravimetric analysis, Fourier‐transform infrared spectroscopy, optical microscopy, and differential scanning calorimetry. [ABSTRACT FROM AUTHOR]

A multiple amides-based linear organic compound (TMC-300) was synthesized and as an efficient nucleator was incorporated into PHBH to fabricate PHBH/TMC-300 composite to investigate effect of TMC-300 on crystallization behavior of PHBH in-depth. Nucleation capacity of TMC-300 on the PHBH is significantly higher than those of two conventional inorganic nucleators. TMC-300 exhibits dual effects on crystallization behavior of PHBH in terms of its weight fraction (fTMC-300). Low fTMC-300 increased substantially crystallization rate, crystallinity and crystal density, and decreased greatly crystallization time of PHBH, but relative higher fTMC-300 hindered slightly crystallization process. Hydrogen bond interaction exists between PHBH and TMC-300 and facilitates excellent dispersion of TMC-300 in PHBH matrix. In-situ FTIR measurement suggests that hydrogen interaction hindered reorganization of ester bond in crystallization process of PHBH. Mechanisms on nucleation of PHBH and effect of TMC-300 on crystallization behavior of PHBH, are proposed and discussed. [ABSTRACT FROM AUTHOR]

Nucleators (nucleating agents) have improved the properties of commodity plastics such as polypropylene (PP), where its properties are now comparable with those of engineering plastics such as polycarbonate and acrylonitrile butadiene styrene. 1 This has enabled commodity plastics to be used in more demanding applications such as baby feeding bottles that need to be sterilized by boiling water and disposable food containers that need very high flow and fast cycle time during production. In order to achieve the targeted performance of the various applications, a higher dosage of nucleator can be used to further enhance the nucleation of PP. However, this would come at the expense of add-on costs since the nucleator is probably the most expensive ingredient (in dollars per kg) in PP stabilization. In this research a non-nucleating coadditive, sodium myristate (NaMy), added into a DHT4A-stabilized homopolypropylene with Milliken Chemical's Hyperform® HPN68L nucleator (disodium salt of bicycle (2.2.1) heptane-2,3-dicarboxylic acid 2) via dry blending was found to be able to boost the nucleation efficiency of HPN68L in PP, thus improving the polymer's physical properties without increasing the HPN68L concentration. Subsequent tests showed that the optimum blend ratio of 300 ppm HPN68L and 200 ppm NaMy had improved the 300 ppm HPN68L-nucleated PP peak crystallization temperature (T c) by 2.3°C, clarity by 20.3%, cycle time by 8.9%, heat deflection temperature by 4°C and flexural modulus by 60 MPa. It was discovered that the improvements were due to improved dispersion of the nucleator in PP. Further investigation also demonstrated that coating of NaMy onto HPN68L via a novel coating technique was better than the dry blend method in improving dispersion of the nucleator, resulting in the best nucleation performance. [ABSTRACT FROM AUTHOR]

The nucleator is a design unbiased method of local stereology for estimating the volume of a bounded object. The only information required lies in the intersection of the object with an isotropic random ray emanating from a fixed point (called the pivotal point) associated with the object. For instance, the volume of a neuron can be estimated from a random ray emanating from its nucleolus. The nucleator is extensively used in biosciences because it is efficient and easy to apply. The estimator variance can be reduced by increasing the number of rays. In an earlier paper a systematic sampling design was proposed, and theoretical variance predictors were derived, for the corresponding volume estimator. Being the only variance predictors hitherto available for the nucleator, our basic goal was to check their statistical performance by means of Monte Carlo resampling on computer reconstructions of real objects. As a plus, the empirical distribution of the volume estimator revealed statistical properties of practical relevance.

In this study, a new liquid crystal polymer, named as smectic liquid crystal polymer (LCPs-P), was synthesized by reacting diosgenyl 4-(10-undecen-1-yloyloxy) benzoate with polymethylhydrosiloxane using chloroplatinic acid as a catalyst. The mesomorphic properties of the LCPs-P were characterized with polarizing optical microscopy, differential scanning calorimetry (DSC), thermogravimetric analysis, and X-ray diffraction (XRD). Then, the influence of the LCPs-P as a new nucleator on the crystallization structures, thermal properties, and kinetic properties of isotactic polypropylene (iPP) was investigated by XRD and DSC. The experimental results indicated that the LCPs-P exhibited fan-shaped texture of a smectic A phase between 55°C and 318°C. The content of the β-crystal (K β) of the iPP blends mainly depended on the LCPs-P content and the crystallization temperature. By optimally combining the LCPs-P content with the crystallization temperature, a high K β could be obtained. When the content of the LCPs-P was 0.9 wt%, the maximum K β could reach 51% after isothermal crystallization for 1 h at 130°C. Moreover, the addition of the LCPs-P could increase the crystallization temperature and shorten the crystallization time of the iPP blends. [ABSTRACT FROM AUTHOR]

