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The function of the hippocampus depends on the process of adult hippocampal neurogenesis which underpins the exceptional neural plasticity of this structure, and is also frequently affected in CNS pathologies. Thus, manipulation of this process represents an important therapeutic goal. To identify potential strategies, organotypic adult brain slices are emerging as a valuable tool. Over the recent years, this methodology has been refined and here we present a combined protocol that brings together these refinements to enable long-term culture of adult hippocampal slices. We employ a sectioning technique that retains essential afferent inputs onto the hippocampus as well as serum-free culture conditions, so allowing an extended culture period. To sustain the neurogenic potential in the slices, we utilize the gliogenesis-inhibitor Indomethacin. Using EdU retention analysis enables us to assess the effects of pharmacological intervention on neurogenesis. With these improvements, we have established an easy and reliable method to study the effects of small molecules/drugs on proliferation and neuron formation ex vivo which will facilitate future discovery driven drug screenings.

This study was aimed to highlight the individual effects of melatonin (MEL) and hyaluronic acid (HA) on bone healing and repair mechanism and to investigate a possible effect, for a topical application. New Zealand rabbits used in this study were divided into three groups for two healing intervals the experimental groups were: 1. Experimental groups (20 rabbits): all animals subjected to surgical operation in right tibia, creating bone defect 3mm in depth and 4mm in diameter filled with 0.1ml. Hyaluronic acid gel and left tibia bone defect filled with melatonin gel. 2. Control group (10 rabbits): induced bone defect on the right side only. Animals’ scarifications were done in 2 weeks and 4 weeks’ durations. Routine processing and sectioning technique was performed for histological evaluation. At the 2weeks healing interval, highest mean value of all measured parameters were recorded at melatonin group while at 4 weeks, there is high significant difference in all parameters; (p-value 0.000) among all control and experimental groups. A significant number of positive effects of MEL, as well as HA, as individual compounds on the bone healing regeneration.

Background: Numerous researches have been done on the permanent maxillary first molars for the presence of an extra canal, especially the mesiobuccal roots for the presence of MB2 canals. Cone beam computed tomography (CBCT) has been used recently in the detection of these canals. However, literature discussing the efficacy and reliability of CBCT in the detection of these canals is scanty. Aims: This study aims to evaluate the efficacy of CBCT as a preoperative diagnostic aid in locating the second mesiobuccal canal in maxillary first molars. Methods: Selected sixty extracted maxillary first molars were placed in the skull base, and CBCT scans were done for evaluating the presence of MB2 canals in the mesiobuccal root. Sectioning of the roots at 3, 5, and 7 mm from the tip was performed and further examined under the microscope for the presence of the MB2 canals. Evaluations were done by two evaluators independently. Results of evaluations were statistically analyzed. Statistical analysis used were standard normal deviation (Z value), interrater reliability (Chronbach's alpha-), P value and receiver operating curve(ROC). Results and Conclusions: Detection rates of MB2 using both the methods did not show any significant difference (P > 0.05). CBCT was found to be a reliable tool for the detection of MB2 canal in maxillary first molar teeth when compared to gold standard sectioning technique.

Background Marginal fit is critical for the success and longevity of a dental restoration. Zirconia crowns can be fabricated either chair-side, in a dental laboratory or in a milling center; each can give different marginal fits results. However, discussion of the marginal fit of zirconia crowns when different fabrication methods are compared is lacking in the literature. Purpose To compare the marginal discrepancy (MD) and absolute marginal discrepancy (AMD) of computer-aided design, and computer-aided manufacturing (CAD-CAM) used in a dental laboratory and a milling center for producing monolithic zirconia crowns. Methods The marginal fit of 30 zirconia crowns cemented to typodont teeth was evaluated by means of a sectioning technique. Fifteen crowns were fabricated with a CEREC inLAB MC X5 from IPS e.max ZirCAD blocks. Fifteen crowns were fabricated using a LAVA milling center from LAVA Plus Zirconia Blocks. The 30 crowns were sectioned with a precision saw, and MD and AMD were subsequently measured using a light microscope. Data were analyzed using the one-way ANOVA technique to investigate significant differences in the marginal fit between the two fabrication systems (α = .05). Results The AMD dimension of the CEREC inLAB system was significantly smaller (P

