Moderate Acid Research Articles

Effects of Zinc and Aluminum on the CuO Crystalline Size for Direct Dimethyl Ether Synthesis from Syngas

AbstractThe effects of zinc and aluminum on the CuO crystalline size for direct dimethyl ether (DME) synthesis from syngas were investigated. Metal oxide catalysts were synthesized with various molar ratios of CuO by the precipitation method, and by the co‐precipitation method with CuO/ZnO (CZ), CuO/ZnO/Al2O3 (CZA), and CZA at ratios of 1:1, 2:2:1, and 6:3:1, respectively. The acid catalysts (γ‐Al2O3, HZSM‐5) were added to the metal oxide catalysts by physical mixing. The catalysts were characterized morphologically and their acidities were determined. Loading of zinc and aluminum at different ratios showed that CZA (2:2:1) gave the smallest CuO crystalline size, appropriate for the methanol synthesis reaction. γ‐Al2O3 has a weak to moderate acidity range, suitable for DME synthesis. Moreover, the bifunctional catalyst, CZA (2:2:1)/γ‐Al2O3, had the highest surface area as well as the highest %CO conversion and %DME selectivity.

Selection of elite Rhizobium strains by biometric techniques for inoculation in common bean

AbstractVariation in plant responses to inoculation with rhizobia strains in different environments can be analyzed with the aid of biometric techniques. The Annicchiarico methodology and the Additive Main Effects and Multiplicative Interaction Analysis (AMMI) and Toler models are here applied to the genotype × environment (GE) interaction to determine the adaptability and phenotypic stability of N2‐fixing bacteria in symbiosis with common bean (Phaseolus vulgaris L.) in environments with high, moderate, and low acidity and with deficiencies or excessive concentrations of nutrients. A randomized block design was used in eight environments, with four replications and seven bacterial genotypes, including two controls with native soil bacterial communities (with or addition without mineral‐N fertilization). Individual and combined analyses of variance and biometric analyses were conducted on the yield values. CIAT899, UFLA02‐127, and native rhizobia were the most stable genotypes in relation to environments (AMMI models). CIAT899 and native rhizobia are the least adapted (Toler models), whereas the genotype UFLA02‐127 has the best response to the environments (Toler models). The Annicchiarico method showed that the reliability of adoption of UFLA02‐127 and native rhizobia fertilized with mineral N exceeds 85%, indicating high probability of increase in common bean yield if adopted in the field. Conversely, native rhizobia have <65% reliability.

CO2 Absorption Using Hollow Fiber Membrane Contactors: Introducing pH Swing Absorption (pHSA) to Overcome Purity Limitation.

Recently, membrane contactors have gained more popularity in the field of CO2 removal; however, achieving high purity and competitive recovery for poor soluble gas (H2, N2, or CH4) remains elusive. Hence, a novel process for CO2 removal from a mixture of gases using hollow fiber membrane contactors is investigated theoretically and experimentally. A theoretical model is constructed to show that the dissolved residual CO2 hinders the capacity of the absorbent when it is regenerated. This model, backed up by experimental investigation, proves that achieving a purity > 99% without consuming excessive chemicals or energy remains challenging in a closed-loop system. As a solution, a novel strategy is proposed: the pH Swing Absorption which consists of manipulating the acido–basic equilibrium of CO2 in the absorption and desorption stages by injecting moderate acid and base amount. It aims at decreasing CO2 residual content in the regenerated absorbent, by converting CO2 into its ionic counterparts ( or ) before absorption and improving CO2 degassing before desorption. Therefore, this strategy unlocks the theoretical limitation due to equilibrium with CO2 residual content in the absorbent and increases considerably the maximum achievable purity. Results also show the dependency of the performance on operating conditions such as total gas pressure and liquid flowrate. For N2/CO2 mixture, this process achieved a nitrogen purity of 99.97% with a N2 recovery rate of 94.13%. Similarly, for H2/CO2 mixture, a maximum H2 purity of 99.96% and recovery rate of 93.96% was obtained using this process. Moreover, the proposed patented process could potentially reduce energy or chemicals consumption.

