Concurrent Synthesis and Immobilization of Ag Nanoparticles over TiO2 via Plasma Reduction for Photocatalytic Treatment of Methyl Blue in Water

Pure TiO₂ nanoparticles (TiO₂NPs) were produced via the sol–gel method and then coated with silver nanoparticles (AgNPs) to reduce their optical band gap. The concurrent synthesis and immobilization of AgNPs over TiO₂NPs was achieved through the interaction of an open-air argon plasma jet with a solution of silver nitrate/stabilizer/TiO₂NPs. The one-pot plasma synthesis and coating of AgNPs over TiO₂NPs is a more straightforward and environmentally friendly method than others. The plasma-produced Ag/TiO₂ nanocomposites were characterized and tested for their photocatalytic potential by degrading different concentrations of methyl blue (MB) in water. The dye concentration, oxidant dose, catalyst dose, and reaction time were also optimized for MB degradation. XRD results revealed the formation of pure AgNPs, pure TiO₂NPs, and Ag/TiO₂ nanocomposites with an average grain size of 12.36 nm, 18.09 nm, and 15.66 nm, respectively. The immobilization of AgNPs over TiO₂NPs was also checked by producing SEM and TEM images. The band gap of AgNPs, TiO₂NPs, and Ag/TiO₂ nanoparticles was measured about 2.58 eV, 3.36 eV, and 2.86 eV, respectively. The ultraviolet (UV) results of the nanocomposites were supportive of the degradation of synthetic dyes in the visible light spectrum. The AgNPs in the composite not only lowered the band gap but also obstructed the electron–hole recombinations. The Ag/TiO₂ composite catalyst showed 90.9% degradation efficiency with a 5 ppm dye concentration after 120 min of light exposure.     

Catalytic Hydrogen Evolution from H2S Cracking over CrxZnS Catalyst in a Cylindrical Single-Layered Dielectric Barrier Discharge Plasma Reactor

The use of non-thermal plasma technology in producing green fuels is a much-appreciated environmentally friendly approach. In this study, an Al₂O₃-supported Cr_xZnS semiconductor catalyst was tested for hydrogen evolution from hydrogen sulfide (H₂S) gas by using a single-layered dielectric barrier discharge (DBD) system. The Al₂O₃-supported Cr_xZnS catalyst (x = 0.20, 0.25, and 0.30) was produced by using a co-impregnation method and characterized for its structural and photocatalytic characteristics. The discharge column of the DBD system was filled with this catalyst and fed with hydrogen sulfide and argon gas. The DBD plasma was sustained with a fixed AC source of 10 kV where plasma produced species and UV radiations activated the catalyst to break H₂S molecules under ambient conditions. The catalyst (hexagonal-cubic-sphalerite structure) showed an inverse relationship between the band gap and the dopant concentration. The hydrogen evolution decreased with an increase in dopant concentration in the nanocomposite. The Cr_0.20ZnS catalyst showed excellent photocatalytic activity under the DBD exposure by delivering 100% conversion efficiency of H₂S into hydrogen. The conversion decreased to 96% and 90% in case of Cr_0.25ZnS and Cr_0.30ZnS, respectively.     

Analysis of Statistically Predicted Rate Constants for Pyrolysis of High-Density Plastic Using R Software

The surge in plastic waste production has forced researchers to work on practically feasible recovery processes. Pyrolysis is a promising and intriguing option for the recycling of plastic waste. Developing a model that simulates the pyrolysis of high-density polyethylene (HDPE) as the most common polymer is important in determining the impact of operational parameters on system behavior. The type and amount of primary products of pyrolysis, such as oil, gas, and waxes, can be predicted statistically using a multiple linear regression model (MLRM) in R software. To the best of our knowledge, the statistical estimation of kinetic rate constants for pyrolysis of high-density plastic through MLRM analysis using R software has never been reported in the literature. In this study, the temperature-dependent rate constants were fixed experimentally at 420 °C. The rate constants with differences of 0.02, 0.03, and 0.04 from empirically set values were analyzed for pyrolysis of HDPE using MLRM in R software. The added variable plots, scatter plots, and 3D plots demonstrated a good correlation between the dependent and predictor variables. The possible changes in the final products were also analyzed by applying a second-order differential equation solver (SODES) in MATLAB version R2020a. The outcomes of experimentally fixed-rate constants revealed an oil yield of 73% to 74%. The oil yield increased to 78% with a difference of 0.03 from the experimentally fixed rate constants, but light wax, heavy wax, and carbon black decreased. The increased oil and gas yield with reduced byproducts verifies the high significance of the conducted statistical analysis. The statistically predicted kinetic rate constants can be used to enhance the oil yield at an industrial scale.     