Abstract Most phase change materials suffer from high supercooling degrees due to poor nucleating rates, and this reduces the effective heat capacities in energy storage systems. The application of carboxylated graphene oxide nanofiller to reduce such high supercooling degrees has been demonstrated in phase change materials for cold thermal energy storage. The efficacy of these modified graphene oxide has been clearly demonstrated by lowered supercooling degree while maintaining equally high latent heat as the phase change materials without nanofillers. The presence of additional carboxylic groups offer high dispersibility without the use of surfactant. [ABSTRACT FROM AUTHOR]

Summary: The pineal gland is a neuroendocrine organ associated with photoperiodic regulation in mammals. The aim of this study was to evaluate the pineal gland at the pre‐pubertal, pubertal and post‐pubertal periods by means of morphology and stereology. The study examined at total of 24 ovine pineal glands collected from healthy female Akkaraman breed. Thick sections (40 μm) were cut and treated with synaptophysin. Following each thick section, six consecutive sections at a thickness of 5 μm were cut. Each thin section was stained with one of the following dyes: Crossman’s modified triple dye, glial fibrillary acidic protein (GFAP), melatonin marker, periodic acid–Schiff, Von Kossa and AgNOR. The pineal gland volume was measured using Cavalieri’s method. The optical fractionator was used to estimate the total number of pinealocytes. The percentage of parenchyma and connective tissue and degree of vascularization were estimated by the area fraction fractionator method. The pineal gland volumes in the pre‐pubertal, pubertal and post‐pubertal groups were 7.53 ± 1.715 mm3, 11.20 ± 1.336 mm3 and 17.75 ± 1.188 mm3, respectively (p < .5). The number of pinealocytes in the pre‐pubertal, pubertal and post‐pubertal groups was 3,244,000 ± 228,076, 4,438,000 ± 243,610, 7,381,766 ± 406,223, respectively (p < .05). The glands of the post‐pubertal group contained the highest amount of connective tissue (11.49 ± 2.103%; p < .5) and the largest GFAP staining area (p < .05). The melatonin staining density was the highest in the pubertal group. The density of lipofuscin staining was higher in the pubertal and post‐pubertal groups. [ABSTRACT FROM AUTHOR]

Pancreas gets affected by fibrosis associated with aging. This study analyzed the age-related fibrotic changes in the exocrine as well as endocrine system of the pancreas. After obtaining necessary ethical clearances 30 post-natal and adult pancreases were collected and processed to obtain resin-embedded sections for transmission electron microscopy and paraffin-embedded sections for H and E staining and light microscopy. The sections were analyzed qualitatively and quantitatively. It was observed with ageing, the ductal epithelial cytoplasm contained many lipoid bodies. The basal lamina and the connective tissue around ducts increased. Periductal fibrosis appeared during fourth decade in Indian population whereas it appears sixth decade in Europeans. There was a direct correlation between area of the ducts and increasing age. Stellate cells and centroacinar cells increased with aging. The cytoplasmic processes of the centroacinar cells covered the acini and ductal epithelial cells, indicating their important function. The centroacinar cells have a regulatory role in secretory process during normal and pathological conditions. Increased fibrosis was noted in and around the islets of Langerhans. Epithelial hyperplasia, papillary projections, and periductal fibrosis around small and medium sized duct started very early in Indian populations indicating the vulnerability to pancreatic diseases in the Indian population in early ages.

Pancreas gets affected by fibrosis associated with aging. This study analyzed the age-related fibrotic changes in the exocrine as well as endocrine system of the pancreas. After obtaining necessary ethical clearances 30 post-natal and adult pancreases were collected and processed to obtain resin-embedded sections for transmission electron microscopy and paraffin-embedded sections for H&E staining and light microscopy. The sections were analyzed qualitatively and quantitatively. It was observed with ageing, the ductal epithelial cytoplasm contained many lipoid bodies. The basal lamina and the connective tissue around ducts increased. Periductal fibrosis appeared during fourth decade in Indian population whereas it appears sixth decade in Europeans. There was a direct correlation between area of the ducts and increasing age. Stellate cells and centroacinar cells increased with aging. The cytoplasmic processes of the centroacinar cells covered the acini and ductal epithelial cells, indicating their important function. The centroacinar cells have a regulatory role in secretory process during normal and pathological conditions. Increased fibrosis was noted in and around the islets of Langerhans. Epithelial hyperplasia, papillary projections, and periductal fibrosis around small and medium sized duct started very early in Indian populations indicating the vulnerability to pancreatic diseases in the Indian population in early ages. [ABSTRACT FROM AUTHOR]