The cytosolic sulfotransferase gene TcSULT1 is involved in deltamethrin tolerance and regulated by CncC in Tribolium castaneum

The sulfuryl transfer reaction catalyzed by cytosolic sulfotransferase (SULT) is one of the major conjugating pathways responsible for the detoxification and subsequent elimination of xenobiotics, however, functional characterization of insect SULTs is still limited. In this study, cDNA encoding a cytosolic sulfotransferase, named TcSULT1, was cloned from the red flour beetle, Tribolium castaneum. Sequence analysis revealed that TcSULT1 had the conserved signature sequences of SULTs, and shared moderate amino acid identities with Bombyx mori and Drosophila SULTs. Analysis of the transcription level showed that TcSULT1 was highly expressed in head, epidermis and malpighian tube, and upregulated at 4 h after exposure to deltamethrin. Knockdown of TcSULT1 significantly increased the susceptibility of beetles to deltamethrin. Both RNAi and dual-luciferase assay revealed that the transcription factor TcCncC regulates the expression of TcSULT1. These data provides insights into the function and regulatory mechanism of insect SULTs.

The Effect of Different Soil Tillage Systems and Crop Residues on the Composition of Weed Communities

The composition of weed communities in agricultural crops is dependent on soil properties and the applied agronomic practices. The current study determined the effect of different tillage systems and crop residue on the soil weed community composition. The research programme encompassed 2013–2015 in a long-term field experiment located in the Experimental Station of Vytautas Magnus University in Lithuania. The soil type in the experimental field was qualified as Endocalcaric Stagnosol (Aric, Drainic, Ruptic, Amphisiltic). Weeds were categorised into communities according to soil pH, nitrogen and moisture indicators. The results of investigations were grouped using cluster analysis. Agricultural crops were dominated by different weed species depending on the soil pH and moisture. Weed species were relatively more frequent indicating nitrogen-rich and very nitrogen-rich soils. In the reduced tillage and no-tillage systems, an increase in the abundance of weed species indicating moderate acidity and low acidity, moderately wet and wet, nitrogen-rich and very nitrogen-rich soils was observed. The application of plant residues decreased the weed species abundance. In the reduced tillage and no-tillage systems, the quantitative distribution of weed was often uneven. By evaluating the association of weed communities with groups of different tillage systems with or without plant residues, their control can be optimised.

The effects of TiO2 crystal-plane-dependent Ir-TiOx interactions on the selective hydrogenation of crotonaldehyde over Ir/TiO2 catalysts

Three supported Ir/TiO2 catalysts, containing anatase TiO2 nanocrystals with predominantly exposed {101}, {100}, and {001} planes, were subjected to various pre-treatments (H2 reduction at different temperatures and O2 re-oxidation) and then tested in the vapor phase selective hydrogenation of crotonaldehyde. The pre-treatments significantly altered the Ir-TiOx interactions, including the morphologies and electronic properties of the Ir species and their surface acidity. These interactions were also closely related to the crystal planes of TiO2, which further supported the observed reaction behaviors of the various Ir/TiO2 catalysts. The best performance was obtained using the Ir/TiO2-{101} catalyst pre-reduced at 300 °C, owing to its higher Ir0 surface concentration and moderate surface acidity compared to the other catalysts. Moreover, these findings indicated the synergistic role of the Ir-TiOx interface in the reaction, as the interfacial sites were responsible for the adsorption/activation of H2 and the C=O bond in the crotonaldehyde molecule. However, pre-reduction at 400 °C resulted in partial encapsulation of the Ir particles by TiOxvia strong metal-support interactions, which is unfavorable for the catalytic reaction owing to the loss of Ir-TiOx interfacial sites.