The general outline of meiosis proposed by Wilson in 1925 included a diffuse stage following pachytene or early diplotene, although such a stage may be missing in some organisms. Different forms of such a stage are known to exist in male and female meiosis of many animals, but usually they are treated separately and not included as a special stage in the scheme of meiosis in modern textbooks. It was shown by a literature research that, up to 1940, the existence of a diffuse stage was recorded in meiosis of many plants (the sectioning technique used at this time made it easy to follow accurately the sequence of meiotic stages) but few authors considered this stage to be a common part of plant meiosis. Its existence was actually observed by many authors at this time, but it became a common tendency to regard it as due to “bad fixation”, or “fixation artefacts” only. Remarks about the existence of such a stage disappeared after the introduction of squash techniques, but started to reappear after 1960. Today, references about the existence of a diffuse stage are known from all groups of plants (Angiospermae, Gymnospermae, Pteridophyta, Bryophyta, Fungi, Algae). The conception of meiosis published by Wilson is thus found to be more close to reality and therefore it is proposed that such a concept is accepted as a general outline of meiosis.

The variation in the position of antipodal cells before and after fertilization in polyembryonic rice strain Ap III was studied by using conventional sectioning technique. It was shown that initially the three antipodal cells lie at the chalazal end of the young embryo sacs. Along with the development of embryo sac, the antipodal cells proliferate into a multicellular structure containing up to about 20 cells. Most of the cellsmigrate to its dorsal side when the embryo sacs turn into mature. In a few embryo sacs the antipodal cells are situated in the positions adjacent to the egg apparatus at the micropylar end, while in other sacs, they spread from the midst of the embryo sac to the micropylar end clinging to the nucellar tissue. Furthermore, it is reported for the first time that cells of some egg apparatus or proembryos disorganize when antipodal cells lie at the micropylar end, indicating that the function of the antipodal cells may vary during the embryogenesis in rice Ap III.

Age estimation is particularly crucial for the conservation of the saiga antelope Saiga tatarica, but modern laboratory methods for aging have not previously been applied to this species. There is an urgent need for evaluation of the techniques that could be used for age estimation in order that long-term ecological data sets can be correctly interpreted and conservation advice given. We evaluated the repeatability, practical feasibility and comparability of three techniques for age estimation of saiga antelopes; the tooth sectioning technique (TS), the tooth eruption and wear technique (TEW), and a visual aging technique routinely used in field studies. We found that TS and TEW gave repeatable results, and agreed well. The visual method underestimated the age of males compared to laboratory methods. It assigned animals consistently to the age class of at least one year old, but less consistently to the age class less than one year old. Although studies of known-age animals are needed to evaluate precision and accuracy of these methods, we suggest that either TS or TEW would be suitable for aging saiga antelopes, with the choice being determined by practicalities such as the availability of the necessary expertise and equipment.

We designed a series of experiments to verify the value of the diffusion coefficient of HNO 3 in ice at -15° C using a serial sectioning technique. Our first series of experiments with diffusion times of 70 to 100 h gave an average value of about 1.7 × 10 -11 cm 2 s -1 (StD 0.8 × 10 -11 ) and a second set of experiments at 1000 h resulted in an apparent diffusion coefficient of 10 -12 cm 2 s -1 . Our conclusion is that the observed gradients of HNO 3 in ice were spurious and the result of serial contamination of the surfaces during sectioning of the ice. We call the diffusion coefficients apparent because in the present experiment we could not distinguish between an undetectable diffusion coefficient and undetectable solubility. In either case, the validity of the previously published results is questionable.

We attempted to settle the potential problems of bias caused by too soft earplugs and poor formation of the growth layers in age readings of common minke whales. Thus, we examined the feasibility of a new technique of incorporating gelatin in order to collect earplugs for age assessment. Frozen sectioning and histology of the earplug core were also used as methods to improve age estimation. Earplugs were collected by filling the space in the external auditory meatus with gelatin, hardening the gelatin, earplug and its fragments, by spraying with cooling gas, and removing the earplug embedded in gelatin. In 174 trials with common minke whales in the Western North Pacific of coastal waters of Japan in 2007–2009, it was revealed that embedding earplugs with gelatin minimized breakage and protected the neonatal line (NL). This method was particularly effective in younger animals. As a result, the readability was improved. We also examined the histological sections, which were sliced using the Kawamoto specialized frozen sectioning technique, and stained them separately with toluidine blue, haematoxylin and eosin, Sudan III, Sudan VII, and alizarin red S to display a clearer core surface image of the growth layers. The histological sections stained with alizarin red S provided the clearest images, in which we could easily identify both dark and pale laminations. This suggested a close relationship with the seasonal changes in calcium intake from feeding. Earlier age estimation methods focused on fat content in the growth layers; however, we found potential for an improvement in the readability of unclear growth layers when focusing on calcium.