Purpose The main aim of this study was to research new treatments following peripheral nerve injury involving melatonin (Mel), acetyl- l -carnitine (ALCAR), and leptin (Lep) using updated unbiased methods at the stereological and electron microscopic levels. Materials and methods Wistar albino rats were randomly divided into nine equal groups; control (Cont), obese control (OG), obese group exposed to sciatic nerve resection (Gap) (OGG), obese group injected intraperitoneally (i.p.) with Mel (OMG), obese group injected with Mel i.p. with gap (OMGG), obese group injected with Lep i.p. (OLG), obese group injected with Lep i.p. with gap (OLGG), obese group injected with ALCAR i.p. (OAG), and obese group injected with ALCAR i.p. with gap (OAGG). Electromyography (EMG) procedures were performed. Following routine histological procedures, stereological analysis was performed for each group. Results In terms of the number of myelinated axons, high significant increase in OGG was observed compared to OG and Cont (p < 0.01). In addition, a highly significant increase in axon surface area and myelin thickness of OGG compared to OG and Cont (p < 0.01) was noted. A significant decrease in myelin thickness/axon diameter ratio of OGG was found in comparison with the other groups. In terms of latency, there was a highly significant decrease in OGG compared to Cont and OG (p < 0.01). Myelinated axon numbers in OAGG, OMGG and OLGG increased highly significantly compared to other groups (p < 0.01). Latency in OMGG, a highly significant increase, was determined in OMG compared to Cont (p < 0.01). In addition, latency values in OGG were highly significantly greater than in OAC and OAGG (p < 0.01). Conclusion In particular, administration of Lep, Mel and ALCAR as neuroprotective agents may make a positive contribution to regeneration and myelination in obese rats. [ABSTRACT FROM AUTHOR]

The porcine liver is frequently used as a large animal model for verification of surgical techniques, as well as experimental therapies. Often, a histological evaluation is required that include measurements of the size, nuclearity or density of hepatocytes. Our aims were to assess the mean number-weighted volume of hepatocytes, the numerical density of hepatocytes, and the fraction of binuclear hepatocytes (Bn HEP) in the porcine liver, and compare the distribution of these parameters among hepatic lobes and macroscopic regions of interest ( ROIs) with different positions related to the liver vasculature. Using disector and nucleator as design-based stereological methods, the morphometry of hepatocytes was quantified in seven healthy piglets. The samples were obtained from all six hepatic lobes and three ROIs (peripheral, paracaval and paraportal) within each lobe. Histological sections (thickness 16 μm) of formalin-fixed paraffin-embedded material were stained with the periodic acid-Schiff reaction to indicate the cell outlines and were assessed in a series of 3-μm-thick optical sections. The mean number-weighted volume of mononuclear hepatocytes (Mn HEP) in all samples was 3670 ± 805 μm3 (mean ± SD). The mean number-weighted volume of Bn HEP was 7050 ± 2550 μm3. The fraction of Bn HEP was 4 ± 2%. The numerical density of all hepatocytes was 146 997 ± 15 738 cells mm−3 of liver parenchyma. The porcine hepatic lobes contained hepatocytes of a comparable size, nuclearity and density. No significant differences were identified between the lobes. The peripheral ROIs of the hepatic lobes contained the largest Mn HEP with the smallest numerical density. The distribution of a larger Mn HEP was correlated with a larger volume of Bn HEP and a smaller numerical density of all hepatocytes. Practical recommendations for designing studies that involve stereological evaluations of the size, nuclearity and density of hepatocytes in porcine liver are provided. [ABSTRACT FROM AUTHOR]

It is shown that, for a three dimensional particle (namely an arbitrary compact domain with piecewise smooth boundary in R^3) the mean wedge volume defined on a given pivotal section is equal to the average nucleator estimator of the particle volume defined on that section. Further, if the particle is convex and it contains the pivotal point, then the flower area of a given pivotal section equals the average surfactor estimator defined on that section. These results are intended to throw some light on the standing conjecture that the functional defined on a pivotal section according to the invariator has a unique general expression. As a plus, the former result leads to a computational formula for the mean wedge volume of a convex polygon which is much simpler than the one published recently, and it is valid whether the fixed pivotal point is interior or exterior to the particle.

