Scanning Electron Microscopy Microphotographs Research Articles

Description of a new whitefly genus and two new species (Hemiptera: Aleyrodidae) from the Western Ghats and Andaman Islands, India

Cerafilum gen. nov. is described for Cerafilum ochlandrae sp. nov. and Cerafilum saddlense sp. nov., from India and colonising bamboo species. Cerafilum gen. nov. is compared with the allied genus Aleuromarginatus Corbett and Setaleyrodes Takahashi and diagnoses and illustrations provided, including habitus, line drawings of holotype, diagnostic characteristics, types’ images and scanning electron microscope microphotographs.

Impact of ply stacking sequence on the mechanical response of hybrid Jute-Banana fiber phenoplast composites

Natural fiber composites are increasingly gaining popularity as a cost-effective and environmentally friendly alternative to synthetic fibers. Incorporating a variety of fibers enhances mechanical properties. The arrangement of fibers plays a crucial role in determining the mechanical characteristics of laminate composites. Therefore, the primary objective of this study is to investigate how the stacking order of jute (J) and banana (B) fibers affects the mechanical behaviour of composites made from phenolic resins. Four different fiber mat stacking sequences (J/B/B/J, B/J/J/B, J/B/J/B, and J/J/B/B) were used for developing the eco-fiber composites using the heat-press technique. Several mechanical parameters were assessed, including tensile strength, flexural strength, impact strength, and inter-laminar shear strength (ILSS). The experimental results indicated that the JBBJ composite exhibits superior tensile strength (46.65 MPa) and modulus (993 MPa) compared to the other composites due to the presence of high-strength jute fibers on the surface. Additionally, the flexural strength of the JBBJ composite (87.24 MPa) was found to be noteworthy. It was observed that the impact strength of jute fibers surpasses that of banana fibers. Consequently, the JBBJ composite demonstrates higher values for energy absorption (0.482 J) and impact strength (120 J m−1) compared to the other composites tested. Moreover, the JBBJ composite displays higher inter-laminar shear strength and hardness values compared to BJJB, JBJB, and JJBB by 30%, 35%, and 43%, respectively. Scanning electron microscope microphotographs reveal strong correlational fracture failure mechanisms, indicative of improved mechanical properties in the JBBJ composite. Based on the experimental results, it is evident that the JBBJ composite can be utilized in lightweight applications.

Xanthan gum in solution and solid-like state: Effect of temperature and polymer concentration

The development and optimization of xanthan-based systems are closely related to its structure and the properties induced in the material which contains it. Considering this, the present work aimed to investigate the effect of temperature and polymer concentration on the rheological properties of xanthan gum (XG) aqueous solutions, and on morphology of corresponding films. Viscoelastic properties of the solutions with 0.4, 1.0 and 2.0 % XG have been studied in oscillatory and continuously shear regimes. A solid-like response over the entire studied frequency range was observed for investigated solutions. The Cox-Merz superposition of complex and apparent viscosities was evidenced only for 0.4 and 1.0 % XG solutions. The effect of XG content on yield stress of solutions was also discussed. The morphology of surface and cross-section of XG films, prepared by casting solution method, were characterized by atomic force microscopy (AFM), scanning electron microscopy (SEM) and polarized optical microscopy (POM). The morphological aspects at nanometric scale, investigated by AFM, highlighted the influence of the XG concentration on the film characteristics, the isotropy/anisotropy balance and the surface texture. SEM and POM microphotographs of film, obtained from 2.0 % XG solution, evidenced an ordered structure of polymer chains and birefringence, respectively.

Provenance and deposition of a lithified volcanic-rich layer (VRL-5.5) at 5.5 Ma from Central Apennines (Italy)