表皮型脂肪酸结合蛋白和脂肪酸合成酶在乳腺浸润性导管癌的表达及临床病理意义

目的 探讨脂肪酸结合蛋白和脂肪酸合成酶与乳腺浸润性导管癌发生发展的关系及作用机制.以探询新的分子标志和早期分子治疗的靶基因.方法 用半定量逆转录聚合酶链反应、免疫组织化学和Western blot等方法检测表皮型脂肪酸结合蛋白(E-FABP)和脂肪酸合成酶(FAS)在76例浸润性乳腺导管癌中的表达变化.结果 E-FABP广泛分布于浸润性导管癌的血管内皮细胞、导管和腺泡的上皮细胞,mRNA和蛋白质的表达量在Ⅲ级浸润性导管癌的较Ⅰ、Ⅱ级明显下调(P<0.05).FAS主要分布于腺泡和导管的上皮细胞,表达量随组织学级数的变化趋势与E-FABP相同,两者的表达具有明显相关性(P<0.05).此外,E-FABP和FAS的表达与及组织学级数相关(P<0.05),与绝经情况、淋巴结转移、雌激素受体和孕激素受体无关(P0.05).结论 在Ⅰ、Ⅱ级浸润性导管癌,E-FABP可能作为FAS的下游分子,结合和转运FAS合成的长链脂肪酸,以维持肿瘤细胞旺盛的代谢;在Ⅲ级导管癌,E-FABP、FAS的表达明显下调,癌细胞的活动可能有赖于其他信号分子起作用.本研究为进一步探寻浸润性乳腺导管癌的分子标志及早期治疗途径提供理论依据.     

Cryoprotectant effect of trehalose in extender on post‐thaw quality and in vivo fertility of water buffalo (Bubalus bubalis) bull spermatozoa

This study was designed to ascertain the cryoprotectant effects of different concentrations of trehalose [0 (T0), 25 (T25), 35 (T35), 45 (T45) mm ], egg yolk [20% (E20), 15% (E15) v/v] and glycerol [7% (G7), 5% (G5) v/v] in Tris‐citric acid‐based extender on post‐thaw quality and in vivo fertility of buffalo bull spermatozoa. Twenty‐five ejaculates were collected from five bulls and split into four parts. After that, the split ejaculates from each of the bull were diluted either in T0E20G7 (control) or T25E20G5 or T35E15G5 or T45E15G5 extender. Finally, the sperm suspension was frozen in 0.54‐ml French straws. Post‐thaw sperm total motility (%), progressive motility (%), rapid velocity (%), average path velocity (μm/s), straightline velocity (μm/s), curvilinear velocity (μm/s), linearity (%), plasma membrane and acrosome integrities (%) were higher (p < .05) in T45E15G5 extender as compared to other treatment groups and control. The fertility rate (56.8% versus 41.3%) was higher (p < .05) in buffaloes inseminated with semen doses cryopreserved in extender containing T45E15G5 combination of cryoprotectants than the control. In conclusion, addition of 45 mm trehalose along with 15% egg yolk and 5% glycerol in extender improves the post‐thaw quality and in vivo fertility of buffalo bull spermatozoa.     

A revised classification of the cleft lip and palate

BACKGROUND:

Submucous cleft palate is characterized by muscular diastasis of the velum in the presence of intact mucosa with variable combinations of bifid uvula and hard palatal defect. Submucous cleft palate is indicated as a separate entity in most previous classifications but it has never been properly classified on an anatomical basis.

OBJECTIVES:

To revise the Smith-modified Kernahan ‘Y’ classification of cleft lip and palate deformities, and to describe the different anatomical subtypes of submucous cleft palate.

METHODS:

The present study was conducted in Hayatabad Medical Complex, Abasin Hospital and Aman Hospital Peshawar, Pakistan, from November 2010 to December 2011. All patients who presented to the outpatient departments with cleft lip and palate, with the exception of previously operated cases, were included. All cases were described according to the Smith-modified Kernahan ‘Y’ classification and the authors’ revised Smith-modified Kernahan ‘Y’ classification. All of the data were organized and analyzed using SPSS version 17 (IBM Corporation, USA).

RESULTS:

A total of 163 cases of cleft lip and palate deformities were studied, of which 59.5% were male and 40.5% were female. Smith modification of the Kernahan ‘Y’ classification completely described the cleft deformities in 93.9% of patients. However, while the Kernahan ‘Y’ classification represented the submucous cleft palate, it did not describe its different anatomical subtypes in 6.13% of patients. The revised Smith-modified Kernahan ‘Y’ classification completely described the cleft deformities of the entire study population, including the different submucous cleft palate patients.

DISCUSSION:

The Smith alphanumeric modification of the Kernahan ‘Y’ classification of cleft lip and palate came into existence after a long search and a series of modifications over the past century. This classification system describes the cleft region, site of the cleft, degree of the cleft, rare and asymmetrical clefts, and are computer database friendly. However, this classification did not describe the different anatomical subtypes of submucous cleft palate that have variable relationships with velopharyngeal insufficiency.

CONCLUSION:

The revised Smith-modified Kernahan ‘Y’ classification described in the present study can describe all types of cleft lip and palate deformities in addition to the different types of submucous cleft palate deformities.