The development of low sugar bitter melon-green tea compound beverage

With fresh bitter melon and green tea as main ingredients, xylitol, sucrose and citric acid as auxiliary ingredients, a new cool health tea beverage was developed. The optimum formula of low sugar bitter melon green tea compound beverage was developed by single factor experiment and orthogonal test based on sensory evaluation. The results showed that the optimum formula was as follows: Bitter melon juice was added at 7%, green tea extract was added at 20%, total xylitol and sucrose was 6% (mass ratio 1:1), citric acid was added at 0.2%, and the volume was fixed to 100% with deionized water. The product has light green color, harmonious aroma, moderate acidity and sweetness, and clear texture. The aftertaste is long, with tea polyphenol content of 342 mg/kg, soluble solids of 5.2% and pH 5.8.

Cardiovascular Conditions in Patients With Aluminum Phosphide Poisoning

Background: Aluminum Phosphide (AlP) is a well-known rodenticide and insecticide, used as a fumigant to control pests and rodents in grain-storage facilities. Its intoxication presents a medical emergency that requires early rigorous management. This study aimed to investigate cardiac function by Electrocardiogram (ECG) changes in patients with AlP intoxication. We also explored the potential relationship between low bicarbonate and cardiac function. Methods: This cross-sectional study investigated 42 patients in the age range of 17-47 years, with a history of orally-administered AlP poisoning, known as “rice tablet”, admitted to the toxicology ward of Imam Reza Hospital from March 2019 to March 2021. The study patients’ demographic data were collected by trained interviewers, using pretested questionnaires. Systolic and diastolic blood pressure, as well as blood samples, were measured 12 hours from admission. Echocardiography was performed during the first 12 hours and on the fifth-day post-admission. All statistical analysis was performed using R 3.6.1. The significance level was set at 0.05 for all statistical tests. Results: In total, 48.78% of patients presented normal bicarbonate levels, and 24.39% and 26.83% had moderate and severe acidity, respectively. Moderately and severely decreased Left Ventricular Ejection Fraction (LVEF) was observed among 21 (51.2%) and 10 (24.4%) patients, respectively. Furthermore, mild Right Ventricular (RV) function was observed among 11 (26.8%) patients. A statistically significant association was observed between bicarbonate level and RV function (P<0.001) and LVEF (P<0.001). Besides, 19.5% of the explored patients expired. The proportion of expired patients was significantly higher in patients with mild RV function, compared to the other patients (P<0.001). Conclusion: Acute AlP intoxication is a worldwide serious problem. Severe metabolic acidosis and ECG abnormalities are associated with poor outcomes in this respect. Thus, conducting early ECG and echocardiography could be desirable instruments to predict prognosis. There is no antidote for AlP poisoning; thus, the replacement of a safer agent for in-store grain protection is strongly suggested.

Extra and intracellular laccase titers of xylophagic bacteria isolated from adult termite

Laccase is an important enzyme in terms of its versatile applicability, but its commercial use is limited by factors such as high production cost, low activity and/or stability under given conditions. The objective of this study was to screen xylophagic bacteria isolated from termites for the production of extracellular and intracellular laccases. Six laccase-positive strains were isolated, namely CA, A3, A5, A6, A7 and A8. They were molecularly identified by sequence analysis of 16S rRNA and classified under the genera Bacillus (A7, A8, CA) and Pseudomonas (A3, A5, A6). Laccase was produced by these bacterial isolates by submerged fermentation and was optimized at 37°C, pH 5.5, 6.2 and 7.0, with agitation and 0.5 mM guaiacol (as carbon source). Laccase activity was determined by measuring the oxidation of guaiacol and ABTS (2,21-azino bis[3-ethylbenzthiazoline-6-sulfonate]). Strain A5 produced extracellular laccase titers ranging from 123 to 168 U ml-1. Guaiacol was identified as a better substrate for the quantification of laccase. In conclusion, bacteria harboring the gut of termites can produce extracellular laccase with activity at medium to moderate acidity.