Two slightly lithified volcanic rich layers (VRL) (former tephra) SVT-2 (San Vittorino) and CAC (Castiglione a Casauria) were sampled from two distinct post-evaporitic Messinian stratigraphic sections (Abruzzo, Central Italy). They crop only few tens of km apart and are predominantly massive, although some specimens show sedimentary structures. Both VRLs were investigated for the first time by field, mesoscopic, X-ray powder diffraction (XRPD), transmission optical microscopy (TOM), scanning electron microscopy (SEM), bulk composition, electron-microprobe analysis (EMPA) and quantitative textural attributes by image analysis. The XRPD analysis detects the presence of a glass phase, plus few (< 2 area %) magmatic-like feldspars, clinopyroxene and biotite and stratigraphically variable sedimentary minerals such as calcite, dolomite, illite and montmorillonite (from 0 to 40 area %). The 2D image analysis performed on SEM microphotographs reveals that both sections are composed of very fine glass shards, magmatic minerals are never isolated, whilst the carbonate crystals mainly fill voids among volcanic particles. Both these VRLs have identical rhyolitic glass compositions that closely overlap with those of previously-studied coeval and stratigraphically related sections occurring in the northern Apennine region and dated as 5.5 Ma. The 2D textural features of glassy particles (length, width, aspect ratio, grain-size distribution, MZ , σi, SKi, KG and roundness) in both SVT-2 and CAC sections are very similar and also close to the northern section of Camporotondo (Marche region). The outcomes provided here indicate that SVT-2 and CAC sections represent the southernmost distal deposits of the same large eruption that occurred about 5.5 Ma (VRL-5.5). They result from distal fallout of tephra through seawater, occasionally remobilised under low energy and localised conditions, especially in the uppermost part of the CAC section. All the VRL-5.5 rocks are probably related to a very large eruption that occurred in the Carpathian-Pannonian magmatic district. The analytical protocols used in this study can be useful to investigate other ancient volcanic-rich layers, corresponding to lithified tephra.

Evaluation of Eco-Friendly Hemp-Fiber-Reinforced Recycled HDPE Composites

The exploitation of natural fibers to reinforce polymers is a promising practice. Thus, biocomposites have gained increased attention in automotive, construction, and agricultural sectors, among others. The present work reports the reinforcement of recycled high-density polyethylene (r-HDPE) with hemp fibers to afford composite materials as sustainable analogues to conventional wood/plastic composite (WPC) products. HDPE bottles (postconsumer waste) were used as r-HDPE and further reinforced by the addition of hemp fibers. For the synthetic part, thirteen composite materials with different filler concentrations (10–75% wt. in hemp fibers) using either Joncryl or polyethylene-grafted maleic anhydride (PE-g-MA) as compatibilizers were prepared via melt mixing. Materials with good integrity were obtained with a fiber load as high as 75% wt. The structural, thermal, mechanical, and antioxidant properties of the r-HDPE/hemp composites were evaluated using multiple complementary characterization techniques. Stereoscopic microscope images demonstrated the satisfactory dispersion of the hemp fibers into the polymeric matrix, while scanning electron microscopy microphotographs revealed an improved adhesion between the filler and the polymeric matrix in the presence of compatibilizers. The incorporation of hemp fibers contributed to the improvement of the elastic modulus of the composites (almost up to threefold increase). The results showed that as the hemp fiber content increased, the antioxidant properties as well as the degradability of the composites increased. It is noteworthy that composites containing 75% wt. hemp fibers neutralized 80% of 2,2-diphenyil-1-picrylhydrazyl radicals within 45 min (DPPH assay). In conclusion, the present research work demonstrates that thermally recycled HDPE reinforced with biomass fibers received from agricultural waste is a valid alternative for the preparation of commodity products with an eco-friendly character compared to conventional wood/plastic composites.

Poly(Lactic Acid) Block Copolymers with Poly(Hexylene Succinate) as Microparticles for Long-Acting Injectables of Risperidone Drug.

In the present work, Risperidone microparticles from poly(lactic acid)/poly(hexylene succinate) (PLA-b-PHSu) block copolymers in different ratios, 95/05, 90/10 and 80/20 w/w, were examined as long-acting injectable formulations. Nuclear magnetic resonance (NMR) was used to verify the successful synthesis of copolymers. Enzymatic hydrolysis showed an increase in weight loss as the content of PHSu increased, while the cytotoxicity studies confirmed the biocompatibility of the copolymers. The polyesters were further used to encapsulate Risperidone by spray drying. The drug-loaded microparticles were studied by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and X-ray diffraction (XRD). SEM microphotographs confirmed that spherically shaped microparticles were prepared with sizes about 5–12 μm, while XRD and differential scanning calorimetry (DSC) studies evidenced that Risperidone was encapsulated in amorphous form. The drug loading and the entrapment efficiency of Risperidone were studied as well as the in vitro release from the prepared microparticles. As the content of PHSu increased, a higher release of Risperidone was observed, with PLA-b-PHSu 80/20 w/w succeeding to release 100% of RIS within 12 days. According to theoretical modeling, the kinetics of RIS release from PLA-b-PHSu microparticles is complex, governed by both diffusion and polymer erosion.