Guanidinopropionic acid (GPA) increases AMPK activity, mitochondrial function and biogenesis in muscle and improves physiological function, for example during aging. Mitochondrial dysfunction is a major contributor to the pathogenesis of Parkinson's disease. Here we tested whether GPA prevents neurodegeneration of the nigrostriatal dopamine system in MPTP-treated mice. Mice were fed a diet of 1% GPA or normal chow for 4 weeks and then treated with either MPTP or saline. Indices of nigrostriatal function were examined by HPLC, immunohistochemistry, stereology, electron microscopy and mitochondrial respiration. MPTP intoxication decreased TH neurons in the SNpc of normal chow-fed mice; however GPA-fed mice remarkably exhibited no loss of TH neurons in the SNpc. MPTP caused a decrease in striatal dopamine of both normal chow- and GPA-fed mice, although this effect was significantly attenuated in GPA-fed mice. GPA-fed mice showed increased AMPK activity, mitochondrial respiration and mitochondrial number in nigrostriatal TH neurons, suggesting that the neuroprotective effects of GPA involved AMPK-dependent increases in mitochondrial function and biogenesis. MPTP treatment produced a decrease in mitochondrial number and volume in normal chow-fed mice but not GPA-fed mice. Our results show the neuroprotective properties of GPA in a mouse model of Parkinson's disease are partially mediated by AMPK and mitochondrial function. Mitochondrial dysfunction is a common problem in neurodegeneration and thus GPA may slow disease progression in other models of neurodegeneration.

We investigated the microscopic structure of transverse sections of the oculomotor, trochlear and abducens nerves of Arabian foals using stereological methods. Bilateral nerve pairs from 2-month-old female Arabian foals were analyzed. The tissues were embedded in plastic blocks, then 1 µm thick sections were cut and stained with osmium tetroxide and methylene blue-azure II. Stereology was performed using light microscopy. Morphometry showed that the right and left pairs of nerves were similar. The transverse sectional areas of the oculomotor, trochlear and abducens nerves were 1.93 ± 0.19 mm2, 0.32 ± 0.06 mm2and 0.70 ± 0.08 mm2, respectively. The oculomotor nerve exhibited a significantly greater number of myelinated axons (16755 ± 1279) and trochlear (2656 ± 494) and the abducens nerves (4468 ± 447). The ratio of the axon diameter to myelinated nerve fiber diameter was 0.58, 0.55 and 0.55 for the oculomotor, trochlear and abducens nerves, respectively. Of the three nerves studied, the abducens nerve exhibited the greatest nerve fiber area, myelin area, nerve and axon diameters, and myelin thickness. The ratio of small myelinated nerve fibers was greatest in the oculomotor nerve. [ABSTRACT FROM AUTHOR]

Through the hydrogen bonding between polyamide 12 (PA12) and N , N′ -dicyclohexylterephthalamide (DCHT) nucleator, the intentionally controlled self-assembly of DCHT and the crystallization behavior of isotactic polypropylene (i PP) matrix are investigated. The introduction of PA12 could severely postpone the condensation of DCHT vapor in i PP matrix due to the reduced vapor concentration. As a result, the nucleating efficiency of DCHT at lower concentration for example i PP/PA12/0.05DCHT even failed at a relatively higher final heating temperature T f. Such a failure of nucleating efficiency could be recoverable after a step-cycle treatment at lower T f , where the sublimation of DCHT can hardly occur. The changes from a cluster-like structure to a network structure driven by hydrogen bonding between DCHT and PA12 could be a reason of nucleation failure and recovery. This means that the nucleating efficiency of DCHT and crystallization of i PP could be tuned by controlling the absorption and release of DCHT vapor at the surface of PA12 particles. For i PP/PA12/0.5DCHT with a higher concentration of DCHT, the absorption of PA12 could only reduce the DCHT vapor concentration in the i PP melt and thus, the dendrite structure of DCHT shows more and thinner branches, which results in better nucleating efficiency of DCHT than that in i PP/0.5DCHT. [Display omitted] • The presence of PA12 could absorb DCHT vapor in i PP matrix and postpone its condensation. • The nucleation failure and recovery of DCHT could be regulated by step-cycle treatment. • The nucleating efficiency of DCHT could be tuned by controlling the absorption and release from PA12. [ABSTRACT FROM AUTHOR]

Although often not considered clinically relevant and, therefore, not diagnosed or treated, minimal hepatic encephalopathy (MHE) has been shown to affect daily functioning, quality of life, driving and overall mortality. To discover early impairments involved in MHE, we studied one of its precipitating factors, portal hypertension. Rats were trained on a stimulus–response task using the Morris water maze. Two groups of animals were used: a SHAM (sham-operated) group (n = 13) and a portal hypertension (PH) group (n = 13). The triple portal vein ligation method was used to create an animal model of an early developmental phase of HE. Brain metabolic activity was studied with cytochrome c-oxidase histochemistry (C.O.). Neuronal nuclear volume was assessed by nucleator probe; the number of glial fibrillary acidic protein-immunoreactive astrocytes (GFAP-IR) and proinflammatory mediators was measured. The results revealed that the PH group was not able to reach the behavioural criterion, in contrast to the SHAM group. The metabolic brain consumption revealed decreased C.O. activity in the ventral striatum. The PH group showed lower density of GFAP-IR and an increase in the tumour necrotic factor-α (TNF-α). The PH group showed decreased neuronal nuclear volume in the dorsal striatum. On the contrary, increased neuronal nuclear volume was found in the ventral striatum. For the first time, a relationship has been established between inflammation, astrocytic and neural damage, and brain metabolic impairment in a model of MHE. Disruption of the striatum and related structures was highlighted as the main target in early stages of HE. Finally, a simple task was presented to assess the subtle impairments found in the clinic, which could provide fresh insights into the development of new tools for the assessment of MHE. [ABSTRACT FROM AUTHOR]