The fit of In-Ceram copings and crowns was investigated in a laboratory study. Two methods were used, one a direct sectioning technique and the other a cement analogue technique using addition-cured polyvinylsiloxane impression material. The former method involved 40 crowns cemented and sectioned on their respective electroformed silver dies. For the second method, 80 analogues were embedded and sectioned. All measurements were made using a Reflex microscope. This showed In-Ceram crowns and copings to fit well with marginal openings and ranging from 1 to 63 microns and a mean of 19 microns. No significant difference in fit was found between chamfer margins and shoulder margins. The addition of porcelain to the In-Ceram coping and repeated firing cycles involved in building a crown did not alter the fit. It is concluded that In-Ceram crowns fit well in comparison to other crown types.

The presence of separate bundles of nerve fibres in the gerbilline endolymphatic sac (ES) is described, paying particular attention to their ultrastructure and localization. One bundle, localized in the area of the subepithelium which separates the sigmoid sinus from the ES, is composed only of myelinated fascicles which, moreover, seem to have an isolated contact with the ES area. Other two single nerve fibres, much smaller in caliber, are localized in the ES subepithelium and laterally to the ES area, still close to the sigmoid sinus. These fibres, composed of myelinated and unmyelinated fascicles, seem to have a rather longitudinal orientation and, moreover, contract close relationships with the rich vascular network of the ES subepithelial tissue. As far as the course is concerned, the serial sectioning technique would suggest that the nerve fibres get very close to the ES epithelial cell layer, going proximal to distal. Speculations on the origin of this nerve contingent in the ES are proposed and discussed in view of possible new theories for pathogenesis and therapy of some inner ear diseases.

International audience; Surface degradation and cracking of dense hydroxyapatite were evaluated through Vickers micro indentation using indentation loads ranged from 25 gf to 2000 gf. Crack lengths, imprint diameters and the number of lateral cracks and chips were measured using SEM. The crack length-indentation load data were analyzed with regard to the specific relations of Palmqvist and fully developed radial cracks. Crack type transition load from Palmqvist to median crack was experimentally assessed through serial sectioning technique. The analytical estimated transition load, based on the theoretical relation of the indentation load and crack lengths showed a good agreement with one obtained from experimental itinerary. Palmqvist and median cracks were identified in low and medium indentation loads, respectively. High indentation load could also lead to the formation of lateral cracks and chips. The tendency for lateral cracking was evaluated taking into account the number of lateral cracks and chips. The chips were found to be appeared just after test in higher indentation load, whereas in medium loads they could be detectable only after several weeks.

This paper presents the research results of the morphology of subsurface damage (SSD) in BK7 glass ground with on-machine fabricated PCD micro tool. Grinding generated damages are assessed and characterised using bonding interface sectioning technique combined with field emission scanning electron microscopy (FESEM). Both the damage depth and surface roughness are found to be influenced by the depth of cut, feed rate and spindle speed. Two major type of grinding damage have been identified likely chipping damage and micro-cracking damage. Lateral, median and cone cracks are found to be existed in the sub-surface. These crack size varies from below to above 1 μm. The mechanism of damage nucleation and propagation are discussed also. Although the machined surface seems to show ductile mode behaviour even at higher material removal, analysis of subsurface damage shows that the material removal is a combined effect of grain dislodgement, micro-cracking and plastic deformation.

The multifocal nature of adenolymphoma of the parotid salivary gland was studied in 24 patients who underwent parotidectomy. Twenty-six resected specimens were examined by a step-serial whole-organ sectioning technique; multiple adenolymphoma was found in 13. The maximum number of synchronous tumours in any gland was four. Salivary epithelial elements were found embedded within lymph nodes in nine resected specimens. Synchronous or metachronous bilateral tumours were found in eight patients. The multifocal nature of adenolymphoma of the parotid gland is demonstrated.