Effect of different enamel pretreating agents on bonding efficacy and survival rates of orthodontic brackets: In vitro study and split-mouth randomized clinical trial

This double invitro study and randomized clinical trial aimed to investigate the bonding failure rates of orthodontic brackets after enamel pretreatment with agents showing different particle sizes. For the invitro study, 80 bovine teeth were randomly divided into 4 groups according to the pretreating method used and their particle sizes: erythritol (14 μm), glycine (18-22 μm), sodium bicarbonate (70 μm), and no pretreatment. Scanning electron microscopy microphotographs were performed after pretreatment. Then, brackets were bonded, and shear bond strength was calculated. For the clinical study, agents with low (erythritol) and high (sodium bicarbonate) particle sizes were chosen. Twenty consecutive patients willing to start fixed orthodontic treatment with vestibular stainless steel brackets were enrolled. Patients were randomly divided into 2 groups following a split-mouth design. Group A underwent a 5-second enamel pretreatment procedure with erythritol for teeth belonging to maxillary left and mandibular right quadrants, whereas the remaining quadrants were pretreated for 5 seconds with sodium bicarbonate powder. In group B, quadrants were inverted. Then, brackets were bonded on the vestibular surfaces of teeth, and patients were visited monthly for 12 months to assess bond failures. Periodontal evaluation of probing pocket depth, bleeding on probing, plaque index, and papilla bleeding index was conducted before bonding and after 1, 3, 6, and 12 months. The invitro study showed that erythritol and control presented significantly higher shear bond strength values for other agents. Bicarbonate showed the lowest values. In the clinical study, 20 patients (aged 16.4 ± 3.9 years) were enrolled, and all completed the study. Erythritol showed a significantly lower failure rate (3%) than sodium bicarbonate (7.5%). Kaplan-Meier survival plots showed statistically significant differences in risk of failure between the 2 groups during the 12-month follow-up. Enamel pretreatment with erythritol can be a viable technique to reduce failure rates of orthodontic brackets. The trial was not registered. The protocol was not published before trial commencement. No funding or grant was received for this research.

Enterogyrus spp. (Monogenea: Ancyrocephalinae) and Aeromonas jandaei co-infection associated with high mortality following transport stress in cultured Nile tilapia.

Monogenean infection of the internal organs is extremely rare when compared to external infections. This study describes mass mortality of Nile tilapia (Oreochromis niloticus L.) originating from co-infection with Enterogyrus spp. and Aeromonas jandaei following transport stress. The first fish deaths occurred on day 1 post-transport, while cumulative mortality reached approximately 90% by day 10 post-stocking. An atypical amount of pale (whitish) faeces floating on the surface of the water as well as typical clinical signs of motile Aeromonas septicemia, were reported. Adult monogeneans and countless eggs of monogeneans were found in the stomachs and the intestines of both moribund and dead fish, respectively. Two strains of A. jandaei were isolated from the kidneys. Scanning electron microscope microphotographs of the stomach revealed the presence of numerous monogeneans penetrating deep into the gastric tissue, and diffuse lesions filled with bacilliform bacteria. Histopathological examination showed multifocal eosinophilic infiltrate, gastric gland and epithelial necrosis with sloughed necrotic debris in the lumen. This is the first report of co-infection by Enterogyrus spp. and A. jandaei in Nile tilapia and the first report of Enterogyrus coronatus, Enterogyrus foratus, and Enterogyrus malbergi parasitizing tilapia in Brazil. These findings indicate that synergic co-infection by Monogenean stomach parasites (E. coronatus, E. foratus, and E. malbergi) and A. jandaei may induce high mortalities in tilapia following transport stress.