ABSTRACT The association cortex of the superior temporal gyrus (STG) is implicated in complex social and linguistic functions. Thus, reliable methods for quantifying cellular variation in this region could greatly benefit researchers interested in addressing the cellular correlates of typical and atypical function associated with these critical cognitive abilities. To facilitate this task, we first present a general set of cytoarchitectonic criteria targeted specifically toward stereological analyses of thick, Nissl-stained sections for the homotypical cortex of the STG, referred to here as BA22/TA. Second, we use the optical fractionator to estimate pyramidal neuron number and the nucleator for pyramidal somal and nuclear volume. We also investigated the influence of age and sex on these parameters, as well as set a typically developing baseline for future comparisons. In 11 typically developing cases aged 4-48 years, the most distinguishing features of BA22/TA were the presence of distinct granular layers, a prominent, jagged layer IIIc, and a distinctly staining VIa. The average number of neurons was 91 ± 15 million, the volume of pyramidal soma 1,512 µm3, and the nuclear volume 348 µm3. We found no correlation with age and neuron number. In contrast, pyramidal somal and nuclear volume were both negatively correlated and linearly associated with age in regression analyses. We found no significant sex differences. Overall, the data support the idea that postnatal neuron numbers are relatively stable through development but also suggest that neuronal volume may be subject to important developmental variation. Both measures are critical variables in the study of developmental neuropathology. J. Comp. Neurol. 523:1054-1072, 2015. © 2015 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

Abstract: Curli are functional amyloids produced by enteric bacteria. The major curli fiber subunit, CsgA, self-assembles into an amyloid fiber in vitro. The minor curli subunit protein, CsgB, is required for CsgA polymerization on the cell surface. Both CsgA and CsgB are composed of five predicted β‐strand–loop–β‐strand–loop repeating units that feature conserved glutamine and asparagine residues. Because of this structural homology, we proposed that CsgB might form an amyloid template that initiates CsgA polymerization on the cell surface. To test this model, we purified wild-type CsgB and found that it self-assembled into amyloid fibers in vitro. Preformed CsgB fibers seeded CsgA polymerization as did soluble CsgB added to the surface of cells secreting soluble CsgA. To define the molecular basis of CsgB nucleation, we generated a series of mutants that removed each of the five repeating units. Each of these CsgB deletion mutants was capable of self-assembly in vitro. In vivo, membrane-localized mutants lacking the first, second, or third repeating units were able to convert CsgA into fibers. However, mutants missing either the fourth or fifth repeating units were unable to complement a csgB mutant. These mutant proteins were not localized to the outer membrane but were instead secreted into the extracellular milieu. Synthetic CsgB peptides corresponding to repeating units 1, 2, and 4 self‐assembled into ordered amyloid polymers, while peptides corresponding to repeating units 3 and 5 did not, suggesting that there are redundant amyloidogenic domains in CsgB. Our results suggest a model where the rapid conversion of CsgB from unstructured protein to a β-sheet-rich amyloid template anchored to the cell surface is mediated by the C-terminal repeating units. [Copyright &y& Elsevier]

Disruption and consequent reorganization of central nervous system circuits following traumatic brain injury may manifest as functional deficits and behavioral morbidities. We previously reported axotomy and neuronal atrophy in the ventral basal (VB) complex of the thalamus, without gross degeneration after experimental diffuse brain injury in adult rats. Pathology in VB coincided with the development of late-onset aberrant behavioral responses to whisker stimulation, which lead to the current hypothesis that neurodegeneration after experimental diffuse brain injury includes the primary somatosensory barrel cortex (S1BF), which receives projection of VB neurons and mediates whisker somatosensation. Over 28 days after midline fluid percussion brain injury, argyrophilic reaction product within superficial layers and layer IV barrels at 1 day progresses into the cortex to subcortical white matter by 7 days, and selective inter-barrel septa and subcortical white matter labeling at 28 days. Cellular consequences were determined by stereological estimates of neuronal nuclear volumes and number. In all cortical layers, neuronal nuclear volumes significantly atrophied by 42-49% at 7 days compared to sham, which marginally attenuated by 28 days. Concomitantly, the number of healthy neurons was reduced by 34-45% at 7 days compared to sham, returning to control levels by 28 days. Progressive neurodegeneration, including argyrophilic reaction product and neuronal nuclear atrophy, indicates injury-induced damage and reorganization of the reciprocal thalamocortical projections that mediate whisker somatosensation. The rodent whisker barrel circuit may serve as a discrete model to evaluate the causes and consequences of circuit reorganization after diffuse brain injury. [ABSTRACT FROM AUTHOR]