Methanol aromatization over Zn-modified HZSM-5 catalysts derived from ZIF-8

Methanol to aromatics (MTA) is an effective way to produce aromatics by non-petroleum route. The acidity and structure of zeolite catalysts are the key to aromatics yield and stability of catalysts in MTA reaction. Here, Zn-modified HZSM-5 catalysts were prepared by physical mixing method (PM), in-situ hydrothermal synthesis method (SH) and steam-assisted crystallization method (SAC) using ZIF-8 as sacrificial template and Zn source. XRD, SEM, TEM, N2 adsorption-desorption, ICP-OES, NH3-TPD, Py-IR, XPS, H2-TPR, TG characterization methods were used to investigate the physical and chemical properties of the catalysts. The influence of preparation methods of catalysts, the addition amount of ZIF-8, different Zn sources and reaction conditions on the products distribution in MTA reaction were investigated. The results showed that the crystallinity of ZnZ8(SAC)/Z5 catalyst was improved and the hierarchical pore structure was obtained successfully after introduced ZIF-8 by steam-assisted crystallization method. Among them, ZnZ8 mainly exists as ZnOH+ species, which improved the utilization rate of Zn atoms and more L acid sites and moderate acid concentration were formed. The addition amount of ZIF-8 can affect the crystalline size, pore structure and the concentration of ZnOH+ species of ZnZ8(SAC)/Z5. An appropriate ratio of B/L acid concentration was formed when adding an appropriate amount of ZIF-8. Compared with the traditional Z5 catalyst modified with Zn(NO3)2 as Zn source (1% ZnZN(SAC)/Z5), there are smaller particle size, larger specific surface area and mesopore volume as well as suitable acid distribution in 1% ZnZ8(SAC)/Z5 catalyst. The preparation method of catalyst, the addition amount of ZIF-8, different Zn sources and reaction conditions have a significant effect on the selectivity of BTX.

Moderate Folic Acid Supplementation in Pregnant Mice Results in Altered Methyl Metabolism and in Sex-Specific Placental Transcription Changes.

Many pregnant women have higher folic acid (FA) intake due to food fortification and increased vitamin use. It is reported that diets containing five-fold higher FA than recommended for mice (5xFASD) during pregnancy resulted in methylenetetrahydrofolate reductase (MTHFR) deficiency and altered choline/methyl metabolism, with neurobehavioral abnormalities in newborns. The goal is to determine whether these changes have their origins in the placenta during embryonic development. Female mice are fed control diet or 5xFASD for a month before mating and maintained on these diets until embryonic day 17.5. 5xFASD led to pseudo-MTHFR deficiency in maternal liver and altered choline/methyl metabolites in maternal plasma (increased methyltetrahydrofolate and decreased betaine). Methylation potential (S-adenosylmethionine:S-adenosylhomocysteine ratio) and glycerophosphocholine are decreased in placenta and embryonic liver. Folic acid supplemented diet results in sex-specific transcriptome profiles in placenta, with validation of dietary expression changes of 29 genes involved in angiogenesis, receptor biology or neurodevelopment, and altered methylation of the serotonin receptor 2A gene. Moderate increases in folate intake during pregnancy result in placental metabolic and gene expression changes, particularly in angiogenesis, which may contribute to abnormal behavior in pups. These results are relevant for determining a safe upper limit for folate intake during pregnancy.

Enhanced aromatic selectivity using the core–shell synergistic effects of HZSM-5/SAPO-5 zeolites in isobutane conversion

HZSM-5 molecular sieves are efficient catalysts in the aromatization of light hydrocarbons and the fabrication of HZSM-5-based core–shell composites has become an important strategy to improve their catalytic performance due to the simultaneous modification of the acidity and pore structures in the catalyst. In this paper, HZSM-5/SAPO-5 (CSZP and CSZC) were synthesized via a two-stage crystallization process using PDDA and CTAB as modifiers of HZSM-5, respectively. The structure, acidity, and the weight of carbon deposition of the resulting molecular sieves catalysts were characterized using various methods and their catalytic behavior in isobutane aromatization investigated. The results show that CSZP exhibits a perfect core–shell structure with a uniform and thin shell composed of nano-SAPO-5, while CSZC has an irregular coat configuration with HZSM-5 covered by a rough and thick shell consisting of flaky micro-SAPO-5 crystals. The introduction of SAPO-5 via an in-situ synthesis decreases the Brønsted acidity of the catalysts to different extents and provides a large number of intergranular mesopores due to the stacking of SAPO-5 on the surface of HZSM-5, which is favorable toward improving the BTEX selectivity (benzene, toluene, ethylbenzene, and xylene) and catalytic stability over CSZP and CSZC. Meanwhile, CSZP has more competitive advantages than CSZC in promoting the mass transfer efficiency due to its significantly thinner shell than CSZC, which combined with its moderate acidity and appropriate mesopore structure result in its excellent selectivity and stability during the aromatization of isobutane.