Cocrystal formation of loratadine-succinic acid and its improved solubility.

Loratadine belongs to Class II compound of biopharmaceutics classification system (BCS) due its low solubility and high membrane permeability. Cocrystal is a system of multicomponent crystalline that mostly employed to improve solubility. Succinic acid is one of common coformer in cocrystal modification. This research aims to investigate cocrystal formation between loratadine and succinic acid and its effect on solubility property of loratadine. Cocrystal of loratadine-succinic acid was prepared by solution method using methanol as the solvent. Cocrystal formation was identified under observation of polarization microscope and analysis of the binary phase diagram. The cocrystal phase was characterized by differential thermal analysis (DTA), powder X-ray diffraction (PXRD), Fourier transform infrared (FTIR), and scanning electron microscopy (SEM). Solubility study was conducted in phosphate-citrate buffer pH 7.0±0.5at 30±0.5°C. Loratadine is known to form cocrystal with succinic acid in 1:1M ratio. Cocrystal phase has lower melting point at 110.9°C. Powder diffractograms exhibited new diffraction peaks at 2θ of 5.28, 10.09, 12.06, 15.74, 21.89, and 28.59° for cocrystal phase. IR spectra showed that there was a shift in C=O and O-H vibration, indicating intermolecular hydrogen bond between loratadine and succinic acid. SEMmicrophotographs showed different morphology for cocrystal phase. Loratadine solubility in cocrystal phase was increased up to 2-fold compared to loratadine alone. Cocrystal of loratadine and succinic acid is formed by stoichiometry of 1:1 via C=O and H-O interaction. Cocrystal phase shows different physicochemical properties and responding to those properties, it shows improved loratadine solubility as well.

Pollen morphology of the some taxa belonging to Veronica L. (Plantaginaceae) and Its taxonomic importance

In this study, the genus Veronica L. (Plantaginaceae) from the Plantaginacae family V. bozakmanii M.A.Fisch., V. triphyllos L., V. persica Poir., V.triloba Opiz., V. anagallis-aquatica L., V. oxycarpa Boiss., V. cinerea Boiss. & Balansa., V. macrostachya Vahl. subsp. mardinensis (Bornm.) M. A. Fisch., V. orientalis L. subsp. orientalis, V. orientalis L. subsp. nimrodi (Richt. ex Stapf) M.A. Fisch taxa were investigated in terms of palynological features. The specimens of this taxa were collected during the field surveys were investigated using Light Microscope (LM) and Scanning Electron Microscope (SEM). As a result of this study some common traits of the taxa found out such as polen tectate, the pollen shapes being subprolate, prolate and the symmetry being heteropolar. Also, the type of the aperture is tricolpate. The SEM microphotographs shows that the ornamentations are reticulate, scabrate-perforate and striate-microreticulate.

Development of barite-filled acrylonitrile butadiene styrene composites: Mechanical, thermal, melt-flow and morphological characterizations

Barite mineral (BRT) was compounded with acrylonitrile butadiene styrene terpolymer (ABS) with four varied filling ratio of 5%, 10%, 15% and 20% by weight. ABS/BRT composites and unfilled ABS were fabricated by twin screw micro-extruder and test samples were shaped using injection molding process. Tensile tests, shore hardness measurements and impact tests, dynamic mechanical analysis (DMA), melt-flow index (MFI) study and scanning electron microscopy (SEM) characterization techniques were performed in order to investigate mechanical, thermo-mechanical, melt-flow and morphological performance of composites, respectively. Mechanical tests results showed that tensile strength and hardness of unfilled ABS were enhanced as BRT content increased. DMA study revealed that in addition to glass transition temperature, storage modulus of ABS raised by BRT inclusions. However, impact energy of ABS exhibited decreasing trend with the loading level of BRT. According to MFI measurements, BRT additions caused no significant change for MFI parameter of ABS regardless of concentration. It was confirmed by SEM microphotographs that the dispersion of BRT particles was found to be more homogeneous into ABS phase for their lower contents. The filling ratio of 10% BRT yield the highest performance among fabricated ABS based composites according to test results.