Different from other semi-crystalline polymers, the crystallization of syndiotactic polypropylene (sPP) into helical sequences under flow is largely inhibited due to favorable formation of trans-planar conformations. The results presented in this study, using micro-FTIR, 2D-WAXS, and 2D-SAXS characterization, indicate that molecular orientation and crystallization in melt-spun sPP monofilaments can be dramatically enhanced by a sorbitol-based nucleator. It is suggested that, similar to the oriented crystallization in the nucleated isotactic polypropylene (iPP), the phase-separated nanofibrils, aligned under flow prior to sPP crystallization, act as shish structure (primary nuclei) to mediate the molecular orientation and crystallization of sPP. [ABSTRACT FROM PUBLISHER]

Abstract: Modelling entorhinal function or evaluating the consequences of neuronal losses which accompany neurodegenerative disorders requires detailed information on the quantitative cellular composition of the normal entorhinal cortex. Using design-based stereological methods, we estimated the numbers, proportions, densities and sectional areas of layer II cells in the medial entorhinal area (MEA), and its constituent caudal entorhinal (CE) and medial entorhinal (ME) fields, in the rat and mouse. We estimated layer II of the MEA to contain ∼58,000 neurons in the rat and ∼24,000 neurons in the mouse. Field CE accounted for more than three-quarters of the total neuron population in both species. In the rat, layer II of the MEA is comprised of 38% ovoid stellate cells, 29% polygonal stellate cells and 17% pyramidal cells. The remainder is comprised of much smaller populations of horizontal bipolar, tripolar, oblique pyramidal and small round cells. In the mouse, MEA layer II is comprised of 52% ovoid stellate cells, 22% polygonal stellate cells and 14% pyramidal cells. Significant species differences in the proportions of ovoid and polygonal stellate cells suggest differences in physiological and functional properties. The majority of MEA layer II cells contribute to the entorhinal-hippocampal pathways. The degree of divergence from MEA layer II cells to the dentate granule cells was similar in the rat and mouse. In both rat and mouse, the only dorsoventral difference we observed is a gradient in polygonal stellate cell sectional area, which may relate to the dorsoventral increase in the size and spacing of individual neuronal firing fields. In summary, we found species-specific cellular compositions of MEA layer II, while, within a species, quantitative parameters other than cell size are stable along the dorsoventral and mediolateral axis of the MEA. [ABSTRACT FROM AUTHOR]

Abstract: myo-Inositol made from a biomass feedstock was used as an additive for poly (l-lactic acid) (PLLA) which was also made from biomass feedstock. The crystallization and stabilization of PLLA by the addition of myo-inositol were evaluated by the melt injection molding process. While the isothermal crystallization of PLLA at 100 °C had finished over 14 min after melting, that of PLLA with 5 wt% myo-inositol finished within 2 min. The crystal growth of PLLA started when the myo-Inositol crystal was added, and the crystallization was promoted. Furthermore, the molecular weight of PLLA with myo-inositol did not decrease during the melt-mixed at 200 °C, different from that of PLLA without the myo-inositol. myo-Inositol prevented the degradation of PLLA during the thermal melting process. The biomass carbon ratio measured by the accelerator mass spectroscopy method showed that the PLLA with 5 wt% myo-inositol was a fully biobased material. It was demonstrated that myo-inositol was a multi-functional biobased additive for the modification of PLLA without decreasing its mechanical properties. [Copyright &y& Elsevier]

Abstract: The crystallisation of polypropylene in the presence of sodium benzoate, graphite powders, Millad 3988 (1,3:2,4-bis(3,4-dimethyl-benzylidene sorbitol)) and NA-11 (sodium 2,2′-methylene bis-(4,6-di-tert-butylphenyl)phosphate) was studied. As a parameter for the effectiveness of nucleators, a free-energy parameter for the nucleation was estimated, on the basis of a theory, from the nucleation temperature during cooling at various rates. The density of actual nuclei was estimated from the radial growth rate of spherulites and the bulk growth rate, the latter obtained by the analysis of crystallisation isotherms. The dispersibility of nucleator particles calculated with reference to the mean volume of particles was various, the cluster size being ranged between unity to several hundred. The Young''s modulus of films prepared from the polymer–nucleator mixtures has been found to correlate with the nucleus density without respect to the kind of nucleator. [Copyright &y& Elsevier]