The grid sectioning technique has been used to obtain the two missing principal axis projections of orthorhombic catalase platelets and to measure directly the unit cell c-value. The negatively stained platelets have a unit cell c-dimension of half that proposed by Unwin (1975) from powder X-ray diffraction. The precision of the grid sectioning technique in positioning sections along a specimen axis shows that the growth fault lines usually observed on negatively stained catalase platelets are rows of missing molecules filled with stain. From these sections conclusions are drawn concerning the action of negative stain on a specimen, the microtomy process, and the specimen/supporting film interaction. Finally the value of microtomy for detailed structural analysis of biological objects is emphasized.

By means of a microtome sectioning technique, lattice diffusion at 343 K of β-naphthol-8 14 C into naphthalene single crystals has been measured in two directions. The results reveal the existence of a molecular diffusion anisotropy: D a =(12.3±0.4)•10 −17 M 2 s −1 D c' =(4.3±0.5)•10 −17 m 2 s −1 La diffusion reticulaire de 8 14 C β-naphtol dans le naphtalene monocristallin a ete mesuree par la methode de sectionnement comptage dans 2 directions cristallographiques differentes. Les resultats font la preuve de l'existence d'une anisotropie de diffusion moleculaire a 343 K: D a =(12,3±0,4(•10 −17 m 2 s −1 D c' =(4,3±0,5)•10 −17 m 2 s −1

The commonly employed methods of sectioning lymph nodes can account for a greater than 30% false pathologic interpretation when studying nodes for the presence of tumor. The failure to identify a tumor within a lymph node is related to the size of the lymph node, size of the lesion, number of sections examined, and the location of the tumor within the node. Analysis of these variables is approached by applying mathematical and computer formulation to numerous model nodes containing lesions of variable size and location. The percentage probabilities of identifying various sized lesions in different sized nodes is calculated in graphic form. These studies propose a functional method of lymph node sectioning which is applicable to improved sectioning technique.

We examined the effect of three methods of porewater extraction on the measured concentrations of seven porewater constituents in vegetated salt marsh sediments. Porewater extraction by standard core sectioning followed by squeezing or centrifuging was compared with two less destructive methods of water collection. The core sectioning technique significantly increased the concentration of total dissolved organic carbon and dimethylsulfide presumably due to root damage by cutting. Sampling technique did not appear to influence interstitial salinity or concentrations of dissolved inorganic carbon, dissolved ammonium, soluble sulfides, and dissolved sulfate as long as proper precautions were taken to prevent the loss of reduced compounds.

Bourque, B. J., K. Morris, and A. Spiess 1978 Determining season of death of mammal teeth from Archaeological sites: a new sectioning technique Science 199:530-531. Brooke, S., and K. Morris 1978 Conservation of marine archaeological artifacts from the Defence: a regional conservation center approach. Paper presented at the 9th Conference on Underwater Archaeology, San Antonio, in press. Christensen, Andrew L. 1979 The role of museums in cultural resource management. American Antiquity 44:161-163. Maine Revised Statutes Annotated 1969 Title 27, chapter 13, sub-chapter II. West Publishing Company, St. Paul, Minnesota. Morris, K., and B. Seifert n.d. Conservation of leather and textiles from the Defence. Journal of the American Institute for Conservation, in press. Pearson, C. 1977 On site conservation requirements for marine archaeological excavations. The International Journal of Nautical Archaeology and Underwater Exploration 6:37-46. Sanford, E. 1975 Conservation of artifacts: a question of survival. Historical Archaeology 9:55-64. Spiess, A. 1976 Determining season of death of archaeological fauna by analysis of teeth. Arctic 29:53-55. United States Federal Register 1977 Vol. 43, 36 CFR 66:5376-5377. U.S. Government Printing Office, Washington, D.C.

The present paper is a review of some different applications of whole-body freeze-dried sections to illustrate the usefulness for studies on mineralized tissues. Thus the application of autoradiography fluorescence microscopy and enzyme histochemistry and their combinations is described.