Modification of kaolinite clay using benzyltriethylammonium chloride as a surfactant: Preparation and characterization

Natural kaolinite clay from Perak, Malaysia with cation exchange capacity (CEC) of 2.5 meq/100g was modified using cationic surfactant, benzyltriethylammonium chloride (BTEA-Cl), at 0.5, 1.0, 1.5 and 2.0 times the CEC. A number of techniques, namely energy dispersive X-ray (EDX) spectroscopy, X-ray diffraction (XRD), Fourier-transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), and Brunauer-Emmett-Teller (BET) nitrogen adsorption-desorption were then used for characterization of the kaolinite and/or organo-modified kaolinite clays. The presence of alkyl groups as a result of successful intercalation of cationic surfactant within the organo-kaolinite layers of the clay was exhibited by the FTIR spectra. The SEM microphotographs exhibited good dispersion of the natural clay particles and slight agglomeration in the organo-modified clay particles. XRD patterns showed that the d001 spacing of the natural kaolinite clay increased from 7.12 Å to between 7.20 - 7.34 Å for the organo-modified clays. Following the BET nitrogen adsorption-desorption technique, all clay samples were of Type IV with narrow hysteresis loops. Surface areas of the clays showed drastic decrease from (25.34 m2/g) for natural kaolinite clay to between 5.90 - 13.11 m2/g for organo-modified clays. The results suggested that modification of natural kaolinite clay using cation surfactant had successfully occurred. The modification can therefore be further applied for alteration and improvement of the properties of natural clays for various industrial applications.

A spectroscopic approach to determine the formation mechanism of biopolymer particles from wheat bran proteins

The mechanism of formation of biopolymer particles, obtained from an aqueous extract of wheat bran, was studied by Fourier transform infrared spectroscopy (FTIR), assisted by energy dispersive spectroscopy (EDS), and scanning electron microscopy (SEM). Spheroidal biopolymer particles, 204−347 nm diameter, were synthesized by heat-induced aggregation of a 21−43 kDa wheat bran protein fraction. There were reductions of 39.5% and 52.78% in the β-sheet and α-helix conformations, respectively, after exposure of proteins to 68.5°C, whereas β-sheet aggregates increased from 0 to 39.87%. SEM microphotographs showed that the internal structure of biopolymer particles consisted of nanospheres aggregated within a network. The overall analysis, plus evidence found in literature, indicated that temperature made individual proteins to exposure thiol groups, favoring disulfide bridges and β-sheet aggregates, which resulted in the assembly of nanospheres. Nanospheres were then agglomerated in a fractal-like way through non-covalent intermolecular interactions, to build the biopolymer particles. Junctions between biopolymer particles were interpreted as intermolecular β-aggregates, so a cluster-like complex was finally assembled. Shape, size, and surface morphology of biopolymer particles were stable during 18 months at 25°C.

Plant proteases from Carica papaya and Vasconcellea quercifolia with potential application for a cleaner processing in tanneries

In the leather industry, proteases can be used as tools to achieve cleaner technology. In the present study, proteolytic preparations obtained from the latex of Carica papaya (Cp) and Vasconcellea quercifolia (Vq) were assayed as dehairing agents for leather processing. Both Cp and Vq showed activity against substrates representative of collagen, keratin, elastin, and epidermis in a range of moderate temperatures (25 to 55 °C). When comparing with a commercial dehairing enzyme, the activity of Cp and Vq on the substrates representative of epidermis and collagen was of around 70% and 100% of the commercial one, respectively, with that of Cp being more keratinolytic. Both Cp and Vq were able to dehair cowhides at 25 °C for 24 h without adding Ca(OH)2 or Na2S, two harmful pollutants used in conventional dehairing, Cp being more effective than Vq. Scanning electron microscopy microphotographs showed epidermis and hair-free hides with clean pores and without significant damage on the grain surface. Further, no damage was detected in collagen fibres and both Cp and Vq showed a slight opening of collagen fibres. We concluded that both Cp and Vq could be used as tools for a cleaner technology in tanneries, either for lime- and sulphide-free dehairing or for the treatment and valorisation of protein waste.