Effect of Lewis/Brønsted acid sites in HZSM−5 zeolite on the selectivity of para-xylene during methylation of toluene with methanol

• The participation of Lewis acid site is good for the dissociation of methanol. • The activity of methanol dissociation has positive correlation with the acid strengths of HZSM-5 zeolites. • ZnOH + /BAS-HZSM−5 with the moderate acid strength is conducive to the formation of PX. The methylation reaction of methanol and toluene to xylenes has been carried out in Brønsted Acid Sites (BAS)−HZSM−5, AlOH 2+ /BAS−HZSM−5 and ZnOH + /BAS−HZSM−5 catalysts. The stronger acid strengths are produced in AlOH 2+ /BAS−HZSM−5 and ZnOH + /BAS−HZSM−5 due to the synergistic effect of Lewis Acid Sites (LAS) and BAS compared to BAS−HZSM−5, which is beneficial to the dissociation of methanol. AlOH 2+ /BAS−HZSM−5 shows the highest activity for methanol dissociation with the strongest acid strength. The Gibbs free energy barrier is only 68.2 kJ·mol −1 , but the formation of Para -xylene (PX) needs to overcome a high barrier of 129.2 kJ·mol −1 . However, ZnOH + /BAS−HZSM−5 exhibits relative high activity for the formation of methoxy with the Gibbs free energy barrier of 113.9 kJ·mol −1 , and 92.9 kJ·mol −1 for PX. Meanwhile, the formation of PX is easiest among three xylenes. Therefore, ZnOH + /BAS−HZSM−5 can be as the promising catalyst for the preparation of PX during methylation of toluene with methanol.

Seeding-induced nano-sized SAPO-34 synthesis with superior MTO performance: Energy-efficient approach with highly reduced OSDA consumption

Methanol-to-olefin conversion is one of the most successful approaches to producing light olefins. It has been proved that SAPO-34 is the best catalyst for this process. This molecular-sieve is characterized by high thermal stability, moderate acid sites, and shape selectivity. In this report, SAPO-34 was synthesized using the seed-assisted method. Effects of OSDA and seed on crystallinity and particle size were investigated using Central Composite Design. Samples were characterized by XRD, FE-SEM, FTIR, BET, EDX, and TPD. Results showed that the samples had excellent physicochemical properties. The design of Experiments could predict the results accurately (R2 > 0.9). It was demonstrated that template was the key factor in the seed-assisted synthesis of SAPO-34. Template consumption was reduced by 50%, and it was proved that the synthesis time could be effectively decreased to 3 h due to rapid nucleation. Samples exhibited 100% methanol conversion and up to 90% selectivity toward ethylene and propylene.

Embryonic zeolites for highly efficient synthesis of dimethyl ether from syngas

Embryonic X-ray amorphous semi-formed MFI-type zeolite units mixed with the Cu–Zn–Al catalyst have been used for the direct synthesis of dimethyl ether (DME) from syngas. The hybrid catalyst with embryonic zeolite (EZ) with the particle size of 5 nm has demonstrated superior performance in terms of activity, selectivity, and stability compared to the crystalline ZSM-5 zeolite counterpart and the amorphous aluminosilicate material. The FTIR pyridine adsorption uncovered several types of active sites in EZ, including Brønsted acid sites of medium strength. The DFT modeling pointed out the key role of defect sites leading to lower strength of the acid sites in the embryonic MFI zeolite in comparison with the fully crystalline material. The effect of embryonic zeolite on the DME synthesis has been assigned to enhanced transport of methanol from Cu to ultra-small zeolite precursor units with moderate acidity, hence promoting the efficient dehydration to DME with high selectivity and stability.