固定内の自己拡散定数 (D*) を求めるのによく用いられている順次切削法では, 実験的に得られたトレーサーの濃度分布は, 通常, ガウス曲線C=M/√πD*t exp(-x2/4D*t) に一致するとして解析されている. ガウス曲線は, 拡散方程式を初期条件にデルタ関数状のトレーサー分布を仮定して解いた解である. しかし, 試料表面に付着されるトレーサーを含む化合物の厚さは, 実際には有限であり, また, その化合物が試料と化学形を異にし, 表面付着層と試料中での拡散定数が異なっている場合もしばしばある. 従来はこうした事情を考慮して拡散方程式が解かれていないので, 本研究では付着層の厚さ (h) が有限値をとり, 付着層中での拡散定数 (DA) と試料中での拡散定数 (DB) が違うとして拡散の偏微分方程式を解き厳密解を得た. その結果, 一定のDB/DA値に対して, r値 (r=h/√DAt) がゼロから無限大に増加するにつれ, 濃度分布はガウス曲線から誤差補関数曲線へと変化していく挙動が定量的に明らかになった. 濃度分布が両曲線のいずれかに一致している場合には, その曲線から正確なD*の値を得るための数学的に厳密な解析法があるが, いずれにも一致しない中間的な分布の場合には, 正確なD*を求めることは困難である. したがって, 自己拡散定数を正確に求めるためには, 濃度分布が両曲線のいずれかに一致するように, あらかじめ実験条件を設定しておく必要がある. こうした実験諸条件の許容範囲を示すために, (r, DB/DA) 平面を濃度分布が1%以内の誤差で, ガウス曲線に一致する領域, 誤差補関数曲線に一致する領域, 両曲線に共に一致しない領域の3領域に分けて図示した. TlCl単結晶にNaClの形でClのラジオアイソトープ, 36Clを付着させ, 36Clの拡散を行なわせて得られる濃度分布を測定し, これらの議論を実験的に例証した.

A tracer sectioning technique was used to measure cation self-diffusion coefficients in fully dense polycrystalline YaO3 and Er2Os under oxidizing conditions. The results are described by the relations for Y2O3 (1400° to 1670°C), and for Er2O3 (1400° to 1700°C). The greater activation energy for erbium diffusion in erbia may be partly attributable to a mass effect.

An electrolytic sectioning technique has been used to measure self-diffusion coefficients in silver single crystals in the temperature range 300–800 °C. The results are analyzed in terms of diffusion through the crystal lattice, enhanced by diffusion along dislocations.

An electrolytic sectioning technique has been used to measure self-diffusion coefficients for gold in the temperature range 360 to 740 °C. At 740 °C our value agrees with previous work at this temperature, while the lower temperature values are larger than predicted by extrapolation of the well-established high-temperature behavior. The results are interpreted in terms of dislocation enhanced diffusion.

The diffusion of gold in gamma uranium has been measured using a radioactive tracer and the sectioning technique. The values of D o and the activation energy are 4.86 × 10 −3 cm 2 /sec and 30 400 cal/mol respectively, fairly close to the values for self-diffusion in gamma uranium.

Self-diffusion of Zr in 12 and 16 mol.% CaO and of Ca in 16 mol.% CaO cubic zirconia was measured by the sectioning technique from 1700° to 2150°C. Lattice self-diffusion coefficients are: Autoradiographs show rapid grain boundary diffusion. DB is estimated as

The self-diffusion of nickel has been studied in polycrystalline samples by a sectioning technique. There is evidence of grain boundary diffusion below temperatures of 1150 °C. The results obtained between 1150° and 1400 °C are representative of volume diffusion and are represented by the expression[Formula: see text]A comparison is made with the results of other self-diffusion studies using Zener's hypothesis.