Among the various inorganic nucleators examined, Talc and an aluminum complex of a phosphoric ester combined with hydrotalcite (NA) were found to be effective for the melt-crystallization of poly(l-lactide) (PLLA) and PLLA/poly(d-lactide) (PDLA) stereo mixture, respectively. NA (1.0 phr (per one hundred resin)) can exclusively nucleate the stereocomplex crystals, while Talc cannot suppress the homo crystallization of PLLA and PDLA in the stereo mixture. Double use of Talc and NA (in 1.0 phr each) is highly effective for enhancing the crystallization temperature of the stereo complex without forming the homo crystals. The stereocomplex crystals nucleated by NA show a significantly lower melting temperature (207 °C) than the single crystal of the stereocomplex (230 °C) in spite of recording a large heat of crystallization ΔHc (54 J/g). Photomicrographic study suggests that the spherulites with a symmetric morphology are formed in the stereo mixture added with NA while the spherulites do not grow in size in the mixture added with Talc. The exclusive growth of the stereocomplex crystals by the melt-crystallization process will open a processing window for the PLLA/PDLA. [Copyright &y& Elsevier]

Bovine cumulus-oocyte complexes (COCs) aspirated from slaughterhouse ovaries are used for in vitro maturation and fertilization after selection on the basis of morphological appearance of the cumulus and ooplasm. In this context, a quantitative characterization of COCs could provide additional criteria for selecting the most competent complexes. Bovine COCs from small (1–4 mm) antral follicles were aspirated from metestrous and proestrous stage ovaries of Holstein–Friesian cows, fixed in glutaraldehyde, randomly embedded in glycol-methacrylate, and sectioned at 20 μm. The unbiased nucleator principle of stereology was used for estimating the mean volumes of complexes, oocytes, cumulus cells, and nuclei of oocytes and cumulus cells. The thickness of the zona pellucida and the relative numerical percentages of the several morphological types (C1, C2 and C3) of cumulus cells were also evaluated. The optical dissector procedure was used for cumulus cell sampling. Quantitative data show that the variability among complexes is generally high, especially for the volume of COCs. There were no linear correlations between the studied parameters, except between the volume of the oocyte and nucleus at metestrus. At proestrus, the volumes of COCs, oocytes and nuclei of oocytes, the volume of follicular cells and the thickness of the inner zona pellucida, were significantly higher than at metestrus. The relative numerical frequency of follicular type C1 cells was lower whereas that of type C3 cells was higher at proestrus than at metestrus. In conclusion, small antral follicles had larger COCs and oocytes at proestrus compared to metestrus and the COCs also had a higher percentage of follicular type C3 cells. Results suggest that for the same type of follicle size there may exist different functional populations of COCs at distinct stages of the bovine ovarian cycle. [Copyright &y& Elsevier]

Summary In design stereology, many estimators require isotropic orientation of a test probe relative to the object in order to attain unbiasedness. In such cases, systematic sampling of orientations becomes imperative on grounds of efficiency and practical applicability. For instance, the planar nucleator and the vertical rotator imply systematic sampling on the circle, whereas the Buffon–Steinhaus method to estimate curve length in the plane, or the vertical designs to estimate surface area and curve length, imply systematic sampling on the semicircle. This leads to the need for predicting the precision of systematic sampling on the circle and the semicircle from a single sample. There are two main prediction approaches, namely the classical one of G. Matheron for non-necessarily periodic measurement functions, and a recent approach based on a global symmetric model of the covariogram, more specific for periodic measurement functions. The latter approach seems at least as satisfactory as the former for small sample sizes, and it is developed here incorporating local errors. Detailed examples illustrating common stereological tools are included. [ABSTRACT FROM AUTHOR]

In this study, the self-assembly phenomenon of nucleator N, N′-dicyclohexylterephthalamide (DCHT) in isotactic polypropylene (i PP) has been investigated and reexamined from the viewpoint of sublimation and condensation. A correlation between the crystallization temperature (T c) of i PP and the final heating temperature (T f) was constructed, in which a "V" shape phenomenon and its dependence on DCHT concentration are presented. With the increase of DCHT concentration, both the onset and the bottom of the "V" shift to a higher T f , which is ascribed to faster saturation of DCHT vapor or slower sublimation rate of DCHT at same T f for the hybrids with high DCHT concentration. A phase diagram distinguishing various assembly structures of DCHT with different nucleation ability is proposed based on the DSC and optical results, in which four regions are included. Considering the strong hydrogen bonding between DCHT molecules, a schematic condensation mechanism for the particular needle-like, agglomerates and flower-like structures were presented. Rheology results also provide indirect evidence to the phase transformation or condensation process, where two step condensation is observed and the lower temperature step could be attributed to the formation of agglomerates structure due to the "cage effect" of i PP supercooling melt to DCHT vapor. [Display omitted] 1. The self-assembly of DCHT in i PP is reexamined from the viewpoint of sublimation/condensation. 2. A "V" shape correlation between T c and T f of i PP/DCHT hybrids is found. 3. A phase diagram distinguishing various assembly structures of DCHT is presented. 4. The mechanism of different assembly structures of DCHT is proposed. [ABSTRACT FROM AUTHOR]