Effect of Ni/Co vermiculite as catalysts for Catalytic pyrolysis of plastic wastes

In this study, the modified vermiculite adjusted with Ni and Co for pyrolysis of plastic is characterized by X-ray diffraction (XRD) and Brunauer Emmett Teller (BET). These results indicate that the ratio of Ni and Co can affect the surface area and pore diameter of catalyst. In addition, the results of GC show that Ni and Co not only have a good selectivity of C3, the main gaseous hydrocarbons of pyrolysis products, but also play an important role in dealing with low quality of oil products of plastic pyrolysis by controlling the concentration of metal oxide particles in the vermiculite layer. The adjustment of the molar ratio of Co and Ni can optimize the hydrogenation/dehydrogenation of metal active sites. It means that the greatly catalytic activity of supported Ni and Co catalysts is caused by moderate total acidity, relatively high surface area, and uniformly dispersed oxide particles on vermiculite support. Therefore, it suggests that adopting the clay catalyst is an efficient and environmentally friendly way to produce valuable products in pyrolysis of plastic waste.

MiRNA-mRNA Regulatory Network Reveals miRNAs in HCT116 in Response to Folic Acid Deficiency via Regulating Vital Genes of Endoplasmic Reticulum Stress Pathway.

Moderate folic acid (FA) intake is an effective strategy that slows colorectal cancer (CRC) progression. However, high consumption of FA may trigger the transition of precancerous tissue towards malignancy. MicroRNAs (miRNAs) are considered to be potential biomarkers of CRC. Thus, identification of miRNAs of dysregulated genes in CRC cells by detailed analysis of mRNA and miRNA expression profile in the context of FA deficiency could substantially increase our understanding of its oncogenesis. mRNA-seq and miRNA-seq analyses were utilized to investigate the expression of miRNAs in FA-deficient CRC cell line–HCT116 through massive parallel sequencing technology. A total of 38 mRNAs and 168 miRNAs were identified to be differentially expressed between CRC groups with or without FA deficiency. We constructed an miRNA-mRNA network for the vital regulatory miRNAs altered in FA-deficient CRC cells. The mRNAs and miRNAs validated by Western blotting and RT-qPCR were consistent with the sequencing results. Results showed that FA deficiency upregulated some miRNAs thereby inhibiting the expression of critical genes in the endoplasmic reticulum (ER) stress pathway. Dysregulated miRNAs in our miRNA-mRNA network could contribute to CRC cell in response to deficient FA. This work reveals novel molecular targets that are likely to provide therapeutic interventions for CRC.

Nickel supported ZIF-8.PEG modified catalyst: A designed active catalyst with high H2 productivity in steam reforming of ethanol at moderate temperature

Steam reforming of renewable ethanol at moderate temperatures is an attractive alternative for hydrogen production than conventional steam reforming of natural gas which is only feasible at very high temperatures (>650 ℃). Formulating a catalyst for this reaction with ideally dispersed metallic active phase can reduce the activation energy and enhance the activity at moderate temperatures. With this purpose in mind, ZIF-8 with high specific surface area has been nominated as catalytic support in this survey for the dispersion of nickel nanoparticles. The support compositional and interfacial properties were further modified by polyethylene glycol (PEG) to prepare an ideal support with high activity at moderate temperatures. Pristine and modified samples were comparatively characterized by XRD, TGA, BET, FTIR, TEM, FESEM, EDS, AAS, H2-TPR and NH3-TPD analyses and catalytically evaluated at 400–450 ℃. TPR profiles of catalysts have demonstrated notable differences in the reduction temperature and quantity of metallic centers which have directly affected the catalytic activity. Lower reduction temperature and higher number of metallic centers were observed for Ni/ZIF-8. PEG which has originated from the tuned interface i.e. high accessibility of nickel centers with highly exposed flower-like structure and lower strength of support/active phase interaction. Thus, Ni/ZIF-8. PEG has revealed considerable improvement in terms of ethanol conversion and H2 yield. At 450 °C, the average H2 yield employing Ni/ZIF-8. PEG catalyst reached 52.6% which was about 16% and 46% higher than those observed by Ni/ZIF-8 and conventional Ni/Al2O3, respectively. Moderate acidity of the ZIF-8. PEG, higher reducibility of active phase and suitable interfacial interactions have resulted in better performance of this catalyst.