Polyol from spent coffee grounds: Performance in a model pour-in-place rigid polyurethane foam system

The objective of this study was to produce a polyol from spent coffee grounds via acid liquification process that meets performance requirements for use in polyurethane applications. The spent coffee grounds based polyol was characterized and evaluated on a fully catalyzed model rigid polyurethane foam system. The pH of the polyol was 6.8, acid value 4.12 mg KOH/g, and hydroxyl value 302.6 mg KOH/g, which are in the range of polyols used in rigid polyurethane foams. The reactivity study confirmed enhanced reactivity of the spent coffee grounds polyol compared to standard sucrose-glycerol initiated polyether polyols, which can be attributed to higher content of primary reactive hydroxyls. Scanning electron microscopy microphotographs of the foams prepared with 10%, 20%, and 30% spent coffee grounds polyol based on total polyols in the formulation revealed a drained dodecahedron type cell structure with intact cell windows as a clear indication of the closed cell structure typical for the rigid polyurethane foams used in thermal insulation applications. Results of this study confirmed the feasibility to produce polyols from spent coffee grounds with performance characteristics suitable for polyurethane application. The fact that spent coffee grounds are readily available industrial waste generated in instant coffee manufacturing, makes this biomass residue a sustainable source of raw materials for scalable production of polyols for polyurethanes.

Enhancement of mechanical, thermal and water uptake performance of TPU/jute fiber green composites via chemical treatments on fiber surface

Abstract Chopped jute fiber (JF) surfaces were modified using alkaline, silane and eco-grade epoxy resin. Surface characteristics of jute fibers were confirmed by FTIR and EDX analyses. JF filled polyurethane elastomer (TPU) composites were prepared via extrusion process. The effect of surface modifications of JF on mechanical, thermo-mechanical, melt-flow, water uptake and morphological properties of TPU-based eco-composites were investigated by tensile and hardness tests, dynamic mechanical analysis (DMA), melt flow index (MFI) test, water absorption measurements and scanning electron microscopy (SEM) techniques, respectively. Mechanical test results showed that silane and epoxy treated JF additions led to increase in tensile strength, modulus and hardness of TPU. Glass transition temperature (Tg) of TPU rose up to higher values after JF inclusions regardless of treatment type. Si-JF filled TPU exhibited the lowest water absorption among composites. Surface treated JFs displayed homogeneous dispersion into TPU and their surface were covered by TPU according to SEM micro-photographs.

Preparation and characterization of rice husk based physical activated carbon

ABSTRACTActivated carbons (ACs) were successfully prepared from rice husk by physical activation method. In the present study, the ACs were prepared at different activation temperatures for a specified activation time interval of 1h in a flow of CO2 gas as an activating agent. The resulted product was analyzed by various characterization techniques, such as Brunauer, Emmett and Teller (BET), Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), Thermogravemetric analysis (TGA) and X-Ray Diffractometry (XRD). The maximum surface area of about 502 m2/g was obtained from the sample activated at 900°C for a time interval of 1h. The SEM microphotographs of the ACs exhibited a well-developed porous structure with different pore sizes. The TGA analysis confirmed the pyrolyzed rick husk (char) conversion that took place around 580°C. The XRD analysis of all the precursors and their resulted ACs were also performed. Wherein, the XRD results established the amorphous carbon structure of the product resulted. The FTIR analysis also confirmed the presence of various peak frequencies of functional groups before and after activation.

Comparison of Fracture Resistance of Two Resin-based Sealers to Root Canal Walls: An In Vitro Study