Curli are surface organelles in Escherichia coli that assemble outside the bacterium through the precipitation of secreted soluble CsgA monomers, requiring the CsgB nucleator protein. Using immunoelectron microscopy and immunoblotting assays, CsgB is shown to be located on the bacterial surface and also as a minor component of wild-type curli. CsgB lacking its 20 N-terminal residues when fused to maltose-binding protein (MBP) can still trigger polymerization of CsgA monomers in vivo. However, the resulting surface organelles are only formed at one of the two bacterial poles and are morphologically distinct from wild-type curli. These Bfco organelles (CsgB-Free Curli-related Organelles) are highly regular structures reacting with anti-CsgA, but not anti-CsgB antibodies. The CsgB of the active MBP-CsgBII fusion is surface exposed but, unlike the native CsgB in wild-type curli, is not detectable in the Bfco organelles. Overexpression of csgB within a csgA mutant results in the formation of short CsgB polymers on the cell surface. It is suggested that in wild-type bacteria, both CsgA and CsgB are secreted proteins. Interaction between CsgA and CsgB triggers wild-type curli formation, resulting in CsgA-CsgB heteropolymers, while surface-anchored CsgB in MBP-CsgBII triggers morphologically distinct, CsgB-free/CsgA Bfco organelles. In the absence of CsgA, CsgB can self-assemble into polymers. [ABSTRACT FROM AUTHOR]

• Biocompatible EBH as a nucleator significantly enhanced crystallizability of biodegradable PES. • EBH interacted with crystalline carbonyl group and amorphous ester group of PES. • Rearrangement of carbonyl segment is faster than that of C C backbone for PES. • EBH increased thermal degradation temperature of PES. A biocompatible linear organic nucleator (EBH) was incorporated into biodegradable linear aliphatic poly(ethylene succinate) (PES) polyester to investigate effect of EBH on crystallization kinetics, aggregated structure and thermal stability of PES. Crystallization kinetic results suggested that EBH enhanced significantly crystallization rate and decreased substantially crystallization time of PES, and EBH is an excellent nucleator of PES. FTIR measurement indicated that hydrogen bond interaction exists between carbonyl group (of crystalline phase) and ester group (of amorphous phase) of PES and EBH. In-situ FTIR results revealed that upon incorporation of EBH, rearrangement of carbonyl group is faster than C C backbone of PES in crystallization process. Thermal degradation temperature of PES increased in the presence of EBH. EBH had little effect on crystal structure of EBH. Mechanisms on nucleation and enhanced thermal stability of PES were proposed and discussed in detail. [ABSTRACT FROM AUTHOR]

• It is unclear if/how xenoestrogens change hepatocellularity and hepatocyte size in fish. • Exposure of male platyfish to 17α-ethynylestradiol for 15 days did not change liver weight. • Ethynylestradiol impacted on hepatocytes as demonstrated by vitellogenin production. • Exposed males did not show proliferation of hepatocytes or changes in their volumes. • Stereology unveiled baseline hepatocellularity data that can be compared with other species. The liver hosts numerous vital functions, such as biotransformation and excretion of xenobiotics. Synthetic oestrogens influence liver structure and function, leading to adaptations or to dysfunctions/injury. They are often stated to induce increases in fish liver weight, but there is controversy regarding how: if by changes in hepatocyte size (hypertrophy) and/or number (hyperplasia). Using platyfish as the experimental model, our primary aim was to assess if/how hepatocytes reacted to a sub-acute oestrogenic exposure. A complementary aim was to generate fundamental structural data for the liver of that model organism. Adult males were injected intramuscularly with 17α-ethinylestradiol (EE2) (25 μg/g), every 72 h for two weeks. Control fish were given solvent only. Body and liver morphometry were registered, and hepatocytes examined through histology and stereology at light microscopy. Immunohistochemistry evaluated hepatocytic vitellogenin (VTG) content. Treated and control fish did not differ as to quantitative parameters. Nevertheless, exposed fish were sensitive to EE2. VTG tagging was positive in their hepatocytes and these tended to be more basophilic, though not fully oestrogenized. We hypothesise that the platyfish liver is not particularly sensitive to the disrupting action of EE2 because of its reproductive mode; with no production peaks of VTG and no huge changes in endogenous sex-steroids. The fish may have had no evolutionary pressure for hepatocytes to be particularly reactive to oestradiol (E2). In the end, this study offers the first unbiased estimation of the liver cellularity in the platyfish, as well of the hepatocytic volume, serving now as a baseline reference. [ABSTRACT FROM AUTHOR]