The addition of wine yeast <i>Starmerella bacillaris</i> to grape skin surface influences must fermentation and glycerol production

Starmerella bacillaris is a non-Saccharomyces yeast recently proposed for grape fermentation in association with Saccharomyces cerevisiae. Due to its high glycerol and moderate volatile acidity production this yeast can contribute to improving wine quality. Some strains have been demonstrated to exhibit antifungal activity against grey mould on grape, which is caused by Botrytis cinerea. The simultaneous presence of these traits in S. bacillaris is of great interest. Indeed, this yeast can be potentially used as a biocontrol agent in vineyards. Research on the ability of S. bacillaris to survive or, even to grow on the surface of grapes is a starting point in the evaluatation of its potential use in vineyards. The preliminary results of our study showed that when applied to the grape surface under laboratory condictions, inoculum sized S. bacillaris with antifungal activity developed and lasted for at least 6 days in high concentrations. In addition, it positively influenced the fermentation process by producing high concentrations of glycerol (average value 4.89 ± 0.47 g/L). Interestingly, a positive effect on wine quality was also observed when the inoculum size was 10 times higher or lower than the reference concentration. When sprayed on the vines in the vineyard and present on the grape skin surface after harvest, S. bacillaris cells can start alcoholic fermentation.

Histomorphological, Histochemical and Histoenzymic Studies on the Dermis of Skin of Goat (Capra hircus)

Background: Skin is a versatile organ, which is extremely important for protection, perception, water regulation and wound healing. The skin of goat is considered extremely durable used by the tannery Industry to make rugs and carpet binding.Methods: The present study was conducted on the skin of goats of either sex to study the age wise changes in the histomorphology, histochemistry and histoenzymology of dermis. The skin samples were collected from Nagpur Muncipal Corporation Slaughter house immediately after natural death and subsequently processed and stained for histological, histochemical and histoenzymic studies. The total of 220 samples, 20 each from different body regions namely dorsal neck, lateral neck, ventral neck, dorsal thorax, lateral thorax, ventral thorax, dorsal abdomen, lateral abdomen, ventral abdomen, lateral thigh and medial thigh were collected. The animals were divided into two groups, viz. six to twelve month of age (Gr I) and above one year age (Gr II).Result: It was observed that the dermis was composed of collagen, elastic, reticular fibers, cells of connective tissue, blood vessels, nerves, hair follicles, sweat glands, sebaceous glands and arrector pili muscles in all body regions in Gr I as well as in Gr II. The dermis was divided into thin superficial papillary layer and a thick deep reticular layer. The dermal papillae were the upward projections of superficial papillary layer between epidermal pegs. In reticular layer, fibroblasts were larger, while in papillary layer, fibroblasts were thin long, compressed and spindle shaped. The collagen fibers were more in number as compared to other fibers in dermis and they were densely arranged in papillary layer and parallel with the skin surface below the epidermis. The elastic fibers were present in between the collagen fibers around the blood vessels and hair follicles. The arteriovenous shunt was found surrounded by capsule of connective tissue consisting of smooth muscle cells. The more number of hair follicles at deep part of papillary layer and few follicles were present in reticular layer. The hair follicle composed of outer root sheath, inner root sheath, cortex and medulla. The depth of primary hair follicle increased with the advancement of age. Moderate PAS positive activity was noted in the papillary layer, while it was weak to moderate in reticular layer. The reticular layer of the dermis showed moderate Sudan black B activity for the presence of lipid than the papillary layer. The mild acid phosphatase activity was seen in the papillary and reticular layer of dermis, while moderate acid phosphatase activity was noticed in the blood vessels. A mild alkaline phosphatase activity was present in dermis in Gr I and Gr II. Conclusion: The present study would form a baseline data on the histomorphology, histochemistry and histoenzymology of skin of goat which would be helpful in future research prospective.