In the present study, the prepared roots obturated by gutta-percha/AH plus and Resilon/Epiphany were tested and compared for fracture resistance. The study also does a scanning electron microscope (SEM) evaluation of the adaptability of these obturating materials to root canal walls. One hundred extracted mandibular premolars were decoronated and the dimensions of the roots were standardized. Each root was prepared to a size of #25 with 6% taper. Roots were gauged after preparation and those requiring more preparation were discarded. Seventy-seven prepared roots were finally selected for the study. The samples were then divided into three groups. Group I with 25 specimens was control group in which no obturation was performed, group II with 26 specimens was obturated by gutta-percha/AH plus sealer, and group III with 26 specimens was filled by Resilon/Epiphany. The method for obturation was cold lateral condensation. The samples were then stored at 100% humidity for 2 weeks. One random sample from groups II and III was subjected to SEM analysis. Groups I, II, and III were then subjected to vertical loading in Instron machine. One-way analysis of variance (ANOVA) test and Tukey's multiple comparison test were used for statistical analysis. Group III exhibited the maximum fracture resistance as compared to groups I and II. The least mean fracture resistance of 370.05 N was seen in group II and the maximum mean fracture resistance of 481.05 kN was observed in group III. One-way ANOVA and Tukey's multiple comparison test between groups I, II, and III, group III showed a highly significant resistance to fracture as compared to groups I and II (p < 0.0001). Scanning electron microscope microphotographs showed a better adaptation of Resilon/Epiphany as compared to gutta-percha/AH plus to the root canal. The Resilon/Epiphany on obturation of root canals creates a monoblock by penetrating inside the dentinal irregularities, which strengthens the root and provides fracture resistance. This fracture resistance was significantly higher in the present study as compared to groups I and II. In the present study, Resilon/Epiphany when used to obturate the prepared canals showed a promising result both in terms of fracture resistance and adaptability to root canal walls. This paves a way for the use of this combination of obturating material not only to strengthen the compromised root strength in clinical scenario but also providing an increased sealing ability which will contribute to the success of root canal treatment.

Characteristics of microorganisms and origin of organic matter in Wufeng Formation and Longmaxi Formation in Sichuan Basin, South China

Abstract To evaluate the characteristics of microorganisms and the origin of organic matter of the Wufeng Formation and Longmaxi Formation (WF-LMX) in Sichuan Basin (South China), the type and number of microorganisms were determined in this study using scanning electron microscope (SEM) microphotographs and microbial extraction. The contribution of various microorganisms to organic matter was analyzed in combination with the data of biomarkers and total organic carbon (TOC). It can be deduced from the paleogeography and pristine/phytane (Pr/Ph) ratio that the microorganisms of WF-LMX resided in 60 m–200 m deep shelf with anoxic bottom water. From SEM microphotographs and microbial microscopy analysis, it was demonstrated that the microorganisms in the WF-LMX can be divided into 3 types: planktonic algae (mainly including acritarchs and green algae), fungi, and benthic algae. Acritarchs were the most common microorganisms in the WF-LMX with the average relative content of 60.5%. The average relative contents of benthic algae, fungi, and green algae were 17.6%, 18.0% and 3.9%, respectively. Since the acritarchs and green algae in the Wufeng Formation and the Longmaxi Formation basically belong to planktonic algae, the relative content of planktonic algae in them is about 64.4%. The strata of WF-LMX can be divided into 3 sections based on the distribution characteristics of various microorganisms. The relative content of acritarchs gradually decreased upwards, while that of benthic algae gradually increased. The multiple proxies of biomarkers proved that the planktonic algae was the main source of organic matter in the WF-LMX. Combining the statistical data of microorganisms, it was considered that the organic matter in WF-LMX was mainly derived from acritarchs, which might be the components of planktonic algae. The fungi had a significant contribution to the organic matter in organic-rich layers (TOC > 2.0%) rather than in organic-poor layers, while green algae and benthic algae made little contribution to the organic matters in WF-LMX.

A new whitefly genus and species, Aleuroparvus theae Dubey (Hemiptera: Aleyrodidae) colonising Assam tea (Camellia sinensis) and Cinnamomum bejolghota, in North-East India.

Puparia of a new whitefly genus and species, Aleuroparvus theae Dubey gen. et sp. nov. are described along with drawings, habitus and type images of habitus and types, and scanning electron microscope microphotographs. It is found infesting an economically important plant, Assam tea, Camellia sinensis (L.) (Theaceae) in Assam, and Cinnamomum bejolghota (Hamilton) (Lauraceae) in Arunachal Pradesh, India. Puparia of A. theae are dimorphic, the females being larger than males. The puparia of the new genus differ from all other genera in having smaller ventral surface, submarginal wax secreting pores and dorsal submargin separated from the dorsal disc by a submarginal ridge. The diagnostic characteristics for puparia of the new genus are compared with closely related genera, Aleuroclava Singh, Aleuropleurocelus Drews Sampson, Dialeuropora Quaintance Baker, Tetralicia Harrison and Tetraleurodes Cockerell.