We describe an apparatus which allows us to measure accurately the self-diffusion coefficients by the standard thin film deposition and sectioning technique. The accuracy of each measurement of the self-diffusion coefficient is about 0,4%. This accuracy allows a positive curvature to be detected in the β−Tl Arrhenius plot. The possibility that this effect be due to preferential diffusion along grain boundaries is discussed. We conclude that the observed curvature reflects the properties of the β−Tl monocristal. Two supplementary experiments allowed us, on the one hand to define satisfactory experimental conditions for the electro-deposition of thallium from a thallous sulphate solution and, on the other hand, to measure accurately the α−β transition temperature of thallium, that is found to be 235,25±0,1°C Nous presentons un ensemble experimental permettant la mesure precise de coefficients d'autodiffusion par la technique du depot mince et du sectionnement. La precision moyenne atteinte sur la mesure du coefficient de diffusion est de 0,4%. Cette precision permet de detecter une courbure positive dans le graphe d'Arrhenius de β-Tl. La possibilite qu'il s'agisse d'un effet de diffusion preferentielle dans les points de grains est discutee. On conclut que la courbure observee reflete les proprietes du monocristal. Deux experiences annexes nous ont permis, d'une part de definir des conditions experimentales satisfaisantes pour le depot electrolytique du thallium en solution sulfurique, et, d'autre part, de mesurer avec precision la temperature de la transition α−β du thallium, soit 235,25±0,1°C.

Food preferences and feeding behaviour of abundant species of oribatid mites in a black pine plantation have been studied by soil sectioning technique. It is suggested that Microtritia minima, Rhysotritia duplicata and Phthiracarus sp. play an important role in the mechanical breakdown of decaying litter and, by contributing to the humification process, help in the accumulation of plant nutrients. Due to poor mobility their contribution to fungal spore dissemination is insignificant. Chamobates incisus was determined to be a fungivorous species while no exact information could be obtained about the precise food of Tectocepheus velatus. Rest of the species seemed to consume large quantities of decaying litter but in view of their low populations throughout, presumably they do not contribute appreciably in the humification process.The speed of decomposition of faecal pellets seemed to be governed by the type of food ingested. The role of oribatid fauna in the litter and soil ecosystems is discussed.

A tracer sectioning technique was employed to measure cation self-diffusion coefficients in fully dense polycrystalline materials under oxidizing conditions. Results are D = 1.65x10/sup -2/ exp(-69,200/RT) cm/sup 2//s for Y/sub 2/O/sub 3/ (1400 to 1670/sup 0/C), and D = 1.48 exp(-102,200/RT) cm/sup 2//s for Er/sub 2/O/sub 3/ (1400 to 1700/sup 0/C). The greater activation energy for erbium diffusion in erbia is attributed to a mass effect. Oxygen diffusion coefficients were extracted from observations in the reoxidation of small single crystals of uniformly reduced oxides produced by vacuum fusion. The oxidation process proceeded by the development of a fully oxidized external shell, the growth of which was rate-limited by diffusion of interstitially dissolved oxygen through the oxidized layer to a sharp interface with the reduced material. The growth of the oxidized shell was followed by means of a thermobalance. Oxygen diffusion coefficients were calculated to be D = 6.01x10/sup -6/ exp(-19,600/RT) cm/sup 2//s for Y/sub 2/O/sub 3/ (1064 to 1276/sup 0/C), and by D = 4.76x10/sup -5/ exp(-30,100/RT) cm/sup 2//s for Er/sub 2/O/sub 3/ (1060 to 1292/sup 0/C).

Alternating translucent and opaque bands on the roots of mammal teeth are used to determine the age and season of death. These structures are preserved in teeth from archeological sites. However, the standard sectioning technique, which includes decalcification, often destroys archeological specimens. A new, less destructive technique provides analyzable solid sections at costs comparable to decalcification.

Submicron sectioning apparatus for studying slow carbon self diffusion in dense polycrystalline tungsten carbide

A recent development, scanning electron microscopy, makes possible, with its high magnification (×100 to ×100 000) and great depth of focus (300 times greater than optical microscopes), three‐dimensional investigation of the structure of the cochlea. In our preliminary study, fresh guinea pig cochleae were fixed by several different methods. The fixed cochleae were frozen and surface specimens of the organ of Corti were prepared by “planing” with a microtome. [G. J. Jako, Frozen Sectioning Technique for Studying Distribution of Dyes and Isotopes in Guinea Pig Cochleae, abstract, Intl. Congr. Biophys., 1st (1961)]. The specimens were then dehydrated and coated with a thin, 500‐A thick, gold film in a vacuum evaporator. The details of specimen preparation and the interpretation of the results will be discussed.

An investigation is made of the error due to truncated impulse response for the block mode or sectioning technique. The upper bound on the error in terms of the sectioning parameters is obtained and shown to be independent of block size; this results in a simpler approach to obtaining an optimal sectioning procedure.